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  • Rails load path questions

    - by HelpMe
    Say I have some custom classes that don't belong in models, controllers etc, I should put this in /lib correct? In rails < 3 I would add this directory to my loadpath and in rails 3+ I would add this to my autoload_path. Is this correct? Now say I have some classes that extends already defined classes. Where should I put this so its run on startup. Forexample say I want to add the method 'foo' on String. class String def foo 'foo; end end Where should I put this class so it's defined on startup? Another weird bug I have is when I try to namespace classes in lib. module MyProject class Foo end end Now in a console: ruby-1.9.2-p136 :004 Bags::Foo LoadError: Expected /Users/me/workspace/my_project/lib/foo.rb to define Foo from /Users/rob/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:492:in `load_missing_constant' from /Users/rob/.rvm/gems/ruby-1.9.2-p136/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:183:in `block in const_missing' I keep getting this error. How can I load this file? Thanks in advance for any help!

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  • Generating jquery 'rules' from business model to UI in asp.net mvc

    - by jim
    Hi all, I've had a good look around and am certain that there's no matching question on SO, so here goes. Has anyone created a 'helper' method on their model that generates jquery (or plain javascript) rules validation dynamically, based on the criteria/rules that are contained within the object and taken from a repository (i.e. DB). What i'm thinking of is a discrete set of partial views (and associated models) that have rules at the business logic 'level' and rather than (or in combination with) validating the rule(s) at postback, translating the same rules into tightly focussed jquery methods that work identically at client (js) and server (c#) levels. I can see benefits here re performance. Also, the rules definitions could be created in a single place (in c#) and the jquery generated off of that, thus allowing single edits to update both code streams. I appreciate that there would be limitations imposed by language specific contstraints but the general principle could be quite interesting if used appropriately. I'm also aware that testibility could be an issue when using two different language structures and hoping to achieve similar test outcomes - but those aside... any thoughts or experiences of similar out there?? cheers jimi

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  • Saving tags into a database table in CakePHP

    - by Cameron
    I have the following setup for my CakePHP app: Posts id title content Topics id title Topic_Posts id topic_id post_id So basically I have a table of Topics (tags) that are all unique and have an id. And then they can be attached to post using the Topic_Posts join table. When a user creates a new post they will fill in the topics by typing them in to a textarea separated by a comma which will then save these into the Topics table if they do not already exist and then save the references into the Topic_posts table. I have the models set up like so: Post model: class Post extends AppModel { public $name = 'Post'; public $hasAndBelongsToMany = array( 'Topic' => array('with' => 'TopicPost') ); } Topic model: class Topic extends AppModel { public $hasMany = array( 'TopicPost' ); } TopicPost model: class TopicPost extends AppModel { public $belongsTo = array( 'Topic', 'Post' ); } And for the New post method I have this so far: public function add() { if ($this->request->is('post')) { //$this->Post->create(); if ($this->Post->saveAll($this->request->data)) { // Redirect the user to the newly created post (pass the slug for performance) $this->redirect(array('controller'=>'posts','action'=>'view','id'=>$this->Post->id)); } else { $this->Session->setFlash('Server broke!'); } } } As you can see I have used saveAll but how do I go about dealing with the Topic data?

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  • [C#] Dynamic user-interface, WPF or not?

    - by pieter.lowie
    Hi, I'm currently working at a application that helps people understand how to do there job. You can see it as a personal coach that guides them trough all the steps they need to do that no normal person could keep remembering. In my previous application we had the ability to show the user up to 4 pictures (what proves to be more then enough). The application would load the data and see how many pictures where in every instruction and then sort out the picture in the best fitting way without messing up the scale and resolution of the pictures. This all was done with GDI+ and worked very well. Ofc, change is something that always happens, my bosses came up with some great ideas. So they want to be able to see movies on the screen, animated gif's, 3D models that can rotate or animate. So I think we had pushed GDI+ to it's limits and it's time to look for something different. I have heard and readed about WPF but have no experience with it. Is it even possible to do all what I ask in WPF? And what about the old picture-merging thing I wrote, can we also get it done in wpf? I tried to make some things working but I didn't went as smooth as I hoped. I'm also concerned about the fact that the interface needs to be dynamic, the one moment it should be showing picture with some text above it, the other moment it should be showing another text with a video under it. I would love to hear some opinions here and if you got some other suggestions I should look into pls tell me. Thnx in advance PS: If WPF is the choice, should I convince my boss to change to .net 4.0?

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  • How do I convert a simple ruby flashcard program into a ROR app?

    - by Mark Wilbur
    What I'm trying to do is make a basic flashcard app on rails. At this point, all I'm looking for is the functionality to iterate through a list of flashcards, quiz the user and let the user know if they were right or not. In ruby, it didn't take me long to write: class Card attr_accessor :answer, :question def initialize(answer = "", question="") @answer = answer @question = question end def quiz puts "What does #@question mean?" answer = gets.chomp if answer == @answer puts "Right" return true else puts "Wrong" return answer end end end class Cardlist attr_accessor :Cards def initialize(Cards = []) @Cards = Cards end def quiz Cards.each do |w| w.quiz end end end The problem I'm having with rails is figuring out where to put the logic to loop through all the cards in the list. I've made models specifying that Card belongs_to cardlist and that Cardlist has_many cards. I know application logic should go in the controller, but if I were to make a "quiz" action for my Cardlist controller, how would I make it iterate through all the cards? After each "quiz" page generated, I'd need to get an answer back from the user, respond (maybe flash) whether it was right or not and then continue onto the next question. Would any of that logic have to go into the view in order to make sure it's sending back the user inputted answers to the controller?

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  • Dynamic use of :default_url in Paperclip

    - by dgilperez
    I'm trying to configure Paperclip to provide different missing images based on the instance's category attribute. Every category of the object has its own missing image. This is my first take: EDIT to add full models: class Service < ActiveRecord::Base attr_accessible :logo, :logo_file_name, :logo_content_type, :logo_file_size, :logo_updated_at belongs_to :category, :counter_cache => true has_attached_file :logo, :path => "/:id-:style-:filename", :url => ":s3_eu_url", :default_url => "/logos/:style/#{self.category.name]}.png", :styles => { :large => "600x400>", :medium => "300x200>", :small => "100x75>", :thumb => "60x42>" } end class Category < ActiveRecord::Base attr_accessible nil has_many :services end In my view, image_tag service.logo.url(:thumb) outputs: undefined method `category' for #<Class:0x0000010a731620> Any ideas? EDIT2: A working default_url is :default_url => "/logos/:style/missing.png", SOLUTION: See my own answer below.

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  • A little confused about MVC and where to put a database query

    - by jax
    OK, so my Joomla app is in MVC format. I am still a little confused about where to put certain operations, in the Controller or in the Model. This function below is in the controller, it gets called when &task=remove. Should the database stuff be in the Model? It does not seem to fit there because I have two models editapp (display a single application) and allapps (display all the applications), now which one would I put the delete operation in? /** * Delete an application */ function remove() { global $mainframe; $cid = JRequest::getVar( 'cid', array(), '', 'array' ); $db =& JFactory::getDBO(); //if there are items to delete if(count($cid)){ $cids = implode( ',', $cid ); $query = "DELETE FROM #__myapp_apps WHERE id IN ( $cids )"; $db->setQuery( $query ); if (!$db->query()){ echo "<script> alert('".$db->getErrorMsg()."');window.history.go(-1); </script>\n"; } } $mainframe->redirect( 'index.php?option=' . $option . '&c=apps'); } I am also confused about how the flow works. For example, there is a display() function in the controller that gets called by default. If I pass a task, does the display() function still run or does it go directly to the function name passed by $task?

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  • What are the best software/website UI design you have even seen?

    - by Edwin
    What are the best UI design in terms of usability and esthetics you have even seen? I mean both desktop software (of all OS) and website. My list: Picasa 3 - the way it organizes photos. Find-and-highlight-as-you-type in google Chrome. Dynamic search hints when entering something in the search box in Gmail. I'm not a Mac OS X user, but I have seen in most windows on the top toolbar there are both the icons and texts shown for each function, as apposed to on Windows I have seen many programs (MS Office included) have many small toolbar icons which you can hardly understand what they do until you hover the mouse on it for a while to see the hints (if any). The ability to search an setting in Eclipse IDE. the way to make 3D models in Google Sketchup. the way to label an email in Gmail. What are you list? Well, I couldn't resist to list some annoying UI design I have experienced and remember at this moment. IE on Windows server, when you visit the new website, you have to click many times to get it added to the white list before you can start browsing, IIRC, it's not fixed in IE 8 when that last time I used it on Windows 2008. The default search behavior in the File Explorer on Windows xp, that animated thing... the dialog that shows up when you are trying to save a plain text CSV file in Excel after applied some formatting options which does not compatible with CSV.

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  • how to format a date with code igniter

    - by Jeff Davidson
    I'm trying to figure out what I'm doing wrong here. I'm wanting to format the date_published field in my query and I'm getting an t_string syntax error in my IDE. $this->db->select('site_news_articles.article_title, site_news_articles.is_sticky,' date_format('site_news_articles.date_published, 'f jS, Y')'); UPDATE: function getNewsTitles($category_id) { $this->db->select('site_news_articles.article_title, site_news_articles.is_sticky'); $this->db->select("DATE_FORMAT(site_news_articles.date_published, '%M %e, %Y') as formatted_date", TRUE); $this->db->from('site_news_articles'); $this->db->where('site_news_articles.news_category_id', $category_id); $this->db->where('site_news_articles.is_approved', 'Yes'); $this->db->where('site_news_articles.status_id', 1); $this->db->order_by('site_news_articles.date_published', 'desc'); $this->db->limit(10); $query = $this->db->get(); return $query->result_array(); } Error Number: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'FROM (site_news_articles) WHERE site_news_articles.news_category_id = 2 A' at line 2 SELECT site_news_articles.article_title, site_news_articles.is_sticky, DATE_FORMAT(site_news_articles.date_published, '%M %e, %Y') as formatted_date FROM (site_news_articles) WHERE site_news_articles.news_category_id = 2 AND site_news_articles.is_approved = 'Yes' AND site_news_articles.status_id = 1 ORDER BY site_news_articles.date_published desc LIMIT 10 Filename: /home/xtremer/public_html/models/sitemodel.php Line Number: 140

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  • Multiple has_many's of the same model

    - by Koning Baard
    I have these models: Person has_many :messages_form_person, :foreign_key => :from_user_id, :class_name => :messages has_many :messages_to_person, :foreign_key => :to_user_id, :class_name => :messages Message belongs_to :to_person, :foreign_key => :to_user_id, :class_name => :person belongs_to :from_person, :foreign_key => :to_user_id, :class_name => :person And this view: person#show <% @person.messages_to_person.each do |message| %> <%=h message.title %> <% end %> But I get this error: TypeError in People#show Showing app/views/people/show.html.erb where line #26 raised: can't convert Symbol into String Extracted source (around line #26): 23: <%=h @person.biography %> 24: </p> 25: 26: <% @person.messages_to_person.each do |message| %> 27: 28: <% end %> 29: I basicly want that people can send eachother messages. Can anyone help me? Thanks.

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  • Periodic GPU performance problem

    - by Peter Lillevold
    Hi folks! I have a WinForms application that uses XNA to animate 3D models in a control. The app have been doing just fine for months but recently I've started to experience periodic pauses in the animation. Setting out to investigate what is going on I have established these facts: It (currently) happens on my machine only Removing everything from my render loop does not improve the problem In 2. I didn't actually remove everything, I limited my loop to set the viewport on my GraphicsDevice and then do a GraphicsDevice.Present. Trying to dig further I fired up PIX to capture some statistics. Screenshots of two PIX runs can be viewed here (Run6) and here (Run14). Run6 is using my original render loop and Run14 is using the bare-bones Present loop. PIX tells me that the GPU is periodically doing something, and I assume this is causing the pauses. What could be the cause of this? Or how do I go about finding out what the GPU is actually doing? Note: I'm using XNA 3.1 on a Windows 7 x64 dual-core machine with 8GB RAM. Note2: also posted this question on the XNA Creators forums here.

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  • Syncing Data to Remote Services, Best Practices for Caching?

    - by viatropos
    I want to be able to publish events to Eventbrite, Eventful, and Google Calendar for my Google Apps. Each service has slightly different properties for events... I will be syncing many other things too, such as users with Google Contacts and MailChimp, Documents with Google Docs and some other services, etc... So I'm wondering, what is the recommended way of retrieving the data for the end user so that it's reasonably maintainable and optimized? Here are the things I'm thinking that I'm having trouble with: My App keeps a central database of all the models (Event, Document, User, Form, etc.), and whenever Admin creates an object (e.g. create through Eventbrite or through our Admin panel), we sync them and store a copy in our local database. When User goes to the site /events, App retrieves the events from the database. Read Events from a target feed, such as the Eventbrite or Eventful feed, and scrap the local database. Basically, I'm wondering, if we're storing all of the data on a remote service, do we really need to have a local database copy of the data? When would we need to have a local database, when wouldn't we?

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  • Rails : can't write unknown attribute `url'

    - by user2954789
    I am new to ruby on rails,and I am learning by creating a blog. I am not able to save to my blogs table and I get this error "can't write unknown attribute url" Blogs migration :db/migrate/ class CreateBlogs < ActiveRecord::Migration --def change --- create_table :blogs do |t| ---- t.string :title ---- t.text :description ---- t.string :slug ---- t.timestamps --- end --end end Blogs Model :/app/models/blogs.rb class Blogs < ActiveRecord::Base --acts_as_url :title --def to_param ---url --end --validates :title, presence:true end Blogs Controller : /app/controllers/blogs_controller.rb class BlogsController < ApplicationController before_action :require_login --def new --- @blogs = Blogs.new --end --def show ---@blogs = Blogs.find(params[:id]) --end --def create ---@blogs = Blogs.new(blogs_params) --if @blogs.save ---flash[:success] = "Your Blog has been created." ---redirect_to home_path --else ---render 'new' --end -end --def blogs_params ---params.require(:blogs).permit(:title,:description) --end private --def require_login ---unless signed_in? ----flash[:error] = "You must be logged in to create a new Blog" ----redirect_to signin_path ---end --end end Blogs Form:/app/views/blogs/new.html.erb Blockquote <%= form_for @blogs, url: blogs_path do |f| %><br/> <%= render 'shared/error_messages_blogs' %><br/> <%= f.label :title %><br/> <%= f.text_field :title %><br/> <%= f.label :description %><br/> <%= f.text_area :description %><br/> <%= f.submit "Submit Blog", class: "btn btn-large btn-primary" %><br/> <% end %><br/> and I have also added "resources :blogs" to my routes.rb file. I get this error in controller at if @blogs.save

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  • Defining and using controller methods in ember.js

    - by OriginalEXE
    first of all, I am total noob when it comes to OOP in JS, this is new to me so treat me like a noob. I am building my first ember.js application and I am stuck (not the first time but I would get unstuck by myself, this is a tough one though). I have two models: forms entries Entries is of course in (one to many) relationship to forms, so each form can have as many properties. Form properties: id : DS.attr( 'number' ), title : DS.attr( 'string' ), views : DS.attr( 'number' ), conversion : DS.attr( 'number' ), entries : DS.hasMany( 'entry' ) Entry properties: id : DS.attr( 'number' ), parent_id: DS.belongsTo( 'form' ) Now, I have forms route that displays all forms in tabled view, and each table row has some info like form id, name etc. and that works great. What I wanted to do is display the number of entries each form has. I figured I should do that via controller, so here is my controller now: // Form controller App.FormController = Ember.ObjectController.extend({ entriescount: function() { var entries = this.get( 'store').find( 'entry' ); return entries.filterBy( 'parent_id', this.get( 'id' ) ).get( 'length' ); }.property( '[email protected]_id') }); Now for some reason, when I use {{entriescount}} in {{#each}} loop, this returns nothing. It also returns nothing in single form route. Note that in both cases, {{title}} for example works. I am wondering, am I going the right way by using controller for this, and how do I get controller to output the data. Thanks

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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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  • Ruby On Rails - Contact form not sending email via localhost

    - by anonymousxxx
    similar problem Rails contact form not working guides: https://github.com/thomasklemm/email_form_rails rails 3.2.x app\models\message.rb class Message include ActiveAttr::Model include ActiveModel::Validations attribute :name attribute :email attribute :subject attribute :body attr_accessible :name, :email, :subject, :body validates_presence_of :name validates_presence_of :email validates :email, email_format: { message: "is not looking like a valid email address"} validates_presence_of :subject validates_length_of :body, maximum: 500 end app\mailers\contact_form.rb class ContactForm < ActionMailer::Base default from: "[email protected]" default to: "[email protected]" def email_form(message) @message = message mail subject: "#{message.subject} #{message.name}" mail body: "#{message.body}" end end development.rb config.action_mailer.delivery_method = :smtp config.action_mailer.perform_deliveries = true config.action_mailer.smtp_settings = { :address => "smtp.gmail.com", :port => 587, :domain => "mydomain.com", :user_name => "[email protected]", :password => "mypassword", :authentication => :plain, :enable_starttls_auto => true } config.action_mailer.default_url_options = { :host => "localhost:3000" } output in command Started POST "/email" for 127.0.0.1 at 2012-09-04 22:10:40 +0700 Processing by HomeController#send_email_form as HTML Parameters: {"utf8"="v", "authenticity_token"="w39BLqCrjTMm4RRi/Sm5hZoEpcw46 npyRy/RS0h48x0=", "message"={"name"="anonymousxxx", "email"="[email protected]", "subject"="Test", "body"="send email"}, "commit"="Create Message"} Redirected to localhost:3000/home/contact Completed 302 Found in 1ms (ActiveRecord: 0.0ms) but email (message) no receive my email,..

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  • Rails Functional Test Failing Due to Association

    - by Koby
    I have an accounts model that holds some basic account info (account name, website, etc). I then have a user model that has the following in the app/models/user.rb belongs_to :account I also have the following in my routes.rb map.resources :account, :has_many => [:users, :othermodel] the problem I'm facing is that the following test is failing: test "should create user" do assert_difference('User.count') do post :create, :user => { } #this is the line it's actually failing on end assert_redirected_to user_path(assigns(:user)) #it doesn't get here yet end The error it gives is "Can't find Account without ID" so I kind of understand WHY it's failing, because of the fact that it doesn't have the account object (or account_id as it were) to know under what account to create the user. I have tried variations of the following but I am completely lost: post :create, :user => { accounts(:one) } #I have the 'fixtures :accounts' syntax at the top of the test class post :create, [accounts(:one), :user] => { } post :create, :user => { accounts(:one), #other params for :user } and like I said, just about every variation I could think of. I can't find much documentation on doing this and this might be why people have moved to Factories for doing test data, but I want to understand things that come standard in Rails before moving onto other things. Can anyone help me get this working?

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  • Trial vs free with limited functionality

    - by Morten K
    Hi everyone, Not a programming question as such, but a bit more business oriented question about software product development. We have just released a small app, and is offering a free, fully functional trial which lasts for 15 days. I have the gut feeling however, that to reach any kind of penetration on the web, we'd need to offer a version which is free forever, but then has a few limitations in terms of functionality (still quite usable, but not full-throttle). For example, the Roboform browser plugin is somewhat similar in purpose to ours. Not functionality wise, but it's basically a little util that saves time and removes some repetitive-action pain. They offer a free version with limitations and then a pro version for around 30 USD. Roboform has gotten very much attention over the years, and I can't help to think that this is because they have a product which is obviously good, but also free, thus adoption becomes much higher than if they had only offered a 15 day trial. I am wondering if any of you have experience in a similar scenario? Or any thoughts on the two models? Again, I know it's not directly programming related, but it's still a question I feel best answered by a community of developers.

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  • Blackberry - custom logic for checkboxes group

    - by SWATI
    if i click on any checkbox all previous checkboxes must get checked "my logic works" if i uncheck a checkbox then all checkboxes after it must get unchecked "how to do that" MyLogic works for storm but not for other models what to do //well what i want to do is i have 5 checkboxes class myscreen { chk_service = new CheckboxField[5]; chk_service[0]= new CheckboxField("1",true) chk_service[1]= new CheckboxField("2",false) chk_service[2]= new CheckboxField("3",false) chk_service[3]= new CheckboxField("4",false) chk_service[4]= new CheckboxField("5",false) CheckboxFieldChangeListener obj = new CheckboxFieldChangeListener(chk_service); chk_service[0].setChangeListener(obj); chk_service[1].setChangeListener(obj); chk_service[2].setChangeListener(obj); chk_service[3].setChangeListener(obj); chk_service[4].setChangeListener(obj); hm4 = new HorizontalFieldManager(); hm4.add(chk_service[0]); hm4.add(chk_service[1]); hm4.add(chk_service[2]); hm4.add(chk_service[3]); hm4.add(chk_service[4]); add(hm4); } public CheckboxFieldChangeListener (CheckboxField[] arrFields) { m_arrFields = arrFields; } public void fieldChanged(Field field, int context) { if(true == ((CheckboxField) field).getChecked()) { for(int i = 0; i < m_arrFields.length; i++) { if(m_arrFields[i]==field) { //a[j]=i; j++; break; } else { CheckboxField oField = m_arrFields[i]; oField.setChecked(true); } } } a[k] = j; if(false == ((CheckboxField) field).getChecked()) { for(int i =field.getIndex(); i < m_arrFields.length; i++) { if(m_arrFields[i]==field) { //a[j]=i; j++; break; } else { CheckboxField oField = m_arrFields[i]; oField.setChecked(false); } } } } }

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  • I need help solving a rather weird error in a WCF service.

    - by Moulde
    Hi.. I have a solution that contains three projects. A main project with my MVC app, a silverlight application and a (silverlight enabled) WCF service project. In my silverlight project i have made a Service Reference to my WCF service. And i pretty much got that working. In my WCF service i have a method that returns an Book object, which got some random fields like title, date etc. In the book class, i have a ICollection field that contains a list of events. The book class is generated using entity framework 4.0, and Lazy Loading is enabled. If i in my getBook(int id) method return a book with the events field not initialized, it works as a charm. But if i initialize the field, i'm getting this error. The server did not provide a meaningful reply; this might be caused by a contract mismatch, a premature session shutdown or an internal server error. I have a few ideas why that is happening, and while writing this i just got another one. The wcf service somehow threw away the reference to the event class. That would be very weird since i have a reference between my main mvc app (with the models) and my WCF service. Since i have enabled lazy loading in EF 4.0, i suspect that it may be the thing generating the error. But i'm not sure why that would be, because i'm not in any way accessing that field. I could understand that i may not be able to access the events field after i recive the object in my silverlight application since the connection between the book object and the entity framework is like broken. Did i mention that Lazy Loading is enabled on my EF instance? And there is no inner exception in the thrown exception. Thanks in advance. Malte Baden Hansen

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  • Generic applet style system for publishing mathematics demonstrations?

    - by Alex
    Anyone who's tried to study mathematics using online resources will have come across these Java applets that demonstrate a particular mathematical idea. Examples: http://www.math.ucla.edu/~tao/java/Mobius.html http://www.mathcs.org/java/programs/FFT/index.html I love the idea of this interactive approach because I believe it is very helpful in conveying mathematical principles. I'd like to create a system for visually designing and publishing these 'mathlets' such that they can be created by teachers with little programming experience. So in order to create this app, i'll need a GUI and a 'math engine'. I'll probably be working with .NET because thats what I know best and i'd like to start experimenting with F#. Silverlight appeals to me as a presentation framework for this project (im not worried about interoperability right now). So my questions are: does anything like this exist already in full form? are there any GUI frameworks for displaying mathematical objects such as graphs & equations? are there decent open source libraries that exposes a mathematical framework (Math.NET looks good, just wondering if there is anything else out there) is there any existing work on taking mathematical models/demos built with maple/matlab/octave/mathematica etc and publishing them to the web?

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  • How do I avoid a race condition in my Rails app?

    - by Cathal
    Hi, I have a really simple Rails application that allows users to register their attendance on a set of courses. The ActiveRecord models are as follows: class Course < ActiveRecord::Base has_many :scheduled_runs ... end class ScheduledRun < ActiveRecord::Base belongs_to :course has_many :attendances has_many :attendees, :through => :attendances ... end class Attendance < ActiveRecord::Base belongs_to :user belongs_to :scheduled_run, :counter_cache => true ... end class User < ActiveRecord::Base has_many :attendances has_many :registered_courses, :through => :attendances, :source => :scheduled_run end A ScheduledRun instance has a finite number of places available, and once the limit is reached, no more attendances can be accepted. def full? attendances_count == capacity end attendances_count is a counter cache column holding the number of attendance associations created for a particular ScheduledRun record. My problem is that I don't fully know the correct way to ensure that a race condition doesn't occur when 1 or more people attempt to register for the last available place on a course at the same time. My Attendance controller looks like this: class AttendancesController < ApplicationController before_filter :load_scheduled_run before_filter :load_user, :only => :create def new @user = User.new end def create unless @user.valid? render :action => 'new' end @attendance = @user.attendances.build(:scheduled_run_id => params[:scheduled_run_id]) if @attendance.save flash[:notice] = "Successfully created attendance." redirect_to root_url else render :action => 'new' end end protected def load_scheduled_run @run = ScheduledRun.find(params[:scheduled_run_id]) end def load_user @user = User.create_new_or_load_existing(params[:user]) end end As you can see, it doesn't take into account where the ScheduledRun instance has already reached capacity. Any help on this would be greatly appreciated.

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  • How to configure multiple mappings using FluentHibernate?

    - by chris.baglieri
    First time rocking it with NHibernate/Fluent so apologies in advance if this is a naive question. I have a set of Models I want to map. When I create my session factory I'm trying to do all mappings at once. I am not using auto-mapping (though I may if what I am trying to do ends up being more painful than it ought to be). The problem I am running into is that it seems only the top map is taking. Given the code snippet below and running a unit test that attempts to save 'bar', it fails and checking the logs I see NHibernate is trying to save a bar entity to the foo table. While I suspect it's my mappings it could be something else that I am simply overlooking. Code that creates the session factory (note I've also tried separate calls into .Mappings): Fluently.Configure().Database(MsSqlConfiguration.MsSql2008 .ConnectionString(c => c .Server(@"localhost\SQLEXPRESS") .Database("foo") .Username("foo") .Password("foo"))) .Mappings(m => { m.FluentMappings.AddFromAssemblyOf<FooMap>() .Conventions.Add(FluentNHibernate.Conventions.Helpers .Table.Is(x => "foos")); m.FluentMappings.AddFromAssemblyOf<BarMap>() .Conventions.Add(FluentNHibernate.Conventions.Helpers .Table.Is(x => "bars")); }) .BuildSessionFactory(); Unit test snippet: using (var session = Data.SessionHelper.SessionFactory.OpenSession()) { var bar = new Bar(); session.Save(bar); Assert.NotNull(bar.Id); }

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  • When to save a mongoose model

    - by kentcdodds
    This is an architectural question. I have models like this: var foo = new mongoose.Schema({ name: String, bars: [{type: ObjectId, ref: 'Bar'}] }); var FooModel = mongoose.model('Foo', foo); var bar = new mongoose.Schema({ foobar: String }); var BarModel = mongoose.model('Bar', bar); Then I want to implement a convenience method like this: BarModel.methods.addFoo = function(foo) { foo.bars = foo.bars || []; // Side note, is this something I should check here? foo.bars.push(this.id); // Here's the line I'm wondering about... Should I include the line below? foo.save(); } The biggest con I see about this is that if I did include foo.save() then I should pass in a callback to addFoo so I avoid issues with the async operation. I'm thinking this is not preferable. But I also think it would be nice to include because addFoo hasn't really "addedFoo" until it's been saved... Am I breaking any design best practices doing it either way?

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  • Sharing code between two or more rails apps... alternatives to git submodules?

    - by jtgameover
    We have two separate rails_app, foo/ and bar/ (separate for good reason). They both depend on some models, etc. in a common/ folder, currently parallel to foo and bar. Our current svn setup uses svn:externals to share common/. This weekend we wanted to try out git. After much research, it appears that the "kosher" way to solve this is using git submodule. We got that working after separating foo,bar,common into separate repositories, but then realized all the strings attached: Always commit the submodule before committing the parent. Always push the submodule before pushing the parent. Make sure that the submodule's HEAD points to a branch before committing to it. (If you're a bash user, I recommend using git-completion to put the current branch name in your prompt.) Always run 'git submodule update' after switching branches or pulling changes. All these gotchas complicate things further than add,commit,push. We're looking for simpler ways to share common in git. This guy seems to have success using the git subtree extension, but that deviates from standard gitand still doesn't look that simple. Is this the best we can do given our project structure? I don't know enough about rails plugins/engines, but that seems like a possible RoR-ish way to share libraries. Thanks in advance.

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