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  • Modifying File while in use using Java

    - by Marquinio
    Hi all, I have this recurrent Java JAR program tasks that tries to modify a file every 60seconds. Problem is that if user is viewing the file than Java program will not be able to modify the file. I get the typical IOException. Anyone knows if there is a way in Java to modify a file currently in use? Or anyone knows what would be the best way to solve this problem? I was thinking of using the File canRead(), canWrite() methods to check if file is in use. If file is in use then I'm thinking of making a backup copy of data that could not be written. Then after 60 seconds add some logic to check if backup file is empty or not. If backup file is not empty then add its contents to main file. If empty then just add new data to main file. Of course, the first thing I will always do is check if file is in use. Thanks for all your ideas.

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  • Why does grails use hsqldb when I ask for mysql?

    - by John
    I'm following the racetrack example from Jason Rudolph's book at InfoQ, using grails-1.2.1. I got up to the part where I was to switch from hsqldb to mysql. I think I've deleted every reference to hsqldb in the DataSource.groovy file, but I get an exception and the stack trace shows it's still using hsqldb. DataSource.groovy dataSource { boolean pooled = true String driverClassName = "com.mysql.jdbc.Driver" String url = "jdbc:mysql://localhost/dfpc2" String dbCreate = "create" String username = "dfpc2" String password = "dfpc2" dialect = org.hibernate.dialect.MySQL5InnoDBDialect } hibernate { cache.use_second_level_cache=true cache.use_query_cache=true cache.provider_class='net.sf.ehcache.hibernate.EhCacheProvider' } // environment specific settings environments { development { } test { } production { } } When I grails run-app it all starts up with no errors. I can navigate to the home page. But when I click on one of the links, I get a stack trace: java.sql.SQLException: Table not found in statement [select this_.id as id0_0_, this_.version as version0_0_, this_.name as name0_0_, this_.variant as variant0_0_ from domainObject this_ limit ?] at org.hsqldb.jdbc.Util.throwError(Unknown Source) at org.hsqldb.jdbc.jdbcPreparedStatement.<init>(Unknown Source) at org.hsqldb.jdbc.jdbcConnection.prepareStatement(Unknown Source) at dfpc2.domainObjectController$_closure2.doCall(script1269434425504953491149.groovy:13) at dfpc2.domainObjectController$_closure2.doCall(script1269434425504953491149.groovy) at java.lang.Thread.run(Thread.java:619) My mysql database shows no tables created. (I don't think groovy's connected to mysql yet.) Things I've checked: mysql-connector-java-5.1.6.jar is in lib directory. I've tried grails clean I tried putting the dataSource info in the development environment (I haven't graduated to test or prod yet), but it seemed to make no difference. The stdout shows I'm using development env. I've googled for solutions, but the only solution I've found is when people don't change the test or production environments.

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  • Deal with undefined values in code or in the template?

    - by David
    I'm writing a web application (in Python, not that it matters). One of the features is that people can leave comments on things. I have a class for comments, basically like so: class Comment: user = ... # other stuff where user is an instance of another class, class User: name = ... # other stuff And of course in my template, I have <div>${comment.user.name}</div> Problem: Let's say I allow people to post comments anonymously. In that case comment.user is None (undefined), and of course accessing comment.user.name is going to raise an error. What's the best way to deal with that? I see three possibilities: Use a conditional in the template to test for that case and display something different. This is the most versatile solution, since I can change the way anonymous comments are displayed to, say, "Posted anonymously" (instead of "Posted by ..."), but I've often been told that templates should be mindless display machines and not include logic like that. Also, other people might wind up writing alternate templates for the same application, and I feel like I should be making things as easy as possible for the template writer. Implement an accessor method for the user property of a Comment that returns a dummy user object when the real user is undefined. This dummy object would have user.name = 'Anonymous' or something like that and so the template could access it and print its name with no error. Put an actual record in my database corresponding to a user with user.name = Anonymous (or something like that), and just assign that user to any comment posted when nobody's logged in. I know I've seen some real-world systems that operate this way. (phpBB?) Is there a prevailing wisdom among people who write these sorts of systems about which of these (or some other solution) is the best? Any pitfalls I should watch out for if I go one way vs. another? Whoever gives the best explanation gets the checkmark.

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  • jQuery: Main nav items selected depending on URL or page name

    - by Ricardo
    Ok, I've looked all over for a solution for this but so far I'm unable to find anything related to what I need to accomplish. What I need is very simple as far as logic goes. I have a nav bar like this one: <nav> <ul> <li><a href="download.shtml">Download</a></li> <li><a href="documentation.shtml">Documentation</a></li> <li><a href="contact.shtml">Contact</a></li> <li><a href="about.shtml">About</a></li> </ul> </nav> And the URLs of the site are straightforward: http://domain.net/download.shtml http://domain.net/documentation.shtml http://domain.net/contact.shtml http://domain.net/about.shtml Question: How can I detect which page/URL I'm on and add a class of .active to the corresponding nav item? The end result would be, for example if I'm in the Download page: <nav> <ul> <li><a href="download.shtml" class="active">Download</a></li> <li><a href="documentation.shtml">Documentation</a></li> <li><a href="contact.shtml">Contact</a></li> <li><a href="about.shtml">About</a></li> </ul> </nav> Thanks in advance for any help on this matter.

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  • WPF validation on Enter Key Up

    - by Martin
    I'm trying to validate a UI change when Enter key is pressed. The UI element is a textbox, which is data binded to a string. My problem is that the data binding hasn't updated TestText when Enter key is Up. It is only updated when I press the button which brings up a message box. /// <summary> /// Interaction logic for Window1.xaml /// </summary> public partial class Window1 : Window, INotifyPropertyChanged { String _testText = new StringBuilder("One").ToString(); public string TestText { get { return _testText; } set { if (value != _testText) { _testText = value; OnPropertyChanged("TestText"); } } } public Window1() { InitializeComponent(); myGrid.DataContext = this; } private void OnPropertyChanged(string property) { if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(property)); } } public event PropertyChangedEventHandler PropertyChanged; private void onKeyUp(object sender, KeyEventArgs e) { if (e.Key != System.Windows.Input.Key.Enter) return; System.Diagnostics.Trace.WriteLine(TestText); } private void button1_Click(object sender, RoutedEventArgs e) { MessageBox.Show(TestText); } } Window XAML: Window x:Class="VerificationTest.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Window1" Height="300" Width="300" KeyUp="onKeyUp" TextBox XAML: TextBox Name="myTextBox" Text="{Binding TestText}" Button XAML: Button Name="button1" Click="button1_Click"

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  • What is the best free cross-platform OpenGL GUI library for a video game?

    - by Jim Buck
    It must come with source. I've looked at these which look semi-promising: glgooey, guichan, and cegui. I've come across others that look more Windows-y than game-y, but that's not the direction I am looking to go in. I would like some simple functionality of typical controls (lists, dropdown box, etc.) but with support for graphical widgets that you would normally find in game frontends. Mouse clicking, dragging, dropping, etc. and sound effect hooks would be nice. (These libs often leave hooks for the external system to tell it when/where mouse events are occurring.) It would get rendered on top of what my own 3D engine is rendering for the game, so it must be able to play nicely with rendering code outside of the lib. The best criteria is whether or not a reasonable 2D game could be implemented just with the GUI library and minimal glue code. (By glue code, I mean init code, hooking up the mouse, and game logic.) I am creating a 3D game, but this criteria gives a pretty solid idea of what level of interactivity I would like in the GUI.

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  • Loop to check all 14 days in the pay period

    - by Rachel Ann Arndt
    Name: Calc_Anniversary Input: Pay_Date, Hire_Date, Termination_Date Output: "Y" if is the anniversary of the employee's Hire_Date, "N" if it is not, and "T" if he has been terminated before his anniversary. Description: Create local variables to hold the month and day of the employee's Date_of_Hire, Termination_Date, and of the processing date using the TO_CHAR function. First check to see if he was terminated before his anniversary. The anniversary could be on any day during the pay period, so there will be a loop to check all 14 days in the pay period to see if one was his anniversary. CREATE OR replace FUNCTION Calc_anniversary( incoming_anniversary_date IN VARCHAR2) RETURN BOOLEAN IS hiredate VARCHAR2(20); terminationdate VARCHAR(20); employeeid VARCHAR2(38); paydate NUMBER := 0; BEGIN SELECT Count(arndt_raw_time_sheet_data.pay_date) INTO paydate FROM arndt_raw_time_sheet_data WHERE paydate = incoming_anniversary_date; WHILE paydate <= 14 LOOP SELECT To_char(employee_id, '999'), To_char(hire_date, 'DD-MON'), To_char(termination_date, 'DD-MON') INTO employeeid, hiredate, terminationdate FROM employees, time_sheet WHERE employees.employee_id = time_sheet.employee_id AND paydate = pay_date; IF terminationdate > hiredate THEN RETURN 'T'; ELSE IF To_char(SYSDATE, 'DD-MON') = To_char(hiredate, 'DD-MON')THEN RETURN 'Y'; ELSE RETURN 'N'; END IF; END IF; paydate := paydate + 1; END LOOP; END; Tables I am using CREATE TABLE Employees ( EMPLOYEE_ID INTEGER, FIRST_NAME VARCHAR2(15), LAST_NAME VARCHAR2(25), ADDRESS_LINE_ONE VARCHAR2(35), ADDRESS_LINE_TWO VARCHAR2(35), CITY VARCHAR2(28), STATE CHAR(2), ZIP_CODE CHAR(10), COUNTY VARCHAR2(10), EMAIL VARCHAR2(16), PHONE_NUMBER VARCHAR2(12), SOCIAL_SECURITY_NUMBER VARCHAR2(11), HIRE_DATE DATE, TERMINATION_DATE DATE, DATE_OF_BIRTH DATE, SPOUSE_ID INTEGER, MARITAL_STATUS CHAR(1), ALLOWANCES INTEGER, PERSONAL_TIME_OFF FLOAT, CONSTRAINT pk_employee_id PRIMARY KEY (EMPLOYEE_ID), CONSTRAINT fk_spouse_id FOREIGN KEY (SPOUSE_ID) REFERENCES EMPLOYEES (EMPLOYEE_ID)) / CREATE TABLE Arndt_Raw_Time_Sheet_data ( EMPLOYEE_ID INTEGER, PAY_DATE DATE, HOURS_WORKED FLOAT, SALES_AMOUNT FLOAT, CONSTRAINT pk_employee_id_pay_date_time PRIMARY KEY (EMPLOYEE_ID, PAY_DATE), CONSTRAINT fk_employee_id_time FOREIGN KEY (EMPLOYEE_ID) REFERENCES EMPLOYEES (EMployee_ID)); error FUNCTION Calc_Anniversary compiled Warning: execution completed with warning

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  • Simplification / optimization of GPS track

    - by GreyCat
    I've got a GPS track, produces by gpxlogger(1) (supplied as a client for gpsd). GPS receiver updates its coordinates every 1 second, gpxlogger's logic is very simple, it writes down location (lat, lon, ele) and a timestamp (time) received from GPS every n seconds (n = 3 in my case). After writing down a several hours worth of track, gpxlogger saves several megabyte long GPX file that includes several thousands of points. Afterwards, I try to plot this track on a map and use it with OpenLayers. It works, but several thousands of points make using the map a sloppy and slow experience. I understand that having several thousands of points of suboptimal. There are myriads of points that can be deleted without losing almost anything: when there are several points making up roughly the straight line and we're moving with the same constant speed between them, we can just leave the first and the last point and throw anything else. I thought of using gpsbabel for such track simplification / optimization job, but, alas, it's simplification filter works only with routes, i.e. analyzing only geometrical shape of path, without timestamps (i.e. not checking that the speed was roughly constant). Is there some ready-made utility / library / algorithm available to optimize tracks? Or may be I'm missing some clever option with gpsbabel?

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  • What is the best Design/Way to keep user connected ?

    - by Fasih Hansmukh
    Am working on a POC for self learning in which I want to keep my user connected in LIVE pattern. For example, A game in which 4 user can play at a time , here I need to keep this user connected to my game . M not good at Socket type of programming and love to do that in Services way.What i wana know is 'What is the best way of doing this'. According to my initial Brain Storming, I have decided that I will use SilverLight(In Browser Or Out of Browser) as Front end [I have no issue in that]. I m more concern in back end. Either I make an handler or make a WCF service or use full duplex service and use pooling mechanism for that. As a random thought I come up with a Timer type logic that will fire every after 10 seconds at clients end and get status like Is it now Its turn to roll a dice Home many user left (in case if some of them left) What are connected user status in game like there score/points ect and update game view according to this at his end Kindly place your best answers here that will help me to learn this. Regards and thanks in Advance EDIT: Starting Bounty as i need more feedback. FH

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  • How can I change the tags/css class of some dynamic text based on output from a helper?

    - by Angela
    I have a repeated line which outputs something like: Call John Jones in -3 days (status) I have a helper called show_status(contact,email) which will output whether that particular email had been sent to that particular contact. If it is "sent," then that entire line should show up as "strike out." Similarly, if the number of days is -3 (<0), the line should be formatted in red. Here's my hack, but there must be a cleaner way to put the logic into the controller? I hard-code a value that wraps around the lines I want formatted, and assign the value based on a separate call to the same helper: <% for call in @campaign.calls %> <% if !show_call_status(@contact,call).blank? %> <%= strike_start = '<s>'%> <%= strike_end = '</s>' %> <% end %> <p> <%= strike_start %> <%= link_to call.title, call_path(call) %> on <%= (@contact.date_entered + call.days).to_s(:long) %> in <%= interval_email(@contact,call) %> days <%= make_call(@contact,call) %> <span class='status'><%= show_call_status(@contact,call) %></span> <%= strike_end %> </p> <% end %> I guess what I'd like to do is not have the if statement in the View. Not sure how to do this.

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  • In ArrayBlockingQueue, why copy into ReentrantLock field into local final variable?

    - by mjlee
    In ArrayBlockingQueue, any method that requires lock will get set 'final' local variable before calling 'lock()'. public boolean offer(E e) { if (e == null) throw new NullPointerException(); final ReentrantLock lock = this.lock; lock.lock(); try { if (count == items.length) return false; else { insert(e); return true; } } finally { lock.unlock(); } } Is there any reason to set a local variable 'lock' from 'this.lock' when field 'this.lock' is final also. Additionally, it also set local variable of E[] before acting on. private E extract() { final E[] items = this.items; E x = items[takeIndex]; items[takeIndex] = null; takeIndex = inc(takeIndex); --count; notFull.signal(); return x; } Is there any reason for copying to local final variable?

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  • Is it possible to replace values in a queryset before sending it to your template?

    - by Issy
    Hi Guys, Wondering if it's possible to change a value returned from a queryset before sending it off to the template. Say for example you have a bunch of records Date | Time | Description 10/05/2010 | 13:30 | Testing... etc... However, based on the day of the week the time may change. However this is static. For example on a monday the time is ALWAYS 15:00. Now you could add another table to configure special cases but to me it seems overkill, as this is a rule. How would you replace that value before sending it to the template? I thought about using the new if tags (if day=1), but this is more of business logic rather then presentation. Tested this in a custom template tag def render(self, context): result = self.model._default_manager.filter(from_date__lte=self.now).filter(to_date__gte=self.now) if self.day == 4: result = result.exclude(type__exact=2).order_by('time') else: result = result.order_by('type') result[0].time = '23:23:23' context[self.varname] = result return '' However it still displays the results from the DB, is this some how related to 'lazy' evaluation of templates? Thanks! Update Responding to comments below: It's not stored wrong in the DB, its stored Correctly However there is a small side case where the value needs to change. So for example I have a From Date & To date, my query checks if todays date is between those. Now with this they could setup a from date - to date for an entire year, and the special cases (like mondays as an example) is taken care off. However if you want to store in the DB you would have to capture several more records to cater for the side case. I.e you would be capturing the same information just to cater for that 1 day when the time changes. (And the time always changes on the same day, and is always the same)

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  • How do I generate reports in R?

    - by Maiasaura
    I've been struggling for a week now trying to figure out how to generate reports in R using either Sweave or Brew. I should say right at the beginning that I have never used Tex before but I understand the logic of it. I have read this document several times. However, I cannot even get a simple example to parse. Brew successfully converts a simple markup file (just a title and some text) to a .tex file (no error). But it never ever converts tex to a pdf. > library(tools) > library(brew) > brew("population.brew", "population.tex") > texi2dvi("population.tex", pdf = TRUE) The last step always fails with: Error in texi2dvi("population.tex", pdf = TRUE) : Running 'texi2dvi' on 'population.tex' failed. What am I doing wrong? The report I am trying to build is fairly simple. I have 157 different analysis to summarize. Each one has 4 plots, 1 table and a summary. I just want output plot 1,2,3,4 output table \pagebreak ... that's it. Can anyone help me get further? I use osx, don't have Tex installed. thanks

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  • Constructing a WeakReference<T> throws COMException

    - by ChaseMedallion
    The following code: IDisposable d = ... new WeakReference<IDisposable>(d); Has started throwing the following exception on SOME machines. What could cause this? System.Runtime.InteropServices.COMException: Unspecified error (Exception from HRESULT: 0x80004005 (E_FAIL)) EDIT: the machines that experience the error are running Windows Server 2008 R2. Windows Server 2012 and desktop machines running windows 7 work fine. (this is true, but I now think a different issue is the relevant difference... see below). EDIT: as an additional note, this occurred right after updating our codebase to Entity Framework 6.1.1.-beta1. In the above code, The IDisposable is a class which wraps an EF DbContext. EDIT: why the votes to close? EDIT: the stack trace of the failure ends at the WeakReference<T> constructor called in the above code: at System.WeakReference`1..ctor(T target, Boolean trackResurrection) // from here on down it's code we wrote/simple LINQ. None of this code has changed recently; // we just upgraded to EF6 and saw this failure start happening at Core.Data.EntityFrameworkDataContext.RegisterDependentDisposable(IDisposable child) at Core.Data.ServiceFactory.GetConstructorParameter[TService](Type parameterType) at System.Linq.Enumerable.WhereSelectListIterator`2.MoveNext() at System.Linq.Buffer`1..ctor(IEnumerable`1 source) at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source) at Core.Data.ServiceFactory.CreateService[TService]() at MVC controller action method EDIT: it turns out that the machines having issues with this were running AppDynamics. Uninstalling that seems to have removed the issue.

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  • How to DRY on CRUD parts of my Rails app?

    - by kolrie
    I am writing an app which - similarly to many apps out there - is 90% regular CRUD things and 10% "juice", where we need nasty business logic and more flexibility and customization. Regarding this 90%, I was trying to stick to the DRY principle as much as I can. As long as controllers go, I have found resource_controller to really work, and I could get rid of all the controllers on that area, replacing them with a generic one. Now I'd like to know how to get the same with the views. On this app I have an overall, application.html.erb layout and then I must have another layout layer, common for all CRUD views and finally a "core" part: On index.html.erb all I need to generate a simple table with the fields and labels I indicate. For new and edit, also generic form edition, indicating labels and fields (with a possibility of providing custom fields if needed). I am not sure I will need show, but if I do it would be the same as new and edit. What plugins and tools (or even articles and general pointer) would help me to get that done? Thanks, Felipe.

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  • Use properties or methods to expose business rules in C#?

    - by Val
    I'm writing a class to encapsulate some business rules, each of which is represented by a boolean value. The class will be used in processing an InfoPath form, so the rules get the current program state by looking up values in a global XML data structure using XPath operations. What's the best (most idiomatic) way to expose these rules to callers -- properties or public methods? Call using properties Rules rules = new Rules(); if ( rules.ProjectRequiresApproval ) { // get approval } else { // skip approval } Call using methods Rules rules = new Rules(); if ( rules.ProjectRequiresApproval() ) { // get approval } else { // skip approval } Rules class exposing rules as properties public class Rules() { private int _amount; private int threshold = 100; public Rules() { _amount = someExpensiveXpathOperation; } // rule property public bool ProjectRequiresApproval { get { return _amount < threshold } } } Rules class exposing rules as methods public class Rules() { private int _amount; private int threshold = 100; public Rules() { _amount = someExpensiveXpathOperation; } // rule method public bool ProjectRequiresApproval() { return _amount < threshold; } } What are the pros and cons of one over the other?

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  • Rails: RESTful Find, Initialize, or Create

    - by Andrew
    I have an app that has Cities in it. I'm looking for some suggestions on how to RESTfully structure a controller so that I can lookup, initialize, and create city records via AJAX requests. For instance: Given a text field city_name A user enters the name of a City, like "Paris, France" The app checks this location to see if there is such a city in the database already If there is, it returns the city object If there is not, it returns a new record initialized with the name "Paris" and the country "France", and prompts the user to confirm they want to add this city to the database If the user says "Yes" the record is saved. If not the record is discarded and the form is cleared. Now, my first approach was to change the Create action to use find_or_create, so that an AJAX post to cities_path would result in either returning the existing city or creating it and returning it. That works ok... However, it would be better to setup controller actions that would take a string input, find , or else initialize and return, then only create if the user confirms the generated record is correct. The ideal scenario would put this all in one action so AJAX request can go to that url, the server responds with JSON objects, and javascript can handle things from there. I'd like to keep all the user-interaction logic client side, and also minimize the number of requests it takes to achieve this. Any suggestions on the cleanest, most RESTful way to accomplish this?

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  • Magento: Attribute always returns default value in catalog view, works fine in product view

    - by colinodell
    I've created a new Yes/No attribute for products. I've extended the Product model to do some custom logic and the custom functions are working everywhere. When I initially tried getting the custom attribute value, I ran into some issue. Magento wasn't loading it for me, so calls to $product-getMyAttributeName() did nothing. In the product views, I got it working with this additional function: public function getAttrVal($attr_name) { return $this->getResource()->getAttribute($attr_name)->getFrontend()->getValue($this); } So that worked great when viewing a product on the frontend. It would fetch the assigned value if set, or the default if not. When I view any Category (grid of all products in that category), the same exact code is being executed. But my getAttrVal() function always returns the default value, even if I've explicitly set this value for my product. I can't, for the life of me, figure out why the attribute loads correctly in the Product view but the Category view always grabs the default value, despite running the same exact code. Any thoughts?

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  • MySQL query against pseudo-key-value pair data in WordPress custom query

    - by andrevr
    I'm writing a custom WordPress query to use some of the data which the Woothemes Diarise theme creates. Diarise is an event planner theme with calendar blah, blah... and uses custom fields to store the event start and end dates in WP custom fields in the *wp_postmeta* table, which implements a key-value store. So for each post in the "event" category, there are 2 records in *wp_postmeta*, named *event_start_date* and *event_end_date* that I'm interested in. The task is to compare a tourist's arrival and departure dates with the start and end dates of events, yielding a what's on list of events available. We thought we'd killed it with a grand flash of logic, that goes like this: Disregard any event that ends before the tourist arrives, and any that begin after the departure date. I wrote this query: SELECT wposts.* FROM wp_posts wposts LEFT JOIN wp_postmeta wpostmeta ON wposts.ID = wpostmeta.post_id LEFT JOIN wp_term_relationships ON (wposts.ID = wp_term_relationships.object_id) LEFT JOIN wp_term_taxonomy ON (wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id) WHERE wp_term_taxonomy.taxonomy = 'category' AND wp_term_taxonomy.term_id IN(3,4) AND ( wpostmeta.meta_key = 'event_start_date' AND NOT ( concat(subst(wpostmeta.meta_value,7,4),'-',subst(wpostmeta.meta_value,4,2),'-',subst(wpostmeta.meta_value,1,2) > '2010-07-31' ) ) AND ( wpostmeta.meta_key = 'event_end_date' AND NOT ( concat(subst(wpostmeta.meta_value,7,4),'-',subst(wpostmeta.meta_value,4,2),'-',subst(wpostmeta.meta_value,1,2) < '2010-05-01' ) ) ) ORDER BY wpostmeta.meta_value ASC And, of course it returns no records. The problem I believe is in the dual reference to wpostmeta.meta_key, but how to get around that?

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  • Altering ManagedObjects In NSArray

    - by Garry
    I have an entity called 'Job' with two boolean attributes named 'completed' and 'logged'. I am trying to retrieve all completed jobs that have not been logged at app start-up and change them to logged. I'm able to get all the completed but unlogged jobs with this fetchRequest: NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(completed == %@ && logged == %@)", [NSNumber numberWithBool:YES], [NSNumber numberWithBool:NO]]; I'm then assigning this predicate to a fetchRequest and calling the [managedObjectContext executeFetchRequest:fetchRequest] method to get an array of all Job entities that meet this criteria. This seems to work fine and is returning the correct number of jobs. What I've been trying to do is loop through the NSArray returned, set the logged attribute to YES and then save. This seems to complete and doesn't return any errors but the changes are not persisted when the application quits. Where am I going wrong? [fetchRequest setPredicate:predicate]; NSError error; NSArray jobsToLog = [managedObjectContext executeFetchRequest:fetchRequest error:&error]; if ([jobsToLog count] > 0) { for (int i = 0; i < [jobsToLog count] - 1; i++) { [[jobsToLog objectAtIndex:i] setLogged:[NSNumber numberWithBool:YES]]; // Commit the changes made to disk error = nil; if (![managedObjectContext save:&error]) { // An error occurred } } } Thanks in anticipation,

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  • What is the best / proper idiom in django for modifying a field during a .save() where you need to o

    - by MDBGuy
    Hi, say I've got: class LogModel(models.Model): message = models.CharField(max_length=512) class Assignment(models.Model): someperson = models.ForeignKey(SomeOtherModel) def save(self, *args, **kwargs): super(Assignment, self).save() old_person = #????? LogModel(message="%s is no longer assigned to %s"%(old_person, self).save() LogModel(message="%s is now assigned to %s"%(self.someperson, self).save() My goal is to save to LogModel some messages about who Assignment was assigned to. Notice that I need to know the old, presave value of this field. I have seen code that suggests, before super().save(), retrieve the instance from the database via primary key and grab the old value from there. This could work, but is a bit messy. In addition, I plan to eventually split this code out of the .save() method via signals - namely pre_save() and post_save(). Trying to use the above logic (Retrieve from the db in pre_save, make the log entry in post_save) seemingly fails here, as pre_save and post_save are two seperate methods. Perhaps in pre_save I can retrieve the old value and stick it on the model as an attribute? I was wondering if there was a common idiom for this. Thanks.

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  • Read Cookies using Javascript

    - by Ajith
    I want to create a cookie using php,an also i need to read it using javascript.ie, by using setcookie('mycookie','hello',time()+34000) in php i am creating a cookie in my system.Now,i need to read it using javascript.Is it possible?If anybody knows please give me some idea.Please....help me.I am using javscript as follows ` function Get_Cookie( check_name ) { // first we'll split this cookie up into name/value pairs // note: document.cookie only returns name=value, not the other components var a_all_cookies = document.cookie.split( ';' ); var a_temp_cookie = ''; var cookie_name = ''; var cookie_value = ''; var b_cookie_found = false; // set boolean t/f default f for ( i = 0; i < a_all_cookies.length; i++ ) { // now we'll split apart each name=value pair a_temp_cookie = a_all_cookies[i].split( '=' ); // and trim left/right whitespace while we're at it cookie_name = a_temp_cookie[0].replace(/^\s+|\s+$/g, ''); // if the extracted name matches passed check_name if ( cookie_name == check_name ) { b_cookie_found = true; // we need to handle case where cookie has no value but exists (no = sign, that is): if ( a_temp_cookie.length > 1 ) { cookie_value = unescape( a_temp_cookie[1].replace(/^\s+|\s+$/g, '') ); } // note that in cases where cookie is initialized but no value, null is returned return cookie_value; break; } a_temp_cookie = null; cookie_name = ''; } if ( !b_cookie_found ) { return null; } } if (Get_Cookie('__gsb')) { alert('Found'); } `

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  • Decimal To Octal Converter, last digit issue

    - by Srishan Supertramp
    I tried making a C program to convert a user entered decimal number to octal. I wrote the C code with my own logic without any research of how other users try to do it. It works fine for the number 601 and some other numbers but for most numbers it returns the octal equivalent with the last digit being 1 less than it should be. For 75 it returns 112 instead of 113. I realize using printf with %o gets the job done but it's kind of defeating the purpose of learning to program. Here's my code: #include <stdio.h> #include <math.h> /* converting decimal to octal */ int main() { int n,x,y,p,s; printf("Enter a decimal number "); scanf("%d",&x); s=0;p=0; while (x!=0) { y=x%8; s=s+y*pow(10,p); x=(x-y)/8; p=p+1; } printf("the octal equivalent is: %d\n",s); getch(); return 0; }

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  • How do you use stl's functions like for_each?

    - by thomas-gies
    I started using stl containers because they came in very handy when I needed functionality of a list, set and map and had nothing else available in my programming environment. I did not care much about the ideas behind it. STL documentations were only interesting up to the point where it came to functions, etc. Then I skipped reading and just used the containers. But yesterday, still being relaxed from my holidays, I just gave it a try and wanted to go a bit more the stl way. So I used the transform function (can I have a little bit of applause for me, thank you). From an academic point of view it really looked interesting and it worked. But the thing that boroughs me is that if you intensify the use of those functions, you need 10ks of helper classes for mostly everything you want to do in your code. The hole logic of the program is sliced in tiny pieces. This slicing is not the result of god coding habits. It's just a technical need. Something, that makes my life probably harder not easier. And I learned the hard way, that you should always choose the simplest approach that solves the problem at hand. And I can't see what, for example, the for_each function is doing for me that justifies the use of a helper class over several simple lines of code that sit inside a normal loop so that everybody can see what is going on. I would like to know, what you are thinking about my concerns? Did you see it like I do when you started working this way and have changed your mind when you got used to it? Are there benefits that I overlooked? Or do you just ignore this stuff as I did (and will go an doing it, probably). Thanks. PS: I know that there is a real for_each loop in boost. But I ignore it here since it is just a convenient way for my usual loops with iterators I guess.

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  • Django: returning a selection of fields from a model based on their values?

    - by AP257
    I am working with some data over which I have little control. I'd like to return ONLY the fields of my model that aren't certain 'uninteresting' values (e.g. '0', 'X' or '-'), and access them individually in the template. My model is like this: class Manors(models.Model): structidx = models.IntegerField(primary_key=True, verbose_name="ID") hills = models.CharField(max_length=100, null=True, blank=True, verbose_name="Number of fields") In my template, I return a QuerySet of Manors, and I'd like to output something like this if the hills field isn't uninteresting: {% for manor in manors %} {% if manor.hills %}<li>Hills blah blah: {{ manor.hills }}</li>{% endif %} {% endfor %} I want to avoid too much logic in the template. Ideally, the manor object would simply not return with the uninteresting fields attached, then I could just do {% if manor.hills %}. I tried writing a model method that returns a dictionary of the interesting values, like this: def get_field_dictionary(self): interesting_fields = {} for field in Manors._meta.fields: if field.value_to_string(self) != "N" and field.value_to_string(self) != "0" and field.value_to_string(self) != "-" and field.value_to_string(self) != "X": interesting_fields[field.name] = field.value_to_string(self) return interesting_fields But I don't know how to access individual values of the dictionary in the template: {% if manor.get_field_dictionary['hills'] %}<li>Hills blah blah: {{ manor.get_field_dictionary['hills'] }}</li>{% endif %} gives a TemplateSyntaxError. Is there a better way to do this?

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