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  • Is there a potential for resource leak/double free here?

    - by nhed
    The following sample (not compiled so I won't vouch for syntax) pulls two resources from resource pools (not allocated with new), then "binds" them together with MyClass for the duration of a certain transaction. The transaction, implemented here by myFunc, attempts to protect against leakage of these resources by tracking their "ownership". The local resource pointers are cleared when its obvious that instantiation of MyClass was successful. The local catch, as well as the destructor ~MyClass return the resources to their pool (double-frees are protected by teh above mentioned clearing of the local pointers). Instantiation of MyClass can fail and result in an exception at two steps (1) actual memory allocation, or (2) at the constructor body itself. I do not have a problem with #1, but in the case of #2, if the exception is thrown AFTER m_resA & m_resB were set. Causing both the ~MyClass and the cleanup code of myFunc to assume responsibility for returning these resources to their pools. Is this a reasonable concern? Options I have considered, but didn't like: Smart pointers (like boost's shared_ptr). I didn't see how to apply to a resource pool (aside for wrapping in yet another instance). Allowing double-free to occur at this level but protecting at the resource pools. Trying to use the exception type - trying to deduce that if bad_alloc was caught that MyClass did not take ownership. This will require a try-catch in the constructor to make sure that any allocation failures in ABC() ...more code here... wont be confused with failures to allocate MyClass. Is there a clean, simple solution that I have overlooked? class SomeExtResourceA; class SomeExtResourceB; class MyClass { private: // These resources come out of a resource pool not allocated with "new" for each use by MyClass SomeResourceA* m_resA; SomeResourceB* m_resB; public: MyClass(SomeResourceA* resA, SomeResourceB* resB): m_resA(resA), m_resB(resB) { ABC(); // ... more code here, could throw exceptions } ~MyClass(){ if(m_resA){ m_resA->Release(); } if(m_resB){ m_resB->Release(); } } }; void myFunc(void) { SomeResourceA* resA = NULL; SomeResourceB* resB = NULL; MyClass* pMyInst = NULL; try { resA = g_pPoolA->Allocate(); resB = g_pPoolB->Allocate(); pMyInst = new MyClass(resA,resB); resA=NULL; // ''ownership succesfully transfered to pMyInst resB=NULL; // ''ownership succesfully transfered to pMyInst // Do some work with pMyInst; ...; delete pMyInst; } catch (...) { // cleanup // need to check if resA, or resB were allocated prior // to construction of pMyInst. if(resA) resA->Release(); if(resB) resB->Release(); delete pMyInst; throw; // rethrow caught exception } }

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  • piecing together a jquery form mailer

    - by Joel
    Hi guys, My newbieness is shining through here...I managed to piece together a form mailer that works great, but now I need to add two more fields, and I'm at a loss as to how to do it. Over the months, I have commented out some things I didn't need, but now I'm stuck. I borrowed from this tutorial to make the original form: http://trevordavis.net/blog/tutorial/ajax-forms-with-jquery/ But then I cannibalized it to make an email signup form for a newsletter, so the fields I need are: recipient email (me-hard coded in) senders email address subject (hardcoded in) first name and city in the body of the message For my form, I have this: <div> <?php include('verify.php'); ?> <form action="index_success.php" method="post" id="sendEmail" class="email"> <h3 class="register2">Newsletter Signup:</h3> <ul class="forms email"> <li class="name"><label for="yourName">Name: </label> <input type="text" name="yourName" class="info" id="yourName" value=" " /><br> </li> <li class="city"><label for="yourCity">City: </label> <input type="text" name="yourCity" class="info" id="yourCity" value=" " /><br> </li> <li class="email"><label for="emailFrom">Email: </label> <input type="text" name="emailFrom" class="info" id="emailFrom" value="<?= $_POST['emailFrom']; ?>" /> <?php if(isset($emailFromError)) echo '<span class="error">'.$emailFromError.'</span>'; ?> </li> <li class="buttons email"> <button type="submit" id="submit">Send</button> <input type="hidden" name="submitted" id="submitted" value="true" /> </li> </ul> </form> </div> emailcontact.js: $(document).ready(function(){ $("#submit").click(function(){ $(".error").hide(); var hasError = false; var emailReg = /^([\w-\.]+@([\w-]+\.)+[\w-]{2,4})?$/; var emailFromVal = $("#emailFrom").val(); if(emailFromVal == '') { $("#emailFrom").after('<span class="error">You forgot to enter the email address to send from.</span>'); hasError = true; } else if(!emailReg.test(emailFromVal)) { $("#emailFrom").after('<span class="error">Enter a valid email address to send from.</span>'); hasError = true; } var subjectVal = $("#subject").val(); if(subjectVal == '') { $("#subject").after('<span class="error">You forgot to enter your name.</span>'); hasError = true; } var messageVal = $("#message").val(); if(messageVal == '') { $("#message").after('<span class="error">You forgot to enter your city.</span>'); hasError = true; } if(hasError == false) { $(this).hide(); $("#sendEmail li.buttons").append('<img src="/wp-content/themes/default/images/template/loading.gif" alt="Loading" id="loading" />'); $.post("/includes/sendemail.php", //emailTo: emailToVal, { emailFrom: emailFromVal, subject: subjectVal, message: messageVal }, function(data){ $("#sendEmail").slideUp("normal", function() { $("#sendEmail").before('<h3 class="register2">Success!</h3><p class="emailbox">You are on the Newsletter email list.</p>'); }); } ); } return false; }); }); sendmail.php: <?php $mailTo = $_POST['emailTo']; $mailFrom = $_POST['emailFrom']; $subject = $_POST['yourName']; $message = $_POST['yourCity']; mail('[email protected]','Rattletree Newsletter', 'Name='.$subject. ' City='.$message, "From: ".$mailFrom); ?> Thanks for any help! I'm going crosseyed trying to figure this one out.

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  • How can I hit my database with an AJAX call using javascript?

    - by tmedge
    I am pretty new at this stuff, so bear with me. I am using ASP.NET MVC. I have created an overlay to cover the page when someone clicks a button corresponding to a certain database entry. Because of this, ALL of my code for this functionality is in a .js file contained within my project. What I need to do is pull the info corresponding to my entry from the database itself using an AJAX call, and place that into my textboxes. Then, after the end-user has made the desired changes, I need to update that entry's values to match the input. I've been surfing the web for a while, and have failed to find an example that fits my needs effectively. Here is my code in my javascript file thus far: function editOverlay(picId) { //pull up an overlay $('body').append('<div class="overlay" />'); var $overlayClass = $('.overlay'); $overlayClass.append('<div class="dataModal" />'); var $data = $('.dataModal'); overlaySetup($overlayClass, $data); //set up form $data.append('<h1>Edit Picture</h1><br /><br />'); $data.append('Picture name: &nbsp;'); $data.append('<input class="picName" /> <br /><br /><br />'); $data.append('Relative url: &nbsp;'); $data.append('<input class="picRelURL" /> <br /><br /><br />'); $data.append('Description: &nbsp;'); $data.append('<textarea class="picDescription" /> <br /><br /><br />'); var $nameBox = $('.picName'); var $urlBox = $('.picRelURL'); var $descBox = $('.picDescription'); var pic = null; //this is where I need to pull the actual object from the db //var imgList = for (var temp in imgList) { if (temp.Id == picId) { pic= temp; } } /* $nameBox.attr('value', pic.Name); $urlBox.attr('value', pic.RelativeURL); $descBox.attr('value', pic.Description); */ //close buttons $data.append('<input type="button" value="Save Changes" class="saveButton" />'); $data.append('<input type="button" value="Cancel" class="cancelButton" />'); $('.saveButton').click(function() { /* pic.Name = $nameBox.attr('value'); pic.RelativeURL = $urlBox.attr('value'); pic.Description = $descBox.attr('value'); */ //make a call to my Save() method in my repository CloseOverlay(); }); $('.cancelButton').click(function() { CloseOverlay(); }); } The stuff I have commented out is what I need to accomplish and/or is not available until prior issues are resolved. Any and all advice is appreciated! Remember, I am VERY new to this stuff (two weeks, to be exact) and will probably need highly explicit instructions. BTW: overlaySetup() and CloseOverlay() are functions I have living someplace else. Thanks!

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  • Sqlite3 : "Database is locked" error

    - by Miraaj
    Hi all, In my cocoa application I am maintaining a SQLite db within resources folder and trying to do some select, delete operations in it but after some time it starts giving me 'Database is locked' error. The methods which I am using for select delete operations are as follows: // method to retrieve data if (sqlite3_open([databasePath UTF8String], &database) != SQLITE_OK) { sqlite3_close(database); NSAssert(0, @"Failed to open database"); } NSLog(@"mailBodyFor:%d andFlag:%d andFlag:%@",UId,x,Ffolder); NSMutableArray *recordsToReturn = [[NSMutableArray alloc] initWithCapacity:2]; NSString *tempMsg; const char *sqlStatementNew; NSLog(@"before switch"); switch (x) { case 9: // tempMsg=[NSString stringWithFormat:@"SELECT * FROM users_messages"]; tempMsg=[NSString stringWithFormat:@"SELECT message,AttachFileOriName as oriFileName,AttachmentFileName as fileName FROM users_messages WHERE id = (select message_id from users_messages_status where id= '%d')",UId]; NSLog(@"mail body query - %@",tempMsg); break; default: break; } sqlStatementNew = [tempMsg cStringUsingEncoding:NSUTF8StringEncoding]; sqlite3_stmt *compiledStatementNew; NSLog(@"before if statement"); if(sqlite3_prepare_v2(database, sqlStatementNew, -1, &compiledStatementNew, NULL) == SQLITE_OK) { NSLog(@"the sql is finalized"); while(sqlite3_step(compiledStatementNew) == SQLITE_ROW) { NSMutableDictionary *recordDict = [[NSMutableDictionary alloc] initWithCapacity:3]; NSString *message; if((char *)sqlite3_column_text(compiledStatementNew, 0)){ message = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatementNew, 0)]; } else{ message = @""; } NSLog(@"message - %@",message); NSString *oriFileName; if((char *)sqlite3_column_text(compiledStatementNew, 1)){ oriFileName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatementNew, 1)]; } else{ oriFileName = @""; } NSLog(@"oriFileName - %@",oriFileName); NSString *fileName; if((char *)sqlite3_column_text(compiledStatementNew, 2)){ fileName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatementNew, 2)]; } else{ fileName = @""; } NSLog(@"fileName - %@",fileName); [recordDict setObject:message forKey:@"message"]; [recordDict setObject:oriFileName forKey:@"oriFileName"]; [recordDict setObject:fileName forKey:@"fileName"]; [recordsToReturn addObject:recordDict]; [recordDict release]; } sqlite3_finalize(compiledStatementNew); sqlite3_close(database); NSLog(@"user messages return -%@",recordsToReturn); return recordsToReturn; } else{ NSLog(@"Error while creating retrieving mailBodyFor in messaging '%s'", sqlite3_errmsg(database)); sqlite3_close(database); } // method to delete data if (sqlite3_open([databasePath UTF8String], &database) != SQLITE_OK) { sqlite3_close(database); NSAssert(0, @"Failed to open database"); } NSString *deleteQuery = [[NSString alloc] initWithFormat:@"delete from users_messages_status where id IN(%@)",ids]; NSLog(@"users_messages_status msg deleteQuery - %@",deleteQuery); sqlite3_stmt *deleteStmnt; const char *sql = [deleteQuery cStringUsingEncoding:NSUTF8StringEncoding]; if(sqlite3_prepare_v2(database, sql, -1, &deleteStmnt, NULL) != SQLITE_OK){ NSLog(@"Error while creating delete statement. '%s'", sqlite3_errmsg(database)); } else{ NSLog(@"successful deletion from users_messages"); } if(SQLITE_DONE != sqlite3_step(deleteStmnt)){ NSLog(@"Error while deleting. '%s'", sqlite3_errmsg(database)); } sqlite3_close(database); Things are going wrong in this sequence Data is retrieved 'Database is locked' error arises on performing delete operation. When I retry to perform 1st step.. it now gives same error. Can anyone suggest me: If I am doing anything wrong or missing some check? Is there any way to unlock it when it gives locked error? Thanks, Miraaj

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  • WCF/REST Get image into picturebox?

    - by Garrith
    So I have wcf rest service which succesfuly runs from a console app, if I navigate to: http://localhost:8000/Service/picture/300/400 my image is displayed note the 300/400 sets the width and height of the image within the body of the html page. The code looks like this: namespace WcfServiceLibrary1 { [ServiceContract] public interface IReceiveData { [OperationContract] [WebInvoke(Method = "GET", BodyStyle = WebMessageBodyStyle.Wrapped, ResponseFormat = WebMessageFormat.Xml, UriTemplate = "picture/{width}/{height}")] Stream GetImage(string width, string height); } public class RawDataService : IReceiveData { public Stream GetImage(string width, string height) { int w, h; if (!Int32.TryParse(width, out w)) { w = 640; } // Handle error if (!Int32.TryParse(height, out h)) { h = 400; } Bitmap bitmap = new Bitmap(w, h); for (int i = 0; i < bitmap.Width; i++) { for (int j = 0; j < bitmap.Height; j++) { bitmap.SetPixel(i, j, (Math.Abs(i - j) < 2) ? Color.Blue : Color.Yellow); } } MemoryStream ms = new MemoryStream(); bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); ms.Position = 0; WebOperationContext.Current.OutgoingResponse.ContentType = "image/jpeg"; return ms; } } } What I want to do now is use a client application "my windows form app" and add that image into a picturebox. Im abit stuck as to how this can be achieved as I would like the width and height of the image from my wcf rest service to be set by the width and height of the picturebox. I have tryed this but on two of the lines have errors and im not even sure if it will work as the code for my wcf rest service seperates width and height with a "/" if you notice in the url. string uri = "http://localhost:8080/Service/picture"; private void button1_Click(object sender, EventArgs e) { StringBuilder sb = new StringBuilder(); sb.AppendLine("<picture>"); sb.AppendLine("<width>" + pictureBox1.Image.Width + "</width>"); // the url looks like this http://localhost:8080/Service/picture/300/400 when accessing the image so I am trying to set this here sb.AppendLine("<height>" + pictureBox1.Image.Height + "</height>"); sb.AppendLine("</picture>"); string picture = sb.ToString(); byte[] getimage = Encoding.UTF8.GetBytes(picture); // not sure this is right HttpWebRequest req = WebRequest.Create(uri); //cant convert webrequest to httpwebrequest req.Method = "GET"; req.ContentType = "image/jpg"; req.ContentLength = getimage.Length; MemoryStream reqStrm = req.GetRequestStream(); //cant convert IO stream to IO Memory stream reqStrm.Write(getimage, 0, getimage.Length); reqStrm.Close(); HttpWebResponse resp = req.GetResponse(); // cant convert web respone to httpwebresponse MessageBox.Show(resp.StatusDescription); pictureBox1.Image = Image.FromStream(reqStrm); reqStrm.Close(); resp.Close(); } So just wondering if some one could help me out with this futile attempt at adding a variable image size from my rest service to a picture box on button click. This is the host app aswell: namespace ConsoleApplication1 { class Program { static void Main(string[] args) { string baseAddress = "http://" + Environment.MachineName + ":8000/Service"; ServiceHost host = new ServiceHost(typeof(RawDataService), new Uri(baseAddress)); host.AddServiceEndpoint(typeof(IReceiveData), new WebHttpBinding(), "").Behaviors.Add(new WebHttpBehavior()); host.Open(); Console.WriteLine("Host opened"); Console.ReadLine();

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  • Jquery, XML and Google Map

    - by EXPennD
    Hi, I'm integrating a Google Map in my website that user could add some thumbnails and details of their own house. Here's a code preview of what I want to happen. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> Jquery and Google Map // var locations = {}; function load() { var map = new GMap2(document.getElementById("map")); map.setCenter(new GLatLng(47.614495, -122.341861), 13); GDownloadUrl("markerdata.xml", function(data) { var xml = GXml.parse(data); var markers = xml.documentElement.getElementsByTagName("marker"); for (var i = 0; i < markers.length; i++) { var name = markers[i].getAttribute("name"); var address = markers[i].getAttribute("address"); var type = markers[i].getAttribute("type"); var latlng = new GLatLng(parseFloat(markers[i].getAttribute("lat")), parseFloat(markers[i].getAttribute("lng"))); var store = {latlng: latlng, name: name, address: address, type: type}; var latlngHash = (latlng.lat().toFixed(6) + "" + latlng.lng().toFixed(6)); latlngHash = latlngHash.replace(".","").replace(".", "").replace("-",""); if (locations[latlngHash] == null) { locations[latlngHash] = [] } locations[latlngHash].push(store); } for (var latlngHash in locations) { var stores = locations[latlngHash]; if (stores.length > 1) { map.addOverlay(createClusteredMarker(stores)); } else { map.addOverlay(createMarker(stores)); } } }); } function createMarker(stores) { var store = stores[0]; var newIcon = MapIconMaker.createMarkerIcon({width: 32, height: 32, primaryColor: "#00ff00"}); var marker = new GMarker(store.latlng, {icon: newIcon}); var html = "<b>" + store.name + "</b> <br/>" + store.address; GEvent.addListener(marker, 'click', function() { marker.openInfoWindowHtml(html); }); return marker; } function createClusteredMarker(stores) { var newIcon = MapIconMaker.createMarkerIcon({width: 44, height: 44, primaryColor: "#00ff00"}); var marker = new GMarker(stores[0].latlng, {icon: newIcon}); var html = ""; for (var i = 0; i < stores.length; i++) { html += "<b>" + stores[i].name + "</b> <br/>" + stores[i].address + "<br/>"; } GEvent.addListener(marker, 'click', function() { marker.openInfoWindowHtml(html); }); return marker; } //]]> description I want this feature to be fully interactive. If possible user can drag and drop a marker to the location on the Google map and the description field would be enabled after adding the marker so user could add details and submit it. Also here's my current situation. The reason why I want it to be done in XML is the Content Management System that I currently use for this project don't allow me to add Database and Php scripts. The only thing that I have access is I could add new HTML on the BODY section and also External Javascript on the HEAD section. Sorry about the way I write it, it sounds like demanding. Its because I'm still learning Jquery. Thanks everyone!

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  • Calling popToRootViewControllerAnimated causing crash. How should I be doing this?

    - by Lewis42
    The app is for taking body measurements. The user can say I want to measure: legs, arms and neck, in the settings tab and in the main tab there is a view which loops round to take each measurement. This is achieved like so: i have tab controller the first tab has a navigation controller the first view controller on the storyboard and has one segue to itself the board loops round until it has all the measurements then it segues to a different controller the problem is: if the user changes which measurements they are taking in the settings tab, the first tab needs to completely reload, as if the app was just starting up, clearing down the whole nav stack etc. at the moment the tab controller calls popToRootViewControllerAnimated on the navigation controller in the measurements tab, but this is causing a crash. Each screen has a slider control and a call to titleForRow:forComponent: is being called on a deleted view causing it to crash. What am I doing wrong?! Here's the tab bar controller code // TabBarController.m // #import "TabBarController.h" #import "TodaysMeasurementObject.h" #import "AppDelegateProtocol.h" #import "AddMeasurementViewController.h" #import "ReadPerson.h" #import "AppDelegate.h" @interface TabBarController () <UITabBarControllerDelegate> @end @implementation TabBarController bool resetWizardView = false; - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; if (self) { } return self; } - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view. self.delegate = self; [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(orientationChanged:) name:UIDeviceOrientationDidChangeNotification object:nil]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(measurementsSettingsUpdated:) name:@"MeasurementsSettingsUpdated" object:nil]; } - (void) measurementsSettingsUpdated:(NSNotification *) notification { // UINavigationController *navigationController = [self.viewControllers objectAtIndex:0]; // AddMeasurementViewController *addMeasurement = [[AddMeasurementViewController alloc] init]; // [navigationController setViewControllers: [[NSArray alloc] initWithObjects:addMeasurement, nil]]; resetWizardView = YES; } - (void) viewDidAppear:(BOOL)animated { if (![ReadPerson userHasRecords]) { [self setSelectedIndex:3]; } } - (void)orientationChanged:(NSNotification *)notification { // We must add a delay here, otherwise we'll swap in the new view // too quickly and we'll get an animation glitch [self performSelector:@selector(showGraphs) withObject:nil afterDelay:0]; } - (void)showGraphs { UIDeviceOrientation deviceOrientation = [UIDevice currentDevice].orientation; if (deviceOrientation == UIDeviceOrientationLandscapeLeft && !isShowingLandscapeView) { [self performSegueWithIdentifier: @"toGraph" sender: self]; isShowingLandscapeView = YES; } else if (deviceOrientation != UIDeviceOrientationLandscapeLeft && isShowingLandscapeView) { [self dismissModalViewControllerAnimated:YES]; isShowingLandscapeView = NO; } } - (void)viewDidUnload { [super viewDidUnload]; // Release any retained subviews of the main view. } - (void)dealloc { [[NSNotificationCenter defaultCenter] removeObserver:self]; [[UIDevice currentDevice] endGeneratingDeviceOrientationNotifications]; } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { if(interfaceOrientation == UIInterfaceOrientationLandscapeRight) { [self performSegueWithIdentifier: @"toGraph" sender: self]; } return false; } - (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController { int tbi = tabBarController.selectedIndex; if (tbi == 0) { [[viewController view] setNeedsDisplay]; if (resetWizardView) { [(UINavigationController*)[self.viewControllers objectAtIndex:0] popToRootViewControllerAnimated: NO]; // ******* POP CALLED HERE ****** resetWizardView = false; } } } - (TodaysMeasurementObject*) theAppDataObject { id<AppDelegateProtocol> theDelegate = (id<AppDelegateProtocol>) [UIApplication sharedApplication].delegate; TodaysMeasurementObject* theDataObject; theDataObject = (TodaysMeasurementObject*) theDelegate.theAppDataObject; return theDataObject; } - (BOOL)shouldAutorotate { return NO; } - (NSUInteger)supportedInterfaceOrientations { return UIInterfaceOrientationMaskPortrait; } @end UPDATED - (void) measurementsSettingsUpdated:(NSNotification *) notification { NSMutableArray *viewControllers = [[NSMutableArray alloc] initWithArray: self.viewControllers]; UINavigationController *navigationController = [viewControllers objectAtIndex:0]; AddMeasurementViewController *addMeasurement = [[AddMeasurementViewController alloc] init]; [navigationController setViewControllers: [[NSArray alloc] initWithObjects:addMeasurement, nil]]; [viewControllers setObject:navigationController atIndexedSubscript:0]; self.viewControllers = viewControllers; } and removed the code from - tabBarController:didSelectViewController: but still the same error. I think the problem is that it's trying to get a value for the slide control after the view has been deleted. But some part of the view must still be alive...? Anyway to kill that off? Or leave it all alive??

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  • how to fetch meaningful

    - by user1298017
    Hi Every body, I have connected my device to serial port. I am using Javax.comm API to fetch the data from my device. On tapping of card i am reading data as below: newData = inputStream.read(); and able to fetch data : 0 128 161 132 132 132 132 132 132 132 101 65 2 226 99 98 132 132 132 132 132 132 132 132 131 134 164 132 132 132 165 134 132 196 230 167 132 132 132 132 132 132 132 197 196 132 133 132 132 164 197 132 132 198 103 255 How can deciper meaning ful text from it. My code is as below: import java.io.*; import java.util.*; import javax.comm.*; import javax.comm.SerialPort; import java.nio.charset.Charset; import java.nio.charset.CharsetDecoder; import java.nio.charset.CharsetEncoder; public class NFCReader3 implements Runnable, SerialPortEventListener { static CommPortIdentifier portId; static Enumeration portList; InputStream inputStream; SerialPort serialPort; Thread readThread; int i=0; public static void main(String[] args) { boolean portFound = false; String defaultPort = "COM9"; portList = CommPortIdentifier.getPortIdentifiers(); while (portList.hasMoreElements()) { portId = (CommPortIdentifier) portList.nextElement(); if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) { if (portId.getName().equals(defaultPort)) { System.out.println("Found port: "+defaultPort); portFound = true; NFCReader3 reader = new NFCReader3(); } } } if (!portFound) { System.out.println("port " + defaultPort + " not found."); } } public NFCReader3() { try { serialPort = (SerialPort) portId.open("SimpleReadApp2S", 2000); } catch (PortInUseException e) {} try { inputStream = serialPort.getInputStream(); } catch (IOException e) {} try { serialPort.addEventListener(this); } catch (TooManyListenersException e) {} serialPort.notifyOnDataAvailable(true); try { serialPort.setSerialPortParams(9600, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE); } catch (UnsupportedCommOperationException e) {} readThread = new Thread(this); readThread.start(); } public void run() { try { Thread.sleep(20000); } catch (InterruptedException e) {} } public void serialEvent(SerialPortEvent event) { StringBuffer inputBuffer = new StringBuffer(); int newData = 0; switch (event.getEventType()) { case SerialPortEvent.BI: case SerialPortEvent.OE: case SerialPortEvent.FE: case SerialPortEvent.PE: case SerialPortEvent.CD: case SerialPortEvent.CTS: case SerialPortEvent.DSR: case SerialPortEvent.RI: case SerialPortEvent.OUTPUT_BUFFER_EMPTY: break; case SerialPortEvent.DATA_AVAILABLE: while (newData != -1) { try { newData = inputStream.read(); System.out.print(newData); System.out.print(" "); if (newData == -1) { break; } if ('\r' == (char)newData) { inputBuffer.append('\n'); } else { inputBuffer.append((char)newData); } } catch (IOException ex) { System.out.println("exception"); System.err.println(ex); return; } } break;

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  • Using javascript, show a certain amount of divs based on an answer

    - by Adam
    I'm building a form that first asks if you have 'foo'. If the answer is 'Yes', a div appears and asks 'How many foo do you have'? Based on the quantity answered, I'd like to show only that many divs. Thus if the user answers 1, only the first div will show. If they answer three, the first three will show. I have it set so that if the user answers no, the question of the amount remains hidden, but if they answer yes, they would be prompted for the quantity. This is what I've got so far... <script type="text/javascript"> $(document).ready(function(){ $(window).load(function() { $('#amt_of_foo,.foo_panels').hide(); }); $('#yes_foo').click(function() { $('#amt_of_foo').show(); }); $('#no_foo').click(function() { $('.foo_panels,#amt_of_foo').hide(); }); }); </script> </head> <body> <ul> <li> <div class="panel section_panel"> <h2>Questions About Your Foo</h2> <span>Do you have foo?:</span> <input type="radio" name="foo" id="no_foo" /> No <br /> <input type="radio" name="foo" id="yes_foo" /> Yes:</span></span> <span id="amt_of_foo"> <span>How many foo do you have?:</span> <span><input id="qty_of_foo" type="text" size="5" /> </span> </span> </div> </li> <!--answered yes to foo, and entered amount--> <div class="foo_panels"> <li> <li> <div class="panel foo_1"> <h1>First foo's information</h1> <span>Foo name:&nbsp;<input type="text" size="20" /></span> </div> </li> <li> <div class="panel foo_2"> <h1>Second foo's information</h1> <span>Foo name:&nbsp;<input type="text" size="20" /></span> </div> </li> <li> <div class="panel foo_3"> <h1>Third foo's information</h1> <span>Foo name:&nbsp;<input type="text" size="20" /></span> </div> </li> </div> <!--answered no to foo--> <li> <div class="panel"> <h1>Next Question, if no foo</h1> </div> </li> </ul> The ul is used for a jQuery 'slider' plugin. the 'panel' class is used for global css.

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  • submit a form and get json response

    - by ruhit
    I have made an application to convert text to image formate and its workingout well. Now I want json response when i fill the form of the html page, my html page is given below...Please help me to do this <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"> <html lang="en"> <head> <title>kandarpa</title> </head> <div> <form action="img.php" method="get"><b>enter your text here:</b><br/> <textarea id="text" name="text" style=" background-color:inherit" cols="50" rows="10"></textarea><br/><br/> <input type="submit" value="Text to Image" name="submit"> </div><br/> <div> <tr> <td>Font Size</td> <td><select name="size"> <option value="8">8</option> <option value="12">12</option> <option value="18">18</option> <option value="24">24</option> <option value="32" selected="selected">32</option> <option value="48">48</option> <option value="64">64</option> </select></td> </tr> </div><br/> <div> <td>Font </td> <td><select name="font" id="font"> <option value="Fonts/arial.ttf">Arial</option> <option value="Fonts/times.ttf">Times New Roman</option> <option value="Fonts/tahoma.ttf">Tahoma</option> <option value="Fonts/Grand Stylus.ttf">Grand Stylus</option> <option value="Fonts/GARAIT.ttf">G</option> </select></td> </tr> </div><br/> <div> <td>Choose your Color </td> <td><select name="color" id="color"> <option value="white">white</option> <option value="black">black</option> <option value="grey">grey</option> <option value="red">red</option> </select></td> </tr> </div> <br/> <div> <td>Height </td> <input type="text" id="height" name="height"> </td><br/><br/> <td>Width</td> <input type="text" id="width" name="width"> </div> </form> </body> </html>

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  • Image change on mouseover with jQuery..

    - by playahabana
    Hi, I am a comlete beginner to pretty much all things web design and am trying to construct my first website. I am attempting to hand code it without the ue of a CMS in order to learn as much as possible as quickly as possible. I am trying to make an imge change on mouseover for my top nav menu, and have the following jQuery functions: $(document).ready(function(){ $(".navlist img").each(function) { rollsrc = $(this).attr("src"); rollON = rollsrc.replace(/.jpg$/ig,"_link.png"); $("<img>").attr("src",rollON); $(".navlist a").mouseover(function(){ }); imgsrc= $(this).children("img").attr("src"); matches = imgsrc.match(/_link.png); if (!matches) { imgsrcON = imgsrc.replace(/.jpg$/ig,"_link.png"); $(this).children("img").attr("src", imagesrcON); } $(".navlist a").mouseout(function(){ $(this).children("img").attr("src", imgsrc); }); }); my html is as follows: <div id="nav"> <ul class="navmenu"> <li><a href="index.html"><img class="swap" src="images/links/home.jpg" alt="Home" border="none"></a></li> <li><a href="#"><img class="swap" src="images/links/ourbar.jpg" alt="Our Bar" border="none"></a> <ul class="navdrop"> <li ><a href="#"><img class="swap" src="images/links/cockteles.jpg" alt="Our Cocktails" border="none"></a></li> <li ><a href="#"><img class="swap" src="images/links/celebrate.jpg" alt="Celebrate in Style" border="none"></a></li> </ul> </li> <li><a href="#"><img class="swap" src="images/links/ourcigars.jpg" alt="Our Cigars" border="none"></a> <ul class="navdrop"> <li><a href="#"><img class="swap" src="images/links/edicionlimitadas.jpg" alt="Edition Limitadas" border="none"></a></li> <li><a href="our_cigars.html"><img class="swap" src="images/links/cigartasting.jpg" alt="Cigar Tastings" border="none"></a></li> </ul> </li> <li><a href="#"><img class="swap" src="images/links/personalcigar.jpg" alt="Personal Cigar Roller" border="none"></a></li> <li><a href="our_cigars.html"><img class="swap" src="images/links/photogallery.jpg" alt="Photo Gallery" border="none"></a></li> <li><a href="#"><img class="swap" src="images/links/contactus.jpg" alt="Contact Us" border="none"></a></li> </ul></div></div><!--end banner--> the image src for the alt image is in the form eg."images/links/home_link.png" and is the same for every image. I have checked this and checked this, could some body please give me a pointer as to where I am going wrong? Or a pointer to a tutorial for this effect? I have looked at a few and this seems to be the best for what I am attempting, but as I said I don't really know what I'm doing so any advice gratefully received.....

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  • Gap between Navbar and Jumbotron

    - by DDK
    I am building I suppose you could call a template for the site I am going to build however I am still pretty new to bootstrap and thus have trouble figuring which CSS rules are affecting elements etc. The problem I am having is I cannot get the Jumbotron unit to sit flush with the bottom of the navbar. I have found a few questions on here about the same problem but the solutions did not work. Here is my code </head> <body> <div class="row"> <div> <img src="http://placehold.it/1600x300" width="100%"> </div> <!-- Static navbar --> <div class="navbar navbar-default navbar-static-top" role="navigation"> <div class="container"> <div class="navbar-header"> <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse"> <span class="sr-only">Toggle navigation</span> <span class="icon-bar"></span> <span class="icon-bar"></span> <span class="icon-bar"></span> </button> </div> <div class="navbar-collapse collapse"> <ul class="nav nav-justified" id="myNav"> <li class="active"><a href="#">Home</a></li> <li><a href="#about">About</a></li> <li><a href="#contact">Contact</a></li> <li><a href="#contact">Services</a></li> </ul> </div><!--/.nav-collapse --> </div> </div> <div class="jumbotron" id="openingtext"> This is where the opening sale text will go </div> <div class="container"> <!-- Example row of columns --> <div class="row"> <div class="col-md-4"> <h2>Heading</h2> <p>Donec id elit non mi porta gravida at eget metus. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Etiam porta sem malesuada magna mollis euismod. Donec sed odio dui. </p> <p><a class="btn btn-default" href="#" role="button">View details &raquo;</a></p> </div> <div class="col-md-4"> <h2>Heading</h2> I would provide the css but as it is all being pulled from an unchanged version of bootstrap and my stylesheet.css has nothing relating to any of these ids etc it seems pointless to do so. I look forward to hearing your solutions guys and girls

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  • jQuery how to add class to a parent div which has a 3rd level child div with a specific class name.

    - by Vikram
    Hello friends I have an issue adding a special class to a couple of my divs. My layout is like this. <div class="container"> <div class="grid-6 push-3 equal" style="height: 999px;"> <div class="block"> <div id="mainbody"> <!-- Body content here --> </div> </div> </div> <div class="grid-2 equal" style="height: 999px;"> <div class="block"> <div id="sidebar-a"> <!-- Sidebar-a content here --> </div> </div> </div> <div class="grid-2 equal" style="height: 999px;"> <div class="block"> <div id="sidebar-b"> <!-- Sidebar-b content here --> </div> </div> </div> <div class="grid-2 equal" style="height: 999px;"> <div class="block"> <div id="sidebar-b"> <!-- Sidebar-c content here --> </div> </div> </div> </div> I want to add a different background color to each of my sidebars via CSS and when I code like: #mainbody { background : #fff; } #sidebar-a { background : #eee; } #sidebar-b { background : #ddd; } #sidebar-c { background : #ccc; } It is applying the background only to that specific class but that specific class is not of equal height. I actually need to apply to this <div class="grid-2 equal" style="height: 999px;"> div. Now the issue is that in this <div class="grid-6 push-3 equal" style="height: 999px;"> and class="grid-2 equal" style="height: 999px;"> the class names grid-6 and grid-2 are generated dynamically by my PHP of 960 Grid System and also the style="height: 999px; is generated by a jQuery script for Equal-Columns. What I want is to add a unique class name like this...... Look for a div with a class of .equal which has a child div with a class of .block and which further has a child div with an ID of sidebar-a. IF TRUE then add a class of .sidebar-a to the maindiv which has a class of .equal So that the result looks like this: <div class="grid-6 equal push-3 mainbody" style="height: 999px;"> <div class="grid-2 equal sidebar-a" style="height: 999px;"> <div class="grid-2 equal sidebar-b" style="height: 999px;"> <div class="grid-2 equal sidebar-c" style="height: 999px;"> Then I'll be able to style it like this: .mainbody { background : #fff; } .sidebar-a { background : #eee; } .sidebar-b { background : #ddd; } .sidebar-c { background : #ccc; } Hence I thought since I am anyway using jQuery in my Template, why not use it to deal with this issue. Please feel free to suggest a better way if you have something else in mind.

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  • PHP setting cookies in a child class

    - by steve
    I am writing a custom session handler and for the life of me I cannot get a cookie to set in it. I'm not outputting anything to the browser before I set the cookie but it still doesn't work. Its killing me. The cookie will set if I set it in the script I define and call on the session handler with. If necessary I will post code. Any ideas people? <?php /* require the needed classes comment out what is not needed */ require_once("classes/sessionmanager.php"); require_once("classes/template.php"); require_once("classes/database.php"); $title=" "; //titlebar of the web browser $description=" "; $keywords=" "; //meta keywords $menutype="default"; //default or customer, customer is elevated $pagetitle="dflsfsf "; //title of the webpage $pagebody=" "; //body of the webpage $template=template::def_instance(); $database=database::def_instance(); $session=sessionmanager::def_instance(); $session->sessions(); session_start(); ?> and this is the one that actually sets the cookie for the session function write($session_id,$session_data) { $session_id = mysql_real_escape_string($session_id); $session_data = mysql_real_escape_string(serialize($session_data)); $expires = time() + 3600; $user_ip = $_SERVER['REMOTE_ADDR']; $bol = FALSE; $time = time(); $newsession = FALSE; $auth = FALSE; $query = "SELECT * FROM 'sessions' WHERE 'expires' > '$time'"; $sessions_result = $this->query($query); $newsession = $this->newsession_check($session_id,$sessions_result); while($sessions_array = mysql_fetch_array($sessions_result) AND $auth = FALSE) { $session_array = $this->strip($session_array); $auth = $this->auth_check($session_array,$session_id); } /* this is an authentic session. build queries and update it */ if($auth = TRUE AND $newsession = FALSE) { $session_data = mysql_real_escape_string($session_data); $update_query1 = "UPDATE 'sessions' SET 'user_ip' = '$user_ip' WHERE 'session_id' = '$session_id'"; $update_query2 = "UPDATE 'sessions' SET 'data' = '$session_data' WHERE 'session_id = '$session_id'"; $update_query3 = "UPDATE 'sessions' SET 'expires' = '$expires' WHERE 'session_id' = '$session_id'"; $this->query($update_query1); $this->query($update_query2); $this->query($update_query3); $bol = TRUE; } elseif($newsession = TRUE) { /* this is a new session, build and create it */ $random_number = $this->obtain_random(); $cookieval = hash("sha512",$random_number); setcookie("rndn",$cookieval); $query = "INSERT INTO sessions VALUES('$session_id','0','$user_ip','$random_number','$session_data','$expires')"; $this->query($query); //echo $cookieval."this is the cookie <<"; $bol = TRUE; } return $bol; }

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  • How do I delete files in a class?

    - by user3682906
    I want to have a CRUD management on my gallery but I have no idea how. I have searched the internet but I did not find what I was looking for. This is my class: class Gallery { public function renderImages($map) { $images = ""; foreach (glob($map ."*.{jpeg,jpg,png,gif}", GLOB_BRACE) as $image){ $images .= "<a href='".$image."' data-lightbox='afbeelding'><img src='".$image."' class='thumbnail'></img></a>"; } return $images; } } and this is my gallery: <div class="gallery"> <center> <a href="index.php">Back:</a> <style> body { margin:0; padding:0; background:#efefef; font-family: "Helvetica Neue", helvetica, arial, sans-serif; color: black; text-align:center; /* used to center div in IE */ } </style> <?php $gallery = new Gallery(); echo $gallery -> renderImages("../images/"); $connection = new DatabaseConnection(); $render = new RenderData(); $page = 1; if(isset($_GET['page'])) { $check = new CheckData(); if($check->PageCheck($_GET['page'])) { $page = $_GET['page']; } } ?> <table> <div id="Intro"> <tr> <td>Hieronder kan je uploaden.</td> </tr> </div> <tr> <td>Max. 500000000Bytes</td> </tr> <tr> <form action="pages/upload_file.php" method="post" enctype="multipart/form-data"> <td><label for="file">Filename:</label></td> </tr> <tr> <td><input type="file" name="file" id="file"></td> </tr> <tr> <td><input type="submit" name="submit" value="Submit"></td> </tr> <tr> <td><input type="submit" name="delete" value="Delete"></td> </tr> </form> </table> How do I make a CRUD management on this? I want to select the photo and then delete it from my computer. I hope you guys can help me out...

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  • Placeholder is not shown in jquery sortable, drag & drop

    - by balakrishnan
    I can't show Place holder for the sortable items in a div. &lt;script type="text/javascript"&gt; $(function() { $("#userContent").sortable({ handle: '.close_button', connectWith: '#userContent', placeholder: 'placeholder', forcePlaceholderSize: true, tolerance: 'pointer', revert: true, }); }); </script> <style type="text/css"> .webtitle_paragraphs { width:98%; float:left; border:1px solid #0099CC; margin:5px; } .close_button { display:block; overflow:visible; visibility:visible; height:20px; background:#0099CC; width:100%; } .placeholder { background: #f0f0f0; border:1px dashed #ddd; visibility: visible !important; } .webtitle input { width:98%; font: bold 20px verdana; border:0px; } .paragraph_txt textarea { width:98%; height:auto; border:0px; } </style> </head> <body> <div id="userContent"> <div class="webtitle_paragraphs" id="div4463_text"> <div class="close_button" id="close_4463"><a onclick="removeDiv('div4463_text');"><img src="images/close_button.png" alt="close" width="15" height="15" border="0" align="right"/></a></div> <div class="webtitle_paragraph"> <div class="webtitle"> <input value="Title" name="webtitle4463" type="text" class="text _4463" /> </div> </div> </div> <div class="webtitle_paragraphs" id="div7192_image"> <div class="close_button" id="close_7192"><a onclick="removeDiv('div7192_image');"><img src="images/close_button.png" alt="close" width="15" height="15" border="0" align="right"/></a></div> <div class="webtitle_paragraph"> <div class="paragraph"><img src="https://localhost/web20/user_site_designs/images/noImage.jpeg" id="img7192" class="imageCntrl" onclick="uploadFile(7192)"/> <input type="hidden" name="imgName7192" id="imgName7192" value="" class="image _7192"/> </div> </div> </div> <div class="webtitle_paragraphs" id="div9683_paragraph"> <div class="close_button" id="close_9683"><a onclick="removeDiv('div9683_paragraph');"><img src="images/close_button.png" alt="close" width="15" height="15" border="0" align="right"/></a></div> <div class="webtitle_paragraph"> <div class="paragraph_txt"> <textarea class="paragraph _9683" name="myTextarea9683" id="myTextarea9683">Paragraphp</textarea> </div> </div> </div> </div> Thanks is advance.

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  • create previous next button for iframe pages

    - by Resu
    This topic may have lots of code out there, BUT I seem to be looking for a variation that isn't based on history, is it possible... So I have this code... <script type="text/javascript"> var pages=new Array(); pages[0]="listItem1.html"; pages[1]="listItem2.html"; pages[2]="listItem3.html"; pages[3]="listItem4.html"; pages[4]="listItem5.html"; var i=0; var end=pages.length; end--; function changeSrc(operation) { if (operation=="next") { if (i==end) { document.getElementById('the_iframe').src=pages[end]; i=0;} else { document.getElementById('the_iframe').src=pages[i]; i++;}} if (operation=="back") { if (i==0) { document.getElementById('the_iframe').src=pages[0]; i=end;} else { document.getElementById('the_iframe').src=pages[i]; i--;}}} </script> </head> <body> <ul id="menu" role="group"> <li><a href="listItem1.html" target="ifrm" role="treeitem">Welcome</a> <ul> <li><a href="listItem2.html" target="ifrm" role="treeitem">Ease of Access Center</a></li> </ul> </li> <li><a href="listItem3.html" target="ifrm">Getting Started</a> <ul> <li><a href="listItem4.html" target="ifrm">Considerations</a></li> <li><a href="listItem5.html" target="ifrm">Changing Perspective</a></li> </ul> </li> </ul> <iframe id="the_iframe" scrolling="no" src="listItem1.htm" name="ifrm" style="width:540px;></iframe> <input type="button" onClick="changeSrc('back');" value="Back" /> <input type="button" onClick="changeSrc('next');" value="Next" /> and if I click on the next or prev button, it does move somewhere,but... let's say my iframe is showing listItem2, then I click on listItem4 in the menu (there is a tree menu involved), then I want to go to listItem3 and I hit the back button...instead of going to listItem3, it goes to listItem2 (or someplace that is not back a page from 4 to 3). It appears that the buttons are navigating based on history?...but I just want a straight forward or backward movement...I don't want my buttons to have this browser-type functionality...If I'm on listItem4 and hit the next button, I want it to go to listItem5. Many Thanks For Any Help!

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  • how to bind input fields to a modal input fields AngularJS

    - by user3919120
    I have a form with a Customer and its properties populating input fields. If the user needs to change the Customer they click on the CustomerName input. A modal opens with a Customer List for them to choose from. There selection populates the input fields in that modal. I need to have that new information put in the already populated input fields. plunkr <div class="form-group"> <div class="input-group"> <span class="input-group-addon">C. Name</span> <input style="width:400px" ng-model="currentItem.CustomerName" class="form-control btn btn-default" ng-click="editJobCustomerModal()" /> </div> </div> <div class="form-group"> <div class="input-group"> <span class="input-group-addon">C. Address</span> <input style="width:390px" ng-model="currentItem.CustomerAddress" class="form-control" type="text"> </div> </div> Modal <div ng-controller="JobCtrl" data-backdrop="static" data-keyboard="false" class="modal fade" id="editJobCustomerModal" tabindex="-1" role="dialog" aria-labelledby="edit" aria-hidden="true"> <div class=" modal-dialog modal-editJobCustomer"> <div class="modal-content"> <div class="modal-header"> <h4 class="modal-title custom_align" id="Heading">Change Job Customer</h4> </div> <div class="modal-body"> <div class="container"> <form ng-submit="submitJob()" enctype="multipart/form-data"> <fieldset> <div class="col-md-8"> <!-- Prepended text--> <div class="form-group"> <div class="input-group"> <span class="input-group-addon">C. Name</span> <input style="width:400px" ng-model="selectedCustomer.CustomerName" class="form-control" type="text" /> </div> </div> <div class="form-group"> <div class="input-group"> <span class="input-group-addon">C. Address</span> <input style="width:390px" ng-model="selectedCustomer.CustomerAddress" class="form-control" type="text"> </div> </div> </fieldset><br /> <input style="float:right" class="btn btn-danger" ng-click="" type="button" value="Update"/> <input style="float:right; margin-right:20px" type="button" class="btn btn-primary" data-dismiss="modal" value="Cancel" /> </form> </div> </div> </div> </div> </div>

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  • Cant center dropdown menu

    - by sonicboom
    I have a dropdown below ive creaeted, but im having troulbe centering the the menu. Ive tried to put <center> tags around it and also set the ul to margin auto 0 but its not working. Is there anything im missing? <style type="text/css"> ul { font-family: Arial, Verdana; font-size: 14px; margin: 0; padding: 0; list-style: none; } ul li { display: block; position: relative; float: left; } li ul { display: none; } ul li a { display: block; text-decoration: none; color: #ffffff; border-top: 1px solid #ffffff; padding: 5px 15px 5px 15px; background: #1e7c9a; margin-left: 1px; white-space: nowrap; } ul li a:hover { background: #3b3b3b; } li:hover ul { display: block; position: absolute; } li:hover li { float: none; font-size: 11px; } li:hover a { background: #3b3b3b; } li:hover li a:hover { background: #1e7c9a; } </style> </head> <body> <ul id="menu"> <li><a href="#">Home</a></li> <li><a href="#">Portfolio</a> <ul> <li><a href="#">Web Design</a></li> <li><a href="#">Graphic Design</a></li> <li><a href="#">Logo Design</a></li> <li><a href="#">Blog Design</a></li> </ul> </li> <li><a href="#">Projects</a> <ul> <li><a href="#">This is a project</a></li> <li><a href="#">So is this</a></li> <li><a href="#">and this</a></li> <li><a href="#">don't forget this too</a></li> </ul> </li> <li><a href="#">Contact</a> <ul> <li><a href="#">Support</a></li> <li><a href="#">Quote</a></li> <li><a href="#">General Enquiry</a></li> </ul> </li> </ul> I went ahead and put it on jsfiddle Here

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  • How to organize pictures on website using css? [on hold]

    - by user3624023
    Here is my website without any CSS: http://www.wmcicompsci.ca/cs20/students/theglowcloud/Bare%20bones%20website/classics_bare.html I am new to CSS and I would like to organize pictures these pictures in this fashion: http://css-tricks.com/examples/SlideinCaptions/ I would just like this layout for the pictures but I do not need the sliding of the captions(although I would like to but it does not work my browser). I would like the captions to be like titles on top of the pictures. Here is my current html code: <!DOCTYPE html> <html> <head> <title> My favourite Fantasy books</title> <meta charset = "utf-8"> <link rel="stylesheet" href="css.css"> </head> <body> <nav id="main_nav"> <ul> <li><a href = " homepage_css.html"> Homepage</a></li> <li><a href="science_fiction_css.html">Science Fiction</a></li> <li><a href="classics_css.html">Classics</a></li> <li><a href="fantasy_css.html">Fantasy</a></li> </ul> </nav> <h1> Fantasy Genre</h1> <p> Here are my favourites:</p> <ul> <li> Goblet of Fire by J.K Rowling (4th book in the Harry Potter Series) </li> <li><img class= displayed src="pics/fantasy/goblet_of_fire.jpg" width="200" alt="Goblet of Fire book cover"></li> <li> Graceling by Kristan Cashore </li> <li><img src="pics/fantasy/graceling.jpg" width="200" alt = " Graceling book cover"></li> <li> Serpent's Shadow by Rick Riordan (3rd book in the Kane Chronicles) </li> <li><img src="pics/fantasy/serpents_shadow.jpg" width="200" alt="Serpent's Shadow book cover"></li> <li> The Hobbit by J.R.R. Tolkein </li> <li><img src="pics/fantasy/the_hobbit.jpg" width="200" alt="The Hobbit book cover"></li> <li> The False Prince by Jennifer Neilson (1st book in the Ascendance Triology) </li> <li><img src="pics/fantasy/the_false_prince.jpg" width="200" alt="The False Prince book cover"></li> </ul>

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  • Persisting objects to a database using a loop

    - by ChaoticLoki
    I have a form that returns multiple values and each value I would like to store in a database, I created a test form for this purpose <form method="post" action="{{ path('submit_exercise', {'page': 1}) }}"> <input type="hidden" name="answers[]" value="Answer 1" "/> <input type="hidden" name="answers[]" value="Answer 2" "/> <input type="hidden" name="answers[]" value="Answer 3" "/> <input type="hidden" name="answers[]" value="Answer 4" "/> <input type="hidden" name="answers[]" value="Answer 5" "/> <input type="hidden" name="answers[]" value="Answer 6" "/> <input type="hidden" name="answers[]" value="Answer 7" "/> <input type="submit" name="submit" /> </form> </body> </html> My submit answers Action is currently written like so. public function submitAnswersAction($page) { //get submitted data $data = $this->get('request')->request->all(); $answers = $data['answers']; //get student ID $user = $this->get('security.context')->getToken()->getUser(); $studentID = $user->getId(); //Get Current time $currentTime = new \DateTime(date("Y-m-d H:m:s")); //var_dump($answers); //var_dump($studentID); //var_dump($currentTime); for($index = 0; $index < count($answers); $index++) { /*echo "Question ". ($index + 1) ."<br />"; echo "Student ID: ". $studentID."<br />"; echo "Page Number: $page <br />"; echo "Answer: $answers[$index]"."<br />"; echo "<br />";*/ $studentAnswer = new StudentAnswer(); $studentAnswer->setStudentID($studentID); $studentAnswer->setPageID($page); $studentAnswer->setQuestionID($index+1); $studentAnswer->setAnswer($answers[$index]); $studentAnswer->setDateCreated($currentTime); $studentAnswer->setReadStatus(0); $database = $this->getDoctrine()->getManager(); $database->persist($studentAnswer); $database->flush(); } return new Response('Answers saved for Student: '.$user->getFullName().' for page: '.$page); When I do a var_dump everything seems to be associated correctly, meaning that the answers array is populated with the right data and so is every other variable, my problem is actually persisting it to the database. when run it returns with this error which seems to me like it doesn't know what variables to put into the row. An exception occurred while executing 'INSERT INTO Student_Answer (student_id, page_id, question_id, answer, read, date_created) VALUES (?, ?, ?, ?, ?, ?)' with params {"1":2,"2":"1","3":1,"4":"Answer 1","5":0,"6":"2012-12-11 12:12:20"}: Any help would be greatly appreciated as this is a personal project to help me try and understand web development a bit more.

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  • Mapping UrlEncoded POST Values in ASP.NET Web API

    - by Rick Strahl
    If there's one thing that's a bit unexpected in ASP.NET Web API, it's the limited support for mapping url encoded POST data values to simple parameters of ApiController methods. When I first looked at this I thought I was doing something wrong, because it seems mighty odd that you can bind query string values to parameters by name, but can't bind POST values to parameters in the same way. To demonstrate here's a simple example. If you have a Web API method like this:[HttpGet] public HttpResponseMessage Authenticate(string username, string password) { …} and then hit with a URL like this: http://localhost:88/samples/authenticate?Username=ricks&Password=sekrit it works just fine. The query string values are mapped to the username and password parameters of our API method. But if you now change the method to work with [HttpPost] instead like this:[HttpPost] public HttpResponseMessage Authenticate(string username, string password) { …} and hit it with a POST HTTP Request like this: POST http://localhost:88/samples/authenticate HTTP/1.1 Host: localhost:88 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Content-type: application/x-www-form-urlencoded Content-Length: 30 Username=ricks&Password=sekrit you'll find that while the request works, it doesn't actually receive the two string parameters. The username and password parameters are null and so the method is definitely going to fail. When I mentioned this over Twitter a few days ago I got a lot of responses back of why I'd want to do this in the first place - after all HTML Form submissions are the domain of MVC and not WebAPI which is a valid point. However, the more common use case is using POST Variables with AJAX calls. The following is quite common for passing simple values:$.post(url,{ Username: "Rick", Password: "sekrit" },function(result) {…}); but alas that doesn't work. How ASP.NET Web API handles Content Bodies Web API supports parsing content data in a variety of ways, but it does not deal with multiple posted content values. In effect you can only post a single content value to a Web API Action method. That one parameter can be very complex and you can bind it in a variety of ways, but ultimately you're tied to a single POST content value in your parameter definition. While it's possible to support multiple parameters on a POST/PUT operation, only one parameter can be mapped to the actual content - the rest have to be mapped to route values or the query string. Web API treats the whole request body as one big chunk of data that is sent to a Media Type Formatter that's responsible for de-serializing the content into whatever value the method requires. The restriction comes from async nature of Web API where the request data is read only once inside of the formatter that retrieves and deserializes it. Because it's read once, checking for content (like individual POST variables) first is not possible. However, Web API does provide a couple of ways to access the form POST data: Model Binding - object property mapping to bind POST values FormDataCollection - collection of POST keys/values ModelBinding POST Values - Binding POST data to Object Properties The recommended way to handle POST values in Web API is to use Model Binding, which maps individual urlencoded POST values to properties of a model object provided as the parameter. Model binding requires a single object as input to be bound to the POST data, with each POST key that matches a property name (including nested properties like Address.Street) being mapped and updated including automatic type conversion of simple types. This is a very nice feature - and a familiar one from MVC - that makes it very easy to have model objects mapped directly from inbound data. The obvious drawback with Model Binding is that you need a model for it to work: You have to provide a strongly typed object that can receive the data and this object has to map the inbound data. To rewrite the example above to use ModelBinding I have to create a class maps the properties that I need as parameters:public class LoginData { public string Username { get; set; } public string Password { get; set; } } and then accept the data like this in the API method:[HttpPost] public HttpResponseMessage Authenticate(LoginData login) { string username = login.Username; string password = login.Password; … } This works fine mapping the POST values to the properties of the login object. As a side benefit of this method definition, the method now also allows posting of JSON or XML to the same endpoint. If I change my request to send JSON like this: POST http://localhost:88/samples/authenticate HTTP/1.1 Host: localhost:88 Accept: application/jsonContent-type: application/json Content-Length: 40 {"Username":"ricks","Password":"sekrit"} it works as well and transparently, courtesy of the nice Content Negotiation features of Web API. There's nothing wrong with using Model binding and in fact it's a common practice to use (view) model object for inputs coming back from the client and mapping them into these models. But it can be  kind of a hassle if you have AJAX applications with a ton of backend hits, especially if many methods are very atomic and focused and don't effectively require a model or view. Not always do you have to pass structured data, but sometimes there are just a couple of simple response values that need to be sent back. If all you need is to pass a couple operational parameters, creating a view model object just for parameter purposes seems like overkill. Maybe you can use the query string instead (if that makes sense), but if you can't then you can often end up with a plethora of 'message objects' that serve no further  purpose than to make Model Binding work. Note that you can accept multiple parameters with ModelBinding so the following would still work:[HttpPost] public HttpResponseMessage Authenticate(LoginData login, string loginDomain) but only the object will be bound to POST data. As long as loginDomain comes from the querystring or route data this will work. Collecting POST values with FormDataCollection Another more dynamic approach to handle POST values is to collect POST data into a FormDataCollection. FormDataCollection is a very basic key/value collection (like FormCollection in MVC and Request.Form in ASP.NET in general) and then read the values out individually by querying each. [HttpPost] public HttpResponseMessage Authenticate(FormDataCollection form) { var username = form.Get("Username"); var password = form.Get("Password"); …} The downside to this approach is that it's not strongly typed, you have to handle type conversions on non-string parameters, and it gets a bit more complicated to test such as setup as you have to seed a FormDataCollection with data. On the other hand it's flexible and easy to use and especially with string parameters is easy to deal with. It's also dynamic, so if the client sends you a variety of combinations of values on which you make operating decisions, this is much easier to work with than a strongly typed object that would have to account for all possible values up front. The downside is that the code looks old school and isn't as self-documenting as a parameter list or object parameter would be. Nevertheless it's totally functionality and a viable choice for collecting POST values. What about [FromBody]? Web API also has a [FromBody] attribute that can be assigned to parameters. If you have multiple parameters on a Web API method signature you can use [FromBody] to specify which one will be parsed from the POST content. Unfortunately it's not terribly useful as it only returns content in raw format and requires a totally non-standard format ("=content") to specify your content. For more info in how FromBody works and several related issues to how POST data is mapped, you can check out Mike Stalls post: How WebAPI does Parameter Binding Not really sure where the Web API team thought [FromBody] would really be a good fit other than a down and dirty way to send a full string buffer. Extending Web API to make multiple POST Vars work? Don't think so Clearly there's no native support for multiple POST variables being mapped to parameters, which is a bit of a bummer. I know in my own work on one project my customer actually found this to be a real sticking point in their AJAX backend work, and we ended up not using Web API and using MVC JSON features instead. That's kind of sad because Web API is supposed to be the proper solution for AJAX backends. With all of ASP.NET Web API's extensibility you'd think there would be some way to build this functionality on our own, but after spending a bit of time digging and asking some of the experts from the team and Web API community I didn't hear anything that even suggests that this is possible. From what I could find I'd say it's not possible primarily because Web API's Routing engine does not account for the POST variable mapping. This means [HttpPost] methods with url encoded POST buffers are not mapped to the parameters of the endpoint, and so the routes would never even trigger a request that could be intercepted. Once the routing doesn't work there's not much that can be done. If somebody has an idea how this could be accomplished I would love to hear about it. Do we really need multi-value POST mapping? I think that that POST value mapping is a feature that one would expect of any API tool to have. If you look at common APIs out there like Flicker and Google Maps etc. they all work with POST data. POST data is very prominent much more so than JSON inputs and so supporting as many options that enable would seem to be crucial. All that aside, Web API does provide very nice features with Model Binding that allows you to capture many POST variables easily enough, and logistically this will let you build whatever you need with POST data of all shapes as long as you map objects. But having to have an object for every operation that receives a data input is going to take its toll in heavy AJAX applications, with a lot of types created that do nothing more than act as parameter containers. I also think that POST variable mapping is an expected behavior and Web APIs non-support will likely result in many, many questions like this one: How do I bind a simple POST value in ASP.NET WebAPI RC? with no clear answer to this question. I hope for V.next of WebAPI Microsoft will consider this a feature that's worth adding. Related Articles Passing multiple POST parameters to Web API Controller Methods Mike Stall's post: How Web API does Parameter Binding Where does ASP.NET Web API Fit?© Rick Strahl, West Wind Technologies, 2005-2012Posted in Web Api   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • ASP.NET GZip Encoding Caveats

    - by Rick Strahl
    GZip encoding in ASP.NET is pretty easy to accomplish using the built-in GZipStream and DeflateStream classes and applying them to the Response.Filter property.  While applying GZip and Deflate behavior is pretty easy there are a few caveats that you have watch out for as I found out today for myself with an application that was throwing up some garbage data. But before looking at caveats let’s review GZip implementation for ASP.NET. ASP.NET GZip/Deflate Basics Response filters basically are applied to the Response.OutputStream and transform it as data is written to it through the ASP.NET Response object. So a Response.Write eventually gets written into the output stream which if a filter is also written through the filter stream’s interface. To perform the actual GZip (and Deflate) encoding typically used by Web pages .NET includes the GZipStream and DeflateStream stream classes which can be readily assigned to the Repsonse.OutputStream. With these two stream classes in place it’s almost trivially easy to create a couple of reusable methods that allow you to compress your HTTP output. In my standard WebUtils utility class (from the West Wind West Wind Web Toolkit) created two static utility methods – IsGZipSupported and GZipEncodePage – that check whether the client supports GZip encoding and then actually encodes the current output (note that although the method includes ‘Page’ in its name this code will work with any ASP.NET output). /// <summary> /// Determines if GZip is supported /// </summary> /// <returns></returns> public static bool IsGZipSupported() { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (!string.IsNullOrEmpty(AcceptEncoding) && (AcceptEncoding.Contains("gzip") || AcceptEncoding.Contains("deflate"))) return true; return false; } /// <summary> /// Sets up the current page or handler to use GZip through a Response.Filter /// IMPORTANT: /// You have to call this method before any output is generated! /// </summary> public static void GZipEncodePage() { HttpResponse Response = HttpContext.Current.Response; if (IsGZipSupported()) { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (AcceptEncoding.Contains("deflate")) { Response.Filter = new System.IO.Compression.DeflateStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); Response.Headers.Remove("Content-Encoding"); Response.AppendHeader("Content-Encoding", "deflate"); } else { Response.Filter = new System.IO.Compression.GZipStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); Response.Headers.Remove("Content-Encoding"); Response.AppendHeader("Content-Encoding", "gzip"); } } } As you can see the actual assignment of the Filter is as simple as: Response.Filter = new DeflateStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); which applies the filter to the OutputStream. You also need to ensure that your response reflects the new GZip or Deflate encoding and ensure that any pages that are cached in Proxy servers can differentiate between pages that were encoded with the various different encodings (or no encoding). To use this utility function now is trivially easy: In any ASP.NET code that wants to compress its Response output you simply use: protected void Page_Load(object sender, EventArgs e) { WebUtils.GZipEncodePage(); Entry = WebLogFactory.GetEntry(); var entries = Entry.GetLastEntries(App.Configuration.ShowEntryCount, "pk,Title,SafeTitle,Body,Entered,Feedback,Location,ShowTopAd", "TEntries"); if (entries == null) throw new ApplicationException("Couldn't load WebLog Entries: " + Entry.ErrorMessage); this.repEntries.DataSource = entries; this.repEntries.DataBind(); } Here I use an ASP.NET page, but the above WebUtils.GZipEncode() method call will work in any ASP.NET application type including HTTP Handlers. The only requirement is that the filter needs to be applied before any other output is sent to the OutputStream. For example, in my CallbackHandler service implementation by default output over a certain size is GZip encoded. The output that is generated is JSON or XML and if the output is over 5k in size I apply WebUtils.GZipEncode(): if (sbOutput.Length > GZIP_ENCODE_TRESHOLD) WebUtils.GZipEncodePage(); Response.ContentType = ControlResources.STR_JsonContentType; HttpContext.Current.Response.Write(sbOutput.ToString()); Ok, so you probably get the idea: Encoding GZip/Deflate content is pretty easy. Hold on there Hoss –Watch your Caching Or is it? There are a few caveats that you need to watch out for when dealing with GZip content. The fist issue is that you need to deal with the fact that some clients don’t support GZip or Deflate content. Most modern browsers support it, but if you have a programmatic Http client accessing your content GZip/Deflate support is by no means guaranteed. For example, WinInet Http clients don’t support GZip out of the box – it has to be explicitly implemented. Other low level HTTP clients on other platforms too don’t support GZip out of the box. The problem is that your application, your Web Server and Proxy Servers on the Internet might be caching your generated content. If you return content with GZip once and then again without, either caching is not applied or worse the wrong type of content is returned back to the client from a cache or proxy. The result is an unreadable response for *some clients* which is also very hard to debug and fix once in production. You already saw the issue of Proxy servers addressed in the GZipEncodePage() function: // Allow proxy servers to cache encoded and unencoded versions separately Response.AppendHeader("Vary", "Content-Encoding"); This ensures that any Proxy servers also check for the Content-Encoding HTTP Header to cache their content – not just the URL. The same thing applies if you do OutputCaching in your own ASP.NET code. If you generate output for GZip on an OutputCached page the GZipped content will be cached (either by ASP.NET’s cache or in some cases by the IIS Kernel Cache). But what if the next client doesn’t support GZip? She’ll get served a cached GZip page that won’t decode and she’ll get a page full of garbage. Wholly undesirable. To fix this you need to add some custom OutputCache rules by way of the GetVaryByCustom() HttpApplication method in your global_ASAX file: public override string GetVaryByCustomString(HttpContext context, string custom) { // Override Caching for compression if (custom == "GZIP") { string acceptEncoding = HttpContext.Current.Response.Headers["Content-Encoding"]; if (string.IsNullOrEmpty(acceptEncoding)) return ""; else if (acceptEncoding.Contains("gzip")) return "GZIP"; else if (acceptEncoding.Contains("deflate")) return "DEFLATE"; return ""; } return base.GetVaryByCustomString(context, custom); } In a page that use Output caching you then specify: <%@ OutputCache Duration="180" VaryByParam="none" VaryByCustom="GZIP" %> To use that custom rule. It’s all Fun and Games until ASP.NET throws an Error Ok, so you’re up and running with GZip, you have your caching squared away and your pages that you are applying it to are jamming along. Then BOOM, something strange happens and you get a lovely garbled page that look like this: Lovely isn’t it? What’s happened here is that I have WebUtils.GZipEncode() applied to my page, but there’s an error in the page. The error falls back to the ASP.NET error handler and the error handler removes all existing output (good) and removes all the custom HTTP headers I’ve set manually (usually good, but very bad here). Since I applied the Response.Filter (via GZipEncode) the output is now GZip encoded, but ASP.NET has removed my Content-Encoding header, so the browser receives the GZip encoded content without a notification that it is encoded as GZip. The result is binary output. Here’s what Fiddler says about the raw HTTP header output when an error occurs when GZip encoding was applied: HTTP/1.1 500 Internal Server Error Cache-Control: private Content-Type: text/html; charset=utf-8 Date: Sat, 30 Apr 2011 22:21:08 GMT Content-Length: 2138 Connection: close ?`I?%&/m?{J?J??t??` … binary output striped here Notice: no Content-Encoding header and that’s why we’re seeing this garbage. ASP.NET has stripped the Content-Encoding header but left our filter intact. So how do we fix this? In my applications I typically have a global Application_Error handler set up and in this case I’ve been using that. One thing that you can do in the Application_Error handler is explicitly clear out the Response.Filter and set it to null at the top: protected void Application_Error(object sender, EventArgs e) { // Remove any special filtering especially GZip filtering Response.Filter = null; … } And voila I get my Yellow Screen of Death or my custom generated error output back via uncompressed content. BTW, the same is true for Page level errors handled in Page_Error or ASP.NET MVC Error handling methods in a controller. Another and possibly even better solution is to check whether a filter is attached just before the headers are sent to the client as pointed out by Adam Schroeder in the comments: protected void Application_PreSendRequestHeaders() { // ensure that if GZip/Deflate Encoding is applied that headers are set // also works when error occurs if filters are still active HttpResponse response = HttpContext.Current.Response; if (response.Filter is GZipStream && response.Headers["Content-encoding"] != "gzip") response.AppendHeader("Content-encoding", "gzip"); else if (response.Filter is DeflateStream && response.Headers["Content-encoding"] != "deflate") response.AppendHeader("Content-encoding", "deflate"); } This uses the Application_PreSendRequestHeaders() pipeline event to check for compression encoding in a filter and adjusts the content accordingly. This is actually a better solution since this is generic – it’ll work regardless of how the content is cleaned up. For example, an error Response.Redirect() or short error display might get changed and the filter not cleared and this code actually handles that. Sweet, thanks Adam. It’s unfortunate that ASP.NET doesn’t natively clear out Response.Filters when an error occurs just as it clears the Response and Headers. I can’t see where leaving a Filter in place in an error situation would make any sense, but hey - this is what it is and it’s easy enough to fix as long as you know where to look. Riiiight! IIS and GZip I should also mention that IIS 7 includes good support for compression natively. If you can defer encoding to let IIS perform it for you rather than doing it in your code by all means you should do it! Especially any static or semi-dynamic content that can be made static should be using IIS built-in compression. Dynamic caching is also supported but is a bit more tricky to judge in terms of performance and footprint. John Forsyth has a great article on the benefits and drawbacks of IIS 7 compression which gives some detailed performance comparisons and impact reviews. I’ll post another entry next with some more info on IIS compression since information on it seems to be a bit hard to come by. Related Content Built-in GZip/Deflate Compression in IIS 7.x HttpWebRequest and GZip Responses © Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET   IIS7  

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  • Transactional Messaging in the Windows Azure Service Bus

    - by Alan Smith
    Introduction I’m currently working on broadening the content in the Windows Azure Service Bus Developer Guide. One of the features I have been looking at over the past week is the support for transactional messaging. When using the direct programming model and the WCF interface some, but not all, messaging operations can participate in transactions. This allows developers to improve the reliability of messaging systems. There are some limitations in the transactional model, transactions can only include one top level messaging entity (such as a queue or topic, subscriptions are no top level entities), and transactions cannot include other systems, such as databases. As the transaction model is currently not well documented I have had to figure out how things work through experimentation, with some help from the development team to confirm any questions I had. Hopefully I’ve got the content mostly correct, I will update the content in the e-book if I find any errors or improvements that can be made (any feedback would be very welcome). I’ve not had a chance to look into the code for transactions and asynchronous operations, maybe that would make a nice challenge lab for my Windows Azure Service Bus course. Transactional Messaging Messaging entities in the Windows Azure Service Bus provide support for participation in transactions. This allows developers to perform several messaging operations within a transactional scope, and ensure that all the actions are committed or, if there is a failure, none of the actions are committed. There are a number of scenarios where the use of transactions can increase the reliability of messaging systems. Using TransactionScope In .NET the TransactionScope class can be used to perform a series of actions in a transaction. The using declaration is typically used de define the scope of the transaction. Any transactional operations that are contained within the scope can be committed by calling the Complete method. If the Complete method is not called, any transactional methods in the scope will not commit.   // Create a transactional scope. using (TransactionScope scope = new TransactionScope()) {     // Do something.       // Do something else.       // Commit the transaction.     scope.Complete(); }     In order for methods to participate in the transaction, they must provide support for transactional operations. Database and message queue operations typically provide support for transactions. Transactions in Brokered Messaging Transaction support in Service Bus Brokered Messaging allows message operations to be performed within a transactional scope; however there are some limitations around what operations can be performed within the transaction. In the current release, only one top level messaging entity, such as a queue or topic can participate in a transaction, and the transaction cannot include any other transaction resource managers, making transactions spanning a messaging entity and a database not possible. When sending messages, the send operations can participate in a transaction allowing multiple messages to be sent within a transactional scope. This allows for “all or nothing” delivery of a series of messages to a single queue or topic. When receiving messages, messages that are received in the peek-lock receive mode can be completed, deadlettered or deferred within a transactional scope. In the current release the Abandon method will not participate in a transaction. The same restrictions of only one top level messaging entity applies here, so the Complete method can be called transitionally on messages received from the same queue, or messages received from one or more subscriptions in the same topic. Sending Multiple Messages in a Transaction A transactional scope can be used to send multiple messages to a queue or topic. This will ensure that all the messages will be enqueued or, if the transaction fails to commit, no messages will be enqueued.     An example of the code used to send 10 messages to a queue as a single transaction from a console application is shown below.   QueueClient queueClient = messagingFactory.CreateQueueClient(Queue1);   Console.Write("Sending");   // Create a transaction scope. using (TransactionScope scope = new TransactionScope()) {     for (int i = 0; i < 10; i++)     {         // Send a message         BrokeredMessage msg = new BrokeredMessage("Message: " + i);         queueClient.Send(msg);         Console.Write(".");     }     Console.WriteLine("Done!");     Console.WriteLine();       // Should we commit the transaction?     Console.WriteLine("Commit send 10 messages? (yes or no)");     string reply = Console.ReadLine();     if (reply.ToLower().Equals("yes"))     {         // Commit the transaction.         scope.Complete();     } } Console.WriteLine(); messagingFactory.Close();     The transaction scope is used to wrap the sending of 10 messages. Once the messages have been sent the user has the option to either commit the transaction or abandon the transaction. If the user enters “yes”, the Complete method is called on the scope, which will commit the transaction and result in the messages being enqueued. If the user enters anything other than “yes”, the transaction will not commit, and the messages will not be enqueued. Receiving Multiple Messages in a Transaction The receiving of multiple messages is another scenario where the use of transactions can improve reliability. When receiving a group of messages that are related together, maybe in the same message session, it is possible to receive the messages in the peek-lock receive mode, and then complete, defer, or deadletter the messages in one transaction. (In the current version of Service Bus, abandon is not transactional.)   The following code shows how this can be achieved. using (TransactionScope scope = new TransactionScope()) {       while (true)     {         // Receive a message.         BrokeredMessage msg = q1Client.Receive(TimeSpan.FromSeconds(1));         if (msg != null)         {             // Wrote message body and complete message.             string text = msg.GetBody<string>();             Console.WriteLine("Received: " + text);             msg.Complete();         }         else         {             break;         }     }     Console.WriteLine();       // Should we commit?     Console.WriteLine("Commit receive? (yes or no)");     string reply = Console.ReadLine();     if (reply.ToLower().Equals("yes"))     {         // Commit the transaction.         scope.Complete();     }     Console.WriteLine(); }     Note that if there are a large number of messages to be received, there will be a chance that the transaction may time out before it can be committed. It is possible to specify a longer timeout when the transaction is created, but It may be better to receive and commit smaller amounts of messages within the transaction. It is also possible to complete, defer, or deadletter messages received from more than one subscription, as long as all the subscriptions are contained in the same topic. As subscriptions are not top level messaging entities this scenarios will work. The following code shows how this can be achieved. try {     using (TransactionScope scope = new TransactionScope())     {         // Receive one message from each subscription.         BrokeredMessage msg1 = subscriptionClient1.Receive();         BrokeredMessage msg2 = subscriptionClient2.Receive();           // Complete the message receives.         msg1.Complete();         msg2.Complete();           Console.WriteLine("Msg1: " + msg1.GetBody<string>());         Console.WriteLine("Msg2: " + msg2.GetBody<string>());           // Commit the transaction.         scope.Complete();     } } catch (Exception ex) {     Console.WriteLine(ex.Message); }     Unsupported Scenarios The restriction of only one top level messaging entity being able to participate in a transaction makes some useful scenarios unsupported. As the Windows Azure Service Bus is under continuous development and new releases are expected to be frequent it is possible that this restriction may not be present in future releases. The first is the scenario where messages are to be routed to two different systems. The following code attempts to do this.   try {     // Create a transaction scope.     using (TransactionScope scope = new TransactionScope())     {         BrokeredMessage msg1 = new BrokeredMessage("Message1");         BrokeredMessage msg2 = new BrokeredMessage("Message2");           // Send a message to Queue1         Console.WriteLine("Sending Message1");         queue1Client.Send(msg1);           // Send a message to Queue2         Console.WriteLine("Sending Message2");         queue2Client.Send(msg2);           // Commit the transaction.         Console.WriteLine("Committing transaction...");         scope.Complete();     } } catch (Exception ex) {     Console.WriteLine(ex.Message); }     The results of running the code are shown below. When attempting to send a message to the second queue the following exception is thrown: No active Transaction was found for ID '35ad2495-ee8a-4956-bbad-eb4fedf4a96e:1'. The Transaction may have timed out or attempted to span multiple top-level entities such as Queue or Topic. The server Transaction timeout is: 00:01:00..TrackingId:947b8c4b-7754-4044-b91b-4a959c3f9192_3_3,TimeStamp:3/29/2012 7:47:32 AM.   Another scenario where transactional support could be useful is when forwarding messages from one queue to another queue. This would also involve more than one top level messaging entity, and is therefore not supported.   Another scenario that developers may wish to implement is performing transactions across messaging entities and other transactional systems, such as an on-premise database. In the current release this is not supported.   Workarounds for Unsupported Scenarios There are some techniques that developers can use to work around the one top level entity limitation of transactions. When sending two messages to two systems, topics and subscriptions can be used. If the same message is to be sent to two destinations then the subscriptions would have the default subscriptions, and the client would only send one message. If two different messages are to be sent, then filters on the subscriptions can route the messages to the appropriate destination. The client can then send the two messages to the topic in the same transaction.   In scenarios where a message needs to be received and then forwarded to another system within the same transaction topics and subscriptions can also be used. A message can be received from a subscription, and then sent to a topic within the same transaction. As a topic is a top level messaging entity, and a subscription is not, this scenario will work.

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  • TOTD #166: Using NoSQL database in your Java EE 6 Applications on GlassFish - MongoDB for now!

    - by arungupta
    The Java EE 6 platform includes Java Persistence API to work with RDBMS. The JPA specification defines a comprehensive API that includes, but not restricted to, how a database table can be mapped to a POJO and vice versa, provides mechanisms how a PersistenceContext can be injected in a @Stateless bean and then be used for performing different operations on the database table and write typesafe queries. There are several well known advantages of RDBMS but the NoSQL movement has gained traction over past couple of years. The NoSQL databases are not intended to be a replacement for the mainstream RDBMS. As Philosophy of NoSQL explains, NoSQL database was designed for casual use where all the features typically provided by an RDBMS are not required. The name "NoSQL" is more of a category of databases that is more known for what it is not rather than what it is. The basic principles of NoSQL database are: No need to have a pre-defined schema and that makes them a schema-less database. Addition of new properties to existing objects is easy and does not require ALTER TABLE. The unstructured data gives flexibility to change the format of data any time without downtime or reduced service levels. Also there are no joins happening on the server because there is no structure and thus no relation between them. Scalability and performance is more important than the entire set of functionality typically provided by an RDBMS. This set of databases provide eventual consistency and/or transactions restricted to single items but more focus on CRUD. Not be restricted to SQL to access the information stored in the backing database. Designed to scale-out (horizontal) instead of scale-up (vertical). This is important knowing that databases, and everything else as well, is moving into the cloud. RBDMS can scale-out using sharding but requires complex management and not for the faint of heart. Unlike RBDMS which require a separate caching tier, most of the NoSQL databases comes with integrated caching. Designed for less management and simpler data models lead to lower administration as well. There are primarily three types of NoSQL databases: Key-Value stores (e.g. Cassandra and Riak) Document databases (MongoDB or CouchDB) Graph databases (Neo4J) You may think NoSQL is panacea but as I mentioned above they are not meant to replace the mainstream databases and here is why: RDBMS have been around for many years, very stable, and functionally rich. This is something CIOs and CTOs can bet their money on without much worry. There is a reason 98% of Fortune 100 companies run Oracle :-) NoSQL is cutting edge, brings excitement to developers, but enterprises are cautious about them. Commercial databases like Oracle are well supported by the backing enterprises in terms of providing support resources on a global scale. There is a full ecosystem built around these commercial databases providing training, performance tuning, architecture guidance, and everything else. NoSQL is fairly new and typically backed by a single company not able to meet the scale of these big enterprises. NoSQL databases are good for CRUDing operations but business intelligence is extremely important for enterprises to stay competitive. RDBMS provide extensive tooling to generate this data but that was not the original intention of NoSQL databases and is lacking in that area. Generating any meaningful information other than CRUDing require extensive programming. Not suited for complex transactions such as banking systems or other highly transactional applications requiring 2-phase commit. SQL cannot be used with NoSQL databases and writing simple queries can be involving. Enough talking, lets take a look at some code. This blog has published multiple blogs on how to access a RDBMS using JPA in a Java EE 6 application. This Tip Of The Day (TOTD) will show you can use MongoDB (a document-oriented database) with a typical 3-tier Java EE 6 application. Lets get started! The complete source code of this project can be downloaded here. Download MongoDB for your platform from here (1.8.2 as of this writing) and start the server as: arun@ArunUbuntu:~/tools/mongodb-linux-x86_64-1.8.2/bin$./mongod./mongod --help for help and startup optionsSun Jun 26 20:41:11 [initandlisten] MongoDB starting : pid=11210port=27017 dbpath=/data/db/ 64-bit Sun Jun 26 20:41:11 [initandlisten] db version v1.8.2, pdfile version4.5Sun Jun 26 20:41:11 [initandlisten] git version:433bbaa14aaba6860da15bd4de8edf600f56501bSun Jun 26 20:41:11 [initandlisten] build sys info: Linuxbs-linux64.10gen.cc 2.6.21.7-2.ec2.v1.2.fc8xen #1 SMP Fri Nov 2017:48:28 EST 2009 x86_64 BOOST_LIB_VERSION=1_41Sun Jun 26 20:41:11 [initandlisten] waiting for connections on port 27017Sun Jun 26 20:41:11 [websvr] web admin interface listening on port 28017 The default directory for the database is /data/db and needs to be created as: sudo mkdir -p /data/db/sudo chown `id -u` /data/db You can specify a different directory using "--dbpath" option. Refer to Quickstart for your specific platform. Using NetBeans, create a Java EE 6 project and make sure to enable CDI and add JavaServer Faces framework. Download MongoDB Java Driver (2.6.3 of this writing) and add it to the project library by selecting "Properties", "LIbraries", "Add Library...", creating a new library by specifying the location of the JAR file, and adding the library to the created project. Edit the generated "index.xhtml" such that it looks like: <h1>Add a new movie</h1><h:form> Name: <h:inputText value="#{movie.name}" size="20"/><br/> Year: <h:inputText value="#{movie.year}" size="6"/><br/> Language: <h:inputText value="#{movie.language}" size="20"/><br/> <h:commandButton actionListener="#{movieSessionBean.createMovie}" action="show" title="Add" value="submit"/></h:form> This page has a simple HTML form with three text boxes and a submit button. The text boxes take name, year, and language of a movie and the submit button invokes the "createMovie" method of "movieSessionBean" and then render "show.xhtml". Create "show.xhtml" ("New" -> "Other..." -> "Other" -> "XHTML File") such that it looks like: <head> <title><h1>List of movies</h1></title> </head> <body> <h:form> <h:dataTable value="#{movieSessionBean.movies}" var="m" > <h:column><f:facet name="header">Name</f:facet>#{m.name}</h:column> <h:column><f:facet name="header">Year</f:facet>#{m.year}</h:column> <h:column><f:facet name="header">Language</f:facet>#{m.language}</h:column> </h:dataTable> </h:form> This page shows the name, year, and language of all movies stored in the database so far. The list of movies is returned by "movieSessionBean.movies" property. Now create the "Movie" class such that it looks like: import com.mongodb.BasicDBObject;import com.mongodb.BasicDBObject;import com.mongodb.DBObject;import javax.enterprise.inject.Model;import javax.validation.constraints.Size;/** * @author arun */@Modelpublic class Movie { @Size(min=1, max=20) private String name; @Size(min=1, max=20) private String language; private int year; // getters and setters for "name", "year", "language" public BasicDBObject toDBObject() { BasicDBObject doc = new BasicDBObject(); doc.put("name", name); doc.put("year", year); doc.put("language", language); return doc; } public static Movie fromDBObject(DBObject doc) { Movie m = new Movie(); m.name = (String)doc.get("name"); m.year = (int)doc.get("year"); m.language = (String)doc.get("language"); return m; } @Override public String toString() { return name + ", " + year + ", " + language; }} Other than the usual boilerplate code, the key methods here are "toDBObject" and "fromDBObject". These methods provide a conversion from "Movie" -> "DBObject" and vice versa. The "DBObject" is a MongoDB class that comes as part of the mongo-2.6.3.jar file and which we added to our project earlier.  The complete javadoc for 2.6.3 can be seen here. Notice, this class also uses Bean Validation constraints and will be honored by the JSF layer. Finally, create "MovieSessionBean" stateless EJB with all the business logic such that it looks like: package org.glassfish.samples;import com.mongodb.BasicDBObject;import com.mongodb.DB;import com.mongodb.DBCollection;import com.mongodb.DBCursor;import com.mongodb.DBObject;import com.mongodb.Mongo;import java.net.UnknownHostException;import java.util.ArrayList;import java.util.List;import javax.annotation.PostConstruct;import javax.ejb.Stateless;import javax.inject.Inject;import javax.inject.Named;/** * @author arun */@Stateless@Namedpublic class MovieSessionBean { @Inject Movie movie; DBCollection movieColl; @PostConstruct private void initDB() throws UnknownHostException { Mongo m = new Mongo(); DB db = m.getDB("movieDB"); movieColl = db.getCollection("movies"); if (movieColl == null) { movieColl = db.createCollection("movies", null); } } public void createMovie() { BasicDBObject doc = movie.toDBObject(); movieColl.insert(doc); } public List<Movie> getMovies() { List<Movie> movies = new ArrayList(); DBCursor cur = movieColl.find(); System.out.println("getMovies: Found " + cur.size() + " movie(s)"); for (DBObject dbo : cur.toArray()) { movies.add(Movie.fromDBObject(dbo)); } return movies; }} The database is initialized in @PostConstruct. Instead of a working with a database table, NoSQL databases work with a schema-less document. The "Movie" class is the document in our case and stored in the collection "movies". The collection allows us to perform query functions on all movies. The "getMovies" method invokes "find" method on the collection which is equivalent to the SQL query "select * from movies" and then returns a List<Movie>. Also notice that there is no "persistence.xml" in the project. Right-click and run the project to see the output as: Enter some values in the text box and click on enter to see the result as: If you reached here then you've successfully used MongoDB in your Java EE 6 application, congratulations! Some food for thought and further play ... SQL to MongoDB mapping shows mapping between traditional SQL -> Mongo query language. Tutorial shows fun things you can do with MongoDB. Try the interactive online shell  The cookbook provides common ways of using MongoDB In terms of this project, here are some tasks that can be tried: Encapsulate database management in a JPA persistence provider. Is it even worth it because the capabilities are going to be very different ? MongoDB uses "BSonObject" class for JSON representation, add @XmlRootElement on a POJO and how a compatible JSON representation can be generated. This will make the fromXXX and toXXX methods redundant.

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