Search Results

Search found 15302 results on 613 pages for 'rails console'.

Page 298/613 | < Previous Page | 294 295 296 297 298 299 300 301 302 303 304 305  | Next Page >

  • In what order does the Asset-Pipeline in Ruby on Rails load JavaScript Files? [on hold]

    - by psycatham
    So, when I decided to remove the tags <script></script> and benefit from the asset-pipeline instead, complications took place. I am working with Google Maps' API V3, and to benefit from their functions and objects that their code provides, you have load the link first <script src="https://maps.googleapis.com/maps/api/js?v=3.exp&libraries=places"></script> Basically, If I put this line before their code, and put their code in script tags, things work out pretty perfecty, but when I use javascript_include_tag instead of script tag in html and copy my code to the file I pointed at -Like This - <script src="https://maps.googleapis.com/maps/api/js?v=3.exp&libraries=places"></script> <%=javascript_include_tag "map_new_marker_drag"%> , the asset-pipeline seems to load That file before loading the link of Google Maps API, thus I get the error : - Uncaught ReferenceError : google is undefined I tried putting the link in javascript_include_tag too -Like this- <%=javascript_include_tag "https://maps.googleapis.com/maps/api/js?v=3.exp&libraries=places" %> <%=javascript_include_tag "map_new_marker_drag"%> , and it generated this <script src="https://maps.googleapis.com/maps/api/js?v=3.exp&amp;libraries=places"></script> <script src="https://maps.gstatic.com/cat_js/intl/en_us/mapfiles/api-3/17/2/%7Bmain,places%7D.js" type="text/javascript"></script> <script src="/assets/map_new_marker_drag.js?body=1"></script> and the same error Uncaught ReferenceError : google is undefined. Do I have to put it in another order? what am I missing about the asset-pipeline mechanisms? What should I do to make the link load before the code so to benefit from their objects and get rid of the error? PS : I tried using jquery functions and so , but I seem not to make it happen. If you still think this is a proper solution, please provide me some code I can use this is the jquery function I used jQuery(function($) { // Asynchronously Load the map API var script = document.createElement('script'); script.src = "http://maps.googleapis.com/maps/api/js?sensor=false&callback=initialize"; document.body.appendChild(script); var scriptTwo = document.createElement('script'); scriptTwo.src = "https://maps.googleapis.com/maps/api/js?v=3.exp&libraries=places"; document.body.appendChild(scripTwo); });

    Read the article

  • Apache FilesMatch regexp: Can it match by the cache buster 10 digit (rails generated) following the filename?

    - by ynkr
    According to the apache FilesMatch docs: The FilesMatch directive provides for access control by filename Basically, I only want to set an expires header for resources that have a 10 digit "cache buster" id appended to the name. So, here is my attempt at such a thing in my httpd.conf <FilesMatch "(jpg|jpeg|png|gif|js|css)\?\d{10}$"> ExpiresActive On ExpiresDefault "now plus 5 minutes" </FilesMatch> And here is an example of a resource I want to match: http://localhost:3000/images/of/elvis/eating-a-bacon-sandwich.png?1306277384 Now obviously my FilesMatch regexp is not matching so I am guessing 1 of 2 things is happening. Either my regexp is wonky or the '?1231231231' cache busting part of the file is not part of what apache considers part of the filename. Can anybody confirm and/or give me a way to cache only those resources that will not persist beyond the next deploy?

    Read the article

  • How do I tell cmake not to create a console window?

    - by user198729
    I can achieve this by gcc : gcc -mwindows -o simple simple.c But only find this in cmake: add_executable(simple WIN32 simple.c) But it's not exactly the same as -mwindows, this will require the entry point to be WinMain, while gcc -mwindows doesn't require this(can be main). How should I do it properly?

    Read the article

  • Heroku and Github integration (how to structure the project)

    - by Noah
    I'm creating a webservice and I want to store the source on github and run the app on heroku. I haven't seen my exact scenario addressed anywhere on the 'net so far, so I'll ask it here: I want to have the following directory structure: /project .git README <-- project readme file TODO.otl <-- project outline ... <-- other project-related stuff /my_rails_app app config ... README <-- rails' readme file In the above, project corresponds to http://github.com/myuser/project, and my_rails_app is the code that should be pushed to heroku. Do I need a separate branch for the rails app, or is there a simpler way that I'm missing? I guess my project-related non-rails files could live in my_rails_app, but the rails README already lives there and it seems inconsistent to overwrite that. However, if I leave it, my github page for the rails app will contain the rails readme, which makes no sense. Thanks, Noah P.S. I tried just setting it up as described above and running git push heroku from the main project folder. Of course, heroku doesn't know I want to deploy the subfolder: -----> Heroku receiving push ! Heroku push rejected, no Rails or Rack app detected.

    Read the article

  • jQuery AJAX request (Rails 3) gets redirected and returns empty message body (only with SSL)!

    - by elsurudo
    I'm trying to do a manual jQuery AJAX request the following way: $("#user_plan_id").change(function() { $("#plan_container").load('/plans/' + this.value); }); I have the "rails.js" file included in my header, and a "<%= csrf_meta_tag %". I see from my log that the request IS getting to the server (although without the authenticity token... does rails.js even do this?), but the response is a 302 (Found) rather than 200, and no data actually gets rendered. Any ideas? Edit: I now see that the first request redirects, and the proper partial gets rendered on the redirect. However, the 2nd response's body (on the client-side) is still empty. I'm guessing jQuery uses the first response and doesn't have a listener set up for the redirect. How do I get around this? Also, another note: the page doing the requesting is an HTTPS page. Here is what my log says: Started GET "/plans/221168073" for 127.0.0.1 at Tue Jun 15 01:24:06 -0400 2010 Processing by PlansController#show as HTML Parameters: {"id"=>"221168073"} DEPRECATION WARNING: Using #request_uri is deprecated. Use fullpath instead. (called from ensure_proper_protocol at /Users/ernestsurudo/Sites/vidfolia/vendor/plugins/ssl_requirement/lib/ssl_requirement.rb:57) Redirected to http://vidfolia.com/plans/221168073 Completed 302 Found in 1ms It turns out that if I turn off SSL requirement for that page, it works! I still have no idea why, though. So I suppose my question is: what is the workaround?

    Read the article

  • Repopulating a collection of Backbone forms with previously submitted data

    - by Brian Wheat
    I am able to post my forms to my database and I have stepped through my back end function to check and see that my Get function is returning the same data I submitted. However I am having trouble understanding how to have this data rendered upon visiting the page again. What am I missing? The intention is to be able to create, read, update, or delete (CRUD) some personal contact data for a variable collection of individuals. //Model var PersonItem = Backbone.Model.extend({ url: "/Application/PersonList", idAttribute: "PersonId", schema: { Title: { type: 'Select', options: function (callback) { $.getJSON("/Application/GetTitles/").done(callback); } }, Salutation: { type: 'Select', options: ['Mr.', 'Mrs.', 'Ms.', 'Dr.'] }, FirstName: 'Text', LastName: 'Text', MiddleName: 'Text', NameSuffix: 'Text', StreetAddress: 'Text', City: 'Text', State: { type: 'Select', options: function (callback) { $.getJSON("/Application/GetStates/").done(callback); } }, ZipCode: 'Text', PhoneNumber: 'Text', DateOfBirth: 'Date', } }); Backbone.Form.setTemplates(template, PersonItem); //Collection var PersonList = Backbone.Collection.extend({ model: PersonItem , url: "/Application/PersonList" }); //Views var PersonItemView = Backbone.Form.extend({ tagName: "li", events: { 'click button.delete': 'remove', 'change input': 'change' }, initialize: function (options) { console.log("ItemView init"); PersonItemView.__super__.initialize.call(this, options); _.bindAll(this, 'render', 'remove'); console.log("ItemView set attr = " + options); }, render: function () { PersonItemView.__super__.render.call(this); $('fieldset', this.el).append("<button class=\"delete\" style=\"float: right;\">Delete</button>"); return this; }, change: function (event) { var target = event.target; console.log('changing ' + target.id + ' from: ' + target.defaultValue + ' to: ' + target.value); }, remove: function () { console.log("delete button pressed"); this.model.destroy({ success: function () { alert('person deleted successfully'); } }); return false; } }); var PersonListView = Backbone.View.extend({ el: $("#application_fieldset"), events: { 'click button#add': 'addPerson', 'click button#save': 'save2db' }, initialize: function () { console.log("PersonListView Constructor"); _.bindAll(this, 'render', 'addPerson', 'appendItem', 'save'); this.collection = new PersonList(); this.collection.bind('add', this.appendItem); //this.collection.fetch(); this.collection.add([new PersonItem()]); console.log("collection length = " + this.collection.length); }, render: function () { var self = this; console.log(this.collection.models); $(this.el).append("<button id='add'>Add Person</button>"); $(this.el).append("<button id='save'>Save</button>"); $(this.el).append("<fieldset><legend>Contact</legend><ul id=\"anchor_list\"></ul>"); _(this.collection.models).each(function (item) { self.appendItem(item); }, this); $(this.el).append("</fieldset>"); }, addPerson: function () { console.log("addPerson clicked"); var item = new PersonItem(); this.collection.add(item); }, appendItem: function (item) { var itemView = new PersonItemView({ model: item }); $('#anchor_list', this.el).append(itemView.render().el); }, save2db: function () { var self = this; console.log("PersonListView save"); _(this.collection.models).each(function (item) { console.log("item = " + item.toJSON()); var cid = item.cid; console.log("item.set"); item.set({ Title: $('#' + cid + '_Title').val(), Salutation: $('#' + cid + '_Salutation').val(), FirstName: $('#' + cid + '_FirstName').val(), LastName: $('#' + cid + '_LastName').val(), MiddleName: $('#' + cid + '_MiddleName').val(), NameSuffix: $('#' + cid + '_NameSuffix').val(), StreetAddress: $('#' + cid + '_StreetAddress').val(), City: $('#' + cid + '_City').val(), State: $('#' + cid + '_State').val(), ZipCode: $('#' + cid + '_ZipCode').val(), PhoneNumber: $('#' + cid + '_PhoneNumber').val(), DateOfBirth: $('#' + cid + '_DateOfBirth').find('input').val() }); if (item.isNew()) { console.log("item.isNew"); self.collection.create(item); } else { console.log("!item.isNew"); item.save(); } }); return false; } }); var personList = new PersonList(); var view = new PersonListView({ collection: personList }); personList.fetch({ success: function () { $("#application_fieldset").append(view.render()); } });

    Read the article

  • jQuery AJAX request (Rails 3) gets redirected and returns empty message body!

    - by elsurudo
    I'm trying to do a manual jQuery AJAX request the following way: $("#user_plan_id").change(function() { $("#plan_container").load('/plans/' + this.value); }); I have the "rails.js" file included in my header, and a "<%= csrf_meta_tag %". I see from my log that the request IS getting to the server (although without the authenticity token... does rails.js even do this?), but the response is a 302 (Found) rather than 200, and no data actually gets rendered. Any ideas? Edit: I now see that the first request redirects, and the proper partial gets rendered on the redirect. However, the 2nd response's body (on the client-side) is still empty. I'm guessing jQuery uses the first response and doesn't have a listener set up for the redirect. How do I get around this? Also, another note: the page doing the requesting is an HTTPS page. Here is what my log says: Started GET "/plans/221168073" for 127.0.0.1 at Tue Jun 15 01:24:06 -0400 2010 Processing by PlansController#show as HTML Parameters: {"id"=>"221168073"} DEPRECATION WARNING: Using #request_uri is deprecated. Use fullpath instead. (called from ensure_proper_protocol at /Users/ernestsurudo/Sites/vidfolia/vendor/plugins/ssl_requirement/lib/ssl_requirement.rb:57) Redirected to http://vidfolia.com/plans/221168073 Completed 302 Found in 1ms Perhaps it has something to do with the deprecation warning?

    Read the article

  • Tuple in C# 4.0

    - by Jalpesh P. Vadgama
    C# 4.0 language includes a new feature called Tuple. Tuple provides us a way of grouping elements of different data type. That enables us to use it a lots places at practical world like we can store a coordinates of graphs etc. In C# 4.0 we can create Tuple with Create method. This Create method offer 8 overload like following. So you can group maximum 8 data types with a Tuple. Followings are overloads of a data type. Create(T1)- Which represents a tuple of size 1 Create(T1,T2)- Which represents a tuple of size 2 Create(T1,T2,T3) – Which represents a tuple of size 3 Create(T1,T2,T3,T4) – Which represents a tuple of size 4 Create(T1,T2,T3,T4,T5) – Which represents a tuple of size 5 Create(T1,T2,T3,T4,T5,T6) – Which represents a tuple of size 6 Create(T1,T2,T3,T4,T5,T6,T7) – Which represents a tuple of size 7 Create(T1,T2,T3,T4,T5,T6,T7,T8) – Which represents a tuple of size 8 Following are some example code for tuple. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TupleExample { class Program { static void Main(string[] args) { var tuple = System.Tuple.Create<string, string, string>("Jalpesh", "P", "Vadgama"); Console.WriteLine(tuple); var t = System.Tuple.Create<int, string>(1, "Jalpesh"); Console.WriteLine(t); } } } Following is a output of above as expected. You can also access values insides Tuple with ItemN property. Where N represents particular number of item in tuple. Following is an example of it. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TupleExample { class Program { static void Main(string[] args) { var tuple = System.Tuple.Create<string, string, string>("Jalpesh", "P", "Vadgama"); Console.WriteLine(tuple.Item1); Console.WriteLine(tuple.Item2); Console.WriteLine(tuple.Item3); } } } Here you can see I have printed items with Item1,Item2 and Item3 . Following is the output of above code.   Even we can create a nested tuple also following is code for nested tuple. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TupleExample { class Program { static void Main(string[] args) { var tuple = System.Tuple.Create(1,"Jalpesh",new Tuple<string,string>("P","Vadgama")); Console.WriteLine(tuple.Item1); Console.WriteLine(tuple.Item2); Console.WriteLine(tuple.Item3); } } } Following is a output above code as expected. As you can see there are unlimited possibilities we can do lots of things with Tuple. Hope you liked it. Stay tuned for more. Till then Happy Programming!!

    Read the article

  • Expert F# &ndash; Pattern Matching with Adam and Eve

    - by MarkPearl
    So I am loving my Expert F# book. I wish I had more time with it, but the little time I get I really enjoy. However today I was completely stumped by what the book was trying to get across with regards to pattern matching. On Page 38 – Chapter 3, it briefly describes F# option values. On this page it gives the code snippet along the code lines below and then goes on to speak briefly about pattern matching... open System type 'a option = | None | Some of 'a let people = [ ("Adam", None); ("Eve", None); ("Cain", Some("Adam", "Eve")); ("Abel", Some("Adam", "Eve")) ] let showParents(name, parents) = match parents with | Some(dad, mum) -> printfn "%s has father %s, mother %s" name dad mum | None -> printfn "%s has no parents!" name Console.WriteLine(showParents("Adam", None))   Originally when I read this code I think I misunderstood the purpose of the example code. I for some reason thought that the showParents function would magically be parsing the people array and looking for a match of name and then showing the parents. But obviously it cannot do this since there is no reference to the people array in the showParents method. After rereading the page I realized that I had just combined the two segments of code together, possibly incorrectly, and that a better example would have been to have a code snippet like the following. let showParents(name, parents) = match parents with | Some(dad, mum) -> printfn "%s has father %s, mother %s" name dad mum | None -> printfn "%s has no parents!" name Console.WriteLine(showParents("Adam", None)) Console.WriteLine(showParents("Cain", Some("Adam", "Eve"))) Console.ReadLine()   However, what if I wanted to have a function that was passed a list of people and a name would then show the parents of the name if there were any, and if not would show that they had no parents… so that doesnt seem to difficult does it… lets look at my very unoptimized noob F# code to try and achieve this… open System let people = [ ("Adam", None); ("Eve", None); ("Cain", Some("Adam", "Eve")); ("Abel", Some("Adam", "Eve")) ] // // returns the name of the person // let showName(person : string * (string * string) option) = let name = fst(person) name // // Returns a string with the parents details or not // let showParents(itemData : string * (string * string) option) = let name = fst(itemData) let parents = snd(itemData) match parents with | Some(dad, mum) -> "Father " + dad + " and Mother " + mum | None -> "Has no parents!" // // Prints the details // let showDetails(person : string * (string * string) option) = Console.WriteLine(showName(person)) Console.WriteLine(showParents(person)) // // Check if the name matches the first portion of person // if so, return true, else return false // let nameMatch(name : string , person : string * (string * string) option) = match name with | x when x = fst(person) -> true | _ -> false // // Searches an array of people and looks for a match of names // let findPerson(name : string, people : (string * (string * string) option) list) = let o = Seq.tryFind(fun x -> nameMatch(name, x)) people if Option.isSome o then o else Option.None // // Try and find a person, if found show their details // else show no match // let FoundPerson = findPerson("Cain", people) match FoundPerson with | None -> Console.WriteLine("Not found") | Some(x) -> showDetails(x) Console.ReadLine() So, my code isn’t the cleanest but it did teach me a bit more F#. The area that I learnt about was the option keyword. The challenge being, if a match of the name isn’t found – and if a name is found but the person doesn’t have parents it should react accordingly. I’m pretty sure I can optimize this code quite a bit more and I think I may come back to it sometime in the future and relook at it, but for now at least I was able to achieve what I wanted.. and my brain has gone just that wee little bit more functional.

    Read the article

  • SQLAuthority News – Amazon Gift Card Raffle for Beta Tester Feedback for NuoDB

    - by pinaldave
    As regular readers know I’ve been spending some time working with the NuoDB beta software. They contacted me last week and asked if I would give you a chance to try their new web-based console for their scalable, SQL-compliant database. They have just put out their final beta release, Beta 9.  It contains a preview of a new web-based “NuoConsole” that will replace and extend the functionality of their current desktop version.  I haven’t spent any time with the new console yet but a really quick look tells me it should make it easier to do deeper monitoring than the older one. It also looks like they have added query-level reporting through the console. I will try to play with it soon. NuoDB is doing a last, big push to get some more feedback from developers before they release their 1.0 product sometime in the next several weeks. Since the console is new, they are especially interested in some quick feedback on it before general availability. For SQLAuthority readers only, NuoDB will raffle off three $50 Amazon gift cards in exchange for your feedback on the NuoConsole preview. Here’s how to Enter Download NuoDBeta 9 here You must build a domain before you can start the console. Launch the Web Console. Windows Code: start java -jar jarnuodbwebconsole.jar Mac, Linux, Solaris, Unix Code: java -jar jar/nuodbwebconsole.jar Access the Web Console: Code: http://localhost:8080 When you have tried it out, go to a short (8 question) survey to enter the raffle Click here for the survey You must complete the survey before midnight EDT on October 17, 2012. Here’s what else they are saying about this last beta before general availability: Beta 9 now supports the Zend PHP framework so that PHP developers can directly integrate web applications with NuoDB. Multi-threaded HDFS support – NuoDB Storage Managers can now be configured to persist data to the high performance Hadoop distributed file system (HDFS). Beta 9 optimizes for multi-thread I/O streams at maximum performance. This enhancement allows users to make Hadoop their core storage with no extra effort which is a pretty cool idea. Improved Performance –On a single transaction node, Beta 9 offers performance comparable with MySQL and MariaDB. As additional nodes are added, NuoDB performance improves significantly at near linear scale. Query & Explain Plan Logging – Beta 9 introduces SQL explain plans for your queries. Qualify queries with the word “EXPLAIN” and NuoDB will respond with the details of the execution plan allowing performance optimization to SQL. Through the NuoConsole, you can now kill hung or long running queries. Java App Server Support – Beta 9 now supports leading Web JEE app servers including JBoss, Tomcat, and ColdFusion. They’ve also reported: Improved PHP/PDO drivers Support for Drupal Faster Ruby on Rails driver The Hibernate Dialect supports version 4.1 And good news for my readers: numerous SQL enhancements They will share the results of the web console feedback with me.  I’ll let you know how it goes. Also the winner of their last contest was Jaime Martínez Lafargue!  Do leave a comment here once you complete the survey.  Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: SQL Authority Tagged: NuoDB

    Read the article

  • android client not working [migrated]

    - by Syeda Zunairah
    i have a java client and c# server the server code is static Socket listeningSocket; static Socket socket; static Thread thrReadRequest; static int iPort = 4444; static int iConnectionQueue = 100; static void Main(string[] args) { Console.WriteLine(IPAddress.Parse(getLocalIPAddress()).ToString()); try { listeningSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); //listeningSocket.Bind(new IPEndPoint(0, iPort)); listeningSocket.Bind(new IPEndPoint(IPAddress.Parse(getLocalIPAddress()), iPort)); listeningSocket.Listen(iConnectionQueue); thrReadRequest = new Thread(new ThreadStart(getRequest)); thrReadRequest.Start(); } catch (Exception e) { Console.WriteLine("Winsock error: " + e.ToString()); //throw; } } static private void getRequest() { int i = 0; while (true) { i++; Console.WriteLine("Outside Try i = {0}", i.ToString()); try { socket = listeningSocket.Accept(); // Receiving //byte[] rcvLenBytes = new byte[4]; //socket.Receive(rcvLenBytes); //int rcvLen = System.BitConverter.ToInt32(rcvLenBytes, 0); //byte[] rcvBytes = new byte[rcvLen]; //socket.Receive(rcvBytes); //String formattedBuffer = System.Text.Encoding.ASCII.GetString(rcvBytes); byte[] buffer = new byte[socket.SendBufferSize]; int iBufferLength = socket.Receive(buffer, 0, buffer.Length, 0); Console.WriteLine("Received {0}", iBufferLength); Array.Resize(ref buffer, iBufferLength); string formattedBuffer = Encoding.ASCII.GetString(buffer); Console.WriteLine("Data received by Client: {0}", formattedBuffer); if (formattedBuffer == "quit") { socket.Close(); listeningSocket.Close(); Environment.Exit(0); } Console.WriteLine("Inside Try i = {0}", i.ToString()); Thread.Sleep(500); } catch (Exception e) { //socket.Close(); Console.WriteLine("Receiving error: " + e.ToString()); Console.ReadKey(); //throw; } finally { socket.Close(); //listeningsocket.close(); } } } static private string getLocalIPAddress() { IPHostEntry host; string localIP = ""; host = Dns.GetHostEntry(Dns.GetHostName()); foreach (IPAddress ip in host.AddressList) { if (ip.AddressFamily == AddressFamily.InterNetwork) { localIP = ip.ToString(); break; } } return localIP; } } and the jave android code is private TCPClient mTcpClient; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); final EditText editText = (EditText) findViewById(R.id.edit_message); Button send = (Button)findViewById(R.id.sendbutton); // connect to the server new connectTask().execute(""); send.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String message = editText.getText().toString(); //sends the message to the server if (mTcpClient != null) { mTcpClient.sendMessage(message); } editText.setText(""); } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main, menu); return true; } public class connectTask extends AsyncTask<String,String,TCPClient> { @Override protected TCPClient doInBackground(String... message) { mTcpClient = new TCPClient(new TCPClient.OnMessageReceived() { @Override public void messageReceived(String message) { publishProgress(message); } }); mTcpClient.run(); return null; } @Override protected void onProgressUpdate(String... values) { super.onProgressUpdate(values); } } } when i run the server it gives output of try i=1. can any one tell me what to do next

    Read the article

  • Inside BackgroundWorker

    - by João Angelo
    The BackgroundWorker is a reusable component that can be used in different contexts, but sometimes with unexpected results. If you are like me, you have mostly used background workers while doing Windows Forms development due to the flexibility they offer for running a background task. They support cancellation and give events that signal progress updates and task completion. When used in Windows Forms, these events (ProgressChanged and RunWorkerCompleted) get executed back on the UI thread where you can freely access your form controls. However, the logic of the progress changed and worker completed events being invoked in the thread that started the background worker is not something you get directly from the BackgroundWorker, but instead from the fact that you are running in the context of Windows Forms. Take the following example that illustrates the use of a worker in three different scenarios: – Console Application or Windows Service; – Windows Forms; – WPF. using System; using System.ComponentModel; using System.Threading; using System.Windows.Forms; using System.Windows.Threading; class Program { static AutoResetEvent Synch = new AutoResetEvent(false); static void Main() { var bw1 = new BackgroundWorker(); var bw2 = new BackgroundWorker(); var bw3 = new BackgroundWorker(); Console.WriteLine("DEFAULT"); var unspecializedThread = new Thread(() => { OutputCaller(1); SynchronizationContext.SetSynchronizationContext( new SynchronizationContext()); bw1.DoWork += (sender, e) => OutputWork(1); bw1.RunWorkerCompleted += (sender, e) => OutputCompleted(1); // Uses default SynchronizationContext bw1.RunWorkerAsync(); }); unspecializedThread.IsBackground = true; unspecializedThread.Start(); Synch.WaitOne(); Console.WriteLine(); Console.WriteLine("WINDOWS FORMS"); var windowsFormsThread = new Thread(() => { OutputCaller(2); SynchronizationContext.SetSynchronizationContext( new WindowsFormsSynchronizationContext()); bw2.DoWork += (sender, e) => OutputWork(2); bw2.RunWorkerCompleted += (sender, e) => OutputCompleted(2); // Uses WindowsFormsSynchronizationContext bw2.RunWorkerAsync(); Application.Run(); }); windowsFormsThread.IsBackground = true; windowsFormsThread.SetApartmentState(ApartmentState.STA); windowsFormsThread.Start(); Synch.WaitOne(); Console.WriteLine(); Console.WriteLine("WPF"); var wpfThread = new Thread(() => { OutputCaller(3); SynchronizationContext.SetSynchronizationContext( new DispatcherSynchronizationContext()); bw3.DoWork += (sender, e) => OutputWork(3); bw3.RunWorkerCompleted += (sender, e) => OutputCompleted(3); // Uses DispatcherSynchronizationContext bw3.RunWorkerAsync(); Dispatcher.Run(); }); wpfThread.IsBackground = true; wpfThread.SetApartmentState(ApartmentState.STA); wpfThread.Start(); Synch.WaitOne(); } static void OutputCaller(int workerId) { Console.WriteLine( "bw{0}.{1} | Thread: {2} | IsThreadPool: {3}", workerId, "RunWorkerAsync".PadRight(18), Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread); } static void OutputWork(int workerId) { Console.WriteLine( "bw{0}.{1} | Thread: {2} | IsThreadPool: {3}", workerId, "DoWork".PadRight(18), Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread); } static void OutputCompleted(int workerId) { Console.WriteLine( "bw{0}.{1} | Thread: {2} | IsThreadPool: {3}", workerId, "RunWorkerCompleted".PadRight(18), Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread); Synch.Set(); } } Output: //DEFAULT //bw1.RunWorkerAsync | Thread: 3 | IsThreadPool: False //bw1.DoWork | Thread: 4 | IsThreadPool: True //bw1.RunWorkerCompleted | Thread: 5 | IsThreadPool: True //WINDOWS FORMS //bw2.RunWorkerAsync | Thread: 6 | IsThreadPool: False //bw2.DoWork | Thread: 5 | IsThreadPool: True //bw2.RunWorkerCompleted | Thread: 6 | IsThreadPool: False //WPF //bw3.RunWorkerAsync | Thread: 7 | IsThreadPool: False //bw3.DoWork | Thread: 5 | IsThreadPool: True //bw3.RunWorkerCompleted | Thread: 7 | IsThreadPool: False As you can see the output between the first and remaining scenarios is somewhat different. While in Windows Forms and WPF the worker completed event runs on the thread that called RunWorkerAsync, in the first scenario the same event runs on any thread available in the thread pool. Another scenario where you can get the first behavior, even when on Windows Forms or WPF, is if you chain the creation of background workers, that is, you create a second worker in the DoWork event handler of an already running worker. Since the DoWork executes in a thread from the pool the second worker will use the default synchronization context and the completed event will not run in the UI thread.

    Read the article

  • How to serve Rails application with Passenger/Apache without domain name?

    - by grifaton
    I am trying to serve a Rails application using Passenger and Apache on a Ubuntu server. The Passenger installation instructions say I should add the following to my Apache configuration file - I assume this is /etc/apache2/httpd.conf. <VirtualHost *:80> ServerName www.yourhost.com DocumentRoot /somewhere/public # <-- be sure to point to 'public'! <Directory /somewhere/public> AllowOverride all # <-- relax Apache security settings Options -MultiViews # <-- MultiViews must be turned off </Directory> </VirtualHost> However, I do not yet have a domain pointing at my server, so I'm not sure what I should put for the ServerName parameter. I have tried the IP address, but when I do that, restarting Apache gives apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName [Sun Jan 17 12:49:26 2010] [error] VirtualHost *:80 -- mixing * ports and non-* ports with a NameVirtualHost address is not supported, proceeding with undefined results apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName [Sun Jan 17 12:49:36 2010] [error] VirtualHost *:80 -- mixing * ports and non-* ports with a NameVirtualHost address is not supported, proceeding with undefined results and pointing the browser at the IP address gives a 500 Internal Server Error. The closest I have got to something sensible is with <VirtualHost efate:80> ServerName efate DocumentRoot /root/jpf/public <Directory /root/jpf/public> AllowOverride all Options -MultiViews </Directory> </VirtualHost> where "efate" is my server's host name. But now pointing my browser at the server's IP address just gives a page saying "It works!" - presumably this is a default page, but I'm not sure where this is being served from. I might be wrong in thinking that the reason I have been unable to get this to work is related to not having a domain name. This is the first time I have used Apache directly - any help would be most gratefully received!

    Read the article

  • Unicorn 3.3.1 and Rack 1.1.0 issues?

    - by user41422
    I'm upgrading from the Ruby Enterprise Edition 1.8.6 to the latest 1.8.7 version with Unicorn to facilitate an upgrade to Rails 2.3.10, and am running into some issues. Should I uninstall the older versions of these gems? Here's the log messages: I'm upgrading from the Ruby Enterprise Edition 1.8.6 to the latest 1.8.7 version with Unicorn to facilitate an upgrade to Rails 2.3.10, and am running into some issues. Should I uninstall the older versions of these gems? I, [2011-02-02T22:06:16.328076 #30672] INFO -- : listening on addr=0.0.0.0:8080 fd=3 I, [2011-02-02T22:06:16.333137 #30672] INFO -- : Refreshing Gem list /srv/ree/bin/unicorn_rails must be run inside RAILS_ROOT: #<Gem::LoadError: can't activate rack (~> 1.1.0, runtime) for ["actionpack-2.3.10", "rails-2.3.10"], already activated rack-1.2.1 for ["unicorn-3.3.1"]> I, [2011-02-02T22:07:12.259436 #30701] INFO -- : listening on addr=0.0.0.0:8080 fd=3 I, [2011-02-02T22:07:12.259952 #30701] INFO -- : Refreshing Gem list /srv/ree/bin/unicorn_rails must be run inside RAILS_ROOT: #<Gem::LoadError: can't activate rack (~> 1.1.0, runtime) for ["actionpack-2.3.10", "rails-2.3.10"], already activated rack-1.2.1 for ["unicorn-3.3.1"]> I, [2011-02-02T22:09:27.787177 #30772] INFO -- : listening on addr=0.0.0.0:8080 fd=3 I, [2011-02-02T22:09:27.787691 #30772] INFO -- : Refreshing Gem list /srv/ree/bin/unicorn_rails must be run inside RAILS_ROOT: #<Gem::LoadError: can't activate rack (~> 1.1.0, runtime) for ["actionpack-2.3.10", "rails-2.3.10"], already activated rack-1.2.1 for ["unicorn-3.3.1"]> I, [2011-02-02T22:10:44.175407 #30846] INFO -- : listening on addr=0.0.0.0:8080 fd=3 I, [2011-02-02T22:10:44.175928 #30846] INFO -- : Refreshing Gem list /srv/ree/bin/unicorn_rails must be run inside RAILS_ROOT: #<Gem::LoadError: can't activate rack (~> 1.1.0, runtime) for ["actionpack-2.3.10", "rails-2.3.10"], already activated rack-1.2.1 for ["unicorn-3.3.1"]>

    Read the article

  • SMO ManagedComputer.ServiceInstances is empty

    - by Mark J Miller
    I am trying to use SMO (VS 2010, SQL Server 2008) to connect to SQL Server and view the server protocol configuration. I can connect and list the Services and ClientProtocols as well as the account MSSQLSERVER service is running under. However, the ServerInstances collection is empty. The only instance on the target server is the default (MSSQLSERVER), shouldn't that be in the collection? How can I get an instance of it so I can inspect the ServerProtocols collection? Here's the code I'm using: class Program { static void Main(string[] args) { //machine hosting installed sql server instance ManagedComputer host = new ManagedComputer("dev-it-db01.dev.interbankfx.lcl"); //ManagedComputer host = new ManagedComputer("MRW-IT-DTP69"); if (host.ServerInstances.Count != 0) { //why is this 0? Is it because only the DEFAULT instance exists? Console.WriteLine("/////////////// INSTANCES ////////////////"); foreach (ServerInstance inst in host.ServerInstances) { Console.WriteLine(inst.Name); } } Console.WriteLine("/////////////// SERVICES ////////////////"); // enumerate sql services (looking for MSSSQLSERVER) foreach (Service svc in host.Services) { Console.WriteLine(svc.Name); } Console.WriteLine("/////////////// DETAILS ////////////////"); // get name of MSSQLSERVER instance from user (pick from list above) Service mssqlserver = host.Services["MSSQLSERVER"]; // print service account: .\{account} == "local account", "LocalSystem", "NetworkService", {domain}\{account} == "domain account" Console.WriteLine("Service Account: {0}", mssqlserver.ServiceAccount); // get client protocols foreach (ClientProtocol cp in host.ClientProtocols) { Console.WriteLine("{0} {1} ({2})", cp.Order, cp.DisplayName, cp.IsEnabled ? "Enabled" : "Disabled"); } } } I've also tried: Urn u = new Urn("ManagedComputer[@Name=dev-it-db01.dev.interbankfx.lcl]/ServerInstance[@Name='MSSQLSERVER']/ServerProtocol[@Name='Tcp']"); ServerProtocol tcp = host.GetSmoObject(u) as ServerProtocol; if (tcp != null) { Console.WriteLine("{0}", tcp.DisplayName); } But I get an error message stating: "child expressions are not supported." Any ideas what's wrong?

    Read the article

  • C# iterator is executed twice when composing two IEnumerable methods

    - by achristoph
    I just started learning about C# iterator but got confused with the flow of the program after reading the output of the program. The foreach with uniqueVals seems to be executed twice. My understanding is that the first few lines up to the line before "Nums in Square: 3" should not be there. Can anyone help to explain why this happens? The output is: Unique: 1 Adding to uniqueVals: 1 Unique: 2 Adding to uniqueVals: 2 Unique: 2 Unique: 3 Adding to uniqueVals: 3 Nums in Square: 3 Unique: 1 Adding to uniqueVals: 1 Square: 1 Number returned from Unique: 1 Unique: 2 Adding to uniqueVals: 2 Square: 2 Number returned from Unique: 4 Unique: 2 Unique: 3 Adding to uniqueVals: 3 Square: 3 Number returned from Unique: 9 static class Program { public static IEnumerable<T> Unique<T>(IEnumerable<T> sequence) { Dictionary<T, T> uniqueVals = new Dictionary<T, T>(); foreach (T item in sequence) { Console.WriteLine("Unique: {0}", item); if (!uniqueVals.ContainsKey(item)) { Console.WriteLine("Adding to uniqueVals: {0}", item); uniqueVals.Add(item, item); yield return item; Console.WriteLine("After Unique yield: {0}", item); } } } public static IEnumerable<int> Square(IEnumerable<int> nums) { Console.WriteLine("Nums in Square: {0}", nums.Count()); foreach (int num in nums) { Console.WriteLine("Square: {0}", num); yield return num * num; Console.WriteLine("After Square yield: {0}", num); } } static void Main(string[] args) { var nums = new int[] { 1, 2, 2, 3 }; foreach (int num in Square(Unique(nums))) Console.WriteLine("Number returned from Unique: {0}", num); Console.Read(); } }

    Read the article

  • jQuery AJAX chained calls + Celery in Django

    - by user1029968
    Currently clicking one of the links in my application, triggers AJAX call (GET) that - if succeeds - triggers the second one and this second one - if succeeds - calls the third one. This way user can be informed which part of process started when clicking the link is currently ongoing. So in the template file in Django project, click callback body for link mentioned looks like below: $("#the-link").click(function(item)) { // CALL 1 $.ajax({ url: {% url ajax_call_1 %}, data: { // something } }) .done(function(call1Result) { // CALL 2 $.ajax({ url: {% url ajax_call_1 %}, data: { // call1Result passed here to CALL 2 } }) .done(function(call2Result) { // CALL 3 $.ajax({ url: {%url ajax_call_3 %}, data: { // call2Result passed here to CALL 3 } }) .done(function(call3Result) { // expected result if everything went fine console.log("wow, it worked!"); console.log(call3Result); }) .fail(function(errorObject) { console.log("call3 failed"); console.log(errorObject); } }) .fail(function(errorObject)) { console.log("call2 failed"); console.log(errorObject); } }) .fail(function(errorObject) { console.log("call1 failed"); console.log(errorObject); }); }); This works fine for me. The thing is, I'd like to prevent interrupting the following calls if the user closes the browser and the calls are not finished (as it will take some time to finish all three), as there is some additional logic in Django view functions called in each GET request. For example, if user clicks the link and closes the browser during CALL 1, is it possible to somehow go on with the following CALL 2 and CALL 3? I know that normally I'd be able to use Celery Task to process the function but is it still possible here with the chained calls mentioned? Any help is much appreciated!

    Read the article

  • VB.NET CInt(Long) behaving differently in 32- and 64-bit environments

    - by LocoDelAssembly
    Hello everybody, this is my first message here. Today I had a problem converting a Long (Int64) to an Integer (Int32). The problem is that my code was always working in 32-bit environments, but when I try THE SAME executable in a 64-bit computer it crashes with a System.OverflowException exception. I've prepared this test code in VS2008 in a new project with default settings: Module Module1 Sub Main() Dim alpha As Long = -1 Dim delta As Integer Try delta = CInt(alpha And UInteger.MaxValue) Console.WriteLine("CINT OK") delta = Convert.ToInt32(alpha And UInteger.MaxValue) Console.WriteLine("Convert.ToInt32 OK") Catch ex As Exception Console.WriteLine(ex.GetType().ToString()) Finally Console.ReadLine() End Try End Sub End Module On my 32-bit setups (Windows XP SP3 32-bit and Windows 7 32-bit) it prints "CINT OK", but in the 64-bit computer (Windows 7 64-bit) that I've tested THE SAME executable it prints the exception name only. Is this behavior documented? I tried to find a reference but failed miserably. For reference I leave the MSIL code too: .method public static void Main() cil managed { .entrypoint .custom instance void [mscorlib]System.STAThreadAttribute::.ctor() = ( 01 00 00 00 ) // Code size 88 (0x58) .maxstack 2 .locals init ([0] int64 alpha, [1] int32 delta, [2] class [mscorlib]System.Exception ex) IL_0000: nop IL_0001: ldc.i4.m1 IL_0002: conv.i8 IL_0003: stloc.0 IL_0004: nop .try { .try { IL_0005: ldloc.0 IL_0006: ldc.i4.m1 IL_0007: conv.u8 IL_0008: and IL_0009: conv.ovf.i4 IL_000a: stloc.1 IL_000b: ldstr "CINT OK" IL_0010: call void [mscorlib]System.Console::WriteLine(string) IL_0015: nop IL_0016: ldloc.0 IL_0017: ldc.i4.m1 IL_0018: conv.u8 IL_0019: and IL_001a: call int32 [mscorlib]System.Convert::ToInt32(int64) IL_001f: stloc.1 IL_0020: ldstr "Convert.ToInt32 OK" IL_0025: call void [mscorlib]System.Console::WriteLine(string) IL_002a: nop IL_002b: leave.s IL_0055 } // end .try catch [mscorlib]System.Exception { IL_002d: dup IL_002e: call void [Microsoft.VisualBasic]Microsoft.VisualBasic.CompilerServices.ProjectData::SetProjectError(class [mscorlib]System.Exception) IL_0033: stloc.2 IL_0034: nop IL_0035: ldloc.2 IL_0036: callvirt instance class [mscorlib]System.Type [mscorlib]System.Exception::GetType() IL_003b: callvirt instance string [mscorlib]System.Type::ToString() IL_0040: call void [mscorlib]System.Console::WriteLine(string) IL_0045: nop IL_0046: call void [Microsoft.VisualBasic]Microsoft.VisualBasic.CompilerServices.ProjectData::ClearProjectError() IL_004b: leave.s IL_0055 } // end handler } // end .try finally { IL_004d: nop IL_004e: call string [mscorlib]System.Console::ReadLine() IL_0053: pop IL_0054: endfinally } // end handler IL_0055: nop IL_0056: nop IL_0057: ret } // end of method Module1::Main I suspect that the instruction that is behaving differently is either conv.ovf.i4 or the ldc.i4.m1/conv.u8 pair. If you know what is going on here please let me know Thanks

    Read the article

  • Javascript - Wait for function to return

    - by LoadData
    So, I am working on a project which requires me to call upon a function to get data from an external source. The issue I am having, I call upon the function - However the code after the function call is continuing before the function has returned a value. Here is the function - function getData() { var myVar; var xmlLoc = $.get("http://ec.urbentom.co.uk/StudentAppData.xml", function(data) { $xml = $(data); myVar = $xml; console.log(myVar); console.log(String($xml)); localStorage.setItem("Data", $xml); console.log(String(localStorage.getItem("Data"))); return myVar; }); return myVar; console.log("Does this continue"); } And here is where it is called upon - $(document).on("pageshow","#Information",function() { $xml = $(getData()); //Here is the function call console.log($xml); //However, it will instantly go to this line before 'getData' has returned a value. $xml.find('AllData').each(function() { $(this).find('item').each(function() { if ($(this).find('Category').text()=="Facilities") { console.log($(this).find('Title').text()); //Do stuff here } else if ($(this).find('Category').text()=="Contacts" || $(this).find('Category').text()=="Information") { console.log($(this).find('Title').text()); //Do stuff here too } }); $('#informationList').html(output).listview().listview("refresh"); console.log("Finished"); }); }); Right now, I'm unsure of why it is not working. My guess is that it is because I am calling a function within a function. Does anyone have any ideas on how this issue can be fixed?

    Read the article

  • Consume WCF Service InProcess using Agatha and WCF

    - by REA_ANDREW
    I have been looking into this lately for a specific reason.  Some integration tests I want to write I want to control the types of instances which are used inside the service layer but I want that control from the test class instance.  One of the problems with just referencing the service is that a lot of the time this will by default be done inside a different process.  I am using StructureMap as my DI of choice and one of the tools which I am using inline with RhinoMocks is StructureMap.AutoMocking.  With StructureMap the main entry point is the ObjectFactory.  This will be process specific so if I decide that the I want a certain instance of a type to be used inside the ServiceLayer I cannot configure the ObjectFactory from my test class as that will only apply to the process which it belongs to. This is were I started thinking about two things: Running a WCF in process Being able to share mocked instances across processes A colleague in work pointed me to a project which is for the latter but I thought that it would be a better solution if I could run the WCF Service in process.  One of the projects which I use when I think about WCF Services is AGATHA, and the one which I have to used to try and get my head around doing this. Another asset I have is a book called Programming WCF Services by Juval Lowy and if you have not heard of it or read it I would definately recommend it.  One of the many topics that is inside this book is the type of configuration you need to communicate with a service in the same process, and it turns out to be quite simple from a config point of view. <system.serviceModel> <services> <service name="Agatha.ServiceLayer.WCF.WcfRequestProcessor"> <endpoint address ="net.pipe://localhost/MyPipe" binding="netNamedPipeBinding" contract="Agatha.Common.WCF.IWcfRequestProcessor"/> </service> </services> <client> <endpoint name="MyEndpoint" address="net.pipe://localhost/MyPipe" binding="netNamedPipeBinding" contract="Agatha.Common.WCF.IWcfRequestProcessor"/> </client> </system.serviceModel>   You can see here that I am referencing the Agatha object and contract here, but also that my binding and the address is something called Named Pipes.  THis is sort of the “Magic” which makes it happen in the same process. Next I need to open the service prior to calling the methods on a proxy which I also need.  My initial attempt at the proxy did not use any Agatha specific coding and one of the pains I found was that you obviously need to give your proxy the known types which the serializer can be aware of.  So we need to add to the known types of the proxy programmatically.  I came across the following blog post which showed me how easy it was http://bloggingabout.net/blogs/vagif/archive/2009/05/18/how-to-programmatically-define-known-types-in-wcf.aspx. First Pass So with this in mind, and inside a console app this was my first pass at consuming a service in process.  First here is the proxy which I made making use of the Agatha IWcfRequestProcessor contract. public class InProcProxy : ClientBase<Agatha.Common.WCF.IWcfRequestProcessor>, Agatha.Common.WCF.IWcfRequestProcessor { public InProcProxy() { } public InProcProxy(string configurationName) : base(configurationName) { } public Agatha.Common.Response[] Process(params Agatha.Common.Request[] requests) { return Channel.Process(requests); } public void ProcessOneWayRequests(params Agatha.Common.OneWayRequest[] requests) { Channel.ProcessOneWayRequests(requests); } } So with the proxy in place I could then use this after opening the service so here is the code which I use inside the console app make the request. static void Main(string[] args) { ComponentRegistration.Register(); ServiceHost serviceHost = new ServiceHost(typeof(Agatha.ServiceLayer.WCF.WcfRequestProcessor)); serviceHost.Open(); Console.WriteLine("Service is running...."); using (var proxy = new InProcProxy()) { foreach (var operation in proxy.Endpoint.Contract.Operations) { foreach (var t in KnownTypeProvider.GetKnownTypes(null)) { operation.KnownTypes.Add(t); } } var request = new GetProductsRequest(); var responses = proxy.Process(new[] { request }); var response = (GetProductsResponse)responses[0]; Console.WriteLine("{0} Products have been retrieved", response.Products.Count); } serviceHost.Close(); Console.WriteLine("Finished"); Console.ReadLine(); } So what I used here is the KnownTypeProvider of Agatha to easily get all the types I need for the service/proxy and add them to the proxy.  My Request handler for this was just a test one which always returned 2 products. public class GetProductsHandler : RequestHandler<GetProductsRequest,GetProductsResponse> { public override Agatha.Common.Response Handle(GetProductsRequest request) { return new GetProductsResponse { Products = new List<ProductDto> { new ProductDto{}, new ProductDto{} } }; } } Second Pass Now after I did this I started reading up some more on some resources including more by Davy Brion and others on Agatha.  Now it turns out that the work I did above to create a derived class of the ClientBase implementing Agatha.Common.WCF.IWcfRequestProcessor was not necessary due to a nice class which is present inside the Agatha code base, RequestProcessorProxy which takes care of this for you! :-) So disregarding that class I made for the proxy and changing my code to use it I am now left with the following: static void Main(string[] args) { ComponentRegistration.Register(); ServiceHost serviceHost = new ServiceHost(typeof(Agatha.ServiceLayer.WCF.WcfRequestProcessor)); serviceHost.Open(); Console.WriteLine("Service is running...."); using (var proxy = new RequestProcessorProxy()) { var request = new GetProductsRequest(); var responses = proxy.Process(new[] { request }); var response = (GetProductsResponse)responses[0]; Console.WriteLine("{0} Products have been retrieved", response.Products.Count); } serviceHost.Close(); Console.WriteLine("Finished"); Console.ReadLine(); }   Cheers for now, Andy References Agatha WCF InProcess Without WCF StructureMap.AutoMocking Cross Process Mocking Agatha Programming WCF Services by Juval Lowy

    Read the article

  • C#: Does an IDisposable in a Halted Iterator Dispose?

    - by James Michael Hare
    If that sounds confusing, let me give you an example. Let's say you expose a method to read a database of products, and instead of returning a List<Product> you return an IEnumerable<Product> in iterator form (yield return). This accomplishes several good things: The IDataReader is not passed out of the Data Access Layer which prevents abstraction leak and resource leak potentials. You don't need to construct a full List<Product> in memory (which could be very big) if you just want to forward iterate once. If you only want to consume up to a certain point in the list, you won't incur the database cost of looking up the other items. This could give us an example like: 1: // a sample data access object class to do standard CRUD operations. 2: public class ProductDao 3: { 4: private DbProviderFactory _factory = SqlClientFactory.Instance 5:  6: // a method that would retrieve all available products 7: public IEnumerable<Product> GetAvailableProducts() 8: { 9: // must create the connection 10: using (var con = _factory.CreateConnection()) 11: { 12: con.ConnectionString = _productsConnectionString; 13: con.Open(); 14:  15: // create the command 16: using (var cmd = _factory.CreateCommand()) 17: { 18: cmd.Connection = con; 19: cmd.CommandText = _getAllProductsStoredProc; 20: cmd.CommandType = CommandType.StoredProcedure; 21:  22: // get a reader and pass back all results 23: using (var reader = cmd.ExecuteReader()) 24: { 25: while(reader.Read()) 26: { 27: yield return new Product 28: { 29: Name = reader["product_name"].ToString(), 30: ... 31: }; 32: } 33: } 34: } 35: } 36: } 37: } The database details themselves are irrelevant. I will say, though, that I'm a big fan of using the System.Data.Common classes instead of your provider specific counterparts directly (SqlCommand, OracleCommand, etc). This lets you mock your data sources easily in unit testing and also allows you to swap out your provider in one line of code. In fact, one of the shared components I'm most proud of implementing was our group's DatabaseUtility library that simplifies all the database access above into one line of code in a thread-safe and provider-neutral way. I went with my own flavor instead of the EL due to the fact I didn't want to force internal company consumers to use the EL if they didn't want to, and it made it easy to allow them to mock their database for unit testing by providing a MockCommand, MockConnection, etc that followed the System.Data.Common model. One of these days I'll blog on that if anyone's interested. Regardless, you often have situations like the above where you are consuming and iterating through a resource that must be closed once you are finished iterating. For the reasons stated above, I didn't want to return IDataReader (that would force them to remember to Dispose it), and I didn't want to return List<Product> (that would force them to hold all products in memory) -- but the first time I wrote this, I was worried. What if you never consume the last item and exit the loop? Are the reader, command, and connection all disposed correctly? Of course, I was 99.999999% sure the creators of C# had already thought of this and taken care of it, but inspection in Reflector was difficult due to the nature of the state machines yield return generates, so I decided to try a quick example program to verify whether or not Dispose() will be called when an iterator is broken from outside the iterator itself -- i.e. before the iterator reports there are no more items. So I wrote a quick Sequencer class with a Dispose() method and an iterator for it. Yes, it is COMPLETELY contrived: 1: // A disposable sequence of int -- yes this is completely contrived... 2: internal class Sequencer : IDisposable 3: { 4: private int _i = 0; 5: private readonly object _mutex = new object(); 6:  7: // Constructs an int sequence. 8: public Sequencer(int start) 9: { 10: _i = start; 11: } 12:  13: // Gets the next integer 14: public int GetNext() 15: { 16: lock (_mutex) 17: { 18: return _i++; 19: } 20: } 21:  22: // Dispose the sequence of integers. 23: public void Dispose() 24: { 25: // force output immediately (flush the buffer) 26: Console.WriteLine("Disposed with last sequence number of {0}!", _i); 27: Console.Out.Flush(); 28: } 29: } And then I created a generator (infinite-loop iterator) that did the using block for auto-Disposal: 1: // simply defines an extension method off of an int to start a sequence 2: public static class SequencerExtensions 3: { 4: // generates an infinite sequence starting at the specified number 5: public static IEnumerable<int> GetSequence(this int starter) 6: { 7: // note the using here, will call Dispose() when block terminated. 8: using (var seq = new Sequencer(starter)) 9: { 10: // infinite loop on this generator, means must be bounded by caller! 11: while(true) 12: { 13: yield return seq.GetNext(); 14: } 15: } 16: } 17: } This is really the same conundrum as the database problem originally posed. Here we are using iteration (yield return) over a large collection (infinite sequence of integers). If we cut the sequence short by breaking iteration, will that using block exit and hence, Dispose be called? Well, let's see: 1: // The test program class 2: public class IteratorTest 3: { 4: // The main test method. 5: public static void Main() 6: { 7: Console.WriteLine("Going to consume 10 of infinite items"); 8: Console.Out.Flush(); 9:  10: foreach(var i in 0.GetSequence()) 11: { 12: // could use TakeWhile, but wanted to output right at break... 13: if(i >= 10) 14: { 15: Console.WriteLine("Breaking now!"); 16: Console.Out.Flush(); 17: break; 18: } 19:  20: Console.WriteLine(i); 21: Console.Out.Flush(); 22: } 23:  24: Console.WriteLine("Done with loop."); 25: Console.Out.Flush(); 26: } 27: } So, what do we see? Do we see the "Disposed" message from our dispose, or did the Dispose get skipped because from an "eyeball" perspective we should be locked in that infinite generator loop? Here's the results: 1: Going to consume 10 of infinite items 2: 0 3: 1 4: 2 5: 3 6: 4 7: 5 8: 6 9: 7 10: 8 11: 9 12: Breaking now! 13: Disposed with last sequence number of 11! 14: Done with loop. Yes indeed, when we break the loop, the state machine that C# generates for yield iterate exits the iteration through the using blocks and auto-disposes the IDisposable correctly. I must admit, though, the first time I wrote one, I began to wonder and that led to this test. If you've never seen iterators before (I wrote a previous entry here) the infinite loop may throw you, but you have to keep in mind it is not a linear piece of code, that every time you hit a "yield return" it cedes control back to the state machine generated for the iterator. And this state machine, I'm happy to say, is smart enough to clean up the using blocks correctly. I suspected those wily guys and gals at Microsoft engineered it well, and I wasn't disappointed. But, I've been bitten by assumptions before, so it's good to test and see. Yes, maybe you knew it would or figured it would, but isn't it nice to know? And as those campy 80s G.I. Joe cartoon public service reminders always taught us, "Knowing is half the battle...". Technorati Tags: C#,.NET

    Read the article

< Previous Page | 294 295 296 297 298 299 300 301 302 303 304 305  | Next Page >