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  • Why can't I handle a KeyboardInterrupt in python?

    - by Josh
    I'm writing python 2.6.6 code on windows that looks like this: try: dostuff() except KeyboardInterrupt: print "Interrupted!" except: print "Some other exception?" finally: print "cleaning up...." print "done." dostuff() is a function that loops forever, reading a line at a time from an input stream and acting on it. I want to be able to stop it and clean up when I hit ctrl-c. What's happening instead is that the code under except KeyboardInterrupt: isn't running at all. The only thing that gets printed is "cleaning up...", and then a traceback is printed that looks like this: Traceback (most recent call last): File "filename.py", line 119, in <module> print 'cleaning up...' KeyboardInterrupt So, exception handling code is NOT running, and the traceback claims that a KeyboardInterrupt occurred during the finally clause, which doesn't make sense because hitting ctrl-c is what caused that part to run in the first place! Even the generic except: clause isn't running. EDIT: Based on the comments, I replaced the contents of the try: block with sys.stdin.read(). The problem still occurs exactly as described, with the first line of the finally: block running and then printing the same traceback.

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  • Google Chrome Extension : Port: Could not establish connection. Receiving end does not exist

    - by tcornelis
    I have been looking for an answer for almost a week now, but having read all the stackoverflow items i can't seem to find a solution that is working for me. The error that i'm having is : Port: Could not establish connection. Receiving end does not exist. lastError:30 set lastError:30 dispatchOnDisconnect messaging:277 folder layout : img developer_icon.png js sidebar.js main.js jquery-2.0.3.js manifest.json my the manifest.json file looks something like this (it is version 2) :` "browser_action": { "default_icon": "./img/developer_icon.png" }, "content_scripts": [ { "matches": ["*://*/*"], "js": ["./js/sidebar.js"], "run_at": "document_end" } ], "background" : { "scripts" : ["./js/main.js","./js/jquery-2.0.3.js"] }, I want to handle the user clicking the extension icon so i could inject a sidebar in the existing website (because the extension i would like to develop requires that amount of space). So in main.js : chrome.browserAction.onClicked.addListener(function(tab) { chrome.tabs.getSelected(null, function(tab){ chrome.tabs.sendMessage( //Selected tab id tab.id, //Params inside a object data {callFunction: "toggleSidebar"}, //Optional callback function function(response) { console.log(response); } ); }); }); and in sidebar.js : chrome.runtime.onMessage.addListener(function(req,sender,sendResponse){ console.log("sidebar handling request"); toggleSidebar(); }); but i'm never able to see the console.log in my console because of the error. Does someone know what i did wrong? Thanks in advance!

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  • Greasemonkey failing to GM_setValue()

    - by HonoredMule
    I have a Greasemonkey script that uses a Javascript object to maintain some stored objects. It covers quite a large volume of information, but substantially less than it successfully stored and retrieved prior to encountering my problem. One value refuses to save, and I can not for the life of me determine why. The following problem code: Works for other larger objects being maintained. Is presently handling a smaller total amount of data than previously worked. Is not colliding with any function or other object definitions. Can (optionally) successfully save the problem storage key as "{}" during code startup. this.save = function(table) { var tables = this.tables; if(table) tables = [table]; for(i in tables) { logger.log(this[tables[i]]); logger.log(JSON.stringify(this[tables[i]])); GM_setValue(tables[i] + "_" + this.user, JSON.stringify(this[tables[i]])); logger.log(tables[i] + "_" + this.user + " updated"); logger.log(GM_getValue(tables[i] + "_" + this.user)); } } The problem is consistently reproducible and the logging statments produce the following output in Firebug: Object { 54,10 = Object } // Expansion shows complete contents as expected, but there is one oddity--Firebug highlights the array keys in purple instead of the usual black for anonymous objects. {"54,10":{"x":54,"y":10,"name":"Lucky Pheasant"}} // The correctly parsed string. bookmarks_HonoredMule saved undefined I have tried altering the format of the object keys, to no effect. Further narrowing down the issue is that this particular value is successfully saved as an empty object ("{}") during code initialization, but skipping that also does not help. Reloading the page confirms that saving of the nonempty object truly failed. Any idea what could cause this behavior? I've thoroughly explored the possibility of hitting size constraints, but it doesn't appear that can be the problem--as previously mentioned, I've already reduced storage usage. Other larger objects save still, and the total number of objects, which was not high already, has further been reduced by an amount greater than the quantity of data I'm attempting to store here.

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  • HTML input not working correctly with AJAX update panels used else where on page

    - by Sean P
    I have some update panels on my page that do some asyncpostbacks to keep some dropdownlists correctly populated. My problem is that on my page i have an HTML input that is handling some file uploads. With the AJAX on the page with asyncpostbacks, and while i step through my code behind, the files arent being uploaded. Using a postbacktrigger (non-async) is not possible because of my layout. Here is my code: <div id="divFileInputs" runat="server"> <input id="file1" name="fileInput" type="file" runat="server" size="50" style="width: 50em" onfocus="AddFileInput()" class="textbox" /></div> <select id="selectFileList" name="ListBox1" size="5" style="width: 50em; text-align: left;" class="textbox" /> <input id="RemoveAttachmentButton" type="button" value="Remove" onclick="RemoveFileInput()" class="removebutton " /> </div> Here is my code behind: Protected Sub CopyAttachments(ByVal issueId As String) Dim files As HttpFileCollection = Request.Files Dim myStream As System.IO.Stream Dim service As New SubmitService.Service For i As Integer = 0 To files.Count - 1 Dim postedFile As HttpPostedFile = files(i) Dim fileNameWithoutPath As String = System.IO.Path.GetFileName(postedFile.FileName) If fileNameWithoutPath.Length > 0 And issueId.Length > 0 Then Dim fileLength As Integer = postedFile.ContentLength Dim fileContents(fileLength) As Byte ' Read the file into the byte array. Send it to the web service. myStream = postedFile.InputStream myStream.Read(fileContents, 0, fileLength) service.ClearQuestAttachToIssue(issueId, fileNameWithoutPath, fileContents) End If Next service = Nothing End Sub When I put a breakpoint in at the declaration of service and then check the value of "files", the count is 0. I am expecting it to be 2 when i have one file uploaded. Anyone know how to fix this?

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  • Java string to double conversion.

    - by wretrOvian
    Hi, I've been reading up on the net about the issues with handling float and double types in java. Unfortunately, the image is still not clear. Hence, i'm asking here direct. :( My MySQL table has various DECIMAL(m,d) columns. The m may range from 5 to 30. d stays a constant at 2. Question 1. What equivalent data-type should i be using in Java to work (i.e store, retrieve, and process) with the size of the values in my table? (I've settled with double - hence this post). Question 2. While trying to parse a double from a string, i'm getting errors Double dpu = new Double(dpuField.getText()); for example - "1" -> java.lang.NumberFormatException: empty String "10" -> 1.0 "101" -> 10.0 "101." -> 101.0 "101.1" -> 101.0 "101.19" -> 101.1 What am i doing wrong? What is the correct way to convert a string to a double value? And what measures should i take to perform operations on such values?

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  • Best practices for (over)using Azure queues

    - by John
    Hi, I'm in the early phases of designing an Azure-based application. One of the things that attracts me to Azure is the scalability, given the variability of the demand I'm likely to expect. As such I'm trying to keep things loosely coupled so I can add instances when I need to. The recommendations I've seen for architecting an application for Azure include keeping web role logic to a minimum, and having processing done in worker roles, using queues to communicate and some sort of back-end store like SQL Azure or Azure Tables. This seems like a good idea to me as I can scale up either or both parts of the application without any issue. However I'm curious if there are any best practices (or if anyone has any experiences) for when it's best to just have the web role talk directly to the data store vs. sending data by the queue? I'm thinking of the case where I have a simple insert to do from the web role - while I could set this up as a message, send it on the queue, and have a worker role pick it up and do the insert, it seems like a lot of double-handling. However I also appreciate that it may be the case that this is better in the long run, in case the web role gets overwhelmed or more complex logic ends up being required for the insert. I realise this might be a case where the answer is "it depends entirely on the situation, check your perf metrics" - but if anyone has any thoughts I'd be very appreciative! Thanks John

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  • java web templates across multiple WAR files

    - by Casey
    I have a multi WAR web application that was designed badly. There is a single WAR that is responsible for handling some authorization against a database and defines a standard web page using a jsp taglib. The main WAR basically checks the privileges of the user and than based on that, displays links to the context path of the other deployed WARS. Each of the other deployed WARs includes this custom tag lib. I am working on redesigning this application, and one of the nice things that I want to retain is that we have other project teams that have developed these WAR modules that "plug into" our current system to take advantage of other things we have to offer. I am not entirely sure how to handle the page templates though. I need a templating system that would be easy enough to use across multiple wars (I was thinking of jsp fragments??). I really only need to define a consistent header and main navigation section. Whatever else is displayed on the page is up to the individual web project. Any suggestions? I hope that this is clear, if not I can elaborate more.

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  • Can tomcat perform ssl redirection by filtering host alias?

    - by Stephen
    Hi, We have a tomcat server (6.0.20) running one web application behind two urls, e.g. www.foo and secure.foo This is configured in the server.xml as one host with a single alias: <Host name="www.foo" appBase="webapps"> <Context docBase="foo" path=""></Context> <Alias>secure.foo</Alias> </Host> Ideally we'd like any requests to secure.foo on port 80 to be automatically redirected to use ssl. However, I can only find instructions for redirecting based on the path after the hostname, so I could add a /* security constraint but then this would apply to both urls. Does anyone know if it's possible to apply the redirection by filtering on hostname requested? (We've already got the ssl connector, certificate, etc. working ok). I know we could do it by sticking an apache server in front of tomcat and handling the redirection there, but I'm curious to know if tomcat can do this on its own. Thanks

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  • Programming texts and reference material for my Kindle DX, creating the ultimate reference device?

    - by mwilliams
    (Revisiting this topic with the release of the Kindle DX) Having owned both generation Kindle readers and now getting a Kindle DX; I'm very excited for true PDF handling on an e-ink device! An image of _Why's book on my Kindle (from my iPhone). This gives me a device capable of storing hundreds of thousands of pages that are full text search capable in the form factor of a magazine. What references (preferably PDF to preserve things such as code samples) would you recommend? Ultimately I would like reference material for every modern and applicable programming language (C, C++, Objective-C, Python, Ruby, Java, .NET (C#, Visual Basic, ASP.NET), Erlang, SQL references) as well as general programming texts and frameworks (algorithms, design patterns, theory, Rails, Django, Cocoa, ORMs, etc) and anything else that could be thought of. With so many developers here using such a wide array of languages, as a professional in your particular field, what books or references would you recommend to me for my Kindle? Creative Commons material a plus (translate that to free) as well as the material being in the PDF file format. File size is not an issue. If this turns out to be a success, I will update with a follow-up with a compiled list generated from all of the answers. Thanks for the assistance and contributing! UPDATE I have been using the Kindle DX a lot now for technical books. Check out this blog post I did for high resolution photos of different material: http://www.matthewdavidwilliams.com/2009/06/12/technical-document-pdfs-on-the-kindle-dx/

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  • Android Frame based animation memory problem

    - by madsleejensen
    Hi all Im trying to create a animation on top of a Camera Surface view. The animation if a box rotating, and to enable transparency i made a bunch of *.png files that i want to just switch out on top of the Camera view. The problem is Android wont allow me to allocate so many images (too much memory required) so the AnimationDrawable is not an option. Will i be able to allocate all the *.png bitmaps if i use OpenGL instead? then i would store all the *.png's as Textures and just make my own animation logic? is am i under the same restrictions there? Any ideas on how to solve this problem ? Ive made a Custom view that loads the image resource on every frame and discards it when next frame is to be displayed. But the performance is terrible. import android.app.Activity; import android.content.res.Resources; import android.graphics.drawable.Drawable; import android.os.SystemClock; import android.util.Log; import android.widget.ImageView; public class FrameAnimationView extends ImageView { private int mFramesPerSecond = 10; private int mTimeBetweenFrames = (1000 / mFramesPerSecond); private int mCurrentFrame = 1; private String[] mFrames; private Thread mAnimationThread; private Resources mResources; private String mIdentifierPrefix; private Activity mContext; private boolean mIsAnimating = false; private Integer[] mDrawableIndentifiers; public FrameAnimationView(Activity context, String[] frames) { super(context); mContext = context; mResources = context.getResources(); mFrames = frames; mIdentifierPrefix = context.getPackageName() + ":drawable/"; mDrawableIndentifiers = new Integer[frames.length]; } private void initAnimationThread() { mAnimationThread = new Thread(new Runnable() { @Override public void run() { while (mIsAnimating) { final int frameToShow = (mCurrentFrame - 1); //Log.e("frame", Integer.toString(frameToShow)); mContext.runOnUiThread(new Runnable() { @Override public void run() { if (mDrawableIndentifiers[frameToShow] == null) { String frameId = mFrames[frameToShow]; int drawableResourceId = mResources.getIdentifier(mIdentifierPrefix + frameId, null, null); mDrawableIndentifiers[frameToShow] = drawableResourceId; } Drawable frame = getResources().getDrawable(mDrawableIndentifiers[frameToShow]); setBackgroundDrawable(frame); if (mCurrentFrame < mFrames.length) { mCurrentFrame++; } else { mCurrentFrame = 1; } } }); try { Thread.sleep(mTimeBetweenFrames); } catch (InterruptedException e) { e.printStackTrace(); } } } }); } public void setFramesPerSecond(int fps) { mFramesPerSecond = fps; mTimeBetweenFrames = (1000 / mFramesPerSecond); } public void startAnimation() { if (mIsAnimating) return; mIsAnimating = true; initAnimationThread(); mAnimationThread.start(); } public void stopAnimation() { if (mIsAnimating) { Thread oldThread = mAnimationThread; mAnimationThread = null; oldThread.interrupt(); mIsAnimating = false; } } }

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  • JQuery click anywhere except certain divs and issues with dynamically added html

    - by jCuga
    I want this webpage to highlight certain elements when you click on one of them, but if you click anywhere else on the page, then all of these elements should no longer be highlighted. I accomplished this task by the following, and it works just fine except for one thing (described below): $(document).click(function() { // Do stuff when clicking anywhere but on elements of class suggestion_box $(".suggestion_box").css('background-color', '#FFFFFF'); }); $(".suggestion_box").click(function() { // means you clicked on an object belonging to class suggestion_box return false; }); // the code for handling onclicks for each element function clickSuggestion() { // remove all highlighting $(".suggestion_box").css('background-color', '#FFFFFF'); // then highlight only a specific item $("div[name=" + arguments[0] + "]").css('background-color', '#CCFFCC'); } This way of enforcing the highlighting of elements works fine until I add more html to the page without having a new page load. This is done by .append() and .prepend() What I suspected from debugging was that the page is not "aware" of the new elements that were added to the page dynamically. Despite the new, dynamically added elements having the appropriate class names/IDs/names/onclicks ect, they never get highlighted like the rest of the elements (which continue to work fine the entire time). I was wondering if a possible reason for why my approach does not work for the dynamically added content is that the page is not able to recognize the elements that were not present during the pageload. And if this is a possibility, then is there a way to reconcile this without a pageload? If this line of reasoning is wrong, then the code I have above is probably not enough to show what's wrong with my webpage. But I'm really just interested in whether or not this line of thought is a possibility.

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  • Large scale Merge Replication strategy - what can go wrong?

    - by niidto
    Hi, I'm developing a piece of software that uses Merge Replication and SQL Compact on Windows Mobile 6. At the moment it is running on 5 devices reasonably well. The issues I've come up against are as follows: The schema has had to change a lot, and will continue to have to change as the application evolves. There have been various errors replicating these schema changes down to the device, uploads failing due to schema inconsistencies. Subscriptions expiring (after 14 days) and unable to reinitialize with upload - AKA, potential data los of unsynced data up to that point. Basically, the worst case scenario is data loss, and when merge replication fails, there seems to be no way back to get the data off. My method until now has been to drop and create the subscription on the device. I don't hear many people doing this, though it seems to solve everything. The long term plan is to role this out to 500+ devices. Any advice on people who have undertaken similar projects, and how to minimise data loss and make it so that there's appropriate error handling code to recover from sync failures would be much appreciated. James

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  • Are there any NOSQL-compatible CMS projects?

    - by Michael
    This question is partially related to an older question (Any CMS is Google App Engine compatible?) , but is slightly more general. It seems that in most CMS systems, the most fragile failure point is the database. Traditional database implementations scale poorly and will never be able to handle unforeseen spikes of traffic. Since Google App Engine was designed to help even small businesses overcome that problem, I had the same question that was asked earlier this year with less than satisfactory answers. But more generally, where are the CMS projects that support NOSQL databases? Looking over Wikipedia's list of CMS platforms, I see without much effort that only traditional RDBMS are supported by every single vendor on the list. I would have expected to see at least one or two projects handling CouchDB or similar engines. I understand the complexities of implementing a NOSQL solution to a problem that is typically solved using the relations cleanly expressed in any RDBMS, but there seems to be a rather wide market gap. Since databases are, today, easily outsourced to Google, Amazon, and others which use NOSQL models, I am amazed that there are not more projects actively pursuing this path. Am I simply not aware? Can someone please point me to projects that have real momentum that are developing on this path? I'm looking for two things: a CMS that has as its backbone a NOSQL database enabling easy database outsourcing (hosted MySQL clusters and similar solutions are not what I'm looking for) a project that is built to run on either a PaaS architecture like Google App Engine or an IaaS architecture like Amazon EC2 Any pointers in that direction would be most welcome.

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  • How might a C# programmer approach writing a solution in javascript?

    - by Ben McCormack
    UPDATE: Perhaps this wasn't clear from my original post, but I'm mainly interested in knowing a best practice for how to structure javascript code while building a solution, not simply learning how to use APIs (though that is certainly important). I need to add functionality to a web site and our team has decided to approach the solution using a web service that receives a call from a JSON-formatted AJAX request from within the web site. The web service has been created and works great. Now I have been tasked with writing the javascript/html side of the solution. If I were solving this problem in C#, I would create separate classes for formatting the request, handling the AJAX request/response, parsing the response, and finally inserting the response somehow into the DOM. I would build properties and methods appropriately into each class, doing my best to separate functionality and structure where appropriate. However, I have to solve this problem in javascript. Firstly, how could I approach my solution in javascript in the way I would approach it from C# as described above? Or more importantly, what's a better way to approach structuring code in javascript? Any advice or links to helpful material on the web would be greatly appreciated. NOTE: Though perhaps not immediately relevant to this question, it may be worth noting that we will be using jQuery in our solution.

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  • The "correct" way of using multilingual support

    - by Felipe Athayde
    I just began working with ASP.NET and I'm trying to bring with me some coding standards I find healthy. Among such standards there is the multilingual support and the use of resources for easily handling future changes. Back when I used to code desktop applications, every text had to be translated, so it was a common practice to have the language files for every languages I would want to offer to the customers. In those files I would map every single text, from button labels to error messages. In ASP.NET, with the help of Visual Studio, I have the resort of using the IDE to generate such Resource Files (from Tools - Generate Local Resource), but then I would have to fill my webpages with labels - at least that is what I've learned from articles and tutorials. However, such approach looks a bit odd and I'm tempted to guess it doesn't smell that good as well. Now to the question: 1) Should I keep every single text in my website as labels and manage its contents in the resource files? It looks/feels odd specially when considering a text with several paragraphs. 2) Whenever I add/remove something, e.g.: a button, to an aspx file I would have to add it to the resource file as well, because generating the resource file again would simply override all my previous changes to it. That doesn't feel like a reusable code at all for me. Any comment suggestion on this one? Perhaps I got it all wrong from tutorials as it doesn't seem like a standardized matter - specially if it required recompiling the entire application whenever some change has to be done.

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  • MVC for a desktop application, connection a view/controller pair with another one

    - by lcf
    Hello. I've had mostly experience with "server-side" mvc frameworks very popular in different languages like ASP.NET MVC or Zend Framework for php, Spring for Java etc. Some of them are also possible to use for desktop applications development but I never tried that. I fully understand that design patterns should not limit implementation, they should generally provide ideas and common rules that can be differently implemented. Now I'm playing with one of those mvc frameworks for usual Desktop Applications development (it does not have many tutorials or a decent quickstart) and I have some questions regarding to the mvc paradigm. Here is one of them: What are common ways to link different views / controllers? If I click a button, special controller for that button dispatches the event that is generated, does something with the model, changes view state. But what if I need to interact with another view? Like, when I click on a button, it changes a model, but also I need to open another window or change state of another window (hiding a button on another window let's say...), without changing actually the model. What are common ways here to address this? Should my first controller generate an event for the second controller (or second view)? Or should the second controller be handling events from first view? Some links or examples for any languages/frameworks would be really helpful, thanks!

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  • Why I can't get all UDP packets?

    - by Jack
    My program use UdpClient to try to receive 27 responses from 27 hosts. The size of the response is 10KB. My broadband incoming bandwidth is 150KB/s. The 27 responses are sent from the hosts almost at the same time and for every 10 secs. However, I can only receive 8 - 17 responses each time. The number of responses that I can receive is quite dynamic but within the range. Can anyone tell me why? why can't I receive all? I understand UDP is not reliable. but I tried receiving 5 - 10 responses at the same time, it worked. I guess the network links are not so bad. The code is very simple. ON the 27 hosts, I just use UdpClient to send 10KB to my machine. On my machine, I have one UdpClient receive datagrams. Each time I get a data, I create a thread to handle it (basically handling it means just print out "I received 10KB", but it runs in a thread). listener = new UDPListener(Port); listener.Start(); while (true) { try { UDPContext context = listener.Accept(); ThreadPool.QueueUserWorkItem(new WaitCallback(HandleMessage), context); } catch (Exception) { } } If I reduce the size of the response down to 3KB, the case gets much better that roughly 25 responses can be received. Any more idea? UDP buffer problems???

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  • RequestBuilder timeouts and browser connection limits per domain.

    - by WesleyJohnson
    This is specifically about GWT's RequestBuilder, but should apply to general XHR as well. My company is having me build a near realtime chat application over HTTP. Yes, I do realize there are better ways to do chat aplications, but this is what they want. Eventually we want it working on the iPad/iPhone as well so flash is out, which rules out websockets and comet as well, I think? Anyway, I'm running into issues were I've set GWT's RequestBuilder timeout to 10 seconds and we get very random and sporadic timeouts. We've got error handling and emailing on the server side and never get any errors, which suggests the underlying XHR request that RequestBuilder is built on, never gets to the server and times out after 10 seconds. We're using these request to poll the server for new messages rather often and also for sending new messages to the server and also polling (less frequently) for other parts of application. What I'm afraid of is that we're running into the browsers limit on concurrent connections to the same domain (2 for IE by default?). Now my question is - If I construct a RequestBuilder and call it's send() method and the browser blocks it from sending until one of the 2 connections per domain is free, does the timeout still start while the request is being blocked or will it not start until the browser actually releases the underlying XHR? I hope that's clear, if not please let me know and I'll try to explain more.

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  • Is there a better way to keep track of session variable creation/access throughout different pages?

    - by Brandon
    Here's what I am working on. At my website I have multiple processes with each one containing multiple steps. Now in one of the processes, there is an error checking routine executed before proceeding to the next step of that process. A session var is set indicating the error status and it will either redirect back to the referrer or display the next page's contents. Now this kind of functionality, I believe, is common throughout web development. The issue that is occurring is that session vars are left around and are not being cleaned up properly. At times this introduces undesired behavior. My website is growing and I find that I am requiring more and more session vars to keep track of different system and error states. So I was thinking about creating a kind of "session variable keeper" to keep track of session var usage. The idea is fairly simple. It will have the notion of a context (e.g. registration process) and allow access to a predefined set of session vars within that context. In addition, the var and context will be paired with an action to proceed to some form of event handling. So if you haven't noticed I'm new to web development. Any thoughts or comments on the idea that I am proposing would be greatly appreciated. The back-end is written in PHP/MySQL.

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  • How should I handle expected errors? eg. "username already exists"

    - by Pheter
    I am struggling to understand how I should design the error handling parts of my code. I recently asked a similar question about how I should go about returning server error codes to the user, eg. 404 errors. I learnt that I should handle the error from within the current part of the application; seem's simple enough. However, what should I do when I can't handle the error from the current link in the chain? For example, I may have a class that is used to manage authentication. One of it's methods could be createUser($username, $password). Within that function, I need to determine if the username already exists. If this is true, how should I alert the calling code about this? Returning null instead of a user object is one way. But how do I then know what caused the error? How should I handle errors in such a way that calling code can easily find out what caused the error? Is there a design pattern commonly used for this kind of situation?

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  • [Ruby on Rails] complex model relationship

    - by siulamvictor
    I am not sure am I doing these correct. I have 3 models, Account, User, and Event. Account contains a group of Users. Each User have its own username and password for login, but they can access the same Account data under the same Account. Events is create by a User, which other Users in the same Account can also read or edit it. I created the following migrations and models. User migration class CreateUsers < ActiveRecord::Migration def self.up create_table :users do |t| t.integer :account_id t.string :username t.string :password t.timestamps end end def self.down drop_table :users end end Account migration class CreateAccounts < ActiveRecord::Migration def self.up create_table :accounts do |t| t.string :name t.timestamps end end def self.down drop_table :accounts end end Event migration class CreateEvents < ActiveRecord::Migration def self.up create_table :events do |t| t.integer :account_id t.integer :user_id t.string :name t.string :location t.timestamps end end def self.down drop_table :events end end Account model class Account < ActiveRecord::Base has_many :users has_many :events end User model class User < ActiveRecord::Base belongs_to :account end Event model class Event < ActiveRecord::Base belongs_to :account belongs_to :user end so.... Is this setting correct? Every time when a user create a new account, the system will as for the user information, i.e. username and password. How can I add them into correct tables? How can I add a new event? I am sorry for such a long question. I am not very understand the rails way in handling such data structure. Thank you guys for answering me. :)

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  • Is it bad practise to initialise fields outside of an explicit constructor

    - by MrTortoise
    So its monday and we are arguing about coding practises. The examples here are a litttle too simple, but the real deal has several constructors. In order to initialise the simple values (eg dates to their min value) I have moved the code out of the constructors and into the field definitions. public class ConstructorExample { string _string = "John"; } public class ConstructorExample2 { string _string; public ConstructorExample2() { _string = "John"; } } How should it be done by the book. I tend to be very case by case and so am maybe a little lax abotu this kind of thing. However i feel that accams razor tells me to move the initialisation out of multiple constructors. Of course I could always move this shared initialisation into a private method. The question is essentially ... is initialising fields where they are defined as opposed to the constructor bad in any way? The argument I am facing is one of error handling, but i do not feel it is relevant as there are no possible exceptions that won't be picked up at compile time.

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  • streaming xml pretty printer in C/C++ using expat or libxml2?

    - by Mark Zeren
    I have a library that outputs xml without whitespace all on one line. In some cases I'd like to pretty print that output. I'm looking for a BSD-ish licensed C/C++ library or sample code that will take a raw xml byte stream and pretty print it. Here's some pseudo code showing one way that I might use this functionality: void my_write(const char* buf, int len); PrettyPrinter pp(bind(&my_write)); while (...) { // ... get some more xml ... const char* buf = xmlSource.get_buf(); int len = xmlSource.get_buf_len(); int written = pp.write(buf, len); // calls my_write with pretty printed xml // ... error handling, maybe call write again, etc. ... } I'd like to avoid instantiating a DOM representation. I already have dependencies on the expat and libxml2 shared libraries, and I'd rather not add any more shared library dependencies.

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  • How to call a method from another class that's been instantiated within the current class

    - by Pavan
    my screen has a few views like such __________________ | _____ | | | | | //viewX is a video screen | | | | | viewX | vY | | //viewY is a custom uiview i created. | |____| | //it contains a method which i would like to call that toggles |_________________| //the hidden property of this view. and when it hides, a little | | //button is replaced no the top right corner on top of viewX | viewZ | //the video layer | | |_________________| //viewZ is a view containing many square views - thumbnails. my question is, i dont know how to register for touch events so that it recognises any touch event on no matter which view the user touches the screen.. atm im handling the touch events for each view inside it. so all works well... however what im trying to do is that when the user taps anywhere else on the screen but on viewY, viewY should dissapear by calling that method in the viewY class. this viewY class is instantiated and has no xib file attached to it. the uiview is created progammatically in the viewY class. this whole class for viewY behviour is instantiated in viewX - the video view. my boss says add delegates.. although i have now clue how to do that... any help? is there anyway i can just make it really simple and be able to say REMOVE VIEW no matter which class im calling from? Also ive seen other people achieve this by using these funky arrows - ... <- etc.. although im not sure if thats what i need or how to implement such a thing. ah i think ive made my question quite complicated but i really mean it to be a simple one, and know it can be done in an easy way!

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  • PDF search on the iPhone

    - by pt2ph8
    After two days trying to read annotations from a PDF using Quartz, I've managed to do it and posted my code. Now I'd like to do the same for another frequently asked question: searching PDF documents with Quartz. Same situation as before, this question has been asked many times with almost no practical answers. So I need some pointers first, as I still haven't implemented this myself. What I tried: I tried using CGPDFScannerScan handling the TJ and Tj operators - returns the right text on some PDF, whereas on other documents it returns mostly random letters. Maybe it's related to text encoding? Someone pointed out that text blocks (marked by BT/ET operators) should be handled instead, but I still haven't managed to do so. Anyone managed to extract text from any PDF? After that, searching should be easy by storing all the text in a NSMutableString and using rangeOfString (if there's a better way please let me know). But then how to highlight the result? I know there are a few operators to find the glyph sizes, so I could calculate the resulting rect based on those values, but I've been reading the spec for hours... it's a bloated mess and I'm going insane. Anyone with a practical explanation? Thanks.

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