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  • CheckBox ListView SelectedValues DependencyProperty Binding

    - by Ristogod
    I am writing a custom control that is a ListView that has a CheckBox on each item in the ListView to indicate that item is Selected. I was able to do so with the following XAML. <ListView x:Class="CheckedListViewSample.CheckBoxListView" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" mc:Ignorable="d"> <ListView.Style> <Style TargetType="{x:Type ListView}"> <Setter Property="SelectionMode" Value="Multiple" /> <Style.Resources> <Style TargetType="ListViewItem"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="ListViewItem"> <Border BorderThickness="{TemplateBinding Border.BorderThickness}" Padding="{TemplateBinding Control.Padding}" BorderBrush="{TemplateBinding Border.BorderBrush}" Background="{TemplateBinding Panel.Background}" SnapsToDevicePixels="True"> <CheckBox IsChecked="{Binding IsSelected, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ListViewItem}}}"> <CheckBox.Content> <ContentPresenter Content="{TemplateBinding ContentControl.Content}" ContentTemplate="{TemplateBinding ContentControl.ContentTemplate}" HorizontalAlignment="{TemplateBinding Control.HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding Control.VerticalContentAlignment}" SnapsToDevicePixels="{TemplateBinding UIElement.SnapsToDevicePixels}" /> </CheckBox.Content> </CheckBox> </Border> </ControlTemplate> </Setter.Value> </Setter> </Style> </Style.Resources> </Style> </ListView.Style> </ListView> I however am trying to attempt one more feature. The ListView has a SelectedItems DependencyProperty that returns a collection of the Items that are checked. However, I need to implement a SelectedValues DependencyProperty. I also am implementing a SelectedValuesPath DependencyProperty. By using the SelectedValuesPath, I indicate the path where the values are found for each selected item. So if my items have an ID property, I can specify using the SelectedValuesPath property "ID". The SelectedValues property would then return a collection of ID values. I have this working also using this code in the code-behind: using System.Windows; using System.Windows.Controls; using System.ComponentModel; using System.Collections; using System.Collections.Generic; namespace CheckedListViewSample { /// <summary> /// Interaction logic for CheckBoxListView.xaml /// </summary> public partial class CheckBoxListView : ListView { public static DependencyProperty SelectedValuesPathProperty = DependencyProperty.Register("SelectedValuesPath", typeof(string), typeof(CheckBoxListView), new PropertyMetadata(string.Empty, null)); public static DependencyProperty SelectedValuesProperty = DependencyProperty.Register("SelectedValues", typeof(IList), typeof(CheckBoxListView), new PropertyMetadata(new List<object>(), null)); [Category("Appearance")] [Localizability(LocalizationCategory.NeverLocalize)] [Bindable(true)] public string SelectedValuesPath { get { return ((string)(base.GetValue(CheckBoxListView.SelectedValuesPathProperty))); } set { base.SetValue(CheckBoxListView.SelectedValuesPathProperty, value); } } [Bindable(true)] [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)] [Category("Appearance")] public IList SelectedValues { get { return ((IList)(base.GetValue(CheckBoxListView.SelectedValuesPathProperty))); } set { base.SetValue(CheckBoxListView.SelectedValuesPathProperty, value); } } public CheckBoxListView() : base() { InitializeComponent(); base.SelectionChanged += new SelectionChangedEventHandler(CheckBoxListView_SelectionChanged); } private void CheckBoxListView_SelectionChanged(object sender, SelectionChangedEventArgs e) { List<object> values = new List<object>(); foreach (var item in SelectedItems) { if (string.IsNullOrWhiteSpace(SelectedValuesPath)) { values.Add(item); } else { try { values.Add(item.GetType().GetProperty(SelectedValuesPath).GetValue(item, null)); } catch { } } } base.SetValue(CheckBoxListView.SelectedValuesProperty, values); e.Handled = true; } } } My problem is that my binding only works one way right now. I'm having trouble trying to figure out how to implement my SelectedValues DependencyProperty so that I could Bind a Collection of values to it, and when the control is loaded, the CheckBoxes are checked with items that have values that correspond to the SelectedValues. I've considered using the PropertyChangedCallBack event, but can't quite figure out how I could write that to achieve my goal. I'm also unsure of how I find the correct ListViewItem to set it as Selected. And lastly, if I can find the ListViewItem and set it to be Selected, won't that fire my SelectionChanged event each time I set a ListViewItem to be Selected?

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  • Stack overflow error after creating a instance using 'new'

    - by Justin
    EDIT - The code looks strange here, so I suggest viewing the files directly in the link given. While working on my engine, I came across a issue that I'm unable to resolve. Hoping to fix this without any heavy modification, the code is below. void Block::DoCollision(GameObject* obj){ obj->DoCollision(this); } That is where the stack overflow occurs. This application works perfectly fine until I create two instances of the class using the new keyword. If I only had 1 instance of the class, it worked fine. Block* a = new Block(0, 0, 0, 5); AddGameObject(a); a = new Block(30, 0, 0, 5); AddGameObject(a); Those parameters are just x,y,z and size. The code is checked before hand. Only a object with a matching Collisonflag and collision type will trigger the DoCollision(); function. ((*list1)->m_collisionFlag & (*list2)->m_type) Maybe my check is messed up though. I attached the files concerned here http://celestialcoding.com/index.php?topic=1465.msg9913;topicseen#new. You can download them without having to sign up. The main suspects, I also pasted the code for below. From GameManager.cpp void GameManager::Update(float dt){ GameList::iterator list1; for(list1=m_gameObjectList.begin(); list1 != m_gameObjectList.end(); ++list1){ GameObject* temp = *list1; // Update logic and positions if((*list1)->m_active){ (*list1)->Update(dt); // Clip((*list1)->m_position); // Modify for bounce affect } else continue; // Check for collisions if((*list1)->m_collisionFlag != GameObject::TYPE_NONE){ GameList::iterator list2; for(list2=m_gameObjectList.begin(); list2 != m_gameObjectList.end(); ++list2){ if(!(*list2)->m_active) continue; if(list1 == list2) continue; if( (*list2)->m_active && ((*list1)->m_collisionFlag & (*list2)->m_type) && (*list1)->IsColliding(*list2)){ (*list1)->DoCollision((*list2)); } } } if(list1==m_gameObjectList.end()) break; } GameList::iterator end    = m_gameObjectList.end(); GameList::iterator newEnd = remove_if(m_gameObjectList.begin(),m_gameObjectList.end(),RemoveNotActive); if(newEnd != end)        m_gameObjectList.erase(newEnd,end); } void GameManager::LoadAllFiles(){ LoadSkin(m_gameTextureList, "Models/Skybox/Images/Top.bmp", GetNextFreeID()); LoadSkin(m_gameTextureList, "Models/Skybox/Images/Right.bmp", GetNextFreeID()); LoadSkin(m_gameTextureList, "Models/Skybox/Images/Back.bmp", GetNextFreeID()); LoadSkin(m_gameTextureList, "Models/Skybox/Images/Left.bmp", GetNextFreeID()); LoadSkin(m_gameTextureList, "Models/Skybox/Images/Front.bmp", GetNextFreeID()); LoadSkin(m_gameTextureList, "Models/Skybox/Images/Bottom.bmp", GetNextFreeID()); LoadSkin(m_gameTextureList, "Terrain/Textures/Terrain1.bmp", GetNextFreeID()); LoadSkin(m_gameTextureList, "Terrain/Textures/Terrain2.bmp", GetNextFreeID()); LoadSkin(m_gameTextureList, "Terrain/Details/TerrainDetails.bmp", GetNextFreeID()); LoadSkin(m_gameTextureList, "Terrain/Textures/Water1.bmp", GetNextFreeID()); Block* a = new Block(0, 0, 0, 5); AddGameObject(a); a = new Block(30, 0, 0, 5); AddGameObject(a); Player* d = new Player(0, 100,0); AddGameObject(d); } void Block::Draw(){ glPushMatrix(); glTranslatef(m_position.x(), m_position.y(), m_position.z()); glRotatef(m_facingAngle, 0, 1, 0); glScalef(m_size, m_size, m_size); glBegin(GL_LINES); glColor3f(255, 255, 255); glVertex3f(m_boundingRect.left, m_boundingRect.top, m_position.z()); glVertex3f(m_boundingRect.right, m_boundingRect.top, m_position.z()); glVertex3f(m_boundingRect.left, m_boundingRect.bottom, m_position.z()); glVertex3f(m_boundingRect.right, m_boundingRect.bottom, m_position.z()); glVertex3f(m_boundingRect.left, m_boundingRect.top, m_position.z()); glVertex3f(m_boundingRect.left, m_boundingRect.bottom, m_position.z()); glVertex3f(m_boundingRect.right, m_boundingRect.top, m_position.z()); glVertex3f(m_boundingRect.right, m_boundingRect.bottom, m_position.z()); glEnd(); // DrawBox(m_position.x(), m_position.y(), m_position.z(), m_size, m_size, m_size, 8); glPopMatrix(); } void Block::DoCollision(GameObject* obj){ GameObject* t = this;   // I modified this to see for sure that it was causing the mistake. // obj->DoCollision(NULL); // Just revert it back to /* void Block::DoCollision(GameObject* obj){     obj->DoCollision(this);   }   */ }

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  • How to associate Wi-Fi beacon info with a virtual "location"?

    - by leander
    We have a piece of embedded hardware that will sense 802.11 beacons, and we're using this to make a map of currently visible bssid -> signalStrength. Given this map, we would like to make a determination: Is this likely to be a location I have been to before? If so, what is its ID? If not, I should remember this location: generate a new ID. Now what should I store (and how should I store it) to make future determinations easier? This is for an augmented-reality app/game. We will be using it to associate particular characters and events with "locations". The device does not have internet or cellular access, so using a geolocation service is out of consideration for the time being. (We don't really need to know where we are in reality, just be able to determine if we return there.) It isn't crucial that it be extremely accurate, but it would be nice if it was tolerant to signal strength changes or the occasional missing beacon. It should be usable in relatively low numbers of access points (e.g. rural house with one wireless router) or many (wandering around a dense metropolis). In the case of a city, it should change location every few minutes of walking (continuously-overlapping signals make this a bit more tricky in naive code). A reasonable number of false positives (match a location when we aren't actually there) is acceptable. The wrong character/event showing up just adds a bit of variety. False negatives (no location match) are a bit more troublesome: this will tend to add a better-matching new location to the saved locations, masking the old one. While we will have additional logic to ensure locations that the device hasn't seen in a while will "orphan" any associated characters or events (if e.g. you move to a different country), we'd prefer not to mask and eventually orphan locations you do visit regularly. Some technical complications: signalStrength is returned as 1-4; presumably it's related to dB, but we are not sure exactly how; in my experiments it tends to stick to either 1 or 4, but occasionally we see numbers in between. (Tech docs on the hardware are sparse.) The device completes a scan of one-quarter of the channel space every second; so it takes about 4-5 seconds to get a complete picture of what's around. The list isn't always complete. (We are making strides to fix this using some slight sampling period randomization, as recommended by the library docs. We're also investigating ways to increase the number of scans without killing our performance; the hardware/libs are poorly behaved when it comes to saturating the bus.) We have only kilobytes to store our history. We have a "working" impl now, but it is relatively naive, and flaky in the face of real-world Wi-Fi behavior. Rough pseudocode: // recordLocation() -- only store strength 4 locations m_savedLocations[g_nextId++] = filterForStrengthGE( m_currentAPs, 4 ); // determineLocation() bestPoints = -inf; foreach ( oldLoc in m_savedLocations ) { points = 0.0; foreach ( ap in m_currentAPs ) { if ( oldLoc.has( ap ) ) { switch ( ap.signalStrength ) { case 3: points += 1.0; break; case 4: points += 2.0; break; } } } points /= oldLoc.numAPs; if ( points > bestPoints ) { bestLoc = oldLoc; bestPoints = points; } } if ( bestLoc && bestPoints > 1.0 ) { if ( bestPoints >= (2.0 - epsilon) ) { // near-perfect match. // update location with any new high-strength APs that have appeared bestLoc.addAPs( filterForStrengthGE( m_currentAPs, 4 ) ); } return bestLoc; } else { return NO_MATCH; } We record a location currently only when we have NO_MATCH and the app determines it's time for a new event. (The "near-perfect match" code above would appear to make it harder to match in the future... It's mostly to keep new powerful APs from being associated with other locations, but you'd think we'd need something to counter this if e.g. an AP doesn't show up in the next 10 times I match a location.) I have a feeling that we're missing some things from set theory or graph theory that would assist in grouping/classification of this data, and perhaps providing a better "confidence level" on matches, and better robustness against missed beacons, signal strength changes, and the like. Also it would be useful to have a good method for mutating locations over time. Any useful resources out there for this sort of thing? Simple and/or robust approaches we're missing?

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  • iphone - UIViewController header view errors

    - by Fiona
    Hi there, So to give a little background: I've an app that has a UITableViewController- (ContactDetailViewController) In this view at the top, I require a few labels and buttons, followed by a group style tableview. So I've created a nib file containing these elements. (ContactHeaderView.xib) Then in the viewDidLoad of ContactDetailViewController I've loaded this nib as the headerView. See implementation file below: #import "ContactDetailViewController.h" #import "DisplayInfoViewController.h" #import "ActionViewController.h" @implementation ContactDetailViewController @synthesize name; @synthesize date; @synthesize nextAction; @synthesize nameLabel; @synthesize usernameLabel; @synthesize nextActionTextField; @synthesize dateLabel; @synthesize contactInfoButton; @synthesize backgroundInfoButton; @synthesize actionDoneButton; - (void)viewDidLoad { [super viewDidLoad]; } - (void)didReceiveMemoryWarning { // Releases the view if it doesn't have a superview. [super didReceiveMemoryWarning]; // Release any cached data, images, etc that aren't in use. } - (void)viewDidUnload { // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } #pragma mark Table view methods - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return 1; } // Customize the number of rows in the table view. - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return 3; } - (UIView *) tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section { if (section == 0){ UIViewController *chv = [[[UIViewController alloc] initWithNibName:@"ContactHeaderView" bundle:nil] autorelease]; // self.nameLabel.text = self.name; return chv.view; }else{ return nil; } } - (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section{ return 300.0; } // Customize the appearance of table view cells. - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; } // Set up the cell... return cell; } - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { // Navigation logic may go here. Create and push another view controller. // AnotherViewController *anotherViewController = [[AnotherViewController alloc] initWithNibName:@"AnotherView" bundle:nil]; // [self.navigationController pushViewController:anotherViewController]; // [anotherViewController release]; } /* // Override to support conditional editing of the table view. - (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath { // Return NO if you do not want the specified item to be editable. return YES; } */ - (void)dealloc { [name release]; [date release]; [nextAction release]; [nameLabel release]; [usernameLabel release]; [nextActionTextField release]; [dateLabel release]; [contactInfoButton release]; [backgroundInfoButton release]; [actionDoneButton release]; [super dealloc]; } -(IBAction)displayContactInfo:(id)sender{ DisplayInfoViewController *divc = [[DisplayInfoViewController alloc] init]; divc.textView = self.nextAction; divc.title = @"Contact Info"; [self.navigationController pushViewController:divc animated:YES]; [divc release]; } -(IBAction)displayBackgroundInfo:(id)sender{ DisplayInfoViewController *divc = [[DisplayInfoViewController alloc] init]; divc.textView = self.nextAction; divc.title = @"Background Info"; [self.navigationController pushViewController:divc animated:YES]; [divc release]; } -(IBAction)actionDone:(id)sender{ ActionViewController *avc = [[ActionViewController alloc] init]; avc.title = @"Action"; avc.nextAction = self.nextAction; [self.navigationController pushViewController:avc animated:YES]; [avc release]; } @end Here's the Header File: #import <UIKit/UIKit.h> @interface ContactDetailViewController : UITableViewController { NSString *name; NSString *date; NSString *nextAction; IBOutlet UILabel *nameLabel; IBOutlet UILabel *usernameLabel; IBOutlet UITextField *nextActionTextField; IBOutlet UILabel *dateLabel; IBOutlet UIButton *contactInfoButton; IBOutlet UIButton *backgroundInfoButton; IBOutlet UIButton *actionDoneButton; } @property (nonatomic, retain) NSString *name; @property (nonatomic, retain) NSString *date; @property (nonatomic, retain) NSString *nextAction; @property (nonatomic, retain) IBOutlet UILabel *nameLabel; @property (nonatomic, retain) IBOutlet UILabel *usernameLabel; @property (nonatomic, retain) IBOutlet UITextField *nextActionTextField; @property (nonatomic, retain) IBOutlet UILabel *dateLabel; @property (nonatomic, retain) IBOutlet UIButton *contactInfoButton; @property (nonatomic, retain) IBOutlet UIButton *backgroundInfoButton; @property (nonatomic, retain) IBOutlet UIButton *actionDoneButton; -(IBAction)displayContactInfo: (id)sender; -(IBAction)displayBackgroundInfo: (id)sender; -(IBAction)actionDone: (id)sender; @end However when I run it, I get the following error message: * Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key nameLabel.' In IB I've hooked up the labels/buttons/textbox to the File's Owner (set the File's Owner Class to: ContactDetailViewController) Anyone any idea what I'm doing wrong? Regards, Fiona

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  • Python - Converting CSV to Objects - Code Design

    - by victorhooi
    Hi, I have a small script we're using to read in a CSV file containing employees, and perform some basic manipulations on that data. We read in the data (import_gd_dump), and create an Employees object, containing a list of Employee objects (maybe I should think of a better naming convention...lol). We then call clean_all_phone_numbers() on Employees, which calls clean_phone_number() on each Employee, as well as lookup_all_supervisors(), on Employees. import csv import re import sys #class CSVLoader: # """Virtual class to assist with loading in CSV files.""" # def import_gd_dump(self, input_file='Gp Directory 20100331 original.csv'): # gd_extract = csv.DictReader(open(input_file), dialect='excel') # employees = [] # for row in gd_extract: # curr_employee = Employee(row) # employees.append(curr_employee) # return employees # #self.employees = {row['dbdirid']:row for row in gd_extract} # Previously, this was inside a (virtual) class called "CSVLoader". # However, according to here (http://tomayko.com/writings/the-static-method-thing) - the idiomatic way of doing this in Python is not with a class-fucntion but with a module-level function def import_gd_dump(input_file='Gp Directory 20100331 original.csv'): """Return a list ('employee') of dict objects, taken from a Group Directory CSV file.""" gd_extract = csv.DictReader(open(input_file), dialect='excel') employees = [] for row in gd_extract: employees.append(row) return employees def write_gd_formatted(employees_dict, output_file="gd_formatted.csv"): """Read in an Employees() object, and write out each Employee() inside this to a CSV file""" gd_output_fieldnames = ('hrid', 'mail', 'givenName', 'sn', 'dbcostcenter', 'dbdirid', 'hrreportsto', 'PHFull', 'PHFull_message', 'SupervisorEmail', 'SupervisorFirstName', 'SupervisorSurname') try: gd_formatted = csv.DictWriter(open(output_file, 'w', newline=''), fieldnames=gd_output_fieldnames, extrasaction='ignore', dialect='excel') except IOError: print('Unable to open file, IO error (Is it locked?)') sys.exit(1) headers = {n:n for n in gd_output_fieldnames} gd_formatted.writerow(headers) for employee in employees_dict.employee_list: # We're using the employee object's inbuilt __dict__ attribute - hmm, is this good practice? gd_formatted.writerow(employee.__dict__) class Employee: """An Employee in the system, with employee attributes (name, email, cost-centre etc.)""" def __init__(self, employee_attributes): """We use the Employee constructor to convert a dictionary into instance attributes.""" for k, v in employee_attributes.items(): setattr(self, k, v) def clean_phone_number(self): """Perform some rudimentary checks and corrections, to make sure numbers are in the right format. Numbers should be in the form 0XYYYYYYYY, where X is the area code, and Y is the local number.""" if self.telephoneNumber is None or self.telephoneNumber == '': return '', 'Missing phone number.' else: standard_format = re.compile(r'^\+(?P<intl_prefix>\d{2})\((?P<area_code>\d)\)(?P<local_first_half>\d{4})-(?P<local_second_half>\d{4})') extra_zero = re.compile(r'^\+(?P<intl_prefix>\d{2})\(0(?P<area_code>\d)\)(?P<local_first_half>\d{4})-(?P<local_second_half>\d{4})') missing_hyphen = re.compile(r'^\+(?P<intl_prefix>\d{2})\(0(?P<area_code>\d)\)(?P<local_first_half>\d{4})(?P<local_second_half>\d{4})') if standard_format.search(self.telephoneNumber): result = standard_format.search(self.telephoneNumber) return '0' + result.group('area_code') + result.group('local_first_half') + result.group('local_second_half'), '' elif extra_zero.search(self.telephoneNumber): result = extra_zero.search(self.telephoneNumber) return '0' + result.group('area_code') + result.group('local_first_half') + result.group('local_second_half'), 'Extra zero in area code - ask user to remediate. ' elif missing_hyphen.search(self.telephoneNumber): result = missing_hyphen.search(self.telephoneNumber) return '0' + result.group('area_code') + result.group('local_first_half') + result.group('local_second_half'), 'Missing hyphen in local component - ask user to remediate. ' else: return '', "Number didn't match recognised format. Original text is: " + self.telephoneNumber class Employees: def __init__(self, import_list): self.employee_list = [] for employee in import_list: self.employee_list.append(Employee(employee)) def clean_all_phone_numbers(self): for employee in self.employee_list: #Should we just set this directly in Employee.clean_phone_number() instead? employee.PHFull, employee.PHFull_message = employee.clean_phone_number() # Hmm, the search is O(n^2) - there's probably a better way of doing this search? def lookup_all_supervisors(self): for employee in self.employee_list: if employee.hrreportsto is not None and employee.hrreportsto != '': for supervisor in self.employee_list: if supervisor.hrid == employee.hrreportsto: (employee.SupervisorEmail, employee.SupervisorFirstName, employee.SupervisorSurname) = supervisor.mail, supervisor.givenName, supervisor.sn break else: (employee.SupervisorEmail, employee.SupervisorFirstName, employee.SupervisorSurname) = ('Supervisor not found.', 'Supervisor not found.', 'Supervisor not found.') else: (employee.SupervisorEmail, employee.SupervisorFirstName, employee.SupervisorSurname) = ('Supervisor not set.', 'Supervisor not set.', 'Supervisor not set.') #Is thre a more pythonic way of doing this? def print_employees(self): for employee in self.employee_list: print(employee.__dict__) if __name__ == '__main__': db_employees = Employees(import_gd_dump()) db_employees.clean_all_phone_numbers() db_employees.lookup_all_supervisors() #db_employees.print_employees() write_gd_formatted(db_employees) Firstly, my preamble question is, can you see anything inherently wrong with the above, from either a class design or Python point-of-view? Is the logic/design sound? Anyhow, to the specifics: The Employees object has a method, clean_all_phone_numbers(), which calls clean_phone_number() on each Employee object inside it. Is this bad design? If so, why? Also, is the way I'm calling lookup_all_supervisors() bad? Originally, I wrapped the clean_phone_number() and lookup_supervisor() method in a single function, with a single for-loop inside it. clean_phone_number is O(n), I believe, lookup_supervisor is O(n^2) - is it ok splitting it into two loops like this? In clean_all_phone_numbers(), I'm looping on the Employee objects, and settings their values using return/assignment - should I be setting this inside clean_phone_number() itself? There's also a few things that I'm sorted of hacked out, not sure if they're bad practice - e.g. print_employee() and gd_formatted() both use __dict__, and the constructor for Employee uses setattr() to convert a dictionary into instance attributes. I'd value any thoughts at all. If you think the questions are too broad, let me know and I can repost as several split up (I just didn't want to pollute the boards with multiple similar questions, and the three questions are more or less fairly tightly related). Cheers, Victor

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  • Adding an overlay to Google maps with path taken

    - by user341652
    Hi, I am trying to write a class to track a person's location(s), and to draw the path they've taken on a MapView. This feature of the program is for the user to track their speed, distance, path, etc. while running/cycling (or whatever else) using their Android phone. This is my first Android application, and I am not sure how to do the Overlay object for the MapView. I also wanted to see if anyone had opinions on the GPS-Tracking part I have written (if it would work, if there is a better way of doing it, code examples would be helpful). I currently have this for my GPSTrackerService: package org.drexel.itrain.logic; import java.util.Vector; import org.drexel.itrain.Constants; import android.app.Notification; import android.app.NotificationManager; import android.app.Service; import android.content.Context; import android.content.Intent; import android.content.SharedPreferences; import android.location.GpsSatellite; import android.location.GpsStatus; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.location.GpsStatus.Listener; import android.os.Binder; import android.os.Bundle; import android.os.IBinder; import android.preference.PreferenceManager; public class GPSTrackingService extends Service { private static final int MAX_REASONABLE_SPEED = 60; private static final String TAG = "OGT.TrackingService"; private Context mContext; private LocationManager mLocationManager; private NotificationManager mNotificationManager; private Notification mNotification; private int mSatellites = 0; private int mTrackingState = Constants.GPS_TRACKING_UNKNOWN; private float mCurrentSpeed = 0; private float mTotalDistance = 0; private Location mPreviousLocation; private Vector<Location> mTrackedLocations; private LocationListener mLocationListener = null; private Listener mStatusListener = null; private IBinder binder = null; @Override public void onCreate() { super.onCreate(); this.mContext = getApplicationContext(); this.mLocationManager = (LocationManager) this.mContext.getSystemService( Context.LOCATION_SERVICE ); this.mNotificationManager = (NotificationManager) this.mContext.getSystemService( Context.NOTIFICATION_SERVICE ); this.mTrackedLocations = new Vector<Location>(); this.binder = new Binder(); SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this.mContext); binder = new Binder(); if(mTrackingState != Constants.GPS_TRACKING_UNKNOWN) { createListeners(); } } @Override public void onDestroy() { destroyListeneres(); } @Override public IBinder onBind(Intent intent) { return binder; } @Override public boolean onUnbind(Intent intent) { return true; } public boolean acceptLocation(Location proposedLocation) { if(!(proposedLocation.hasSpeed() || proposedLocation.hasAccuracy())) { return false; } else if(proposedLocation.getSpeed() >= MAX_REASONABLE_SPEED) { return false; } return true; } public void updateNotification() { //TODO Alert that no GPS sattelites are available (or are available) } public void startTracking() { this.mTrackingState = Constants.GPS_TRACKING_STARTED; this.mTotalDistance = 0; this.mCurrentSpeed = 0; this.mTrackedLocations = new Vector<Location>(); this.mPreviousLocation = null; createListeners(); } public void pauseTracking() { this.mTrackingState = Constants.GPS_TRACKING_PAUSED; this.mPreviousLocation = null; this.mCurrentSpeed = 0; } public void resumeTracking() { if(this.mTrackingState == Constants.GPS_TRACKING_STOPPED){ this.startTracking(); } this.mTrackingState = Constants.GPS_TRACKING_STARTED; } public void stopTracking() { this.mTrackingState = Constants.GPS_TRACKING_STOPPED; destroyListeneres(); } private void createListeners() { /** * LocationListener receives locations from */ this.mLocationListener = new LocationListener() { @Override public void onStatusChanged(String provider, int status, Bundle extras) { // TODO Auto-generated method stub } @Override public void onProviderEnabled(String provider) { // TODO Auto-generated method stub } @Override public void onProviderDisabled(String provider) { // TODO Auto-generated method stub } @Override public void onLocationChanged(Location location) { if(mTrackingState == Constants.GPS_TRACKING_STARTED && acceptLocation(location)) { if(mPreviousLocation != null) { //Add the distance between the new location and the previous location mTotalDistance += mPreviousLocation.distanceTo(location); } if(location.hasSpeed()) { mCurrentSpeed = location.getSpeed(); } else { mCurrentSpeed = -1; //-1 means speed N/A } mPreviousLocation = location; mTrackedLocations.add(location); } } }; /** * Receives updates reguarding the GPS Status */ this.mStatusListener = new GpsStatus.Listener() { @Override public synchronized void onGpsStatusChanged(int event) { switch( event ) { case GpsStatus.GPS_EVENT_SATELLITE_STATUS: { GpsStatus status = mLocationManager.getGpsStatus( null ); mSatellites = 0; Iterable<GpsSatellite> list = status.getSatellites(); for( GpsSatellite satellite : list ) { if( satellite.usedInFix() ) { mSatellites++; } } updateNotification(); break; } default: break; } } }; } /** * Destroys the LocationListenere and the GPSStatusListener */ private void destroyListeneres() { this.mLocationListener = null; this.mStatusListener = null; } /** * Gets the total distance traveled by the * * @return the total distance traveled (in meters) */ public float getDistance() { return mTotalDistance; } /** * Gets the current speed of the last good location * * @return the current speed (in meters/second) */ public float getSpeed() { return mCurrentSpeed; } } Any assistance would be much appreciated. This is my group's first Android app, and we are a little pressed for time at the moment. The project is for a class, and is available from SourceForge (currently called iTrain, soon to be renamed). Thanks in Advance, Steve

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  • pass an ID with hyperlik but cant get this ID value from a fk in one table when i click in insert

    - by susan
    Something strange happened in my codes, actually I have a hyperlink that pass ID value in a query string to second page.in second page i have 2 sql datasource that both these sql datasources should get this id value and pass it to a filter parameter to show sth in datalist. so in another word I have a first page that has an hyperlink read ID value from a datasource and pass it to second page.its like below: <asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl='<%# "~/forumpage.aspx?ID="+Eval("ID")%>'><%#Eval("title")%> </asp:HyperLink> then in second page i have one sql datasource with a query like this ...where ID=@id and get this id in query string from db.it work great . but i have problem with second sql datasource in second page it has a query sth like below:...forms.question_id=@id then in sql reference both to query string as ID that get by first page in hyperlink. but when i click in insert button show me error with fk. error:Error:The INSERT statement conflicted with the FOREIGN KEY constraint "FK_forumreply_forumquestions". The conflict occurred in database "forum", table "dbo.forumquestions", column 'ID'. The statement has been terminated. my tables (question(ID,user_id(fk),Cat_id(fk),title,bodytext) (reply(ID,userr_id(fk),questionn_id(fk),titlereply,bodytestreply); When by hand in cb i gave a number in questionn_id like 1 it show me successful but when it want read from a filter by datasource this field face with problem. plzzzz help i really need skip from this part.and cause i am new i guess I cant understand the logic way clearly. <asp:SqlDataSource ID="sdsreply" runat="server" ConnectionString="<%$ ConnectionStrings:forumConnectionString %>" SelectCommand="SELECT forumreply.ID, forumreply.userr_id, forumreply.questionn_id, forumreply.bodytextreply, forumreply.datetimereply, forumquestions.ID AS Expr1, forumusers.ID AS Expr2, forumusers.username FROM forumquestions INNER JOIN forumreply ON forumquestions.ID = forumreply.questionn_id INNER JOIN forumusers ON forumquestions.user_id = forumusers.ID AND forumreply.userr_id = forumusers.ID where forumreply.questionn_id=@questionn_id"> <SelectParameters> <asp:QueryStringParameter Name="questionn_id" QueryStringField="ID" /> </SelectParameters> </asp:SqlDataSource> it is cb for second page in insert button: { if (Session["userid"] != null) { lblreply.Text = Session["userid"].ToString(); } else { Session["userid"]=null; } if (HttpContext.Current.User.Identity.IsAuthenticated) { lblshow.Text = string.Empty; string d = HttpContext.Current.User.Identity.Name; lblshow.Text =d + "???? ??? ?????." ; foreach (DataListItem item in DataList2.Items) { Label questionn_idLabel = (Label)item.FindControl("questionn_idLabel"); Label userr_idLabel = (Label)item.FindControl("userr_idLabel"); lbltest.Text = string.Empty; lbltest.Text = questionn_idLabel.Text; lblreply.Text = string.Empty; lblreply.Text = userr_idLabel.Text; } } else { lblshow.Text = "??? ??? ??? ??? ?? ?? ?????? ???? ???? ???? ????? ??? ??? ? ??? ????? ???????."; } } { if(HttpContext.Current.User.Identity.IsAuthenticated) { if (Page.IsValid) { SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["forumConnectionString"].ConnectionString); try { con.Open(); SqlCommand cmd = new SqlCommand("insert into forumreply (userr_id,questionn_id,bodytextreply,datetimereply)values(@userr_id,@questionn_id,@bodytextreply,@datetimereply)", con); cmd.Parameters.AddWithValue("userr_id",lblreply.Text); cmd.Parameters.AddWithValue("questionn_id",lbltest.Text); cmd.Parameters.AddWithValue("bodytextreply",txtbody.Text); cmd.Parameters.AddWithValue("datetimereply",DateTime.Now ); cmd.ExecuteNonQuery(); } catch (Exception exp) { Response.Write("<b>Error:</b>"); Response.Write(exp.Message); } finally { con.Close(); } lblmsg.Text = "???? ??? ?? ?????? ??? ?????.thx"; lblshow.Visible = false; //lbltxt.Text = txtbody.Text; txtbody.Text = string.Empty; } } else { lblmsg.Text = string.Empty; Session["rem"] = Request.UrlReferrer.AbsoluteUri; Response.Redirect("~/login.aspx"); } }

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  • Get the property, as a string, from an Expression<Func<TModel,TProperty>>

    - by Jaxidian
    I use some strongly-typed expressions that get serialized to allow my UI code to have strongly-typed sorting and searching expressions. These are of type Expression<Func<TModel,TProperty>> and are used as such: SortOption.Field = (p => p.FirstName);. I've gotten this working perfectly for this simple case. The code that I'm using for parsing the "FirstName" property out of there is actually reusing some existing functionality in a third-party product that we use and it works great, until we start working with deeply-nested properties(SortOption.Field = (p => p.Address.State.Abbreviation);). This code has some very different assumptions in the need to support deeply-nested properties. As for what this code does, I don't really understand it and rather than changing that code, I figured I should just write from scratch this functionality. However, I don't know of a good way to do this. I suspect we can do something better than doing a ToString() and performing string parsing. So what's a good way to do this to handle the trivial and deeply-nested cases? Requirements: Given the expression p => p.FirstName I need a string of "FirstName". Given the expression p => p.Address.State.Abbreviation I need a string of "Address.State.Abbreviation" While it's not important for an answer to my question, I suspect my serialization/deserialization code could be useful to somebody else who finds this question in the future, so it is below. Again, this code is not important to the question - I just thought it might help somebody. Note that DynamicExpression.ParseLambda comes from the Dynamic LINQ stuff and Property.PropertyToString() is what this question is about. /// <summary> /// This defines a framework to pass, across serialized tiers, sorting logic to be performed. /// </summary> /// <typeparam name="TModel">This is the object type that you are filtering.</typeparam> /// <typeparam name="TProperty">This is the property on the object that you are filtering.</typeparam> [Serializable] public class SortOption<TModel, TProperty> : ISerializable where TModel : class { /// <summary> /// Convenience constructor. /// </summary> /// <param name="property">The property to sort.</param> /// <param name="isAscending">Indicates if the sorting should be ascending or descending</param> /// <param name="priority">Indicates the sorting priority where 0 is a higher priority than 10.</param> public SortOption(Expression<Func<TModel, TProperty>> property, bool isAscending = true, int priority = 0) { Property = property; IsAscending = isAscending; Priority = priority; } /// <summary> /// Default Constructor. /// </summary> public SortOption() : this(null) { } /// <summary> /// This is the field on the object to filter. /// </summary> public Expression<Func<TModel, TProperty>> Property { get; set; } /// <summary> /// This indicates if the sorting should be ascending or descending. /// </summary> public bool IsAscending { get; set; } /// <summary> /// This indicates the sorting priority where 0 is a higher priority than 10. /// </summary> public int Priority { get; set; } #region Implementation of ISerializable /// <summary> /// This is the constructor called when deserializing a SortOption. /// </summary> protected SortOption(SerializationInfo info, StreamingContext context) { IsAscending = info.GetBoolean("IsAscending"); Priority = info.GetInt32("Priority"); // We just persisted this by the PropertyName. So let's rebuild the Lambda Expression from that. Property = DynamicExpression.ParseLambda<TModel, TProperty>(info.GetString("Property"), default(TModel), default(TProperty)); } /// <summary> /// Populates a <see cref="T:System.Runtime.Serialization.SerializationInfo"/> with the data needed to serialize the target object. /// </summary> /// <param name="info">The <see cref="T:System.Runtime.Serialization.SerializationInfo"/> to populate with data. </param> /// <param name="context">The destination (see <see cref="T:System.Runtime.Serialization.StreamingContext"/>) for this serialization. </param> public void GetObjectData(SerializationInfo info, StreamingContext context) { // Just stick the property name in there. We'll rebuild the expression based on that on the other end. info.AddValue("Property", Property.PropertyToString()); info.AddValue("IsAscending", IsAscending); info.AddValue("Priority", Priority); } #endregion }

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  • how do I use html block snippets with dynamic content inside a django template that extends another

    - by stackoverflowusername
    Hi. Can someone please help me figure out a way to achieve the following (see snippets below) in Django templates? I know that you cannot use more than one extends, but I am new to django and I do not know the proper syntax for something like this. I want to be able to do this so that I can use my nested div layout for css reasons without having to type it like that each time and risking a typo. In words, I want to be able to have a page template extend my base.html file and then use html snippets of dynamic template content (i.e. template for loops or other template logic devices, not just a context variable I set from my view controller). ------------------------------------------------------------ base.html ------------------------------------------------------------ <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html;charset=utf-8" /> <title>{% block title %}Title{% endblock %}</title> </head> <body> <div class="wrapper"> <div class="header"> This is the common header </div> <div class="nav"> This is the common nav </div> {% if messages %} <div class="messages"> <ul> {% for message in messages %} <li{% if message.tags %} class="{{ message.tags }}"{% endif %}>{{ message }}</li> {% endfor %} </ul> </div> {% endif %} <div class="content"> {% block content %}Page Content{% endblock %} </div> <div class="footer"> This is the common footer </div> </div> </body> </html> ------------------------------------------------------------ columnlayout2.html ------------------------------------------------------------ <div class="twocol container2"> <div class="container1"> <div class="col1"> {% block twocol_col1 %}{% endblock %} </div> <div class="col2"> {% block twocol_col2 %}{% endblock %} </div> </div> </div> ------------------------------------------------------------ columnlayout3.html ------------------------------------------------------------ <div class="threecol container3"> <div class="container2"> <div class="container1"> <div class="col1"> {% block threecol_col1 %}{% endblock %} </div> <div class="col2"> {% block threecol_col2 %}{% endblock %} </div> <div class="col3"> {% block threecol_col3 %}{% endblock %} </div> </div> </div> </div> ------------------------------------------------------------ page.html ------------------------------------------------------------ {% extends "base.html" %} {% block content %} {% extends "columnlayout2.html" %} {% block twocol_col1 %}twocolumn column 1{% endblock %} {% block twocol_col2 %}twocolumn column 2{% endblock %} {% extends "columnlayout3.html" %} {% block threecol_col1 %}threecol column 1{% endblock %} {% block threecol_col2 %}threecol column 2{% endblock %} {% block threecol_col3 %}threecol column 3{% endblock %} {% endblock %} ------------------------------------------------------------ page.html output ------------------------------------------------------------ <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html;charset=utf-8" /> <title>Title</title> </head> <body> <div class="wrapper"> <div class="header"> This is the common header </div> <div class="nav"> This is the common nav </div> <div class="content"> <div class="twocol container2"> <div class="container1"> <div class="col1"> twocolumn column 1 </div> <div class="col2"> twocolumn column 2 </div> </div> </div> <div class="threecol container3"> <div class="container2"> <div class="container1"> <div class="col1"> threecol column 1 </div> <div class="col2"> threecol column 2 </div> <div class="col3"> threecol column 3 </div> </div> </div> </div> </div> <div class="footer"> This is the common footer </div> </div> </body> </html>

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  • Need some suggestions on my softwares architecture. [Code review]

    - by Sergio Tapia
    I'm making an open source C# library for other developers to use. My key concern is ease of use. This means using intuitive names, intuitive method usage and such. This is the first time I've done something with other people in mind, so I'm really concerned about the quality of the architecture. Plus, I wouldn't mind learning a thing or two. :) I have three classes: Downloader, Parser and Movie I was thinking that it would be best to only expose the Movie class of my library and have Downloader and Parser remain hidden from invocation. Ultimately, I see my library being used like this. using FreeIMDB; public void Test() { var MyMovie = Movie.FindMovie("The Matrix"); //Now MyMovie would have all it's fields set and ready for the big show. } Can you review how I'm planning this, and point out any wrong judgement calls I've made and where I could improve. Remember, my main concern is ease of use. Movie.cs using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Drawing; namespace FreeIMDB { public class Movie { public Image Poster { get; set; } public string Title { get; set; } public DateTime ReleaseDate { get; set; } public string Rating { get; set; } public string Director { get; set; } public List<string> Writers { get; set; } public List<string> Genres { get; set; } public string Tagline { get; set; } public string Plot { get; set; } public List<string> Cast { get; set; } public string Runtime { get; set; } public string Country { get; set; } public string Language { get; set; } public Movie FindMovie(string Title) { Movie film = new Movie(); Parser parser = Parser.FromMovieTitle(Title); film.Poster = parser.Poster(); film.Title = parser.Title(); film.ReleaseDate = parser.ReleaseDate(); //And so an so forth. } public Movie FindKnownMovie(string ID) { Movie film = new Movie(); Parser parser = Parser.FromMovieID(ID); film.Poster = parser.Poster(); film.Title = parser.Title(); film.ReleaseDate = parser.ReleaseDate(); //And so an so forth. } } } Parser.cs using System; using System.Collections.Generic; using System.Linq; using System.Text; using HtmlAgilityPack; namespace FreeIMDB { /// <summary> /// Provides a simple, and intuitive way for searching for movies and actors on IMDB. /// </summary> class Parser { private Downloader downloader = new Downloader(); private HtmlDocument Page; #region "Page Loader Events" private Parser() { } public static Parser FromMovieTitle(string MovieTitle) { var newParser = new Parser(); newParser.Page = newParser.downloader.FindMovie(MovieTitle); return newParser; } public static Parser FromActorName(string ActorName) { var newParser = new Parser(); newParser.Page = newParser.downloader.FindActor(ActorName); return newParser; } public static Parser FromMovieID(string MovieID) { var newParser = new Parser(); newParser.Page = newParser.downloader.FindKnownMovie(MovieID); return newParser; } public static Parser FromActorID(string ActorID) { var newParser = new Parser(); newParser.Page = newParser.downloader.FindKnownActor(ActorID); return newParser; } #endregion #region "Page Parsing Methods" public string Poster() { //Logic to scrape the Poster URL from the Page element of this. return null; } public string Title() { return null; } public DateTime ReleaseDate() { return null; } #endregion } } ----------------------------------------------- Do you guys think I'm heading towards a good path, or am I setting myself up for a world of hurt later on? My original thought was to separate the downloading, the parsing and the actual populating to easily have an extensible library. Imagine if one day the website changed its HTML, I would then only have to modifiy the parsing class without touching the Downloader.cs or Movie.cs class. Thanks for reading and for helping!

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  • Vector of Object Pointers, general help and confusion

    - by Staypuft
    Have a homework assignment in which I'm supposed to create a vector of pointers to objects Later on down the load, I'll be using inheritance/polymorphism to extend the class to include fees for two-day delivery, next day air, etc. However, that is not my concern right now. The final goal of the current program is to just print out every object's content in the vector (name & address) and find it's shipping cost (weight*cost). My Trouble is not with the logic, I'm just confused on few points related to objects/pointers/vectors in general. But first my code. I basically cut out everything that does not mater right now, int main, will have user input, but right now I hard-coded two examples. #include <iostream> #include <string> #include <vector> using namespace std; class Package { public: Package(); //default constructor Package(string d_name, string d_add, string d_zip, string d_city, string d_state, double c, double w); double calculateCost(double, double); void Print(); ~Package(); private: string dest_name; string dest_address; string dest_zip; string dest_city; string dest_state; double weight; double cost; }; Package::Package() { cout<<"Constucting Package Object with default values: "<<endl; string dest_name=""; string dest_address=""; string dest_zip=""; string dest_city=""; string dest_state=""; double weight=0; double cost=0; } Package::Package(string d_name, string d_add, string d_zip, string d_city, string d_state, string r_name, string r_add, string r_zip, string r_city, string r_state, double w, double c){ cout<<"Constucting Package Object with user defined values: "<<endl; string dest_name=d_name; string dest_address=d_add; string dest_zip=d_zip; string dest_city=d_city; string dest_state=d_state; double weight=w; double cost=c; } Package::~Package() { cout<<"Deconstructing Package Object!"<<endl; delete Package; } double Package::calculateCost(double x, double y){ return x+y; } int main(){ double cost=0; vector<Package*> shipment; cout<<"Enter Shipping Cost: "<<endl; cin>>cost; shipment.push_back(new Package("tom r","123 thunder road", "90210", "Red Bank", "NJ", cost, 10.5)); shipment.push_back(new Package ("Harry Potter","10 Madison Avenue", "55555", "New York", "NY", cost, 32.3)); return 0; } So my questions are: I'm told I have to use a vector of Object Pointers, not Objects. Why? My assignment calls for it specifically, but I'm also told it won't work otherwise. Where should I be creating this vector? Should it be part of my Package Class? How do I go about adding objects into it then? Do I need a copy constructor? Why? What's the proper way to deconstruct my vector of object pointers? Any help would be appreciated. I've searched for a lot of related articles on here and I realize that my program will have memory leaks. Using one of the specialized ptrs from boost:: will not be available for me to use. Right now, I'm more concerned with getting the foundation of my program built. That way I can actually get down to the functionality I need to create. Thanks.

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  • Patching this Code to apply dynamic (iPhone) background position

    - by Brian
    I posted a question previously that got off topic, I'm reposting with better code that I have VERIFIED is compatible with iPhone (it works with mine anyway!) I just want to apply background-position coordinates to the body element and call the script conditionally for iPhone, iPod, & iPad. Here's my conditional call for those devices: var deviceAgent = navigator.userAgent.toLowerCase(); var agentID = deviceAgent.match(/(iphone|ipod|ipad)/); if (agentID) { // do something } else { //do this } Now, I've found this excellent script that sets the "top: x" dynamically on the basis of scroll position. Everyone has told me (and ALL of the tutorials and Google search results as well) that it's impossible to set scroll position dynamically for iPhone because of the viewport issue. HOWEVER, they are wrong because if you scroll to the bottom of the page and view this javascript demo on iPhone, you can scroll and the <div style="background-position: fixed; top: x (variable)"></div> div DOES stay centered on iPhone. I really hope this question helps alot of people, I thought it was impossible, but it's NOT... I just need help stitching it together! The original code (you can test it on iPhone yourself) is here: http://stevenbenner.com/2010/04/calculate-page-size-and-view-port-position-in-javascript/ So I just need help getting the following code to apply the dynamic "background-position: 0 x" to the BODY tag where x is centered and relative to the viewport position. Also, needs to be nested inside the above code that is conditional for iPhone and similar devices. // Page Size and View Port Dimension Tools // http://stevenbenner.com/2010/04/calculate-page-size-and-view-port-position-in-javascript/ if (!sb_windowTools) { var sb_windowTools = new Object(); }; sb_windowTools = { scrollBarPadding: 17, // padding to assume for scroll bars // EXAMPLE METHODS // center an element in the viewport centerElementOnScreen: function(element) { var pageDimensions = this.updateDimensions(); element.style.top = ((this.pageDimensions.verticalOffset() + this.pageDimensions.windowHeight() / 2) - (this.scrollBarPadding + element.offsetHeight / 2)) + 'px'; element.style.left = ((this.pageDimensions.windowWidth() / 2) - (this.scrollBarPadding + element.offsetWidth / 2)) + 'px'; element.style.position = 'absolute'; }, // INFORMATION GETTERS // load the page size, view port position and vertical scroll offset updateDimensions: function() { this.updatePageSize(); this.updateWindowSize(); this.updateScrollOffset(); }, // load page size information updatePageSize: function() { // document dimensions var viewportWidth, viewportHeight; if (window.innerHeight && window.scrollMaxY) { viewportWidth = document.body.scrollWidth; viewportHeight = window.innerHeight + window.scrollMaxY; } else if (document.body.scrollHeight > document.body.offsetHeight) { // all but explorer mac viewportWidth = document.body.scrollWidth; viewportHeight = document.body.scrollHeight; } else { // explorer mac...would also work in explorer 6 strict, mozilla and safari viewportWidth = document.body.offsetWidth; viewportHeight = document.body.offsetHeight; }; this.pageSize = { viewportWidth: viewportWidth, viewportHeight: viewportHeight }; }, // load window size information updateWindowSize: function() { // view port dimensions var windowWidth, windowHeight; if (self.innerHeight) { // all except explorer windowWidth = self.innerWidth; windowHeight = self.innerHeight; } else if (document.documentElement && document.documentElement.clientHeight) { // explorer 6 strict mode windowWidth = document.documentElement.clientWidth; windowHeight = document.documentElement.clientHeight; } else if (document.body) { // other explorers windowWidth = document.body.clientWidth; windowHeight = document.body.clientHeight; }; this.windowSize = { windowWidth: windowWidth, windowHeight: windowHeight }; }, // load scroll offset information updateScrollOffset: function() { // viewport vertical scroll offset var horizontalOffset, verticalOffset; if (self.pageYOffset) { horizontalOffset = self.pageXOffset; verticalOffset = self.pageYOffset; } else if (document.documentElement && document.documentElement.scrollTop) { // Explorer 6 Strict horizontalOffset = document.documentElement.scrollLeft; verticalOffset = document.documentElement.scrollTop; } else if (document.body) { // all other Explorers horizontalOffset = document.body.scrollLeft; verticalOffset = document.body.scrollTop; }; this.scrollOffset = { horizontalOffset: horizontalOffset, verticalOffset: verticalOffset }; }, // INFORMATION CONTAINERS // raw data containers pageSize: {}, windowSize: {}, scrollOffset: {}, // combined dimensions object with bounding logic pageDimensions: { pageWidth: function() { return sb_windowTools.pageSize.viewportWidth > sb_windowTools.windowSize.windowWidth ? sb_windowTools.pageSize.viewportWidth : sb_windowTools.windowSize.windowWidth; }, pageHeight: function() { return sb_windowTools.pageSize.viewportHeight > sb_windowTools.windowSize.windowHeight ? sb_windowTools.pageSize.viewportHeight : sb_windowTools.windowSize.windowHeight; }, windowWidth: function() { return sb_windowTools.windowSize.windowWidth; }, windowHeight: function() { return sb_windowTools.windowSize.windowHeight; }, horizontalOffset: function() { return sb_windowTools.scrollOffset.horizontalOffset; }, verticalOffset: function() { return sb_windowTools.scrollOffset.verticalOffset; } } };

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  • JQuery Dynamic Element - In DOM but unable to bind

    - by Grant80
    Hi All, I'm new to using JQuery so bear with me. I had implmented some code based on a js file that I found online which enables a series of div tags within a nested structure on my page to step through and show each one individually on the page. This all works great when I define the div tags as static entries in the masterpage. I should add that this is being implemented in a SharePoint master page. Ultimately though, with a static collection of div tags ideally containing an image with some descriptive text, and a hyperlink its not very flexible. Roll on my changes to make this a little more configurable. I have implemented some additional code that will read from a SharePoint list via an ajax call to the lists web service. For each entry in the list I am building a div tag that contains the information required dynamically. For testing, I am only pulling the title through at present. I have used the following code: $('#beltDiv').append(divHTML) to append the divs in the loop that are created to my nested structure on the page. I figured that this would cause the fade code to work as expected but I was wrong. It doesn't do anything at all. When check the source on the page, the div tags are not shown. They are however available in the DOM model when viewed through the IE developer toolbar. The issue (I think) looks to be that the initiation of the featureFade code is not working due to the div tags being unavailable. Is there a way to address this? The code used is shown below: <script type="text/javascript"> $(document).ready(function() { var soapEnv = "<soapenv:Envelope xmlns:soapenv='http://schemas.xmlsoap.org/soap/envelope/'> \ <soapenv:Body> \ <GetListItems xmlns='http://schemas.microsoft.com/sharepoint/soap/'> \ <listName>Carousel Items</listName> \ <viewFields> \ <ViewFields> \ <FieldRef Name='Title' /> \ </ViewFields> \ </viewFields> \ </GetListItems> \ </soapenv:Body> \ </soapenv:Envelope>"; $.ajax({ url: "_vti_bin/lists.asmx", type: "POST", dataType: "xml", data: soapEnv, complete: processResult, contentType: "text/xml; charset=\"utf-8\"" }); }); function processResult(xData, status) { $(xData.responseXML).find("z\\:row").each(function() { var divHTML = "<div id=\"divPanel_" + $(this).attr("ows_Title") + "\" class=\"panel\" style=\"background:url('http://devSP2010/sites/SPSOPS/Style Library/SharePointOps/Images/01.jpg') no-repeat; width:650px; height:55px;\"><div><div class=\"content\"><div><P><A style=\"COLOR: #cc0000\" href=\"www.google.com\">" + $(this).attr("ows_Title") + "</A></P><P>&nbsp;</P><P>&nbsp;</P><P>&nbsp;</P><P>&nbsp;</P></div></div></div></div>"; $("#beltDiv").append(divHTML); }); } featureFade.setup({ galleryid: 'headlines', beltclass: 'belt', panelclass: 'panel', autostep: { enable: true, moveby: 1, pause: 10000 }, panelbehavior: { speed: 1000, wraparound: true }, stepImgIDs: ["ftOne", "ftTwo", "ftThree", "ftFour","ftFive"], defaultButtons: { itemOn: "Style Library/SharePointOps/Images/dotOn.png", itemOff: "Style Library/SharePointOps/Images/dotOff.png" } }); The section where the div tags are dynamically appended is shown below. I've commented out the static div tags that work as expected. The only change is that these are implmented by the JQuery logic: <div class="homeFeature" style="display:inline-block"> <div id="headlines" class="headlines"> <div id="beltDiv" class="belt"> <!-- <div id="divPanel_ct01" class="panel" style="position:absolute;background-image:url('http://devsp2010/sites/spsops/Style Library/SharePointOps/Images/01.jpg'); background-repeat:no-repeat">Static Test 1</div> <div id="divPanel_ct02" class="panel" style="position:absolute;background-image:url('http://devsp2010/sites/spsops/Style Library/SharePointOps/Images/02.jpg'); background-repeat:no-repeat">Static Test 2</div> --> </div> </div> I'm stumped as to why it's not recognising the dynamically added elements in the DOM. Any help would be greatly appreciated on this. I'm happy to provide any further information on this. Thanks in advance, Grant Further to the answer recieved: I have modified the function call: function processResult(xData, status) { $(xData.responseXML).find("z\\:row").each( function() { /*alert($(this).attr("ows_ImagePath"));*/ var divHTML = "<div id=\"divPanel_" + $(this).attr("ows_Title") + "\" class=\"panel\" style=\"background:url('http://devSP2010/sites/SPSOPS/Style Library/SharePointOps/Images/ClydePort01big.jpg') no-repeat; width:650px; height:55px;\"><div><div class=\"content\"><div><P><A style=\"COLOR: #cc0000\" href=\"www.google.com\">" + $(this).attr("ows_Title") + "</A></P><P>&nbsp;</P><P>&nbsp;</P><P>&nbsp;</P><P>&nbsp;</P></div></div></div></div>"; $("#beltDiv").append(divHTML); } ); featureFade.setup( { galleryid: 'headlines', beltclass: 'belt', panelclass: 'panel', autostep: { enable: true, moveby: 1, pause: 10000 }, panelbehavior: { speed: 1000, wraparound: true }, stepImgIDs: ["ftOne", "ftTwo", "ftThree", "ftFour","ftFive"], defaultButtons: { itemOn: "Style Library/SharePointOps/Images/dotOn.png", itemOff: "Style Library/SharePointOps/Images/dotOff.png" } } ); }

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  • Clicking Elements in Android Doesn't Display the Correct Values

    - by Devin
    I apologize if this code looks a bit like a mess (considering the length); I figured I'd just include everything that goes on in my program at the moment. I'm attempting to create a fairly simple Tic Tac Toe app for Android. I've set up my UI nicely so far so that there are a "grid" of TextViews. As a sort of "debug" right now, I have it so that when one clicks on a TextView, it should display the value of buttonId in a message box. Right now, it displays the correct assigned value for the first element I click, but no matter what I click afterwards, it always just displays the first value buttonID had. I attempted to debug it but couldn't exactly find a point where it would pull the old value (to the best of my knowledge, it reassigned the value). There's a good possibility I'm missing something small, because this is my first Android project (of any note). Can someone help get different values of buttonId to appear or point out the error in my logic? The code: package com.TicTacToe.app; import com.TicTacToe.app.R; //Other import statements public class TicTacToe extends Activity { public String player = "X"; public int ALERT_ID; public int buttonId; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //Sets up instances of UI elements final TextView playerText = (TextView)findViewById(R.id.CurrentPlayerDisp); final Button button = (Button) findViewById(R.id.SetPlayer); final TextView location1 = (TextView)findViewById(R.id.location1); final TextView location2 = (TextView)findViewById(R.id.location2); final TextView location3 = (TextView)findViewById(R.id.location3); final TextView location4 = (TextView)findViewById(R.id.location4); final TextView location5 = (TextView)findViewById(R.id.location5); final TextView location6 = (TextView)findViewById(R.id.location6); final TextView location7 = (TextView)findViewById(R.id.location7); final TextView location8 = (TextView)findViewById(R.id.location8); final TextView location9 = (TextView)findViewById(R.id.location9); playerText.setText(player); //Handlers for events button.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { // Perform action on click if (player.equals("X")){ player = "O"; playerText.setText(player); } else if(player.equals("O")){ player = "X"; playerText.setText(player); } //Sets up the dialog buttonId = 0; ALERT_ID = 0; onCreateDialog(ALERT_ID); showDialog(ALERT_ID); } }); location1.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //Sets up the dialog buttonId = 1; ALERT_ID = 0; onCreateDialog(ALERT_ID); showDialog(ALERT_ID); } }); location2.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //Sets up the dialog buttonId = 2; ALERT_ID = 0; onCreateDialog(ALERT_ID); showDialog(ALERT_ID); } }); location3.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //Sets up the dialog buttonId = 3; ALERT_ID = 0; onCreateDialog(ALERT_ID); showDialog(ALERT_ID); } }); location4.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //Sets up the dialog buttonId = 4; ALERT_ID = 0; onCreateDialog(ALERT_ID); showDialog(ALERT_ID); } }); location5.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //Sets up the dialog buttonId = 5; ALERT_ID = 0; onCreateDialog(ALERT_ID); showDialog(ALERT_ID); } }); location6.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //Sets up the dialog buttonId = 6; ALERT_ID = 0; onCreateDialog(ALERT_ID); showDialog(ALERT_ID); } }); location7.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //Sets up the dialog buttonId = 7; ALERT_ID = 0; onCreateDialog(ALERT_ID); showDialog(ALERT_ID); } }); location8.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //Sets up the dialog buttonId = 8; ALERT_ID = 0; onCreateDialog(ALERT_ID); showDialog(ALERT_ID); } }); location9.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //Sets up the dialog buttonId = 9; ALERT_ID = 0; onCreateDialog(ALERT_ID); showDialog(ALERT_ID); } }); } protected Dialog onCreateDialog(int id){ String msgString = "You are on spot " + buttonId; AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setMessage(msgString) .setCancelable(false) .setNeutralButton("Ok", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int id) { dialog.cancel(); } }); AlertDialog alert = builder.create(); return alert; } }

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  • OpenGL, draw two polygons in the same time (by mouse clicks)

    - by YoungSalafi
    im trying to draw 2 polygons at the same time depending on user input from the opengl screen... so i made 2 arrays which each one of them will carry the vertices of each polygon ... i think my logic is right but the program still prints only polygon and delete the old polygon if you draw a polygon again . and its acting weird too please check the code yourself here it is : P.S dont mind the delete function right now.. i know it missing something. #include <windows.h> #include <gl/gl.h> #include <gl/glut.h> void Draw(); void Set_Transformations(); void Initialize(int argc, char *argv[]); void OnKeyPress(unsigned char key, int x, int y); void DeleteVer(); void MouseClick(int bin, int state , int x , int y); void GetOGLPos(int x, int y,float* arrY,float* arrX); void DrawPolygon(float* arrX,float* arrY); float xPos[20]; float yPos[20]; float xPos2[20]; float yPos2[20]; float fx = 0,fy = 0; float size = 10; int count = 0; bool done = false; bool flag = true; void Initialize(int argc, char *argv[]) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_RGBA); glutInitWindowPosition(100, 100); glutInitWindowSize(600, 600); glutCreateWindow("OpenGL Lab1"); Set_Transformations(); glutDisplayFunc(Draw); glutMouseFunc(MouseClick); glutKeyboardFunc(OnKeyPress); glutMainLoop(); } void Set_Transformations() { glClearColor(1, 1, 1, 1); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(-200, 200, -200, 200); } void OnKeyPress(unsigned char key, int x, int y) { if (key == 27) exit(0); switch(key) { case 13: //enter key it will draw done = true; glutPostRedisplay(); flag=!flag; // this flag to switch to the other array that the vertices will be stored in, in order to draw the second polygon break; } } void MouseClick(int button, int state , int x , int y) { switch (button) { case GLUT_RIGHT_BUTTON: if (state == GLUT_DOWN) { if (count>0) { DeleteVer(); //dont mind this right now } } break; case GLUT_LEFT_BUTTON: if (state == GLUT_DOWN) { if(count<20) { if(flag =true){ // drawing first polygon GetOGLPos(x, y,xPos,yPos);} if (flag=false) //drawing second polygon after Enter is pressed GetOGLPos(x, y,xPos2,yPos2); } } break; } } void GetOGLPos(int x, int y,float* arrY,float* arrX) //getting the vertices from the user { GLint viewport[4]; GLdouble modelview[16]; GLdouble projection[16]; GLfloat winX, winY, winZ; GLdouble posX, posY, posZ; glGetDoublev( GL_MODELVIEW_MATRIX, modelview ); glGetDoublev( GL_PROJECTION_MATRIX, projection ); glGetIntegerv( GL_VIEWPORT, viewport ); winX = (float)x; winY = (float)viewport[3] - (float)y; glReadPixels( x, int(winY), 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &winZ ); gluUnProject( winX, winY, winZ, modelview, projection, viewport, &posX, &posY, &posZ); arrX[count] = posX; arrY[count] = posY; count++; glPointSize( 6.0 ); glBegin(GL_POINTS); glVertex2f(posX,posY); glEnd(); glFlush(); } void DeleteVer(){ //dont mind this glColor3f ( 1, 1, 1); glBegin(GL_POINTS); glVertex2f(xPos[count-1],yPos[count-1]); glEnd(); glFlush(); xPos[count] = NULL; yPos[count] = NULL; count--; glColor3f ( 0, 0, 0); } void DrawPolygon(float* arrX,float* arrY) { int n=0; glColor3f ( 0, 0, 0); glBegin(GL_POLYGON); while(n<count) { glVertex2f(arrX[n],arrY[n]); n++; } count=0; glEnd(); glFlush(); } void Draw() //main drawing func { glClear(GL_COLOR_BUFFER_BIT); glColor3f(0, 0, 0); if(done) { DrawPolygon(xPos,yPos); DrawPolygon(xPos2,yPos2); } glFlush(); } int main(int argc, char *argv[]) { Initialize(argc, argv); return 0; }

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  • error - inherited class field undeclared according to g++

    - by infoholic_anonymous
    I have a code that has the following logic. g++ gives me the error that I have not declared n in my iterator2. What could be wrong? template <typename T> class List{ template <typename TT> class Node; Node<T> *head; /* (...) */ template <bool D> class iterator1{ protected: Node<T> n; public: iterator1( Node<T> *nn ) { n = nn } /* (...) */ }; template <bool D> class iterator2 : public iterator1<D>{ public: iterator2( Node<T> *nn ) : iterator1<D>( nn ) {} void fun( Node<T> *nn ) { n = nn; } /* (...) */ }; }; EDIT : I attach the actual header file. iterator1 would be iterable_frame and iterator2 - switchable_frame. #ifndef LST_H #define LST_H template <typename T> class List { public: template <typename TT> class Node; private: Node<T> *head; public: List() { head = new Node<T>; } ~List() { empty_list(); delete head; } List( const List &l ); inline bool is_empty() const { return head->next[0] == head; } void empty_list(); template <bool DIM> class iterable_frame { protected: Node<T> *head; Node<T> **caret; public: iterable_frame( const List &l ) { head = *(caret = &l.head); } iterable_frame( const iterable_frame &i ) { head = *(caret = i.caret); } ~iterable_frame() {} /* (...) - a few methods follow */ template <bool _DIM> friend class supervised_frame; }; template <bool DIM> class switchable_frame : public iterable_frame<DIM> { Node<T> *main_head; public: switchable_frame( const List& l ) : iterable_frame<DIM>(l) { main_head = head; } inline bool next_frame() { caret = &head->next[!DIM]; head = *caret; return head != main_head; } }; template <bool DIM> class supervised_frame { iterable_frame<DIM> sentinels; iterable_frame<DIM> cells; public: supervised_frame( const List &l ) : sentinels(l), cells(l) {} ~supervised_frame() {} /* (...) - a few methods follow */ }; template <typename TT> class Node { unsigned index[2]; TT num; Node<TT> *next[2]; public: Node( unsigned x = 0, unsigned y = 0 ) { index[0]=x; index[1]=y; next[0] = this; next[1] = this; } Node( unsigned x, unsigned y, TT d ) { index[0]=x; index[1]=y; num=d; next[0] = this; next[1] = this; } Node( const Node &n ) { index[0] = n.index[0]; index[1] = n.index[1]; num = n.num; next[0] = next[1] = this; } ~Node() {} friend class List; }; }; #include "List.cpp" #endif the exact error log is the following: In file included from main.cpp:1: List.h: In member function ‘bool List<T>::switchable_frame<DIM>::next_frame()’: List.h:77: error: ‘caret’ was not declared in this scope

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  • How to improve Varnish performance?

    - by Darkseal
    We're experiencing a strange problem with our current Varnish configuration. 4x Web Servers (IIS 6.5 on Windows 2003 Server, each installed on a Intel(R) Xeon(R) CPU E5450 @ 3.00GHz Quad Core, 4GB RAM) 3x Varnish Servers (varnish-3.0.3 revision 9e6a70f on Ubuntu 12.04.2 LTS - 64 bit/precise, Kernel Linux 3.2.0-29-generic, each installed on a Intel(R) Xeon(R) CPU E5450 @ 3.00GHz Quad Core, 4GB RAM) The Varnish Servers performance are awfully bad in general, to the point that if we shut down one of them the other two are unable to fullfill all the requests and start to skip beats resulting in pending requests, timeouts, 404, etc. What can we do to improve our Varnish performance? Considering that we're getting less than 5k request per seconds during our max peak, we should be able to serve our pages even with a single one of them without any problem. We use a standard, vanilla CFG, as shown by this varnishadm param.show output: acceptor_sleep_decay 0.900000 [] acceptor_sleep_incr 0.001000 [s] acceptor_sleep_max 0.050000 [s] auto_restart on [bool] ban_dups on [bool] ban_lurker_sleep 0.010000 [s] between_bytes_timeout 60.000000 [s] cc_command "exec gcc -std=gnu99 -g -O2 -pthread -fpic -shared - Wl,-x -o %o %s" cli_buffer 8192 [bytes] cli_timeout 20 [seconds] clock_skew 10 [s] connect_timeout 0.700000 [s] critbit_cooloff 180.000000 [s] default_grace 10.000000 [seconds] default_keep 0.000000 [seconds] default_ttl 120.000000 [seconds] diag_bitmap 0x0 [bitmap] esi_syntax 0 [bitmap] expiry_sleep 1.000000 [seconds] fetch_chunksize 128 [kilobytes] fetch_maxchunksize 262144 [kilobytes] first_byte_timeout 60.000000 [s] group varnish (113) gzip_level 6 [] gzip_memlevel 8 [] gzip_stack_buffer 32768 [Bytes] gzip_tmp_space 0 [] gzip_window 15 [] http_gzip_support off [bool] http_max_hdr 64 [header lines] http_range_support on [bool] http_req_hdr_len 8192 [bytes] http_req_size 32768 [bytes] http_resp_hdr_len 8192 [bytes] http_resp_size 32768 [bytes] idle_send_timeout 60 [seconds] listen_address :80 listen_depth 1024 [connections] log_hashstring on [bool] log_local_address off [bool] lru_interval 2 [seconds] max_esi_depth 5 [levels] max_restarts 4 [restarts] nuke_limit 50 [allocations] pcre_match_limit 10000 [] pcre_match_limit_recursion 10000 [] ping_interval 3 [seconds] pipe_timeout 60 [seconds] prefer_ipv6 off [bool] queue_max 100 [%] rush_exponent 3 [requests per request] saintmode_threshold 10 [objects] send_timeout 600 [seconds] sess_timeout 5 [seconds] sess_workspace 16384 [bytes] session_linger 50 [ms] session_max 100000 [sessions] shm_reclen 255 [bytes] shm_workspace 8192 [bytes] shortlived 10.000000 [s] syslog_cli_traffic on [bool] thread_pool_add_delay 2 [milliseconds] thread_pool_add_threshold 2 [requests] thread_pool_fail_delay 200 [milliseconds] thread_pool_max 2000 [threads] thread_pool_min 5 [threads] thread_pool_purge_delay 1000 [milliseconds] thread_pool_stack unlimited [bytes] thread_pool_timeout 300 [seconds] thread_pool_workspace 65536 [bytes] thread_pools 2 [pools] thread_stats_rate 10 [requests] user varnish (106) vcc_err_unref on [bool] vcl_dir /etc/varnish vcl_trace off [bool] vmod_dir /usr/lib/varnish/vmods waiter default (epoll, poll) This is our default.vcl file: LINK sub vcl_recv { # BASIC recv COMMANDS: # # lookup -> search the item in the cache # pass -> always serve a fresh item (no-caching) # pipe -> like pass but ensures a direct-connection with the backend (no-cache AND no-proxy) # Allow the backend to serve up stale content if it is responding slow. # This defines when Varnish should use a stale object if it has one in the cache. set req.grace = 30s; if (client.ip == "127.0.0.1") { # request from NGINX - do not alter X-Forwarded-For set req.http.HTTPS = "on"; } else { # Add an X-Forwarded-For to keep track of original request unset req.http.HTTPS; unset req.http.X-Forwarded-For; set req.http.X-Forwarded-For = client.ip; } set req.backend = www_director; # Strip all cookies to force an anonymous request when the back-end servers are down. if (!req.backend.healthy) { unset req.http.Cookie; } ## HHTP Accept-Encoding if (req.http.Accept-Encoding) { if (req.http.Accept-Encoding ~ "gzip") { set req.http.Accept-Encoding = "gzip"; } else if (req.http.Accept-Encoding ~ "deflate") { set req.http.Accept-Encoding = "deflate"; } else { unset req.http.Accept-Encoding; } } if (req.request != "GET" && req.request != "HEAD" && req.request != "PUT" && req.request != "POST" && req.request != "TRACE" && req.request != "OPTIONS" && req.request != "DELETE") { /* non-RFC2616 or CONNECT */ return (pipe); } if (req.request != "GET" && req.request != "HEAD") { /* only deal with GET and HEAD by default */ return (pass); } if (req.http.Authorization) { return (pass); } if (req.http.HTTPS ~ "on") { return (pass); } ###################################################### # COOKIE HANDLING ###################################################### # METHOD 1: do not remove cookies, but pass the page if they contain TB_NC if (!(req.url ~ "(?i)\.(png|gif|ipeg|jpg|ico|swf|css|js)(\?[a-z0-9]+)?$")) { if (req.http.Cookie && req.http.Cookie ~ "TB_NC") { return (pass); } } return (lookup); } # Code determining what to do when serving items from the IIS Server sub vcl_fetch { unset beresp.http.Server; set beresp.http.Server = "Server-1"; # Allow items to be stale if needed. This is the maximum time Varnish should keep an object. set beresp.grace = 1h; if (req.url ~ "(?i)\.(png|gif|ipeg|jpg|ico|swf|css|js)(\?[a-z0-9]+)?$") { unset beresp.http.set-cookie; } # Default Varnish VCL logic if (!beresp.cacheable || beresp.ttl <= 0s || beresp.http.Set-Cookie || beresp.http.Vary == "*") { set beresp.ttl = 120 s; return(hit_for_pass); } # Not Cacheable if it has specific TB_NC no-caching cookie if (req.http.Cookie && req.http.Cookie ~ "TB_NC") { set beresp.http.X-Cacheable = "NO:Got Cookie"; set beresp.ttl = 120 s; return(hit_for_pass); } # Not Cacheable if it has Cache-Control private else if (beresp.http.Cache-Control ~ "private") { set beresp.http.X-Cacheable = "NO:Cache-Control=private"; set beresp.ttl = 120 s; return(hit_for_pass); } # Not Cacheable if it has Cache-Control no-cache or Pragma no-cache else if (beresp.http.Cache-Control ~ "no-cache" || beresp.http.Pragma ~ "no-cache") { set beresp.http.X-Cacheable = "NO:Cache-Control=no-cache (or pragma no-cache)"; set beresp.ttl = 120 s; return(hit_for_pass); } # If we reach to this point, the object is cacheable. # Cacheable but with not enough ttl: we need to extend the lifetime of the object artificially # NOTE: Varnish default TTL is set in /etc/sysconfig/varnish # and can be checked using the following command: # varnishadm param.show default_ttl else if (beresp.ttl < 1s) { set beresp.ttl = 5s; set beresp.grace = 5s; set beresp.http.X-Cacheable = "YES:FORCED"; } # Cacheable and with valid TTL. else { set beresp.http.X-Cacheable = "YES"; } # DEBUG INFO (Cookies) # set beresp.http.X-Cookie-Debug = "Request cookie: " + req.http.Cookie; return(deliver); } sub vcl_error { set obj.http.Content-Type = "text/html; charset=utf-8"; if (obj.status == 404) { synthetic {" <!-- Markup for the 404 page goes here --> "}; } else if (obj.status == 500) { synthetic {" <!-- Markup for the 500 page goes here --> "}; } else if (obj.status == 503) { if (req.restarts < 4) { return(restart); } else { synthetic {" <!-- Markup for the 503 page goes here --> "}; } } else { synthetic {" <!-- Markup for a generic error page goes here --> "}; } } sub vcl_deliver { if (obj.hits > 0) { set resp.http.X-Cache = "HIT"; } else { set resp.http.X-Cache = "MISS"; } } Thanks in advance,

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  • Nagios plugin script not working as expected

    - by Linker3000
    I have modified an off-the-shelf Nagios plugin perl script to (in theory) return a one or zero according to the existence, or not, of a file on a remote linux server. The script runs a remote ssh session and logs in as the nagios user. The remote linux servers have private keys setup for that user, and on the bash command line the script works as expected, but when run as a plugin it always returns '1' (true) even if the file does not exist. Some help with the logic or a comment on why things are not working as expected within Nagios would be appreciated. I'd prefer to use this ssh login method rather than having to install nrpe on all the linux servers. To run from a command line (assuming remote server has a user called nagios with a valid private key): ./check_reboot_required -e ssh -H remote-servers-ip-addr -p 'filename-to-check' -v Ta. #! /usr/bin/perl -w # # # License Information: # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. # ############################################################################ use POSIX; use strict; use Getopt::Long; use lib "/usr/lib/nagios/plugins" ; use vars qw($host $opt_V $opt_h $opt_v $verbose $PROGNAME $pattern $opt_p $mmin $opt_e $opt_t $opt_H $status $state $msg $msg_q $MAILQ $SHELL $device $used $avail $percent $fs $blocks $CMD $RMTOS); use utils qw(%ERRORS &print_revision &support &usage ); sub print_help (); sub print_usage (); sub process_arguments (); $ENV{'PATH'}=''; $ENV{'BASH_ENV'}=''; $ENV{'ENV'}=''; $PROGNAME = "check_reboot_required"; Getopt::Long::Configure('bundling'); $status = process_arguments(); if ($status){ print "ERROR: processing arguments\n"; exit $ERRORS{'UNKNOWN'}; } $SIG{'ALRM'} = sub { print ("ERROR: timed out waiting for $CMD on $host\n"); exit $ERRORS{'WARNING'}; }; $host = $opt_H; $pattern = $opt_p; print "Pattern >" . $pattern . "< " if $verbose; alarm($opt_t); #$CMD = "/usr/bin/find " . $pattern . " -type f 2>/dev/null| /usr/bin/wc -l"; $CMD = "[ -f " . $pattern . " ] && echo 1 || echo 0"; alarm($opt_t); ## get cmd output from remote system if (! open (OUTPUT, "$SHELL $host $CMD|" ) ) { print "ERROR: could not open $CMD on $host\n"; exit $ERRORS{'UNKNOWN'}; } my $perfdata = ""; my $state = "3"; my $msg = "Indeterminate result"; # only first line is relevant in this iteration. while (<OUTPUT>) { my $result = chomp($_); $msg = $result; print "Shell returned >" . $result . "< length is " . length($result) . " " if $verbose; if ( $result == 1 ) { $msg = "Reboot required (NB: Result still not accurate)" . $result ; $state = $ERRORS{'WARNING'}; last; } elsif ( $result == 0 ) { $msg = "No reboot required (NB: Result still not accurate) " . $result ; $state = $ERRORS{'OK'}; last; } else { $msg = "Output received, but it was neither a 1 nor a 0" ; last; } } close (OUTPUT); print "$msg | $perfdata\n"; exit $state; ##################################### #### subs sub process_arguments(){ GetOptions ("V" => \$opt_V, "version" => \$opt_V, "v" => \$opt_v, "verbose" => \$opt_v, "h" => \$opt_h, "help" => \$opt_h, "e=s" => \$opt_e, "shell=s" => \$opt_e, "p=s" => \$opt_p, "pattern=s" => \$opt_p, "t=i" => \$opt_t, "timeout=i" => \$opt_t, "H=s" => \$opt_H, "hostname=s" => \$opt_H ); if ($opt_V) { print_revision($PROGNAME,'$Revision: 1.0 $ '); exit $ERRORS{'OK'}; } if ($opt_h) { print_help(); exit $ERRORS{'OK'}; } if (defined $opt_v ){ $verbose = $opt_v; } if (defined $opt_e ){ if ( $opt_e eq "ssh" ) { if (-x "/usr/local/bin/ssh") { $SHELL = "/usr/local/bin/ssh"; } elsif ( -x "/usr/bin/ssh" ) { $SHELL = "/usr/bin/ssh"; } else { print_usage(); exit $ERRORS{'UNKNOWN'}; } } elsif ( $opt_e eq "rsh" ) { $SHELL = "/usr/bin/rsh"; } else { print_usage(); exit $ERRORS{'UNKNOWN'}; } } else { print_usage(); exit $ERRORS{'UNKNOWN'}; } unless (defined $opt_t) { $opt_t = $utils::TIMEOUT ; # default timeout } unless (defined $opt_H) { print_usage(); exit $ERRORS{'UNKNOWN'}; } return $ERRORS{'OK'}; } sub print_usage () { print "Usage: $PROGNAME -e <shell> -H <hostname> -p <directory/file pattern> [-t <timeout>] [-v verbose]\n"; } sub print_help () { print_revision($PROGNAME,'$Revision: 0.1 $'); print "\n"; print_usage(); print "\n"; print " Checks for the presence of a 'reboot-required' file on a remote host via SSH or RSH\n"; print "-e (--shell) = ssh or rsh (required)\n"; print "-H (--hostname) = remote server name (required)"; print "-p (--pattern) = File pattern for find command (default = /var/run/reboot-required)\n"; print "-t (--timeout) = Plugin timeout in seconds (default = $utils::TIMEOUT)\n"; print "-h (--help)\n"; print "-V (--version)\n"; print "-v (--verbose) = debugging output\n"; print "\n\n"; support(); }

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  • Introducing the Earthquake Locator – A Bing Maps Silverlight Application, part 1

    - by Bobby Diaz
    Update: Live demo and source code now available!  The recent wave of earthquakes (no pun intended) being reported in the news got me wondering about the frequency and severity of earthquakes around the world. Since I’ve been doing a lot of Silverlight development lately, I decided to scratch my curiosity with a nice little Bing Maps application that will show the location and relative strength of recent seismic activity. Here is a list of technologies this application will utilize, so be sure to have everything downloaded and installed if you plan on following along. Silverlight 3 WCF RIA Services Bing Maps Silverlight Control * Managed Extensibility Framework (optional) MVVM Light Toolkit (optional) log4net (optional) * If you are new to Bing Maps or have not signed up for a Developer Account, you will need to visit www.bingmapsportal.com to request a Bing Maps key for your application. Getting Started We start out by creating a new Silverlight Application called EarthquakeLocator and specify that we want to automatically create the Web Application Project with RIA Services enabled. I cleaned up the web app by removing the Default.aspx and EarthquakeLocatorTestPage.html. Then I renamed the EarthquakeLocatorTestPage.aspx to Default.aspx and set it as my start page. I also set the development server to use a specific port, as shown below. RIA Services Next, I created a Services folder in the EarthquakeLocator.Web project and added a new Domain Service Class called EarthquakeService.cs. This is the RIA Services Domain Service that will provide earthquake data for our client application. I am not using LINQ to SQL or Entity Framework, so I will use the <empty domain service class> option. We will be pulling data from an external Atom feed, but this example could just as easily pull data from a database or another web service. This is an important distinction to point out because each scenario I just mentioned could potentially use a different Domain Service base class (i.e. LinqToSqlDomainService<TDataContext>). Now we can start adding Query methods to our EarthquakeService that pull data from the USGS web site. Here is the complete code for our service class: using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.ServiceModel.Syndication; using System.Web.DomainServices; using System.Web.Ria; using System.Xml; using log4net; using EarthquakeLocator.Web.Model;   namespace EarthquakeLocator.Web.Services {     /// <summary>     /// Provides earthquake data to client applications.     /// </summary>     [EnableClientAccess()]     public class EarthquakeService : DomainService     {         private static readonly ILog log = LogManager.GetLogger(typeof(EarthquakeService));           // USGS Data Feeds: http://earthquake.usgs.gov/earthquakes/catalogs/         private const string FeedForPreviousDay =             "http://earthquake.usgs.gov/earthquakes/catalogs/1day-M2.5.xml";         private const string FeedForPreviousWeek =             "http://earthquake.usgs.gov/earthquakes/catalogs/7day-M2.5.xml";           /// <summary>         /// Gets the earthquake data for the previous week.         /// </summary>         /// <returns>A queryable collection of <see cref="Earthquake"/> objects.</returns>         public IQueryable<Earthquake> GetEarthquakes()         {             var feed = GetFeed(FeedForPreviousWeek);             var list = new List<Earthquake>();               if ( feed != null )             {                 foreach ( var entry in feed.Items )                 {                     var quake = CreateEarthquake(entry);                     if ( quake != null )                     {                         list.Add(quake);                     }                 }             }               return list.AsQueryable();         }           /// <summary>         /// Creates an <see cref="Earthquake"/> object for each entry in the Atom feed.         /// </summary>         /// <param name="entry">The Atom entry.</param>         /// <returns></returns>         private Earthquake CreateEarthquake(SyndicationItem entry)         {             Earthquake quake = null;             string title = entry.Title.Text;             string summary = entry.Summary.Text;             string point = GetElementValue<String>(entry, "point");             string depth = GetElementValue<String>(entry, "elev");             string utcTime = null;             string localTime = null;             string depthDesc = null;             double? magnitude = null;             double? latitude = null;             double? longitude = null;             double? depthKm = null;               if ( !String.IsNullOrEmpty(title) && title.StartsWith("M") )             {                 title = title.Substring(2, title.IndexOf(',')-3).Trim();                 magnitude = TryParse(title);             }             if ( !String.IsNullOrEmpty(point) )             {                 var values = point.Split(' ');                 if ( values.Length == 2 )                 {                     latitude = TryParse(values[0]);                     longitude = TryParse(values[1]);                 }             }             if ( !String.IsNullOrEmpty(depth) )             {                 depthKm = TryParse(depth);                 if ( depthKm != null )                 {                     depthKm = Math.Round((-1 * depthKm.Value) / 100, 2);                 }             }             if ( !String.IsNullOrEmpty(summary) )             {                 summary = summary.Replace("</p>", "");                 var values = summary.Split(                     new string[] { "<p>" },                     StringSplitOptions.RemoveEmptyEntries);                   if ( values.Length == 3 )                 {                     var times = values[1].Split(                         new string[] { "<br>" },                         StringSplitOptions.RemoveEmptyEntries);                       if ( times.Length > 0 )                     {                         utcTime = times[0];                     }                     if ( times.Length > 1 )                     {                         localTime = times[1];                     }                       depthDesc = values[2];                     depthDesc = "Depth: " + depthDesc.Substring(depthDesc.IndexOf(":") + 2);                 }             }               if ( latitude != null && longitude != null )             {                 quake = new Earthquake()                 {                     Id = entry.Id,                     Title = entry.Title.Text,                     Summary = entry.Summary.Text,                     Date = entry.LastUpdatedTime.DateTime,                     Url = entry.Links.Select(l => Path.Combine(l.BaseUri.OriginalString,                         l.Uri.OriginalString)).FirstOrDefault(),                     Age = entry.Categories.Where(c => c.Label == "Age")                         .Select(c => c.Name).FirstOrDefault(),                     Magnitude = magnitude.GetValueOrDefault(),                     Latitude = latitude.GetValueOrDefault(),                     Longitude = longitude.GetValueOrDefault(),                     DepthInKm = depthKm.GetValueOrDefault(),                     DepthDesc = depthDesc,                     UtcTime = utcTime,                     LocalTime = localTime                 };             }               return quake;         }           private T GetElementValue<T>(SyndicationItem entry, String name)         {             var el = entry.ElementExtensions.Where(e => e.OuterName == name).FirstOrDefault();             T value = default(T);               if ( el != null )             {                 value = el.GetObject<T>();             }               return value;         }           private double? TryParse(String value)         {             double d;             if ( Double.TryParse(value, out d) )             {                 return d;             }             return null;         }           /// <summary>         /// Gets the feed at the specified URL.         /// </summary>         /// <param name="url">The URL.</param>         /// <returns>A <see cref="SyndicationFeed"/> object.</returns>         public static SyndicationFeed GetFeed(String url)         {             SyndicationFeed feed = null;               try             {                 log.Debug("Loading RSS feed: " + url);                   using ( var reader = XmlReader.Create(url) )                 {                     feed = SyndicationFeed.Load(reader);                 }             }             catch ( Exception ex )             {                 log.Error("Error occurred while loading RSS feed: " + url, ex);             }               return feed;         }     } }   The only method that will be generated in the client side proxy class, EarthquakeContext, will be the GetEarthquakes() method. The reason being that it is the only public instance method and it returns an IQueryable<Earthquake> collection that can be consumed by the client application. GetEarthquakes() calls the static GetFeed(String) method, which utilizes the built in SyndicationFeed API to load the external data feed. You will need to add a reference to the System.ServiceModel.Web library in order to take advantage of the RSS/Atom reader. The API will also allow you to create your own feeds to serve up in your applications. Model I have also created a Model folder and added a new class, Earthquake.cs. The Earthquake object will hold the various properties returned from the Atom feed. Here is a sample of the code for that class. Notice the [Key] attribute on the Id property, which is required by RIA Services to uniquely identify the entity. using System; using System.Collections.Generic; using System.Linq; using System.Runtime.Serialization; using System.ComponentModel.DataAnnotations;   namespace EarthquakeLocator.Web.Model {     /// <summary>     /// Represents an earthquake occurrence and related information.     /// </summary>     [DataContract]     public class Earthquake     {         /// <summary>         /// Gets or sets the id.         /// </summary>         /// <value>The id.</value>         [Key]         [DataMember]         public string Id { get; set; }           /// <summary>         /// Gets or sets the title.         /// </summary>         /// <value>The title.</value>         [DataMember]         public string Title { get; set; }           /// <summary>         /// Gets or sets the summary.         /// </summary>         /// <value>The summary.</value>         [DataMember]         public string Summary { get; set; }           // additional properties omitted     } }   View Model The recent trend to use the MVVM pattern for WPF and Silverlight provides a great way to separate the data and behavior logic out of the user interface layer of your client applications. I have chosen to use the MVVM Light Toolkit for the Earthquake Locator, but there are other options out there if you prefer another library. That said, I went ahead and created a ViewModel folder in the Silverlight project and added a EarthquakeViewModel class that derives from ViewModelBase. Here is the code: using System; using System.Collections.ObjectModel; using System.ComponentModel.Composition; using System.ComponentModel.Composition.Hosting; using Microsoft.Maps.MapControl; using GalaSoft.MvvmLight; using EarthquakeLocator.Web.Model; using EarthquakeLocator.Web.Services;   namespace EarthquakeLocator.ViewModel {     /// <summary>     /// Provides data for views displaying earthquake information.     /// </summary>     public class EarthquakeViewModel : ViewModelBase     {         [Import]         public EarthquakeContext Context;           /// <summary>         /// Initializes a new instance of the <see cref="EarthquakeViewModel"/> class.         /// </summary>         public EarthquakeViewModel()         {             var catalog = new AssemblyCatalog(GetType().Assembly);             var container = new CompositionContainer(catalog);             container.ComposeParts(this);             Initialize();         }           /// <summary>         /// Initializes a new instance of the <see cref="EarthquakeViewModel"/> class.         /// </summary>         /// <param name="context">The context.</param>         public EarthquakeViewModel(EarthquakeContext context)         {             Context = context;             Initialize();         }           private void Initialize()         {             MapCenter = new Location(20, -170);             ZoomLevel = 2;         }           #region Private Methods           private void OnAutoLoadDataChanged()         {             LoadEarthquakes();         }           private void LoadEarthquakes()         {             var query = Context.GetEarthquakesQuery();             Context.Earthquakes.Clear();               Context.Load(query, (op) =>             {                 if ( !op.HasError )                 {                     foreach ( var item in op.Entities )                     {                         Earthquakes.Add(item);                     }                 }             }, null);         }           #endregion Private Methods           #region Properties           private bool autoLoadData;         /// <summary>         /// Gets or sets a value indicating whether to auto load data.         /// </summary>         /// <value><c>true</c> if auto loading data; otherwise, <c>false</c>.</value>         public bool AutoLoadData         {             get { return autoLoadData; }             set             {                 if ( autoLoadData != value )                 {                     autoLoadData = value;                     RaisePropertyChanged("AutoLoadData");                     OnAutoLoadDataChanged();                 }             }         }           private ObservableCollection<Earthquake> earthquakes;         /// <summary>         /// Gets the collection of earthquakes to display.         /// </summary>         /// <value>The collection of earthquakes.</value>         public ObservableCollection<Earthquake> Earthquakes         {             get             {                 if ( earthquakes == null )                 {                     earthquakes = new ObservableCollection<Earthquake>();                 }                   return earthquakes;             }         }           private Location mapCenter;         /// <summary>         /// Gets or sets the map center.         /// </summary>         /// <value>The map center.</value>         public Location MapCenter         {             get { return mapCenter; }             set             {                 if ( mapCenter != value )                 {                     mapCenter = value;                     RaisePropertyChanged("MapCenter");                 }             }         }           private double zoomLevel;         /// <summary>         /// Gets or sets the zoom level.         /// </summary>         /// <value>The zoom level.</value>         public double ZoomLevel         {             get { return zoomLevel; }             set             {                 if ( zoomLevel != value )                 {                     zoomLevel = value;                     RaisePropertyChanged("ZoomLevel");                 }             }         }           #endregion Properties     } }   The EarthquakeViewModel class contains all of the properties that will be bound to by the various controls in our views. Be sure to read through the LoadEarthquakes() method, which handles calling the GetEarthquakes() method in our EarthquakeService via the EarthquakeContext proxy, and also transfers the loaded entities into the view model’s Earthquakes collection. Another thing to notice is what’s going on in the default constructor. I chose to use the Managed Extensibility Framework (MEF) for my composition needs, but you can use any dependency injection library or none at all. To allow the EarthquakeContext class to be discoverable by MEF, I added the following partial class so that I could supply the appropriate [Export] attribute: using System; using System.ComponentModel.Composition;   namespace EarthquakeLocator.Web.Services {     /// <summary>     /// The client side proxy for the EarthquakeService class.     /// </summary>     [Export]     public partial class EarthquakeContext     {     } }   One last piece I wanted to point out before moving on to the user interface, I added a client side partial class for the Earthquake entity that contains helper properties that we will bind to later: using System;   namespace EarthquakeLocator.Web.Model {     /// <summary>     /// Represents an earthquake occurrence and related information.     /// </summary>     public partial class Earthquake     {         /// <summary>         /// Gets the location based on the current Latitude/Longitude.         /// </summary>         /// <value>The location.</value>         public string Location         {             get { return String.Format("{0},{1}", Latitude, Longitude); }         }           /// <summary>         /// Gets the size based on the Magnitude.         /// </summary>         /// <value>The size.</value>         public double Size         {             get { return (Magnitude * 3); }         }     } }   View Now the fun part! Usually, I would create a Views folder to place all of my View controls in, but I took the easy way out and added the following XAML code to the default MainPage.xaml file. Be sure to add the bing prefix associating the Microsoft.Maps.MapControl namespace after adding the assembly reference to your project. The MVVM Light Toolkit project templates come with a ViewModelLocator class that you can use via a static resource, but I am instantiating the EarthquakeViewModel directly in my user control. I am setting the AutoLoadData property to true as a way to trigger the LoadEarthquakes() method call. The MapItemsControl found within the <bing:Map> control binds its ItemsSource property to the Earthquakes collection of the view model, and since it is an ObservableCollection<T>, we get the automatic two way data binding via the INotifyCollectionChanged interface. <UserControl x:Class="EarthquakeLocator.MainPage"     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"     xmlns:bing="clr-namespace:Microsoft.Maps.MapControl;assembly=Microsoft.Maps.MapControl"     xmlns:vm="clr-namespace:EarthquakeLocator.ViewModel"     mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480" >     <UserControl.Resources>         <DataTemplate x:Key="EarthquakeTemplate">             <Ellipse Fill="Red" Stroke="Black" StrokeThickness="1"                      Width="{Binding Size}" Height="{Binding Size}"                      bing:MapLayer.Position="{Binding Location}"                      bing:MapLayer.PositionOrigin="Center">                 <ToolTipService.ToolTip>                     <StackPanel>                         <TextBlock Text="{Binding Title}" FontSize="14" FontWeight="Bold" />                         <TextBlock Text="{Binding UtcTime}" />                         <TextBlock Text="{Binding LocalTime}" />                         <TextBlock Text="{Binding DepthDesc}" />                     </StackPanel>                 </ToolTipService.ToolTip>             </Ellipse>         </DataTemplate>     </UserControl.Resources>       <UserControl.DataContext>         <vm:EarthquakeViewModel AutoLoadData="True" />     </UserControl.DataContext>       <Grid x:Name="LayoutRoot">           <bing:Map x:Name="map" CredentialsProvider="--Your-Bing-Maps-Key--"                   Center="{Binding MapCenter, Mode=TwoWay}"                   ZoomLevel="{Binding ZoomLevel, Mode=TwoWay}">             <bing:MapItemsControl ItemsSource="{Binding Earthquakes}"                                   ItemTemplate="{StaticResource EarthquakeTemplate}" />         </bing:Map>       </Grid> </UserControl>   The EarthquakeTemplate defines the Ellipse that will represent each earthquake, the Width and Height that are determined by the Magnitude, the Position on the map, and also the tooltip that will appear when we mouse over each data point. Running the application will give us the following result (shown with a tooltip example): That concludes this portion of our show but I plan on implementing additional functionality in later blog posts. Be sure to come back soon to see the next installments in this series. Enjoy!   Additional Resources USGS Earthquake Data Feeds Brad Abrams shows how RIA Services and MVVM can work together

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  • Metro: Declarative Data Binding

    - by Stephen.Walther
    The goal of this blog post is to describe how declarative data binding works in the WinJS library. In particular, you learn how to use both the data-win-bind and data-win-bindsource attributes. You also learn how to use calculated properties and converters to format the value of a property automatically when performing data binding. By taking advantage of WinJS data binding, you can use the Model-View-ViewModel (MVVM) pattern when building Metro style applications with JavaScript. By using the MVVM pattern, you can prevent your JavaScript code from spinning into chaos. The MVVM pattern provides you with a standard pattern for organizing your JavaScript code which results in a more maintainable application. Using Declarative Bindings You can use the data-win-bind attribute with any HTML element in a page. The data-win-bind attribute enables you to bind (associate) an attribute of an HTML element to the value of a property. Imagine, for example, that you want to create a product details page. You want to show a product object in a page. In that case, you can create the following HTML page to display the product details: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Application1</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- Application1 references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> </head> <body> <h1>Product Details</h1> <div class="field"> Product Name: <span data-win-bind="innerText:name"></span> </div> <div class="field"> Product Price: <span data-win-bind="innerText:price"></span> </div> <div class="field"> Product Picture: <br /> <img data-win-bind="src:photo;alt:name" /> </div> </body> </html> The HTML page above contains three data-win-bind attributes – one attribute for each product property displayed. You use the data-win-bind attribute to set properties of the HTML element associated with the data-win-attribute. The data-win-bind attribute takes a semicolon delimited list of element property names and data source property names: data-win-bind=”elementPropertyName:datasourcePropertyName; elementPropertyName:datasourcePropertyName;…” In the HTML page above, the first two data-win-bind attributes are used to set the values of the innerText property of the SPAN elements. The last data-win-bind attribute is used to set the values of the IMG element’s src and alt attributes. By the way, using data-win-bind attributes is perfectly valid HTML5. The HTML5 standard enables you to add custom attributes to an HTML document just as long as the custom attributes start with the prefix data-. So you can add custom attributes to an HTML5 document with names like data-stephen, data-funky, or data-rover-dog-is-hungry and your document will validate. The product object displayed in the page above with the data-win-bind attributes is created in the default.js file: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { var product = { name: "Tesla", price: 80000, photo: "/images/TeslaPhoto.png" }; WinJS.Binding.processAll(null, product); } }; app.start(); })(); In the code above, a product object is created with a name, price, and photo property. The WinJS.Binding.processAll() method is called to perform the actual binding (Don’t confuse WinJS.Binding.processAll() and WinJS.UI.processAll() – these are different methods). The first parameter passed to the processAll() method represents the root element for the binding. In other words, binding happens on this element and its child elements. If you provide the value null, then binding happens on the entire body of the document (document.body). The second parameter represents the data context. This is the object that has the properties which are displayed with the data-win-bind attributes. In the code above, the product object is passed as the data context parameter. Another word for data context is view model.  Creating Complex View Models In the previous section, we used the data-win-bind attribute to display the properties of a simple object: a single product. However, you can use binding with more complex view models including view models which represent multiple objects. For example, the view model in the following default.js file represents both a customer and a product object. Furthermore, the customer object has a nested address object: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { var viewModel = { customer: { firstName: "Fred", lastName: "Flintstone", address: { street: "1 Rocky Way", city: "Bedrock", country: "USA" } }, product: { name: "Bowling Ball", price: 34.55 } }; WinJS.Binding.processAll(null, viewModel); } }; app.start(); })(); The following page displays the customer (including the customer address) and the product. Notice that you can use dot notation to refer to child objects in a view model such as customer.address.street. <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Application1</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- Application1 references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> </head> <body> <h1>Customer Details</h1> <div class="field"> First Name: <span data-win-bind="innerText:customer.firstName"></span> </div> <div class="field"> Last Name: <span data-win-bind="innerText:customer.lastName"></span> </div> <div class="field"> Address: <address> <span data-win-bind="innerText:customer.address.street"></span> <br /> <span data-win-bind="innerText:customer.address.city"></span> <br /> <span data-win-bind="innerText:customer.address.country"></span> </address> </div> <h1>Product</h1> <div class="field"> Name: <span data-win-bind="innerText:product.name"></span> </div> <div class="field"> Price: <span data-win-bind="innerText:product.price"></span> </div> </body> </html> A view model can be as complicated as you need and you can bind the view model to a view (an HTML document) by using declarative bindings. Creating Calculated Properties You might want to modify a property before displaying the property. For example, you might want to format the product price property before displaying the property. You don’t want to display the raw product price “80000”. Instead, you want to display the formatted price “$80,000”. You also might need to combine multiple properties. For example, you might need to display the customer full name by combining the values of the customer first and last name properties. In these situations, it is tempting to call a function when performing binding. For example, you could create a function named fullName() which concatenates the customer first and last name. Unfortunately, the WinJS library does not support the following syntax: <span data-win-bind=”innerText:fullName()”></span> Instead, in these situations, you should create a new property in your view model that has a getter. For example, the customer object in the following default.js file includes a property named fullName which combines the values of the firstName and lastName properties: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { var customer = { firstName: "Fred", lastName: "Flintstone", get fullName() { return this.firstName + " " + this.lastName; } }; WinJS.Binding.processAll(null, customer); } }; app.start(); })(); The customer object has a firstName, lastName, and fullName property. Notice that the fullName property is defined with a getter function. When you read the fullName property, the values of the firstName and lastName properties are concatenated and returned. The following HTML page displays the fullName property in an H1 element. You can use the fullName property in a data-win-bind attribute in exactly the same way as any other property. <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Application1</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- Application1 references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> </head> <body> <h1 data-win-bind="innerText:fullName"></h1> <div class="field"> First Name: <span data-win-bind="innerText:firstName"></span> </div> <div class="field"> Last Name: <span data-win-bind="innerText:lastName"></span> </div> </body> </html> Creating a Converter In the previous section, you learned how to format the value of a property by creating a property with a getter. This approach makes sense when the formatting logic is specific to a particular view model. If, on the other hand, you need to perform the same type of formatting for multiple view models then it makes more sense to create a converter function. A converter function is a function which you can apply whenever you are using the data-win-bind attribute. Imagine, for example, that you want to create a general function for displaying dates. You always want to display dates using a short format such as 12/25/1988. The following JavaScript file – named converters.js – contains a shortDate() converter: (function (WinJS) { var shortDate = WinJS.Binding.converter(function (date) { return date.getMonth() + 1 + "/" + date.getDate() + "/" + date.getFullYear(); }); // Export shortDate WinJS.Namespace.define("MyApp.Converters", { shortDate: shortDate }); })(WinJS); The file above uses the Module Pattern, a pattern which is used through the WinJS library. To learn more about the Module Pattern, see my blog entry on namespaces and modules: http://stephenwalther.com/blog/archive/2012/02/22/windows-web-applications-namespaces-and-modules.aspx The file contains the definition for a converter function named shortDate(). This function converts a JavaScript date object into a short date string such as 12/1/1988. The converter function is created with the help of the WinJS.Binding.converter() method. This method takes a normal function and converts it into a converter function. Finally, the shortDate() converter is added to the MyApp.Converters namespace. You can call the shortDate() function by calling MyApp.Converters.shortDate(). The default.js file contains the customer object that we want to bind. Notice that the customer object has a firstName, lastName, and birthday property. We will use our new shortDate() converter when displaying the customer birthday property: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { var customer = { firstName: "Fred", lastName: "Flintstone", birthday: new Date("12/1/1988") }; WinJS.Binding.processAll(null, customer); } }; app.start(); })(); We actually use our shortDate converter in the HTML document. The following HTML document displays all of the customer properties: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Application1</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- Application1 references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/converters.js"></script> </head> <body> <h1>Customer Details</h1> <div class="field"> First Name: <span data-win-bind="innerText:firstName"></span> </div> <div class="field"> Last Name: <span data-win-bind="innerText:lastName"></span> </div> <div class="field"> Birthday: <span data-win-bind="innerText:birthday MyApp.Converters.shortDate"></span> </div> </body> </html> Notice the data-win-bind attribute used to display the birthday property. It looks like this: <span data-win-bind="innerText:birthday MyApp.Converters.shortDate"></span> The shortDate converter is applied to the birthday property when the birthday property is bound to the SPAN element’s innerText property. Using data-win-bindsource Normally, you pass the view model (the data context) which you want to use with the data-win-bind attributes in a page by passing the view model to the WinJS.Binding.processAll() method like this: WinJS.Binding.processAll(null, viewModel); As an alternative, you can specify the view model declaratively in your markup by using the data-win-datasource attribute. For example, the following default.js script exposes a view model with the fully-qualified name of MyWinWebApp.viewModel: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { // Create view model var viewModel = { customer: { firstName: "Fred", lastName: "Flintstone" }, product: { name: "Bowling Ball", price: 12.99 } }; // Export view model to be seen by universe WinJS.Namespace.define("MyWinWebApp", { viewModel: viewModel }); // Process data-win-bind attributes WinJS.Binding.processAll(); } }; app.start(); })(); In the code above, a view model which represents a customer and a product is exposed as MyWinWebApp.viewModel. The following HTML page illustrates how you can use the data-win-bindsource attribute to bind to this view model: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Application1</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- Application1 references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> </head> <body> <h1>Customer Details</h1> <div data-win-bindsource="MyWinWebApp.viewModel.customer"> <div class="field"> First Name: <span data-win-bind="innerText:firstName"></span> </div> <div class="field"> Last Name: <span data-win-bind="innerText:lastName"></span> </div> </div> <h1>Product</h1> <div data-win-bindsource="MyWinWebApp.viewModel.product"> <div class="field"> Name: <span data-win-bind="innerText:name"></span> </div> <div class="field"> Price: <span data-win-bind="innerText:price"></span> </div> </div> </body> </html> The data-win-bindsource attribute is used twice in the page above: it is used with the DIV element which contains the customer details and it is used with the DIV element which contains the product details. If an element has a data-win-bindsource attribute then all of the child elements of that element are affected. The data-win-bind attributes of all of the child elements are bound to the data source represented by the data-win-bindsource attribute. Summary The focus of this blog entry was data binding using the WinJS library. You learned how to use the data-win-bind attribute to bind the properties of an HTML element to a view model. We also discussed several advanced features of data binding. We examined how to create calculated properties by including a property with a getter in your view model. We also discussed how you can create a converter function to format the value of a view model property when binding the property. Finally, you learned how to use the data-win-bindsource attribute to specify a view model declaratively.

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  • Top things web developers should know about the Visual Studio 2013 release

    - by Jon Galloway
    ASP.NET and Web Tools for Visual Studio 2013 Release NotesASP.NET and Web Tools for Visual Studio 2013 Release NotesSummary for lazy readers: Visual Studio 2013 is now available for download on the Visual Studio site and on MSDN subscriber downloads) Visual Studio 2013 installs side by side with Visual Studio 2012 and supports round-tripping between Visual Studio versions, so you can try it out without committing to a switch Visual Studio 2013 ships with the new version of ASP.NET, which includes ASP.NET MVC 5, ASP.NET Web API 2, Razor 3, Entity Framework 6 and SignalR 2.0 The new releases ASP.NET focuses on One ASP.NET, so core features and web tools work the same across the platform (e.g. adding ASP.NET MVC controllers to a Web Forms application) New core features include new templates based on Bootstrap, a new scaffolding system, and a new identity system Visual Studio 2013 is an incredible editor for web files, including HTML, CSS, JavaScript, Markdown, LESS, Coffeescript, Handlebars, Angular, Ember, Knockdown, etc. Top links: Visual Studio 2013 content on the ASP.NET site are in the standard new releases area: http://www.asp.net/vnext ASP.NET and Web Tools for Visual Studio 2013 Release Notes Short intro videos on the new Visual Studio web editor features from Scott Hanselman and Mads Kristensen Announcing release of ASP.NET and Web Tools for Visual Studio 2013 post on the official .NET Web Development and Tools Blog Scott Guthrie's post: Announcing the Release of Visual Studio 2013 and Great Improvements to ASP.NET and Entity Framework Okay, for those of you who are still with me, let's dig in a bit. Quick web dev notes on downloading and installing Visual Studio 2013 I found Visual Studio 2013 to be a pretty fast install. According to Brian Harry's release post, installing over pre-release versions of Visual Studio is supported.  I've installed the release version over pre-release versions, and it worked fine. If you're only going to be doing web development, you can speed up the install if you just select Web Developer tools. Of course, as a good Microsoft employee, I'll mention that you might also want to install some of those other features, like the Store apps for Windows 8 and the Windows Phone 8.0 SDK, but they do download and install a lot of other stuff (e.g. the Windows Phone SDK sets up Hyper-V and downloads several GB's of VM's). So if you're planning just to do web development for now, you can pick just the Web Developer Tools and install the other stuff later. If you've got a fast internet connection, I recommend using the web installer instead of downloading the ISO. The ISO includes all the features, whereas the web installer just downloads what you're installing. Visual Studio 2013 development settings and color theme When you start up Visual Studio, it'll prompt you to pick some defaults. These are totally up to you -whatever suits your development style - and you can change them later. As I said, these are completely up to you. I recommend either the Web Development or Web Development (Code Only) settings. The only real difference is that Code Only hides the toolbars, and you can switch between them using Tools / Import and Export Settings / Reset. Web Development settings Web Development (code only) settings Usually I've just gone with Web Development (code only) in the past because I just want to focus on the code, although the Standard toolbar does make it easier to switch default web browsers. More on that later. Color theme Sigh. Okay, everyone's got their favorite colors. I alternate between Light and Dark depending on my mood, and I personally like how the low contrast on the window chrome in those themes puts the emphasis on my code rather than the tabs and toolbars. I know some people got pretty worked up over that, though, and wanted the blue theme back. I personally don't like it - it reminds me of ancient versions of Visual Studio that I don't want to think about anymore. So here's the thing: if you install Visual Studio Ultimate, it defaults to Blue. The other versions default to Light. If you use Blue, I won't criticize you - out loud, that is. You can change themes really easily - either Tools / Options / Environment / General, or the smart way: ctrl+q for quick launch, then type Theme and hit enter. Signing in During the first run, you'll be prompted to sign in. You don't have to - you can click the "Not now, maybe later" link at the bottom of that dialog. I recommend signing in, though. It's not hooked in with licensing or tracking the kind of code you write to sell you components. It is doing good things, like  syncing your Visual Studio settings between computers. More about that here. So, you don't have to, but I sure do. Overview of shiny new things in ASP.NET land There are a lot of good new things in ASP.NET. I'll list some of my favorite here, but you can read more on the ASP.NET site. One ASP.NET You've heard us talk about this for a while. The idea is that options are good, but choice can be a burden. When you start a new ASP.NET project, why should you have to make a tough decision - with long-term consequences - about how your application will work? If you want to use ASP.NET Web Forms, but have the option of adding in ASP.NET MVC later, why should that be hard? It's all ASP.NET, right? Ideally, you'd just decide that you want to use ASP.NET to build sites and services, and you could use the appropriate tools (the green blocks below) as you needed them. So, here it is. When you create a new ASP.NET application, you just create an ASP.NET application. Next, you can pick from some templates to get you started... but these are different. They're not "painful decision" templates, they're just some starting pieces. And, most importantly, you can mix and match. I can pick a "mostly" Web Forms template, but include MVC and Web API folders and core references. If you've tried to mix and match in the past, you're probably aware that it was possible, but not pleasant. ASP.NET MVC project files contained special project type GUIDs, so you'd only get controller scaffolding support in a Web Forms project if you manually edited the csproj file. Features in one stack didn't work in others. Project templates were painful choices. That's no longer the case. Hooray! I just did a demo in a presentation last week where I created a new Web Forms + MVC + Web API site, built a model, scaffolded MVC and Web API controllers with EF Code First, add data in the MVC view, viewed it in Web API, then added a GridView to the Web Forms Default.aspx page and bound it to the Model. In about 5 minutes. Sure, it's a simple example, but it's great to be able to share code and features across the whole ASP.NET family. Authentication In the past, authentication was built into the templates. So, for instance, there was an ASP.NET MVC 4 Intranet Project template which created a new ASP.NET MVC 4 application that was preconfigured for Windows Authentication. All of that authentication stuff was built into each template, so they varied between the stacks, and you couldn't reuse them. You didn't see a lot of changes to the authentication options, since they required big changes to a bunch of project templates. Now, the new project dialog includes a common authentication experience. When you hit the Change Authentication button, you get some common options that work the same way regardless of the template or reference settings you've made. These options work on all ASP.NET frameworks, and all hosting environments (IIS, IIS Express, or OWIN for self-host) The default is Individual User Accounts: This is the standard "create a local account, using username / password or OAuth" thing; however, it's all built on the new Identity system. More on that in a second. The one setting that has some configuration to it is Organizational Accounts, which lets you configure authentication using Active Directory, Windows Azure Active Directory, or Office 365. Identity There's a new identity system. We've taken the best parts of the previous ASP.NET Membership and Simple Identity systems, rolled in a lot of feedback and made big enhancements to support important developer concerns like unit testing and extensiblity. I've written long posts about ASP.NET identity, and I'll do it again. Soon. This is not that post. The short version is that I think we've finally got just the right Identity system. Some of my favorite features: There are simple, sensible defaults that work well - you can File / New / Run / Register / Login, and everything works. It supports standard username / password as well as external authentication (OAuth, etc.). It's easy to customize without having to re-implement an entire provider. It's built using pluggable pieces, rather than one large monolithic system. It's built using interfaces like IUser and IRole that allow for unit testing, dependency injection, etc. You can easily add user profile data (e.g. URL, twitter handle, birthday). You just add properties to your ApplicationUser model and they'll automatically be persisted. Complete control over how the identity data is persisted. By default, everything works with Entity Framework Code First, but it's built to support changes from small (modify the schema) to big (use another ORM, store your data in a document database or in the cloud or in XML or in the EXIF data of your desktop background or whatever). It's configured via OWIN. More on OWIN and Katana later, but the fact that it's built using OWIN means it's portable. You can find out more in the Authentication and Identity section of the ASP.NET site (and lots more content will be going up there soon). New Bootstrap based project templates The new project templates are built using Bootstrap 3. Bootstrap (formerly Twitter Bootstrap) is a front-end framework that brings a lot of nice benefits: It's responsive, so your projects will automatically scale to device width using CSS media queries. For example, menus are full size on a desktop browser, but on narrower screens you automatically get a mobile-friendly menu. The built-in Bootstrap styles make your standard page elements (headers, footers, buttons, form inputs, tables etc.) look nice and modern. Bootstrap is themeable, so you can reskin your whole site by dropping in a new Bootstrap theme. Since Bootstrap is pretty popular across the web development community, this gives you a large and rapidly growing variety of templates (free and paid) to choose from. Bootstrap also includes a lot of very useful things: components (like progress bars and badges), useful glyphicons, and some jQuery plugins for tooltips, dropdowns, carousels, etc.). Here's a look at how the responsive part works. When the page is full screen, the menu and header are optimized for a wide screen display: When I shrink the page down (this is all based on page width, not useragent sniffing) the menu turns into a nice mobile-friendly dropdown: For a quick example, I grabbed a new free theme off bootswatch.com. For simple themes, you just need to download the boostrap.css file and replace the /content/bootstrap.css file in your project. Now when I refresh the page, I've got a new theme: Scaffolding The big change in scaffolding is that it's one system that works across ASP.NET. You can create a new Empty Web project or Web Forms project and you'll get the Scaffold context menus. For release, we've got MVC 5 and Web API 2 controllers. We had a preview of Web Forms scaffolding in the preview releases, but they weren't fully baked for RTM. Look for them in a future update, expected pretty soon. This scaffolding system wasn't just changed to work across the ASP.NET frameworks, it's also built to enable future extensibility. That's not in this release, but should also hopefully be out soon. Project Readme page This is a small thing, but I really like it. When you create a new project, you get a Project_Readme.html page that's added to the root of your project and opens in the Visual Studio built-in browser. I love it. A long time ago, when you created a new project we just dumped it on you and left you scratching your head about what to do next. Not ideal. Then we started adding a bunch of Getting Started information to the new project templates. That told you what to do next, but you had to delete all of that stuff out of your website. It doesn't belong there. Not ideal. This is a simple HTML file that's not integrated into your project code at all. You can delete it if you want. But, it shows a lot of helpful links that are current for the project you just created. In the future, if we add new wacky project types, they can create readme docs with specific information on how to do appropriately wacky things. Side note: I really like that they used the internal browser in Visual Studio to show this content rather than popping open an HTML page in the default browser. I hate that. It's annoying. If you're doing that, I hope you'll stop. What if some unnamed person has 40 or 90 tabs saved in their browser session? When you pop open your "Thanks for installing my Visual Studio extension!" page, all eleventy billion tabs start up and I wish I'd never installed your thing. Be like these guys and pop stuff Visual Studio specific HTML docs in the Visual Studio browser. ASP.NET MVC 5 The biggest change with ASP.NET MVC 5 is that it's no longer a separate project type. It integrates well with the rest of ASP.NET. In addition to that and the other common features we've already looked at (Bootstrap templates, Identity, authentication), here's what's new for ASP.NET MVC. Attribute routing ASP.NET MVC now supports attribute routing, thanks to a contribution by Tim McCall, the author of http://attributerouting.net. With attribute routing you can specify your routes by annotating your actions and controllers. This supports some pretty complex, customized routing scenarios, and it allows you to keep your route information right with your controller actions if you'd like. Here's a controller that includes an action whose method name is Hiding, but I've used AttributeRouting to configure it to /spaghetti/with-nesting/where-is-waldo public class SampleController : Controller { [Route("spaghetti/with-nesting/where-is-waldo")] public string Hiding() { return "You found me!"; } } I enable that in my RouteConfig.cs, and I can use that in conjunction with my other MVC routes like this: public class RouteConfig { public static void RegisterRoutes(RouteCollection routes) { routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); routes.MapMvcAttributeRoutes(); routes.MapRoute( name: "Default", url: "{controller}/{action}/{id}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional } ); } } You can read more about Attribute Routing in ASP.NET MVC 5 here. Filter enhancements There are two new additions to filters: Authentication Filters and Filter Overrides. Authentication filters are a new kind of filter in ASP.NET MVC that run prior to authorization filters in the ASP.NET MVC pipeline and allow you to specify authentication logic per-action, per-controller, or globally for all controllers. Authentication filters process credentials in the request and provide a corresponding principal. Authentication filters can also add authentication challenges in response to unauthorized requests. Override filters let you change which filters apply to a given action method or controller. Override filters specify a set of filter types that should not be run for a given scope (action or controller). This allows you to configure filters that apply globally but then exclude certain global filters from applying to specific actions or controllers. ASP.NET Web API 2 ASP.NET Web API 2 includes a lot of new features. Attribute Routing ASP.NET Web API supports the same attribute routing system that's in ASP.NET MVC 5. You can read more about the Attribute Routing features in Web API in this article. OAuth 2.0 ASP.NET Web API picks up OAuth 2.0 support, using security middleware running on OWIN (discussed below). This is great for features like authenticated Single Page Applications. OData Improvements ASP.NET Web API now has full OData support. That required adding in some of the most powerful operators: $select, $expand, $batch and $value. You can read more about OData operator support in this article by Mike Wasson. Lots more There's a huge list of other features, including CORS (cross-origin request sharing), IHttpActionResult, IHttpRequestContext, and more. I think the best overview is in the release notes. OWIN and Katana I've written about OWIN and Katana recently. I'm a big fan. OWIN is the Open Web Interfaces for .NET. It's a spec, like HTML or HTTP, so you can't install OWIN. The benefit of OWIN is that it's a community specification, so anyone who implements it can plug into the ASP.NET stack, either as middleware or as a host. Katana is the Microsoft implementation of OWIN. It leverages OWIN to wire up things like authentication, handlers, modules, IIS hosting, etc., so ASP.NET can host OWIN components and Katana components can run in someone else's OWIN implementation. Howard Dierking just wrote a cool article in MSDN magazine describing Katana in depth: Getting Started with the Katana Project. He had an interesting example showing an OWIN based pipeline which leveraged SignalR, ASP.NET Web API and NancyFx components in the same stack. If this kind of thing makes sense to you, that's great. If it doesn't, don't worry, but keep an eye on it. You're going to see some cool things happen as a result of ASP.NET becoming more and more pluggable. Visual Studio Web Tools Okay, this stuff's just crazy. Visual Studio has been adding some nice web dev features over the past few years, but they've really cranked it up for this release. Visual Studio is by far my favorite code editor for all web files: CSS, HTML, JavaScript, and lots of popular libraries. Stop thinking of Visual Studio as a big editor that you only use to write back-end code. Stop editing HTML and CSS in Notepad (or Sublime, Notepad++, etc.). Visual Studio starts up in under 2 seconds on a modern computer with an SSD. Misspelling HTML attributes or your CSS classes or jQuery or Angular syntax is stupid. It doesn't make you a better developer, it makes you a silly person who wastes time. Browser Link Browser Link is a real-time, two-way connection between Visual Studio and all connected browsers. It's only attached when you're running locally, in debug, but it applies to any and all connected browser, including emulators. You may have seen demos that showed the browsers refreshing based on changes in the editor, and I'll agree that's pretty cool. But it's really just the start. It's a two-way connection, and it's built for extensiblity. That means you can write extensions that push information from your running application (in IE, Chrome, a mobile emulator, etc.) back to Visual Studio. Mads and team have showed off some demonstrations where they enabled edit mode in the browser which updated the source HTML back on the browser. It's also possible to look at how the rendered HTML performs, check for compatibility issues, watch for unused CSS classes, the sky's the limit. New HTML editor The previous HTML editor had a lot of old code that didn't allow for improvements. The team rewrote the HTML editor to take advantage of the new(ish) extensibility features in Visual Studio, which then allowed them to add in all kinds of features - things like CSS Class and ID IntelliSense (so you type style="" and get a list of classes and ID's for your project), smart indent based on how your document is formatted, JavaScript reference auto-sync, etc. Here's a 3 minute tour from Mads Kristensen. The previous HTML editor had a lot of old code that didn't allow for improvements. The team rewrote the HTML editor to take advantage of the new(ish) extensibility features in Visual Studio, which then allowed them to add in all kinds of features - things like CSS Class and ID IntelliSense (so you type style="" and get a list of classes and ID's for your project), smart indent based on how your document is formatted, JavaScript reference auto-sync, etc. Lots more Visual Studio web dev features That's just a sampling - there's a ton of great features for JavaScript editing, CSS editing, publishing, and Page Inspector (which shows real-time rendering of your page inside Visual Studio). Here are some more short videos showing those features. Lots, lots more Okay, that's just a summary, and it's still quite a bit. Head on over to http://asp.net/vnext for more information, and download Visual Studio 2013 now to get started!

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  • Using Durandal to Create Single Page Apps

    - by Stephen.Walther
    A few days ago, I gave a talk on building Single Page Apps on the Microsoft Stack. In that talk, I recommended that people use Knockout, Sammy, and RequireJS to build their presentation layer and use the ASP.NET Web API to expose data from their server. After I gave the talk, several people contacted me and suggested that I investigate a new open-source JavaScript library named Durandal. Durandal stitches together Knockout, Sammy, and RequireJS to make it easier to use these technologies together. In this blog entry, I want to provide a brief walkthrough of using Durandal to create a simple Single Page App. I am going to demonstrate how you can create a simple Movies App which contains (virtual) pages for viewing a list of movies, adding new movies, and viewing movie details. The goal of this blog entry is to give you a sense of what it is like to build apps with Durandal. Installing Durandal First things first. How do you get Durandal? The GitHub project for Durandal is located here: https://github.com/BlueSpire/Durandal The Wiki — located at the GitHub project — contains all of the current documentation for Durandal. Currently, the documentation is a little sparse, but it is enough to get you started. Instead of downloading the Durandal source from GitHub, a better option for getting started with Durandal is to install one of the Durandal NuGet packages. I built the Movies App described in this blog entry by first creating a new ASP.NET MVC 4 Web Application with the Basic Template. Next, I executed the following command from the Package Manager Console: Install-Package Durandal.StarterKit As you can see from the screenshot of the Package Manager Console above, the Durandal Starter Kit package has several dependencies including: · jQuery · Knockout · Sammy · Twitter Bootstrap The Durandal Starter Kit package includes a sample Durandal application. You can get to the Starter Kit app by navigating to the Durandal controller. Unfortunately, when I first tried to run the Starter Kit app, I got an error because the Starter Kit is hard-coded to use a particular version of jQuery which is already out of date. You can fix this issue by modifying the App_Start\DurandalBundleConfig.cs file so it is jQuery version agnostic like this: bundles.Add( new ScriptBundle("~/scripts/vendor") .Include("~/Scripts/jquery-{version}.js") .Include("~/Scripts/knockout-{version}.js") .Include("~/Scripts/sammy-{version}.js") // .Include("~/Scripts/jquery-1.9.0.min.js") // .Include("~/Scripts/knockout-2.2.1.js") // .Include("~/Scripts/sammy-0.7.4.min.js") .Include("~/Scripts/bootstrap.min.js") ); The recommendation is that you create a Durandal app in a folder off your project root named App. The App folder in the Starter Kit contains the following subfolders and files: · durandal – This folder contains the actual durandal JavaScript library. · viewmodels – This folder contains all of your application’s view models. · views – This folder contains all of your application’s views. · main.js — This file contains all of the JavaScript startup code for your app including the client-side routing configuration. · main-built.js – This file contains an optimized version of your application. You need to build this file by using the RequireJS optimizer (unfortunately, before you can run the optimizer, you must first install NodeJS). For the purpose of this blog entry, I wanted to start from scratch when building the Movies app, so I deleted all of these files and folders except for the durandal folder which contains the durandal library. Creating the ASP.NET MVC Controller and View A Durandal app is built using a single server-side ASP.NET MVC controller and ASP.NET MVC view. A Durandal app is a Single Page App. When you navigate between pages, you are not navigating to new pages on the server. Instead, you are loading new virtual pages into the one-and-only-one server-side view. For the Movies app, I created the following ASP.NET MVC Home controller: public class HomeController : Controller { public ActionResult Index() { return View(); } } There is nothing special about the Home controller – it is as basic as it gets. Next, I created the following server-side ASP.NET view. This is the one-and-only server-side view used by the Movies app: @{ Layout = null; } <!DOCTYPE html> <html> <head> <title>Index</title> </head> <body> <div id="applicationHost"> Loading app.... </div> @Scripts.Render("~/scripts/vendor") <script type="text/javascript" src="~/App/durandal/amd/require.js" data-main="/App/main"></script> </body> </html> Notice that I set the Layout property for the view to the value null. If you neglect to do this, then the default ASP.NET MVC layout will be applied to the view and you will get the <!DOCTYPE> and opening and closing <html> tags twice. Next, notice that the view contains a DIV element with the Id applicationHost. This marks the area where virtual pages are loaded. When you navigate from page to page in a Durandal app, HTML page fragments are retrieved from the server and stuck in the applicationHost DIV element. Inside the applicationHost element, you can place any content which you want to display when a Durandal app is starting up. For example, you can create a fancy splash screen. I opted for simply displaying the text “Loading app…”: Next, notice the view above includes a call to the Scripts.Render() helper. This helper renders out all of the JavaScript files required by the Durandal library such as jQuery and Knockout. Remember to fix the App_Start\DurandalBundleConfig.cs as described above or Durandal will attempt to load an old version of jQuery and throw a JavaScript exception and stop working. Your application JavaScript code is not included in the scripts rendered by the Scripts.Render helper. Your application code is loaded dynamically by RequireJS with the help of the following SCRIPT element located at the bottom of the view: <script type="text/javascript" src="~/App/durandal/amd/require.js" data-main="/App/main"></script> The data-main attribute on the SCRIPT element causes RequireJS to load your /app/main.js JavaScript file to kick-off your Durandal app. Creating the Durandal Main.js File The Durandal Main.js JavaScript file, located in your App folder, contains all of the code required to configure the behavior of Durandal. Here’s what the Main.js file looks like in the case of the Movies app: require.config({ paths: { 'text': 'durandal/amd/text' } }); define(function (require) { var app = require('durandal/app'), viewLocator = require('durandal/viewLocator'), system = require('durandal/system'), router = require('durandal/plugins/router'); //>>excludeStart("build", true); system.debug(true); //>>excludeEnd("build"); app.start().then(function () { //Replace 'viewmodels' in the moduleId with 'views' to locate the view. //Look for partial views in a 'views' folder in the root. viewLocator.useConvention(); //configure routing router.useConvention(); router.mapNav("movies/show"); router.mapNav("movies/add"); router.mapNav("movies/details/:id"); app.adaptToDevice(); //Show the app by setting the root view model for our application with a transition. app.setRoot('viewmodels/shell', 'entrance'); }); }); There are three important things to notice about the main.js file above. First, notice that it contains a section which enables debugging which looks like this: //>>excludeStart(“build”, true); system.debug(true); //>>excludeEnd(“build”); This code enables debugging for your Durandal app which is very useful when things go wrong. When you call system.debug(true), Durandal writes out debugging information to your browser JavaScript console. For example, you can use the debugging information to diagnose issues with your client-side routes: (The funny looking //> symbols around the system.debug() call are RequireJS optimizer pragmas). The main.js file is also the place where you configure your client-side routes. In the case of the Movies app, the main.js file is used to configure routes for three page: the movies show, add, and details pages. //configure routing router.useConvention(); router.mapNav("movies/show"); router.mapNav("movies/add"); router.mapNav("movies/details/:id");   The route for movie details includes a route parameter named id. Later, we will use the id parameter to lookup and display the details for the right movie. Finally, the main.js file above contains the following line of code: //Show the app by setting the root view model for our application with a transition. app.setRoot('viewmodels/shell', 'entrance'); This line of code causes Durandal to load up a JavaScript file named shell.js and an HTML fragment named shell.html. I’ll discuss the shell in the next section. Creating the Durandal Shell You can think of the Durandal shell as the layout or master page for a Durandal app. The shell is where you put all of the content which you want to remain constant as a user navigates from virtual page to virtual page. For example, the shell is a great place to put your website logo and navigation links. The Durandal shell is composed from two parts: a JavaScript file and an HTML file. Here’s what the HTML file looks like for the Movies app: <h1>Movies App</h1> <div class="container-fluid page-host"> <!--ko compose: { model: router.activeItem, //wiring the router afterCompose: router.afterCompose, //wiring the router transition:'entrance', //use the 'entrance' transition when switching views cacheViews:true //telling composition to keep views in the dom, and reuse them (only a good idea with singleton view models) }--><!--/ko--> </div> And here is what the JavaScript file looks like: define(function (require) { var router = require('durandal/plugins/router'); return { router: router, activate: function () { return router.activate('movies/show'); } }; }); The JavaScript file contains the view model for the shell. This view model returns the Durandal router so you can access the list of configured routes from your shell. Notice that the JavaScript file includes a function named activate(). This function loads the movies/show page as the first page in the Movies app. If you want to create a different default Durandal page, then pass the name of a different age to the router.activate() method. Creating the Movies Show Page Durandal pages are created out of a view model and a view. The view model contains all of the data and view logic required for the view. The view contains all of the HTML markup for rendering the view model. Let’s start with the movies show page. The movies show page displays a list of movies. The view model for the show page looks like this: define(function (require) { var moviesRepository = require("repositories/moviesRepository"); return { movies: ko.observable(), activate: function() { this.movies(moviesRepository.listMovies()); } }; }); You create a view model by defining a new RequireJS module (see http://requirejs.org). You create a RequireJS module by placing all of your JavaScript code into an anonymous function passed to the RequireJS define() method. A RequireJS module has two parts. You retrieve all of the modules which your module requires at the top of your module. The code above depends on another RequireJS module named repositories/moviesRepository. Next, you return the implementation of your module. The code above returns a JavaScript object which contains a property named movies and a method named activate. The activate() method is a magic method which Durandal calls whenever it activates your view model. Your view model is activated whenever you navigate to a page which uses it. In the code above, the activate() method is used to get the list of movies from the movies repository and assign the list to the view model movies property. The HTML for the movies show page looks like this: <table> <thead> <tr> <th>Title</th><th>Director</th> </tr> </thead> <tbody data-bind="foreach:movies"> <tr> <td data-bind="text:title"></td> <td data-bind="text:director"></td> <td><a data-bind="attr:{href:'#/movies/details/'+id}">Details</a></td> </tr> </tbody> </table> <a href="#/movies/add">Add Movie</a> Notice that this is an HTML fragment. This fragment will be stuffed into the page-host DIV element in the shell.html file which is stuffed, in turn, into the applicationHost DIV element in the server-side MVC view. The HTML markup above contains data-bind attributes used by Knockout to display the list of movies (To learn more about Knockout, visit http://knockoutjs.com). The list of movies from the view model is displayed in an HTML table. Notice that the page includes a link to a page for adding a new movie. The link uses the following URL which starts with a hash: #/movies/add. Because the link starts with a hash, clicking the link does not cause a request back to the server. Instead, you navigate to the movies/add page virtually. Creating the Movies Add Page The movies add page also consists of a view model and view. The add page enables you to add a new movie to the movie database. Here’s the view model for the add page: define(function (require) { var app = require('durandal/app'); var router = require('durandal/plugins/router'); var moviesRepository = require("repositories/moviesRepository"); return { movieToAdd: { title: ko.observable(), director: ko.observable() }, activate: function () { this.movieToAdd.title(""); this.movieToAdd.director(""); this._movieAdded = false; }, canDeactivate: function () { if (this._movieAdded == false) { return app.showMessage('Are you sure you want to leave this page?', 'Navigate', ['Yes', 'No']); } else { return true; } }, addMovie: function () { // Add movie to db moviesRepository.addMovie(ko.toJS(this.movieToAdd)); // flag new movie this._movieAdded = true; // return to list of movies router.navigateTo("#/movies/show"); } }; }); The view model contains one property named movieToAdd which is bound to the add movie form. The view model also has the following three methods: 1. activate() – This method is called by Durandal when you navigate to the add movie page. The activate() method resets the add movie form by clearing out the movie title and director properties. 2. canDeactivate() – This method is called by Durandal when you attempt to navigate away from the add movie page. If you return false then navigation is cancelled. 3. addMovie() – This method executes when the add movie form is submitted. This code adds the new movie to the movie repository. I really like the Durandal canDeactivate() method. In the code above, I use the canDeactivate() method to show a warning to a user if they navigate away from the add movie page – either by clicking the Cancel button or by hitting the browser back button – before submitting the add movie form: The view for the add movie page looks like this: <form data-bind="submit:addMovie"> <fieldset> <legend>Add Movie</legend> <div> <label> Title: <input data-bind="value:movieToAdd.title" required /> </label> </div> <div> <label> Director: <input data-bind="value:movieToAdd.director" required /> </label> </div> <div> <input type="submit" value="Add" /> <a href="#/movies/show">Cancel</a> </div> </fieldset> </form> I am using Knockout to bind the movieToAdd property from the view model to the INPUT elements of the HTML form. Notice that the FORM element includes a data-bind attribute which invokes the addMovie() method from the view model when the HTML form is submitted. Creating the Movies Details Page You navigate to the movies details Page by clicking the Details link which appears next to each movie in the movies show page: The Details links pass the movie ids to the details page: #/movies/details/0 #/movies/details/1 #/movies/details/2 Here’s what the view model for the movies details page looks like: define(function (require) { var router = require('durandal/plugins/router'); var moviesRepository = require("repositories/moviesRepository"); return { movieToShow: { title: ko.observable(), director: ko.observable() }, activate: function (context) { // Grab movie from repository var movie = moviesRepository.getMovie(context.id); // Add to view model this.movieToShow.title(movie.title); this.movieToShow.director(movie.director); } }; }); Notice that the view model activate() method accepts a parameter named context. You can take advantage of the context parameter to retrieve route parameters such as the movie Id. In the code above, the context.id property is used to retrieve the correct movie from the movie repository and the movie is assigned to a property named movieToShow exposed by the view model. The movie details view displays the movieToShow property by taking advantage of Knockout bindings: <div> <h2 data-bind="text:movieToShow.title"></h2> directed by <span data-bind="text:movieToShow.director"></span> </div> Summary The goal of this blog entry was to walkthrough building a simple Single Page App using Durandal and to get a feel for what it is like to use this library. I really like how Durandal stitches together Knockout, Sammy, and RequireJS and establishes patterns for using these libraries to build Single Page Apps. Having a standard pattern which developers on a team can use to build new pages is super valuable. Once you get the hang of it, using Durandal to create new virtual pages is dead simple. Just define a new route, view model, and view and you are done. I also appreciate the fact that Durandal did not attempt to re-invent the wheel and that Durandal leverages existing JavaScript libraries such as Knockout, RequireJS, and Sammy. These existing libraries are powerful libraries and I have already invested a considerable amount of time in learning how to use them. Durandal makes it easier to use these libraries together without losing any of their power. Durandal has some additional interesting features which I have not had a chance to play with yet. For example, you can use the RequireJS optimizer to combine and minify all of a Durandal app’s code. Also, Durandal supports a way to create custom widgets (client-side controls) by composing widgets from a controller and view. You can download the code for the Movies app by clicking the following link (this is a Visual Studio 2012 project): Durandal Movie App

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  • Node.js Adventure - Host Node.js on Windows Azure Worker Role

    - by Shaun
    In my previous post I demonstrated about how to develop and deploy a Node.js application on Windows Azure Web Site (a.k.a. WAWS). WAWS is a new feature in Windows Azure platform. Since it’s low-cost, and it provides IIS and IISNode components so that we can host our Node.js application though Git, FTP and WebMatrix without any configuration and component installation. But sometimes we need to use the Windows Azure Cloud Service (a.k.a. WACS) and host our Node.js on worker role. Below are some benefits of using worker role. - WAWS leverages IIS and IISNode to host Node.js application, which runs in x86 WOW mode. It reduces the performance comparing with x64 in some cases. - WACS worker role does not need IIS, hence there’s no restriction of IIS, such as 8000 concurrent requests limitation. - WACS provides more flexibility and controls to the developers. For example, we can RDP to the virtual machines of our worker role instances. - WACS provides the service configuration features which can be changed when the role is running. - WACS provides more scaling capability than WAWS. In WAWS we can have at most 3 reserved instances per web site while in WACS we can have up to 20 instances in a subscription. - Since when using WACS worker role we starts the node by ourselves in a process, we can control the input, output and error stream. We can also control the version of Node.js.   Run Node.js in Worker Role Node.js can be started by just having its execution file. This means in Windows Azure, we can have a worker role with the “node.exe” and the Node.js source files, then start it in Run method of the worker role entry class. Let’s create a new windows azure project in Visual Studio and add a new worker role. Since we need our worker role execute the “node.exe” with our application code we need to add the “node.exe” into our project. Right click on the worker role project and add an existing item. By default the Node.js will be installed in the “Program Files\nodejs” folder so we can navigate there and add the “node.exe”. Then we need to create the entry code of Node.js. In WAWS the entry file must be named “server.js”, which is because it’s hosted by IIS and IISNode and IISNode only accept “server.js”. But here as we control everything we can choose any files as the entry code. For example, I created a new JavaScript file named “index.js” in project root. Since we created a C# Windows Azure project we cannot create a JavaScript file from the context menu “Add new item”. We have to create a text file, and then rename it to JavaScript extension. After we added these two files we should set their “Copy to Output Directory” property to “Copy Always”, or “Copy if Newer”. Otherwise they will not be involved in the package when deployed. Let’s paste a very simple Node.js code in the “index.js” as below. As you can see I created a web server listening at port 12345. 1: var http = require("http"); 2: var port = 12345; 3:  4: http.createServer(function (req, res) { 5: res.writeHead(200, { "Content-Type": "text/plain" }); 6: res.end("Hello World\n"); 7: }).listen(port); 8:  9: console.log("Server running at port %d", port); Then we need to start “node.exe” with this file when our worker role was started. This can be done in its Run method. I found the Node.js and entry JavaScript file name, and then create a new process to run it. Our worker role will wait for the process to be exited. If everything is OK once our web server was opened the process will be there listening for incoming requests, and should not be terminated. The code in worker role would be like this. 1: public override void Run() 2: { 3: // This is a sample worker implementation. Replace with your logic. 4: Trace.WriteLine("NodejsHost entry point called", "Information"); 5:  6: // retrieve the node.exe and entry node.js source code file name. 7: var node = Environment.ExpandEnvironmentVariables(@"%RoleRoot%\approot\node.exe"); 8: var js = "index.js"; 9:  10: // prepare the process starting of node.exe 11: var info = new ProcessStartInfo(node, js) 12: { 13: CreateNoWindow = false, 14: ErrorDialog = true, 15: WindowStyle = ProcessWindowStyle.Normal, 16: UseShellExecute = false, 17: WorkingDirectory = Environment.ExpandEnvironmentVariables(@"%RoleRoot%\approot") 18: }; 19: Trace.WriteLine(string.Format("{0} {1}", node, js), "Information"); 20:  21: // start the node.exe with entry code and wait for exit 22: var process = Process.Start(info); 23: process.WaitForExit(); 24: } Then we can run it locally. In the computer emulator UI the worker role started and it executed the Node.js, then Node.js windows appeared. Open the browser to verify the website hosted by our worker role. Next let’s deploy it to azure. But we need some additional steps. First, we need to create an input endpoint. By default there’s no endpoint defined in a worker role. So we will open the role property window in Visual Studio, create a new input TCP endpoint to the port we want our website to use. In this case I will use 80. Even though we created a web server we should add a TCP endpoint of the worker role, since Node.js always listen on TCP instead of HTTP. And then changed the “index.js”, let our web server listen on 80. 1: var http = require("http"); 2: var port = 80; 3:  4: http.createServer(function (req, res) { 5: res.writeHead(200, { "Content-Type": "text/plain" }); 6: res.end("Hello World\n"); 7: }).listen(port); 8:  9: console.log("Server running at port %d", port); Then publish it to Windows Azure. And then in browser we can see our Node.js website was running on WACS worker role. We may encounter an error if we tried to run our Node.js website on 80 port at local emulator. This is because the compute emulator registered 80 and map the 80 endpoint to 81. But our Node.js cannot detect this operation. So when it tried to listen on 80 it will failed since 80 have been used.   Use NPM Modules When we are using WAWS to host Node.js, we can simply install modules we need, and then just publish or upload all files to WAWS. But if we are using WACS worker role, we have to do some extra steps to make the modules work. Assuming that we plan to use “express” in our application. Firstly of all we should download and install this module through NPM command. But after the install finished, they are just in the disk but not included in the worker role project. If we deploy the worker role right now the module will not be packaged and uploaded to azure. Hence we need to add them to the project. On solution explorer window click the “Show all files” button, select the “node_modules” folder and in the context menu select “Include In Project”. But that not enough. We also need to make all files in this module to “Copy always” or “Copy if newer”, so that they can be uploaded to azure with the “node.exe” and “index.js”. This is painful step since there might be many files in a module. So I created a small tool which can update a C# project file, make its all items as “Copy always”. The code is very simple. 1: static void Main(string[] args) 2: { 3: if (args.Length < 1) 4: { 5: Console.WriteLine("Usage: copyallalways [project file]"); 6: return; 7: } 8:  9: var proj = args[0]; 10: File.Copy(proj, string.Format("{0}.bak", proj)); 11:  12: var xml = new XmlDocument(); 13: xml.Load(proj); 14: var nsManager = new XmlNamespaceManager(xml.NameTable); 15: nsManager.AddNamespace("pf", "http://schemas.microsoft.com/developer/msbuild/2003"); 16:  17: // add the output setting to copy always 18: var contentNodes = xml.SelectNodes("//pf:Project/pf:ItemGroup/pf:Content", nsManager); 19: UpdateNodes(contentNodes, xml, nsManager); 20: var noneNodes = xml.SelectNodes("//pf:Project/pf:ItemGroup/pf:None", nsManager); 21: UpdateNodes(noneNodes, xml, nsManager); 22: xml.Save(proj); 23:  24: // remove the namespace attributes 25: var content = xml.InnerXml.Replace("<CopyToOutputDirectory xmlns=\"\">", "<CopyToOutputDirectory>"); 26: xml.LoadXml(content); 27: xml.Save(proj); 28: } 29:  30: static void UpdateNodes(XmlNodeList nodes, XmlDocument xml, XmlNamespaceManager nsManager) 31: { 32: foreach (XmlNode node in nodes) 33: { 34: var copyToOutputDirectoryNode = node.SelectSingleNode("pf:CopyToOutputDirectory", nsManager); 35: if (copyToOutputDirectoryNode == null) 36: { 37: var n = xml.CreateNode(XmlNodeType.Element, "CopyToOutputDirectory", null); 38: n.InnerText = "Always"; 39: node.AppendChild(n); 40: } 41: else 42: { 43: if (string.Compare(copyToOutputDirectoryNode.InnerText, "Always", true) != 0) 44: { 45: copyToOutputDirectoryNode.InnerText = "Always"; 46: } 47: } 48: } 49: } Please be careful when use this tool. I created only for demo so do not use it directly in a production environment. Unload the worker role project, execute this tool with the worker role project file name as the command line argument, it will set all items as “Copy always”. Then reload this worker role project. Now let’s change the “index.js” to use express. 1: var express = require("express"); 2: var app = express(); 3:  4: var port = 80; 5:  6: app.configure(function () { 7: }); 8:  9: app.get("/", function (req, res) { 10: res.send("Hello Node.js!"); 11: }); 12:  13: app.get("/User/:id", function (req, res) { 14: var id = req.params.id; 15: res.json({ 16: "id": id, 17: "name": "user " + id, 18: "company": "IGT" 19: }); 20: }); 21:  22: app.listen(port); Finally let’s publish it and have a look in browser.   Use Windows Azure SQL Database We can use Windows Azure SQL Database (a.k.a. WACD) from Node.js as well on worker role hosting. Since we can control the version of Node.js, here we can use x64 version of “node-sqlserver” now. This is better than if we host Node.js on WAWS since it only support x86. Just install the “node-sqlserver” module from NPM, copy the “sqlserver.node” from “Build\Release” folder to “Lib” folder. Include them in worker role project and run my tool to make them to “Copy always”. Finally update the “index.js” to use WASD. 1: var express = require("express"); 2: var sql = require("node-sqlserver"); 3:  4: var connectionString = "Driver={SQL Server Native Client 10.0};Server=tcp:{SERVER NAME}.database.windows.net,1433;Database={DATABASE NAME};Uid={LOGIN}@{SERVER NAME};Pwd={PASSWORD};Encrypt=yes;Connection Timeout=30;"; 5: var port = 80; 6:  7: var app = express(); 8:  9: app.configure(function () { 10: app.use(express.bodyParser()); 11: }); 12:  13: app.get("/", function (req, res) { 14: sql.open(connectionString, function (err, conn) { 15: if (err) { 16: console.log(err); 17: res.send(500, "Cannot open connection."); 18: } 19: else { 20: conn.queryRaw("SELECT * FROM [Resource]", function (err, results) { 21: if (err) { 22: console.log(err); 23: res.send(500, "Cannot retrieve records."); 24: } 25: else { 26: res.json(results); 27: } 28: }); 29: } 30: }); 31: }); 32:  33: app.get("/text/:key/:culture", function (req, res) { 34: sql.open(connectionString, function (err, conn) { 35: if (err) { 36: console.log(err); 37: res.send(500, "Cannot open connection."); 38: } 39: else { 40: var key = req.params.key; 41: var culture = req.params.culture; 42: var command = "SELECT * FROM [Resource] WHERE [Key] = '" + key + "' AND [Culture] = '" + culture + "'"; 43: conn.queryRaw(command, function (err, results) { 44: if (err) { 45: console.log(err); 46: res.send(500, "Cannot retrieve records."); 47: } 48: else { 49: res.json(results); 50: } 51: }); 52: } 53: }); 54: }); 55:  56: app.get("/sproc/:key/:culture", function (req, res) { 57: sql.open(connectionString, function (err, conn) { 58: if (err) { 59: console.log(err); 60: res.send(500, "Cannot open connection."); 61: } 62: else { 63: var key = req.params.key; 64: var culture = req.params.culture; 65: var command = "EXEC GetItem '" + key + "', '" + culture + "'"; 66: conn.queryRaw(command, function (err, results) { 67: if (err) { 68: console.log(err); 69: res.send(500, "Cannot retrieve records."); 70: } 71: else { 72: res.json(results); 73: } 74: }); 75: } 76: }); 77: }); 78:  79: app.post("/new", function (req, res) { 80: var key = req.body.key; 81: var culture = req.body.culture; 82: var val = req.body.val; 83:  84: sql.open(connectionString, function (err, conn) { 85: if (err) { 86: console.log(err); 87: res.send(500, "Cannot open connection."); 88: } 89: else { 90: var command = "INSERT INTO [Resource] VALUES ('" + key + "', '" + culture + "', N'" + val + "')"; 91: conn.queryRaw(command, function (err, results) { 92: if (err) { 93: console.log(err); 94: res.send(500, "Cannot retrieve records."); 95: } 96: else { 97: res.send(200, "Inserted Successful"); 98: } 99: }); 100: } 101: }); 102: }); 103:  104: app.listen(port); Publish to azure and now we can see our Node.js is working with WASD through x64 version “node-sqlserver”.   Summary In this post I demonstrated how to host our Node.js in Windows Azure Cloud Service worker role. By using worker role we can control the version of Node.js, as well as the entry code. And it’s possible to do some pre jobs before the Node.js application started. It also removed the IIS and IISNode limitation. I personally recommended to use worker role as our Node.js hosting. But there are some problem if you use the approach I mentioned here. The first one is, we need to set all JavaScript files and module files as “Copy always” or “Copy if newer” manually. The second one is, in this way we cannot retrieve the cloud service configuration information. For example, we defined the endpoint in worker role property but we also specified the listening port in Node.js hardcoded. It should be changed that our Node.js can retrieve the endpoint. But I can tell you it won’t be working here. In the next post I will describe another way to execute the “node.exe” and Node.js application, so that we can get the cloud service configuration in Node.js. I will also demonstrate how to use Windows Azure Storage from Node.js by using the Windows Azure Node.js SDK.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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  • What Every Developer Should Know About MSI Components

    - by Alois Kraus
    Hopefully nothing. But if you have to do more than simple XCopy deployment and you need to support updates, upgrades and perhaps side by side scenarios there is no way around MSI. You can create Msi files with a Visual Studio Setup project which is severely limited or you can use the Windows Installer Toolset. I cannot talk about WIX with my German colleagues because WIX has a very special meaning. It is funny to always use the long name when I talk about deployment possibilities. Alternatively you can buy commercial tools which help you to author Msi files but I am not sure how good they are. Given enough pain with existing solutions you can also learn the MSI Apis and create your own packaging solution. If I were you I would use either a commercial visual tool when you do easy deployments or use the free Windows Installer Toolset. Once you know the WIX schema you can create well formed wix xml files easily with any editor. Then you can “compile” from the wxs files your Msi package. Recently I had the “pleasure” to get my hands dirty with C++ (again) and the MSI technology. Installation is a complex topic but after several month of digging into arcane MSI issues I can safely say that there should exist an easier way to install and update files as today. I am not alone with this statement as John Robbins (creator of the cool tool Paraffin) states: “.. It's a brittle and scary API in Windows …”. To help other people struggling with installation issues I present you the advice I (and others) found useful and what will happen if you ignore this advice. What is a MSI file? A MSI file is basically a database with tables which reference each other to control how your un/installation should work. The basic idea is that you declare via these tables what you want to install and MSI controls the how to get your stuff onto or off your machine. Your “stuff” consists usually of files, registry keys, shortcuts and environment variables. Therefore the most important tables are File, Registry, Environment and Shortcut table which define what will be un/installed. The key to master MSI is that every resource (file, registry key ,…) is associated with a MSI component. The actual payload consists of compressed files in the CAB format which can either be embedded into the MSI file or reside beside the MSI file or in a subdirectory below it. To examine MSI files you need Orca a free MSI editor provided by MS. There is also another free editor called Super Orca which does support diffs between MSI and it does not lock the MSI files. But since Orca comes with a shell extension I tend to use only Orca because it is so easy to right click on a MSI file and open it with this tool. How Do I Install It? Double click it. This does work for fresh installations as well as major upgrades. Updates need to be installed via the command line via msiexec /i <msi> REINSTALL=ALL REINSTALLMODE=vomus   This tells the installer to reinstall all already installed features (new features will NOT be installed). The reinstallmode letters do force an overwrite of the old cached package in the %WINDIR%\Installer folder. All files, shortcuts and registry keys are redeployed if they are missing or need to be replaced with a newer version. When things did go really wrong and you want to overwrite everything unconditionally use REINSTALLMODE=vamus. How To Enable MSI Logs? You can download a MSI from Microsoft which installs some registry keys to enable full MSI logging. The log files can be found in your %TEMP% folder and are called MSIxxxx.log. Alternatively you can add to your msiexec command line the option msiexec …. /l*vx <LogFileName> Personally I find it rather strange that * does not mean full logging. To really get all logs I need to add v and x which is documented in the msiexec help but I still find this behavior unintuitive. What are MSI components? The whole MSI logic is bound to the concept of MSI components. Nearly every msi table has a Component column which binds an installable resource to a component. Below are the screenshots of the FeatureComponents and Component table of an example MSI. The Feature table defines basically the feature hierarchy.  To find out what belongs to a feature you need to look at the FeatureComponents table where for each feature the components are listed which will be installed when a feature is installed. The MSI components are defined in the  Component table. This table has as first column the component name and as second column the component id which is a GUID. All resources you want to install belong to a MSI component. Therefore nearly all MSI tables have a Component_ column which contains the component name. If you look e.g. a the File table you see that every file belongs to a component which is true for all other tables which install resources. The component table is the glue between all other tables which contain the resources you want to install. So far so easy. Why is MSI then so complex? Most MSI problems arise from the fact that you did violate a MSI component rule in one or the other way. When you install a feature the reference count for all components belonging to this feature will increase by one. If your component is installed by more than one feature it will get a higher refcount. When you uninstall a feature its refcount will drop by one. Interesting things happen if the component reference count reaches zero: Then all associated resources will be deleted. That looks like a reasonable thing and it is. What it makes complex are the strange component rules you have to follow. Below are some important component rules from the Tao of the Windows Installer … Rule 16: Follow Component Rules Components are a very important part of the Installer technology. They are the means whereby the Installer manages the resources that make up your application. The SDK provides the following guidelines for creating components in your package: Never create two components that install a resource under the same name and target location. If a resource must be duplicated in multiple components, change its name or target location in each component. This rule should be applied across applications, products, product versions, and companies. Two components must not have the same key path file. This is a consequence of the previous rule. The key path value points to a particular file or folder belonging to the component that the installer uses to detect the component. If two components had the same key path file, the installer would be unable to distinguish which component is installed. Two components however may share a key path folder. Do not create a version of a component that is incompatible with all previous versions of the component. This rule should be applied across applications, products, product versions, and companies. Do not create components containing resources that will need to be installed into more than one directory on the user’s system. The installer installs all of the resources in a component into the same directory. It is not possible to install some resources into subdirectories. Do not include more than one COM server per component. If a component contains a COM server, this must be the key path for the component. Do not specify more than one file per component as a target for the Start menu or a Desktop shortcut. … And these rules do not even talk about component ids, update packages and upgrades which you need to understand as well. Lets suppose you install two MSIs (MSI1 and MSI2) which have the same ComponentId but different component names. Both do install the same file. What will happen when you uninstall MSI2?   Hm the file should stay there. But the component names are different. Yes and yes. But MSI uses not use the component name as key for the refcount. Instead the ComponentId column of the Component table which contains a GUID is used as identifier under which the refcount is stored. The components Comp1 and Comp2 are identical from the MSI perspective. After the installation of both MSIs the Component with the Id {100000….} has a refcount of two. After uninstallation of one MSI there is still a refcount of one which drops to zero just as expected when we uninstall the last msi. Then the file which was the same for both MSIs is deleted. You should remember that MSI keeps a refcount across MSIs for components with the same component id. MSI does manage components not the resources you did install. The resources associated with a component are then and only then deleted when the refcount of the component reaches zero.   The dependencies between features, components and resources can be described as relations. m,k are numbers >= 1, n can be 0. Inside a MSI the following relations are valid Feature    1  –> n Components Component    1 –> m Features Component      1  –>  k Resources These relations express that one feature can install several components and features can share components between them. Every (meaningful) component will install at least one resource which means that its name (primary key to stay in database speak) does occur in some other table in the Component column as value which installs some resource. Lets make it clear with an example. We want to install with the feature MainFeature some files a registry key and a shortcut. We can then create components Comp1..3 which are referenced by the resources defined in the corresponding tables.   Feature Component Registry File Shortcuts MainFeature Comp1 RegistryKey1     MainFeature Comp2   File.txt   MainFeature Comp3   File2.txt Shortcut to File2.txt   It is illegal that the same resource is part of more than one component since this would break the refcount mechanism. Lets illustrate this:            Feature ComponentId Resource Reference Count Feature1 {1000-…} File1.txt 1 Feature2 {2000-….} File1.txt 1 The installation part works well but what happens when you uninstall Feature2? Component {20000…} gets a refcount of zero where MSI deletes all resources belonging to this component. In this case File1.txt will be deleted. But Feature1 still has another component {10000…} with a refcount of one which means that the file was deleted too early. You just have ruined your installation. To fix it you then need to click on the Repair button under Add/Remove Programs to let MSI reinstall any missing registry keys, files or shortcuts. The vigilant reader might has noticed that there is more in the Component table. Beside its name and GUID it has also an installation directory, attributes and a KeyPath. The KeyPath is a reference to a file or registry key which is used to detect if the component is already installed. This becomes important when you repair or uninstall a component. To find out if the component is already installed MSI checks if the registry key or file referenced by the KeyPath property does exist. When it does not exist it assumes that it was either already uninstalled (can lead to problems during uninstall) or that it is already installed and all is fine. Why is this detail so important? Lets put all files into one component. The KeyPath should be then one of the files of your component to check if it was installed or not. When your installation becomes corrupt because a file was deleted you cannot repair it with the Repair button under Add/Remove Programs because MSI checks the component integrity via the Resource referenced by its KeyPath. As long as you did not delete the KeyPath file MSI thinks all resources with your component are installed and never executes any repair action. You get even more trouble when you try to remove files during an upgrade (you cannot remove files during an update) from your super component which contains all files. The only way out and therefore best practice is to assign for every resource you want to install an extra component. This ensures painless updatability and repairs and you have much less effort to remove specific files during an upgrade. In effect you get this best practice relation Feature 1  –> n Components Component   1  –>  1 Resources MSI Component Rules Rule 1 – One component per resource Every resource you want to install (file, registry key, value, environment value, shortcut, directory, …) must get its own component which does never change between versions as long as the install location is the same. Penalty If you add more than one resources to a component you will break the repair capability of MSI because the KeyPath is used to check if the component needs repair. MSI ComponentId Files MSI 1.0 {1000} File1-5 MSI 2.0 {2000} File2-5 You want to remove File1 in version 2.0 of your MSI. Since you want to keep the other files you create a new component and add them there. MSI will delete all files if the component refcount of {1000} drops to zero. The files you want to keep are added to the new component {2000}. Ok that does work if your upgrade does uninstall the old MSI first. This will cause the refcount of all previously installed components to reach zero which means that all files present in version 1.0 are deleted. But there is a faster way to perform your upgrade by first installing your new MSI and then remove the old one.  If you choose this upgrade path then you will loose File1-5 after your upgrade and not only File1 as intended by your new component design.   Rule 2 – Only add, never remove resources from a component If you did follow rule 1 you will not need Rule 2. You can add in a patch more resources to one component. That is ok. But you can never remove anything from it. There are tricky ways around that but I do not want to encourage bad component design. Penalty Lets assume you have 2 MSI files which install under the same component one file   MSI1 MSI2 {1000} - ComponentId {1000} – ComponentId File1.txt File2.txt   When you install and uninstall both MSIs you will end up with an installation where either File1 or File2 will be left. Why? It seems that MSI does not store the resources associated with each component in its internal database. Instead Windows will simply query the MSI that is currently uninstalled for all resources belonging to this component. Since it will find only one file and not two it will only uninstall one file. That is the main reason why you never can remove resources from a component!   Rule 3 Never Remove A Component From an Update MSI. This is the same as if you change the GUID of a component by accident for your new update package. The resulting update package will not contain all components from the previously installed package. Penalty When you remove a component from a feature MSI will set the feature state during update to Advertised and log a warning message into its log file when you did enable MSI logging. SELMGR: ComponentId '{2DCEA1BA-3E27-E222-484C-D0D66AEA4F62}' is registered to feature 'xxxxxxx, but is not present in the Component table.  Removal of components from a feature is not supported! MSI (c) (24:44) [07:53:13:436]: SELMGR: Removal of a component from a feature is not supported Advertised means that MSI treats all components of this feature as not installed. As a consequence during uninstall nothing will be removed since it is not installed! This is not only bad because uninstall does no longer work but this feature will also not get the required patches. All other features which have followed component versioning rules for update packages will be updated but the one faulty feature will not. This results in very hard to find bugs why an update was only partially successful. Things got better with Windows Installer 4.5 but you cannot rely on that nobody will use an older installer. It is a good idea to add to your update msiexec call MSIENFORCEUPGRADECOMPONENTRULES=1 which will abort the installation if you did violate this rule.

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  • Extending NerdDinner: Adding Geolocated Flair

    - by Jon Galloway
    NerdDinner is a website with the audacious goal of “Organizing the world’s nerds and helping them eat in packs.” Because nerds aren’t likely to socialize with others unless a website tells them to do it. Scott Hanselman showed off a lot of the cool features we’ve added to NerdDinner lately during his popular talk at MIX10, Beyond File | New Company: From Cheesy Sample to Social Platform. Did you miss it? Go ahead and watch it, I’ll wait. One of the features we wanted to add was flair. You know about flair, right? It’s a way to let folks who like your site show it off in their own site. For example, here’s my StackOverflow flair: Great! So how could we add some of this flair stuff to NerdDinner? What do we want to show? If we’re going to encourage our users to give up a bit of their beautiful website to show off a bit of ours, we need to think about what they’ll want to show. For instance, my StackOverflow flair is all about me, not StackOverflow. So how will this apply to NerdDinner? Since NerdDinner is all about organizing local dinners, in order for the flair to be useful it needs to make sense for the person viewing the web page. If someone visits from Egypt visits my blog, they should see information about NerdDinners in Egypt. That’s geolocation – localizing site content based on where the browser’s sitting, and it makes sense for flair as well as entire websites. So we’ll set up a simple little callout that prompts them to host a dinner in their area: Hopefully our flair works and there is a dinner near your viewers, so they’ll see another view which lists upcoming dinners near them: The Geolocation Part Generally website geolocation is done by mapping the requestor’s IP address to a geographic area. It’s not an exact science, but I’ve always found it to be pretty accurate. There are (at least) three ways to handle it: You pay somebody like MaxMind for a database (with regular updates) that sits on your server, and you use their API to do lookups. I used this on a pretty big project a few years ago and it worked well. You use HTML 5 Geolocation API or Google Gears or some other browser based solution. I think those are cool (I use Google Gears a lot), but they’re both in flux right now and I don’t think either has a wide enough of an install base yet to rely on them. You might want to, but I’ve heard you do all kinds of crazy stuff, and sometimes it gets you in trouble. I don’t mean talk out of line, but we all laugh behind your back a bit. But, hey, it’s up to you. It’s your flair or whatever. There are some free webservices out there that will take an IP address and give you location information. Easy, and works for everyone. That’s what we’re doing. I looked at a few different services and settled on IPInfoDB. It’s free, has a great API, and even returns JSON, which is handy for Javascript use. The IP query is pretty simple. We hit a URL like this: http://ipinfodb.com/ip_query.php?ip=74.125.45.100&timezone=false … and we get an XML response back like this… <?xml version="1.0" encoding="UTF-8"?> <Response> <Ip>74.125.45.100</Ip> <Status>OK</Status> <CountryCode>US</CountryCode> <CountryName>United States</CountryName> <RegionCode>06</RegionCode> <RegionName>California</RegionName> <City>Mountain View</City> <ZipPostalCode>94043</ZipPostalCode> <Latitude>37.4192</Latitude> <Longitude>-122.057</Longitude> </Response> So we’ll build some data transfer classes to hold the location information, like this: public class LocationInfo { public string Country { get; set; } public string RegionName { get; set; } public string City { get; set; } public string ZipPostalCode { get; set; } public LatLong Position { get; set; } } public class LatLong { public float Lat { get; set; } public float Long { get; set; } } And now hitting the service is pretty simple: public static LocationInfo HostIpToPlaceName(string ip) { string url = "http://ipinfodb.com/ip_query.php?ip={0}&timezone=false"; url = String.Format(url, ip); var result = XDocument.Load(url); var location = (from x in result.Descendants("Response") select new LocationInfo { City = (string)x.Element("City"), RegionName = (string)x.Element("RegionName"), Country = (string)x.Element("CountryName"), ZipPostalCode = (string)x.Element("CountryName"), Position = new LatLong { Lat = (float)x.Element("Latitude"), Long = (float)x.Element("Longitude") } }).First(); return location; } Getting The User’s IP Okay, but first we need the end user’s IP, and you’d think it would be as simple as reading the value from HttpContext: HttpContext.Current.Request.UserHostAddress But you’d be wrong. Sorry. UserHostAddress just wraps HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"], but that doesn’t get you the IP for users behind a proxy. That’s in another header, “HTTP_X_FORWARDED_FOR". So you can either hit a wrapper and then check a header, or just check two headers. I went for uniformity: string SourceIP = string.IsNullOrEmpty(Request.ServerVariables["HTTP_X_FORWARDED_FOR"]) ? Request.ServerVariables["REMOTE_ADDR"] : Request.ServerVariables["HTTP_X_FORWARDED_FOR"]; We’re almost set to wrap this up, but first let’s talk about our views. Yes, views, because we’ll have two. Selecting the View We wanted to make it easy for people to include the flair in their sites, so we looked around at how other people were doing this. The StackOverflow folks have a pretty good flair system, which allows you to include the flair in your site as either an IFRAME reference or a Javascript include. We’ll do both. We have a ServicesController to handle use of the site information outside of NerdDinner.com, so this fits in pretty well there. We’ll be displaying the same information for both HTML and Javascript flair, so we can use one Flair controller action which will return a different view depending on the requested format. Here’s our general flow for our controller action: Get the user’s IP Translate it to a location Grab the top three upcoming dinners that are near that location Select the view based on the format (defaulted to “html”) Return a FlairViewModel which contains the list of dinners and the location information public ActionResult Flair(string format = "html") { string SourceIP = string.IsNullOrEmpty( Request.ServerVariables["HTTP_X_FORWARDED_FOR"]) ? Request.ServerVariables["REMOTE_ADDR"] : Request.ServerVariables["HTTP_X_FORWARDED_FOR"]; var location = GeolocationService.HostIpToPlaceName(SourceIP); var dinners = dinnerRepository. FindByLocation(location.Position.Lat, location.Position.Long). OrderByDescending(p => p.EventDate).Take(3); // Select the view we'll return. // Using a switch because we'll add in JSON and other formats later. string view; switch (format.ToLower()) { case "javascript": view = "JavascriptFlair"; break; default: view = "Flair"; break; } return View( view, new FlairViewModel { Dinners = dinners.ToList(), LocationName = string.IsNullOrEmpty(location.City) ? "you" : String.Format("{0}, {1}", location.City, location.RegionName) } ); } Note: I’m not in love with the logic here, but it seems like overkill to extract the switch statement away when we’ll probably just have two or three views. What do you think? The HTML View The HTML version of the view is pretty simple – the only thing of any real interest here is the use of an extension method to truncate strings that are would cause the titles to wrap. public static string Truncate(this string s, int maxLength) { if (string.IsNullOrEmpty(s) || maxLength <= 0) return string.Empty; else if (s.Length > maxLength) return s.Substring(0, maxLength) + "..."; else return s; }   So here’s how the HTML view ends up looking: <%@ Page Title="" Language="C#" Inherits="System.Web.Mvc.ViewPage<FlairViewModel>" %> <%@ Import Namespace="NerdDinner.Helpers" %> <%@ Import Namespace="NerdDinner.Models" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Nerd Dinner</title> <link href="/Content/Flair.css" rel="stylesheet" type="text/css" /> </head> <body> <div id="nd-wrapper"> <h2 id="nd-header">NerdDinner.com</h2> <div id="nd-outer"> <% if (Model.Dinners.Count == 0) { %> <div id="nd-bummer"> Looks like there's no Nerd Dinners near <%:Model.LocationName %> in the near future. Why not <a target="_blank" href="http://www.nerddinner.com/Dinners/Create">host one</a>?</div> <% } else { %> <h3> Dinners Near You</h3> <ul> <% foreach (var item in Model.Dinners) { %> <li> <%: Html.ActionLink(String.Format("{0} with {1} on {2}", item.Title.Truncate(20), item.HostedBy, item.EventDate.ToShortDateString()), "Details", "Dinners", new { id = item.DinnerID }, new { target = "_blank" })%></li> <% } %> </ul> <% } %> <div id="nd-footer"> More dinners and fun at <a target="_blank" href="http://nrddnr.com">http://nrddnr.com</a></div> </div> </div> </body> </html> You’d include this in a page using an IFRAME, like this: <IFRAME height=230 marginHeight=0 src="http://nerddinner.com/services/flair" frameBorder=0 width=160 marginWidth=0 scrolling=no></IFRAME> The Javascript view The Javascript flair is written so you can include it in a webpage with a simple script include, like this: <script type="text/javascript" src="http://nerddinner.com/services/flair?format=javascript"></script> The goal of this view is very similar to the HTML embed view, with a few exceptions: We’re creating a script element and adding it to the head of the document, which will then document.write out the content. Note that you have to consider if your users will actually have a <head> element in their documents, but for website flair use cases I think that’s a safe bet. Since the content is being added to the existing page rather than shown in an IFRAME, all links need to be absolute. That means we can’t use Html.ActionLink, since it generates relative routes. We need to escape everything since it’s being written out as strings. We need to set the content type to application/x-javascript. The easiest way to do that is to use the <%@ Page ContentType%> directive. <%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<NerdDinner.Models.FlairViewModel>" ContentType="application/x-javascript" %> <%@ Import Namespace="NerdDinner.Helpers" %> <%@ Import Namespace="NerdDinner.Models" %> document.write('<script>var link = document.createElement(\"link\");link.href = \"http://nerddinner.com/content/Flair.css\";link.rel = \"stylesheet\";link.type = \"text/css\";var head = document.getElementsByTagName(\"head\")[0];head.appendChild(link);</script>'); document.write('<div id=\"nd-wrapper\"><h2 id=\"nd-header\">NerdDinner.com</h2><div id=\"nd-outer\">'); <% if (Model.Dinners.Count == 0) { %> document.write('<div id=\"nd-bummer\">Looks like there\'s no Nerd Dinners near <%:Model.LocationName %> in the near future. Why not <a target=\"_blank\" href=\"http://www.nerddinner.com/Dinners/Create\">host one</a>?</div>'); <% } else { %> document.write('<h3> Dinners Near You</h3><ul>'); <% foreach (var item in Model.Dinners) { %> document.write('<li><a target=\"_blank\" href=\"http://nrddnr.com/<%: item.DinnerID %>\"><%: item.Title.Truncate(20) %> with <%: item.HostedBy %> on <%: item.EventDate.ToShortDateString() %></a></li>'); <% } %> document.write('</ul>'); <% } %> document.write('<div id=\"nd-footer\"> More dinners and fun at <a target=\"_blank\" href=\"http://nrddnr.com\">http://nrddnr.com</a></div></div></div>'); Getting IP’s for Testing There are a variety of online services that will translate a location to an IP, which were handy for testing these out. I found http://www.itouchmap.com/latlong.html to be most useful, but I’m open to suggestions if you know of something better. Next steps I think the next step here is to minimize load – you know, in case people start actually using this flair. There are two places to think about – the NerdDinner.com servers, and the services we’re using for Geolocation. I usually think about caching as a first attack on server load, but that’s less helpful here since every user will have a different IP. Instead, I’d look at taking advantage of Asynchronous Controller Actions, a cool new feature in ASP.NET MVC 2. Async Actions let you call a potentially long-running webservice without tying up a thread on the server while waiting for the response. There’s some good info on that in the MSDN documentation, and Dino Esposito wrote a great article on Asynchronous ASP.NET Pages in the April 2010 issue of MSDN Magazine. But let’s think of the children, shall we? What about ipinfodb.com? Well, they don’t have specific daily limits, but they do throttle you if you put a lot of traffic on them. From their FAQ: We do not have a specific daily limit but queries that are at a rate faster than 2 per second will be put in "queue". If you stay below 2 queries/second everything will be normal. If you go over the limit, you will still get an answer for all queries but they will be slowed down to about 1 per second. This should not affect most users but for high volume websites, you can either use our IP database on your server or we can whitelist your IP for 5$/month (simply use the donate form and leave a comment with your server IP). Good programming practices such as not querying our API for all page views (you can store the data in a cookie or a database) will also help not reaching the limit. So the first step there is to save the geolocalization information in a time-limited cookie, which will allow us to look up the local dinners immediately without having to hit the geolocation service.

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