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  • jQuery AJAX: How to pass large HTML tags as parameters?

    - by marknt15
    Hello, How can I pass a large HTML tag data to my PHP using jQuery AJAX? When I'm receiving the result it is wrong. Thanks in advance. Cheers, Mark jQuery AJAX code: $('#saveButton').click(function() { // do AJAX and store tree structure to a PHP array (to be saved later in database) var treeInnerHTML = $("#demo_1").html(); alert(treeInnerHTML); var ajax_url = 'ajax_process.php'; var params = 'tree_contents=' + treeInnerHTML; $.ajax({ type: 'POST', url: ajax_url, data: params, success: function(data) { $("#show_tree").html(data); }, error: function(req, status, error) { } }); }); treeInnerHTML actual value: <ul class="ltr"> <li id="phtml_1" class="open"><a href="#"><ins>&nbsp;</ins>Root node 1</a> <ul> <li class="leaf" id="phtml_2"><a href="#"><ins>&nbsp;</ins>Child node 1</a></li> <li class="last leaf" id="phtml_3"><a href="#"><ins>&nbsp;</ins>Child node 2</a></li> </ul> </li> <li id="phtml_5" class="file last leaf"><a href="#"><ins>&nbsp;</ins>Root node 2</a></li> </ul> Returned result from my show_tree div: <ul class="\&quot;ltr\&quot;"> <li id="\&quot;phtml_1\&quot;" class="\&quot;open\&quot;"><a href="%5C%22#%5C%22"><ins></ins></a></li></ul>

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  • autologin component doesn't work on remote server

    - by user606521
    I am using autologin component from http://milesj.me/code/cakephp/auto-login (v 3.5.1). It works on my localhost WAMP server but fails on remote server. I am using this settings in beforeFilter() callback: $this->AutoLogin->settings = array( // Model settings 'model' => 'User', 'username' => 'username', 'password' => 'password', // Controller settings 'plugin' => '', 'controller' => 'users', // Cookie settings 'cookieName' => 'rememberMe', 'expires' => '+1 month', // Process logic 'active' => true, 'redirect' => true, 'requirePrompt' => true ); On remote server it simply doesn't autolog users after the browser was closed. I can't figure out what may cause the problem. -------------------- edit I figured out what is causing the problem but I don't know how to fix this. First of all cookie is set like this: $this->Cookie->write('key',array('username' => 'someusername', 'hash' => 'somehash', ...) ); Then it's readed like this: $cookie = $this->Cookie->read('key'); On my WAMP server $cookie is array('username' => 'someusername', 'hash' => 'somehash', ...) and on remote server returned $cookie is string(159) "{\"username\":\"YWxlay5iYXJzsdsdZXdza2ldssd21haWwuY29t\",\"password\":\"YWxlazc3ODEy\",\"hash\":\"aa15bffff9ca12cdcgfgb351d8bfg2f370bf458\",\"time\":1339923926}" and it should be: array( 'username' => "YWxlay5iYXJzsdsdZXdza2ldssd21haWwuY29t", 'password' => "YWxlazc3ODEy", ...) Why the retuned cookie is string not array?

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  • P0ST variables to web server?

    - by OverTheRainbow
    Hello I've been trying several things from Google to POST data to a web server, but none of them work: I'm still stuck at how to convert the variables into the request, considering that the second variable is an SQL query so it has spaces. Does someone know the correct way to use a WebClient to POST data? I'd rather use WebClient because it requires less code than HttpWebRequest/HttpWebResponse. Here's what I tried so far: Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim wc = New WebClient() 'convert data wc.Headers.Add("Content-Type", "application/x-www-form-urlencoded") Dim postData = String.Format("db={0}&query={1}", _ HttpUtility.UrlEncode("books.sqlite"), _ HttpUtility.UrlEncode("SELECT id,title FROM boooks")) 'Dim bytArguments As Byte() = Encoding.ASCII.GetBytes("db=books.sqlite|query=SELECT * FROM books") 'POST query Dim bytRetData As Byte() = wc.UploadData("http://localhost:9999/get", "POST", postData) RichTextBox1.Text = Encoding.ASCII.GetString(bytRetData) Exit Sub Dim client = New WebClient() Dim nv As New Collection nv.Add("db", "books.sqlite") nv.Add("query", "SELECT id,title FROM books") Dim address As New Uri("http://localhost:9999/get") 'Dim bytRetData As Byte() = client.UploadValues(address, "POST", nv) RichTextBox1.Text = Encoding.ASCII.GetString(bytRetData) Exit Sub 'Dim wc As New WebClient() 'convert data wc.Headers.Add("Content-Type", "application/x-www-form-urlencoded") Dim bytArguments As Byte() = Encoding.ASCII.GetBytes("db=books.sqlite|query=SELECT * FROM books") 'POST query 'Dim bytRetData As Byte() = wc.UploadData("http://localhost:9999/get", "POST", bytArguments) RichTextBox1.Text = Encoding.ASCII.GetString(bytRetData) Exit Sub End Sub Thank you.

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  • Newbie question: undefined local variable or method , why??

    - by Mellon
    I am new in Rails (I am using Rails 3.0.3), currently I am following the book "Agile Web Development with Rails" to develop a simple rails application. I followed the book to: --create a model 'Cart' class; --implement 'add_to_cart' method in my 'store_controller', I have a line of code <%=button_to "Add to Cart", :action => add_to_cart, :id => product %> in my /store/index.html.erb As you see, there is :action => add_to_cart in my index.html.erb, which will invoke the add_to_cart method in my *Controllers/store_controller.rb* But after I refresh the browser, I got the error "undefined local variable or method 'add_to_cart'", apparently I do have the method add_to_cart in my 'store_controller.rb', why I got this error??? What is the possible cause??? Here are my codes: store_controller.rb class StoreController < ApplicationController def index @products = Product.find_products_for_sale end def add_to_cart product = Product.find(params[:id]) @cart = find_cart @cart.add_product(product) end private def find_cart session[:cart] ||= Cart.new end end /store/index.html.erb <h1>Your Pragmatic Catalog</h1> <% @products.each do |product| -%> <div class="entry"> <%= image_tag(product.image_url) %> <h3><%=h product.title %></h3> <%= product.description %> <div class="price-line"> <span class="price"><%= number_to_currency(product.price) %></span> <!-- START_HIGHLIGHT --> <!-- START:add_to_cart --> **<%= button_to 'Add to Cart', :action => 'add_to_cart', :id => product %>** <!-- END:add_to_cart --> <!-- END_HIGHLIGHT --> </div> </div> <% end %> Model/cart.rb class Cart attr_reader :items def initialize @items = [] end def add_product(product) @items << product end end

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  • jquery noob problem with variables (scope?)

    - by aharon
    I'm trying to retrieve data from a php file named return that just contains <?php echo 'here is a string'; ?> I'm doing this through an html file containing <!DOCTYPE html> <html> <head> <script src="http://code.jquery.com/jquery-latest.min.js"></script> <script> var x; $.get("return.php", function(data){ x = data; }) function showAlert() {alert(x);} $(document).ready(function(){ alert(x); }); </script> </head> <body> <input type = "button" value = "Click here" onClick="showAlert();"> </body> </html> When the button is clicked it retrieves and displays the code fine, but on the $(document).ready thing, it displays "undefined" instead of the data in return.php. Any solutions? Thanks.

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  • Anchor tags are blank

    - by ryanday
    I'm having a problem where the my anchor tags sometimes aren't displaying their links. This is happening on Mobile Safari on multiple iPhones, and in the iPhone simulator. I'm using jQtouch r147, PhoneGap, and jQuery 1.4.2. I'm generating the data from a database call, and adding anchor tags to a list like this: for(var i=0;i<data.rows.length;i++) { var item = $('<li></li>'); var name = data.rows.item(i).name; var anchor = $('<a href="#lpage">'+name+'</a>'); item.addClass('arrow'); // This line always displays the name, even when I can't see // the name in the browser debug.log('The name: ' + name); (function(info) { anchor.bind('tap', function(e) { debug.log('Touch start ' + info.id); }); })(data.rows.item(i)); item.append(anchor); if( anchor.html() == null ) { debug.log('html is blank'); } $('#myUL').append(item); } Sometimes my list of names shows fine(http://imagebin.org/101462), and sometimes it is just blank(http://imagebin.org/101464). When the list is blank, I see the debug.log() line show me 'html is blank', and I also see the log line show me that the variable 'name' does, in fact, contain a valid name. When I check for anchor.html() == null, I've also tried to .remove() the anchor tag, and re-create it. But it always comes back without the name displayed. This happens on the mobile device and in the simulator, but I've never seen it happen in Safari or in Chrome. Has anyone seen something like this? I can't find the cause, and I can't get it to stop. Thank you for any ideas or suggestions!

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  • generation of random numbers in java

    - by S.PRATHIBA
    Hi all, I want to create 30 tables which consists of the following fields.For example, Service_ID Service_Type consumer_feedback 75 Computing 1 35 Printer 0 33 Printer -1 3 rows in set (0.00 sec) mysql select * from consumer2; Service_ID Service_Type consumer_feedback 42 data 0 75 computing 0 mysql select * from consumer3; Service_ID Service_Type consumer_feedback 43 data -1 41 data 1 72 computing -1 As you can infer from the above tables, i am getting the feedback values.I have generated these consumer_feedback values,Service_ID,Service_Type using the concept of random numbers .I have used the funtion int min1=31;//printer int max1=35;//the values are generated if the Service_Type is printer. int provider1 = (int) (Math.random() * (max1 - min1 + 1) ) + min1; int min2=41;//data int max2 =45 int provider2 = (int) (Math.random() * (max2 - min2 + 1) ) + min2; int min3=71;//computing int max3=75; int provider3 = (int) (Math.random() * (max3 - min3 + 1) ) + min3; int min5 = -1;//feedback values int max5 =1; int feedback = (int) (Math.random() * (max5 - min5 + 1) ) + min5; I need the Service_Types to be distributed uniformly in all the 30 tables.Similarly I need feedback value of 1 to be generated many times other than 0 and -1.Please Help me.

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  • How do you pass a BitmapImage from a background thread to the UI thread in WPF?

    - by DanM
    I have a background thread that generates a series of BitmapImage objects. Each time the background thread finishes generating a bitmap, I would like to show this bitmap to the user. The problem is figuring out how to pass the BitmapImage from the background thread to the UI thread. This is an MVVM project, so my view has an Image element: <Image Source="{Binding GeneratedImage}" /> My view-model has a property GeneratedImage: private BitmapImage _generatedImage; public BitmapImage GeneratedImage { get { return _generatedImage; } set { if (value == _generatedImage) return; _generatedImage= value; RaisePropertyChanged("GeneratedImage"); } } My view-model also has the code that creates the background thread: public void InitiateGenerateImages(List<Coordinate> coordinates) { ThreadStart generatorThreadStarter = delegate { GenerateImages(coordinates); }; var generatorThread = new Thread(generatorThreadStarter); generatorThread.ApartmentState = ApartmentState.STA; generatorThread.IsBackground = true; generatorThread.Start(); } private void GenerateImages(List<Coordinate> coordinates) { foreach (var coordinate in coordinates) { var backgroundThreadImage = GenerateImage(coordinate); // I'm stuck here...how do I pass this to the UI thread? } } I'd like to somehow pass backgroundThreadImage to the UI thread, where it will become uiThreadImage, then set GeneratedImage = uiThreadImage so the view can update. I've looked at some examples dealing with the WPF Dispatcher, but I can't seem to come up with an example that addresses this issue. Please advise.

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  • ASP.NET MVC application architecture "guidelines"

    - by Joe Future
    I'm looking for some feedback on my ASP.NET MVC based CMS application architecture. Domain Model - depends on nothing but the System classes to define types. For now, mostly anemic. Repository Layer - abstracted data access, only called by the services layer Services Layer - performs business logic on domain models. Exposes view models to the controllers. ViewModelMapper - service that translates back and forth between view models and domain models Controllers - super thin "traffic cop" style functionality that interacts with the service layer and only talks in terms of view models, never domain models My domain model is mostly used as data transfer (DTO) objects and has minimal logic at the moment. I'm finding this is nice because it depends on nothing (not even classes in the services layer). The services layer is a bit tricky... I only want the controllers to have access to viewmodels for ease of GUI programming. However, some of the services need to talk to each other. For example, I have an eventing service that notifies other listener services when content is tagged, when blog posts are created, etc. Currently, the methods that take domain models as inputs or return them are marked internal so they can't be used by the controllers. Sounds like overkill? Not enough abstraction? I'm mainly doing this as a learning exercise in being strict about architecture, not for an actual product, so please no feedback along the lines of "right depends on what you want to do". thanks! Jason

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  • Django: Applying Calculations To A Query Set

    - by TheLizardKing
    I have a QuerySet that I wish to pass to a generic view for pagination: links = Link.objects.annotate(votes=Count('vote')).order_by('-created')[:300] This is my "hot" page which lists my 300 latest submissions (10 pages of 30 links each). I want to now sort this QuerySet by an algorithm that HackerNews uses: (p - 1) / (t + 2)^1.5 p = votes minus submitter's initial vote t = age of submission in hours Now because applying this algorithm over the entire database would be pretty costly I am content with just the last 300 submissions. My site is unlikely to be the next digg/reddit so while scalability is a plus it is required. My question is now how do I iterate over my QuerySet and sort it by the above algorithm? For more information, here are my applicable models: class Link(models.Model): category = models.ForeignKey(Category, blank=False, default=1) user = models.ForeignKey(User) created = models.DateTimeField(auto_now_add=True) modified = models.DateTimeField(auto_now=True) url = models.URLField(max_length=1024, unique=True, verify_exists=True) name = models.CharField(max_length=512) def __unicode__(self): return u'%s (%s)' % (self.name, self.url) class Vote(models.Model): link = models.ForeignKey(Link) user = models.ForeignKey(User) created = models.DateTimeField(auto_now_add=True) def __unicode__(self): return u'%s vote for %s' % (self.user, self.link) Notes: I don't have "downvotes" so just the presence of a Vote row is an indicator of a vote or a particular link by a particular user.

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  • Django: Filtering datetime field by *only* the year value?

    - by unclaimedbaggage
    Hi folks, I'm trying to spit out a django page which lists all entries by the year they were created. So, for example: 2010: Note 4 Note 5 Note 6 2009: Note 1 Note 2 Note 3 It's proving more difficult than I would have expected. The model from which the data comes is below: class Note(models.Model): business = models.ForeignKey(Business) note = models.TextField() created = models.DateTimeField(auto_now_add=True) updated = models.DateTimeField(auto_now=True) class Meta: db_table = 'client_note' @property def note_year(self): return self.created.strftime('%Y') def __unicode__(self): return '%s' % self.note I've tried a few different ways, but seem to run into hurdles down every path. I'm guessing an effective 'group by' method would do the trick (PostGres DB Backend), but I can't seem to find any Django functionality that supports it. I tried getting individual years from the database but I struggled to find a way of filtering datetime fields by just the year value. Finally, I tried adding the note_year @property but because it's derived, I can't filter those values. Any suggestions for an elegant way to do this? I figure it should be pretty straightforward, but I'm having a heckuva time with it. Any ideas much appreciated.

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  • Type or namespace could not be found

    - by Jason Shultz
    I'm using LINQ to SQL to connect my database to my home page. I created my datacontext (named businessModel.dbml) In it I have two tables named Category and Business. In home controller I reference the model and attempt to return to the view the table: var dataContext = new businessModelDataContext(); var business = from b in dataContext.Businesses select b; ViewData["WelcomeMessage"] = "Welcome to Jerome, Arizona!"; ViewData["MottoMessage"] = "Largest Ghost Town in America!"; return View(business); and in the view I have this: <%@ Import Namespace="WelcomeToJerome.Models" %> and <% foreach (business b in (IEnumerable)ViewData.Model) { %> <li><%= b.Title %></li> <% } %> Yet, in the view business is cursed with the red underline and say's that The type or namespace name 'business' could not be found (are you missing a using directive or an assembly reference?) What am I doing wrong? This has had me stumped all afternoon. link to all the code in pastebin: http://pastebin.com/es4RnS2q

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  • Trying to get django app to work with mod_wsgi on CentOS 5

    - by David
    I'm running CentOS 5, and am trying to get a django application working with mod_wsgi. I'm using .wsgi settings I got working on Ubuntu. Here is the error: [Thu Mar 04 10:52:15 2010] [error] [client 10.1.0.251] SystemError: dynamic module not initialized properly [Thu Mar 04 10:52:15 2010] [error] [client 10.1.0.251] mod_wsgi (pid=23630): Target WSGI script '/data/hosting/cubedev/apache/django.wsgi' cannot be loaded as Python module. [Thu Mar 04 10:52:15 2010] [error] [client 10.1.0.251] mod_wsgi (pid=23630): Exception occurred processing WSGI script '/data/hosting/cubedev/apache/django.wsgi'. [Thu Mar 04 10:52:15 2010] [error] [client 10.1.0.251] Traceback (most recent call last): [Thu Mar 04 10:52:15 2010] [error] [client 10.1.0.251] File "/data/hosting/cubedev/apache/django.wsgi", line 8, in [Thu Mar 04 10:52:15 2010] [error] [client 10.1.0.251] import django.core.handlers.wsgi [Thu Mar 04 10:52:15 2010] [error] [client 10.1.0.251] File "/opt/python2.6/lib/python2.6/site-packages/django/core/handlers/wsgi.py", line 1, in [Thu Mar 04 10:52:15 2010] [error] [client 10.1.0.251] from threading import Lock [Thu Mar 04 10:52:15 2010] [error] [client 10.1.0.251] File "/opt/python2.6/lib/python2.6/threading.py", line 13, in [Thu Mar 04 10:52:15 2010] [error] [client 10.1.0.251] from functools import wraps [Thu Mar 04 10:52:15 2010] [error] [client 10.1.0.251] File "/opt/python2.6/lib/python2.6/functools.py", line 10, in [Thu Mar 04 10:52:15 2010] [error] [client 10.1.0.251] from _functools import partial, reduce [Thu Mar 04 10:52:15 2010] [error] [client 10.1.0.251] SystemError: dynamic module not initialized properly And here is my .wsgi file import os import sys os.environ['PYTHON_EGG_CACHE'] = '/tmp/django/' os.environ['DJANGO_SETTINGS_MODULE'] = 'cube.settings' sys.path.append('/data/hosting/cubedev') import django.core.handlers.wsgi application = django.core.handlers.wsgi.WSGIHandler()

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  • How should I organize my mvc templates?

    - by CatZ
    Hi, In the new version of MVC we have been given display and editor templates. I was wondering how to make the best possible use of these. I was at first thinking in the line of creating one for a collection and one for an item in the case I want to display either as a list or single but it does not really make sense to me. I'll show you what I mean and please comment if this is wrong. I have trouble figuring it out myself. <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<IEnumerable<DisplayPhoneModel>>" %> <% foreach (var item in Model){%> <%= Html.DisplayFor(x => item) %> <%}%> So in my tiny reality that would for every item in the model search for a display template for DisplayPhoneModel. That display template could then simply look like. <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<DisplayPhoneModel>" %> <%= Html.LabelFor(x => x.PhoneType) %>&nbsp;<%= Html.LabelFor(x => x.PhoneNumber) %> So, question is if there is a better way to handle this? Am I at all on the right path?

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  • Creating a json array and json items with jquery?

    - by user246114
    Hi, I made a simple javascript class like this: function Horse() { this.color = 'brown'; this.speed = 'somewhat slow'; } I attached a few instances to some elements, like this: $("#horse1").data('d', new Horse()); $("#horse2").data('d', new Horse()); $("#horse3").data('d', new Horse()); now I want to create a JSON array with a JSON representation of each horse object. So I'm doing this: // How do I create an empty JSON array here?: var myJsonArray = ?; var children = $("#horses").children(); for (var i = 0, m = children.size(); i < m; i++) { var panel = children[i]; var horse = $(panel).data('h'); // And how do I create a JSON rep of my horse here? var myJsonHorse = new JsonHorse(?); // Finally, how do I add it to the json array? myJsonArray.push(myJsonHorse); } yeah my end goal is to have a single json array of all the horses after iterating over all the children - not sure if this should be done in plain javascript or in jquery? Thanks

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  • Jquery and PHP rating function problem

    - by Sergio
    I know that I was already posted similar question but I just can't find the answer and figure it out how to solve this problem. I'm trying to customize Jquery Star Rating plugin (link text) but I do not know what to do to show the message based on response of PHP script. Jquery script successfully send rating data to PHP scripts that query the database and based on that echo message of proper or improper rating. What should I add to an existing JS code so I can get echo from PHP and base on that write a message on some DIV beside rating star? Jquery: $('#gal').rating('gl.php?gal_no=<?=$gal_no;?>&id=<?=$id;?>', {maxvalue:10,increment:.5, curvalue: <?=$cur;?>}); Simplified PHP code: $br=mysql_query("SELECT count(gal) as total FROM ...") if ... { echo '0'; } else echo '1'; } Jquery code successfully transmitted data to PHP script and when the PHP done with checking data echo the result ('1' or '0'). How can I get this PHP result back to Jquery and based on them write a message? Something like: if(data=="1") { $("#error").show("fast").html('not correct').css({'background-color':'#F5F5F5','border-color' : '#F69'}); }else{ $("#error").show("fast").html('correct').css({'background-color' : '#FFF','border-color' : '#3b5998'}); } If someone has an idea...I would appreciate it.

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  • From where to send mails in a MVC framework, so that there is no duplication of code?

    - by Sabya
    It's a MVC question. Here is the situation: I am writing an application where I have "groups". You can invite other persons to your groups by typing their email and clicking "invite". There are two ways this functionality can be called: a) web interface and b) API After the mail sending is over I want to report to the user which mails were sent successfully (i.e., if the SMTP send succeeded. Currently, I am not interested in reporting mail bounces). So, I am thinking how should I design so that there is no code duplication. That is, API and web-interface should share the bulk of the code. To do this, I can create the method "invite" inside the model "group". So, the API and and the Web-interface can just call: group-invite($emailList); This method can send the emails. But the, problem is, then I have to access the mail templates, create the views for the mails, and then send the mails. Which should actually be in the "View" part or at least in the "Controller" part. What is the most elegant design in this situation? Note: I am really thinking to write this in the Model. My only doubt is: previously I thought sending mails also as "presentation". Since it is may be considered as a different form of generating output.

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  • How do you refactor a large messy codebase?

    - by Ricket
    I have a big mess of code. Admittedly, I wrote it myself - a year ago. It's not well commented but it's not very complicated either, so I can understand it -- just not well enough to know where to start as far as refactoring it. I violated every rule that I have read about over the past year. There are classes with multiple responsibilities, there are indirect accesses (I forget the technical term - something like foo.bar.doSomething()), and like I said it is not well commented. On top of that, it's the beginnings of a game, so the graphics is coupled with the data, or the places where I tried to decouple graphics and data, I made the data public in order for the graphics to be able to access the data it needs... It's a huge mess! Where do I start? How would you start on something like this? My current approach is to take variables and switch them to private and then refactor the pieces that break, but that doesn't seem to be enough. Please suggest other strategies for wading through this mess and turning it into something clean so that I can continue where I left off!

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  • ruby on rails one-to-many relationship

    - by fenec
    I would like to model a betting system relationship using the power of rails. so lets start with doing something very simple modelling the relationship from a user to a bet.i would like to have a model bet with 2 primary keys. here are my migrations enter code here class CreateBets < ActiveRecord::Migration def self.up create_table :bets do |t| t.integer :user_1_id t.integer :user_2_id t.integer :amount t.timestamps end end def self.down drop_table :bets end end class CreateUsers < ActiveRecord::Migration def self.up create_table :users do |t| t.string :name t.timestamps end end def self.down drop_table :users end end the models enter code here class Bet < ActiveRecord::Base belongs_to :user_1,:class_name=:User belongs_to :user_2,:class_name=:User end class User < ActiveRecord::Base has_many :bets, :foreign_key =:user_1) has_many :bets, :foreign_key =:user_2) end when i test here in the console my relationships I got an error enter code here u1=User.create :name="aa" = # u2=User.create :name="bb" = # b=Bet.create(:user_1=u1,:user_2=u2) *****error***** QUESTIONS: 1 How do I define the relationships between these tables correctly? 2 are there any conventions to name the attributes (ex:user_1_id...) thank you for your help

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  • Web Shop Schema - Document Db

    - by Maxem
    I'd like to evaluate a document db, probably mongo db in an ASP.Net MVC web shop. A little reasoning at the beginning: There are about 2 million products. The product model would be pretty bad for rdbms as there'd be many different kinds of products with unique attributes. For example, there'd be books which have isbn, authors, title, pages etc as well as dvds with play time, directors, artists etc and quite a few more types. In the end, I'd have about 9 different products with a combined column count (counting common columns like title only once) of about 70 to 100 whereas each individual product has 15 columns at most. The three commonly used ways in RDBMS would be: EAV model which would have pretty bad performance characteristics and would make it either impractical or perform even worse if I'd like to display the author of a book in a list of different products (think start page, recommended products etc.). Ignore the column count and put it all in the product table: Although I deal with somewhat bigger databases (row wise), I don't have any experience with tables with more than 20 columns as far as performance is concered but I guess 100 columns would have some implications. Create a table for each product type: I personally don't like this approach as it complicates everything else. C# Driver / Classes: I'd like to use the NoRM driver and so far I think i'll try to create a product dto that contains all properties (grouped within detail classes like book details, except for those properties that should be displayed on list views etc.). In the app I'll use BookBehavior / DvdBehaviour which are wrappers around a product dto but only expose the revelent Properties. My questions now: Are my performance concerns with the many columns approach valid? Did I overlook something and there is a much better way to do it in an RDBMS? Is MongoDb on Windows stable enough? Does my approach with different behaviour wrappers make sense?

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  • Modeling complex hierarchies

    - by jdn
    To gain some experience, I am trying to make an expert system that can answer queries about the animal kingdom. However, I have run into a problem modeling the domain. I originally considered the animal kingdom hierarchy to be drawn like -animal -bird -carnivore -hawk -herbivore -bluejay -mammals -carnivores -herbivores This I figured would allow me to make queries easily like "give me all birds", but would be much more expensive to say "give me all carnivores", so I rewrote the hierarchy to look like: -animal -carnivore -birds -hawk -mammals -xyz -herbivores -birds -bluejay -mammals But now it will be much slower to query "give me all birds." This is of course a simple example, but it got me thinking that I don't really know how to model complex relationships that are not so strictly hierarchical in nature in the context of writing an expert system to answer queries as stated above. A directed, cyclic graph seems like it could mathematically solve the problem, but storing this in a relational database and maintaining it (updates) would seem like a nightmare to me. I would like to know how people typically model such things. Explanations or pointers to resources to read further would be acceptable and appreciated.

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  • Need help with a SQL CTE Query

    - by Chuck
    I have a table that I need to get some specific data from for a view. Here's the base table structure with some sample data: | UserID | ReportsToUserID | Org ID | ------------------------------------- | 1 | NULL | 1 | ------------------------------------- | 2 | 1 | 1 | ------------------------------------- | 3 | 2 | 1 | ------------------------------------- | 4 | 3 | 1 | ------------------------------------- The users will be entering reports and users can see the reports of users who report to them and any users who report to those users. Users who report to no one can see everything in their organization Given my sample data above, user 1 can see the reports of 2, 3, & 4; user 2 can see the reports of 3 & 4; and user 3 can see the reports of 4. For the view, I'd like to have the data returned as follows: | UserID | CanSeeUserID | OrgID | -------------------------------------------- | 1 | 2 | 1 | -------------------------------------------- | 1 | 3 | 1 | -------------------------------------------- | 1 | 4 | 1 | -------------------------------------------- | 2 | 3 | 1 | -------------------------------------------- etc... Below is my current code, any help is greatly appreciated. WITH CTEUsers (UserID, CanSeeUserID, OrgID) AS ( SELECT e.ID, e.ReportsToUserID, e.OrgID FROM Users e WITH(NOLOCK) WHERE COALESCE(ReportsToUserID,0) = 0 --ReportsToUserID can be NULL or 0 UNION ALL SELECT e.ReportsToUserID, e.ID,e.OrgID FROM Users e WITH(NOLOCK) JOIN CTEUsers c ON e.ID = c.UserID ) SELECT * FROM CTEUsers

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  • Django: DatabaseError column does not exist

    - by Rosarch
    I'm having a problem with Django 1.2.4. Here is a model: class Foo(models.Model): # ... ftw = models.CharField(blank=True) bar = models.ForeignKey(Bar) Right after flushing the database, I use the shell: Python 2.6.6 (r266:84292, Sep 15 2010, 15:52:39) [GCC 4.4.5] on linux2 Type "help", "copyright", "credits" or "license" for more information. (InteractiveConsole) >>> from apps.foo.models import Foo >>> Foo.objects.all() Traceback (most recent call last): File "<console>", line 1, in <module> File "/usr/local/lib/python2.6/dist-packages/django/db/models/query.py", line 67, in __repr__ data = list(self[:REPR_OUTPUT_SIZE + 1]) File "/usr/local/lib/python2.6/dist-packages/django/db/models/query.py", line 82, in __len__ self._result_cache.extend(list(self._iter)) File "/usr/local/lib/python2.6/dist-packages/django/db/models/query.py", line 271, in iterator for row in compiler.results_iter(): File "/usr/local/lib/python2.6/dist-packages/django/db/models/sql/compiler.py", line 677, in results_iter for rows in self.execute_sql(MULTI): File "/usr/local/lib/python2.6/dist-packages/django/db/models/sql/compiler.py", line 732, in execute_sql cursor.execute(sql, params) File "/usr/local/lib/python2.6/dist-packages/django/db/backends/util.py", line 15, in execute return self.cursor.execute(sql, params) File "/usr/local/lib/python2.6/dist-packages/django/db/backends/postgresql_psycopg2/base.py", line 44, in execute return self.cursor.execute(query, args) DatabaseError: column foo_foo.bar_id does not exist LINE 1: ...t_omg", "foo_foo"."ftw", "foo_foo... What am I doing wrong here?

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  • Synchronizing DataGridView (DataTable) with the DB

    - by Ezekiel Rage
    Hi! I have the following situation: there is a table in the DB that is queried when the form loads and the retrieved data is filled into a DataGridView via the DataTable underneath. After the data is loaded the user is free to modify the data (add / delete rows, modify entries). The form has 2 buttons: Apply and Refresh. The first one sends the changes to the database, the second one re-reads the data from the DB and erases any changes that have been made by the user. My question is: is this the best way to keep a DataGridView synchronized with the DB (from a users point of view)? For now these are the downsides: the user must keep track of what he is doing and must press the button every while the modifications are lost if the form is closed / app crash / ... I tried sending the changes to the DB on CellEndEdit event but then the user also needs some Undo/Redo functionality and that is ... well ... a different story. So, any suggestions?

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  • How to develop for iphone application about "retrieving database file on web"?

    - by coverboy
    Hi...all experts! I'm a newbie to iphone developer. Well, currently, I'm developing iphone for Location Based Service. That application need to have these functions. 1. hierarchical tree-view on navigation bar. 2. list up page 3. detail page for example, Let's say. I have top category like "Restaurant, Hotel, Gift Shop" Second level "New York, LA, London,....." Third Level displays all Data with 1 photo. Fourth Level displays Detail of that "Restaurant or Hotel, Gift shop, ..." So, My Only Interest is "How to retrieve the data from remote database server. not using iphone local one." Because, that locations, and shops should be updated frequently, (you know some shops closed, new shops opens.) So, till now, I figured out that using XML to retrieve data. However, using XML is the most effective way to implement? Is there any other way to accomplish this work? You know, transferring XML data via 3G Network is really slow. XML file have more bytes than plist file. I'm currently a beginner of iphone development. So, please help me find a right way!! And, one more question, if I use xml way. Is it possible to Paging? (First page 10 lists up, below that more button...) well, you might guess each category have hundreds of shops!!

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