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  • BlueJ Chpt 4 - Auction Project - How to make removeLot method work after entering a new lot

    - by Ellaine Ryan
    Hi All I am learning Java through BlueJ I would like to add a removeLot method to the Auction Class in BlueJ Chpt 4. This involves also returning the lot with the given number or null if there is no such lot. If you enter , say 5 lots and then use the remove method, this codes removes whichever lot you specify. However if you enter a new lot after using the removeLot method - an internal error message comes up regarding lotnumbering . Any ideas? Thanks Elaine public Lot removeLot(int number) { if((number >= 1) ) { } Lot lot = getLot (number); if(lot !=null) { lots.remove(lot); } return lot; }

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  • Problems with rails and saving to the database.

    - by Grantismo
    I've been having some difficulty in understanding the source of a problem. Below is a listing of the model classes. Essentially the goal is to have the ability to add sentences to the end of the story, or to add stories to an existing sentence_block. Right now, I'm only attempting to allow users to add sentences, and automatically create a new sentence_block for the new sentence. class Story < ActiveRecord::Base has_many :sentence_blocks, :dependent => :destroy has_many :sentences, :through => :sentence_blocks accepts_nested_attributes_for :sentence_blocks end class SentenceBlock < ActiveRecord::Base belongs_to :story has_many :sentences, :dependent => :destroy end class Sentence < ActiveRecord::Base belongs_to :sentence_block def story @sentence_block = SentenceBlock.find(self.sentence_block_id) Story.find(@sentence_block.story_id) end end The problem is occurring when using the show method of the Story. The Story method is as follows, and the associated show method for a sentence is also included. Sentence.show def show @sentence = Sentence.find(params[:id]) respond_to do |format| format.html {redirect_to(@sentence.story)} format.xml { render :xml => @sentence } end end Story.show def show @story = Story.find(params[:id]) @sentence_block = @story.sentence_blocks.build @new_sentence = @sentence_block.sentences.build(params[:sentence]) respond_to do |format| if @new_sentence.content != nil and @new_sentence.sentence_block_id != nil and @sentence_block.save and @new_sentence.save flash[:notice] = 'Sentence was successfully added.' format.html # new.html.erb format.xml { render :xml => @story } else @sentence_block.destroy format.html format.xml { render :xml => @story } end end end I'm getting a "couldn't find Sentence_block without and id" error. So I'm assuming that for some reason the sentence_block isn't getting saved to the database. Can anyone help me with my understanding of the behavior and why I'm getting the error? I'm trying to ensure that every time the view depicts show for a story, an unnecessary sentence_block and sentence isn't created, unless someone submits the form, I'm not really sure how to accomplish this. Any help would be appreciated.

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  • jQuery arrays - newbie needs a kick start

    - by Jonny Wood
    I've only really started using this site and alredy I am very impressed by the community here! This is my third question in less than three days. Hopefully I'll be able to start answering questions soon instead of just asking them! I'm fairly new to jQuery and can't find a decent tutorial on Arrays. I'd like to be able to create an array that targets several ID's on my page and performs the same effect for each. For example I have tabs set up with the following: $('.tabs div.tab').hide(); $('.tabs div:first').show(); $('.tabs ul li:first a').addClass('current'); $('.tabs ul li a').click(function(){ $('.tabs ul li a').removeClass('current'); $(this).addClass('current'); var currentTab = $(this).attr('href'); $('.tabs div.tab').hide(); $(currentTab).show(); return false; }); I've used the class .tag to target the tabs as there are several sets on the same page, but I've heard jQuery works much faster when targetting ID's How would I add an array to the above code to target 4 different ID's? I've looked at var myArray = new Array('#id1', 'id2', 'id3', 'id4'); And also var myValues = [ '#id1', 'id2', 'id3', 'id4' ]; Which is correct and how do I then use the array in the code for my tabs...?

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  • Learning Haskell maps, folds, loops and recursion

    - by Darknight
    I've only just dipped my toe in the world of Haskell as part of my journey of programming enlightenment (moving on from, procedural to OOP to concurrent to now functional). I've been trying an online Haskell Evaluator. However I'm now stuck on a problem: Create a simple function that gives the total sum of an array of numbers. In a procedural language this for me is easy enough (using recursion) (c#) : private int sum(ArrayList x, int i) { if (!(x.Count < i + 1)) { int t = 0; t = x.Item(i); t = sum(x, i + 1) + t; return t; } } All very fine however my failed attempt at Haskell was thus: let sum x = x+sum in map sum [1..10] this resulted in the following error (from that above mentioned website): Occurs check: cannot construct the infinite type: a = a -> t Please bear in mind I've only used Haskell for the last 30 minutes! I'm not looking simply for an answer but a more explanation of it. Thanks in advanced.

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  • Show / Hiding Divs

    - by Rob
    After cobbling together a few questions I've managed to get this far to showing / hiding divs: $(document).ready(function(){ $('.box').hide(); $('#categories').onMouseOver(function() { $('.box').hide(); $('#div' + $(this).val()).show(); }); }); HTML: <div id="categories"> <div id="btn-top20"><a href="">Top 20 Villas</a></div> <div id="btn-villaspec"><a href="">Villa Specials</a></div> <div id="btn-staffpicks"><a href="">Our Staff Picks</a></div> </div> <div id="category-content"> <div id="divarea1" class="box"> Content 1 </div> <div id="divarea2" class="box"> Content 2 </div> <div id="divarea3" class="box"> Content 3 </div> </div> What am I missing?

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  • gridview column popup window

    - by peter
    i want to implement ajax hover menu and i have a grid gridview1 like this <asp:GridView ID="GridView1" OnRowCommand="ScheduleGridView_RowCommand" runat="server" AutoGenerateColumns="False" Height="60px" Style="text-align: center" Width="869px" EnableViewState="False"> <Columns> <asp:BoundField HeaderText="Topic" DataField="Topic" /> <asp:BoundField DataField="Moderator" HeaderText="Moderator" /> <asp:BoundField DataField="Expert" HeaderText="Expert" /> <asp:BoundField DataField="StartTime" HeaderText="Start"> <HeaderStyle Width="175px" /> </asp:BoundField> <asp:BoundField DataField="EndTime" HeaderText="End"> <HeaderStyle Width="175px" /> </asp:BoundField> <asp:TemplateField HeaderText="Join" ShowHeader="False"> <ItemTemplate> <asp:Button ID="JoinBT" runat="server" CommandName="Join" Text="Join" Width="52px" /> </ItemTemplate> <HeaderStyle Height="15px" /> </asp:TemplateField> </Columns> </asp:GridView> so i registered <%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="asp" %> and added I added this way in code of gridview columns But i am getting fixed Edit/delete link in a new column rather than Hover menu,,Can any one tell me the solution to get hover menu

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  • Java: How can a constructor return a value?

    - by HH
    $ cat Const.java public class Const { String Const(String hello) { return hello; } public static void main(String[] args) { System.out.println(new Const("Hello!")); } } $ javac Const.java Const.java:7: cannot find symbol symbol : constructor Const(java.lang.String) location: class Const System.out.println(new Const("Hello!")); ^ 1 error

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  • Is there a difference here?

    - by HotHead
    Please consider following code: 1. uint16 a = 0x0001; if(a < 0x0002) { // do something } 2. uint16 a = 0x0001; if(a < uint16(0x0002)) { // do something } 3. uint16 a = 0x0001; if(a < static_cast<uint16>(0x0002)) { // do something } 4. uint16 a = 0x0001; uint16 b = 0x0002; if(a < b) { // do something } What compiler does in backgorund and what is the best (and correct) way to do above testing? p.s. sorry, but I couldn't find the better title :) Thank you in advance!

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  • Static struct in C++

    - by pingvinus
    Hi, I want to define an structure, where some math constants would be stored. Here what I've got now: struct consts { //salt density kg/m3 static const double gamma; }; const double consts::gamma = 2350; It works fine, but there would be more than 10 floating point constants, so I doesn't want to wrote 'static const' before each of them. And define something like that: static const struct consts { //salt density kg/m3 double gamma; }; const double consts::gamma = 2350; It look fine, but I got these errors: 1. member function redeclaration not allowed 2. a nonstatic data member may not be defined outside its class I wondering if there any C++ way to do it?

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  • How to extract only part of string in PHP?

    - by shin
    I have a following string and I want to extract image123.jpg. ..here_can_be_any_length "and_here_any_length/image123.jpg" and_here_also_any_length image123 can be any length (newimage123456 etc) and with extension of jpg, jpeg, gif or png. I assume I need to use preg_match, but I am not really sure how to code it. Any help will be appreciated. Thanks in advance.

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  • User Management: Managing users in user-defined "groups", database schema and logistics

    - by Kevin Brown
    I'm a noob, development wise and logistically-wise. I'm developing a site that lets people take a test... My client wants the ability for a user with the roll/privledge "admin" (a step below a super-admin) to be allowed to create users and only see/edit the users that they create... The users created in that "category" or group need some information that their superior provides. For example, I log in as a "manager", I have the ability to invite people to take the test, and manage those people. Before adding those people, I will have filled out a short survey about myself... Right now, the users that are invited will be asked some of the same questions as the manager. I'd like to cut down the redundancy by using the information put into the database by the manager and apply it to the invited users. How do I set up my database to work with this criterion? I'm a little confused about how to do this! Let me know if I can add more details... (This is a mysql and php app)

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  • Python: needs more than 1 value to unpack

    - by Rosarch
    What am I doing wrong to get this error? replacements = {} replacements["**"] = ("<strong>", "</strong>") replacements["__"] = ("<em>", "</em>") replacements["--"] = ("<blink>", "</blink>") replacements["=="] = ("<marquee>", "</marquee>") replacements["@@"] = ("<code>", "</code>") for delimiter, (open_tag, close_tag) in replacements: # error here message = self.replaceFormatting(delimiter, message, open_tag, close_tag); The error: Traceback (most recent call last): File "", line 1, in for shit, (a, b) in replacements: ValueError: need more than 1 value to unpack All the values tuples have two values. Right?

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  • linux tooling for starting as a net programmer

    - by alfredo dobrekk
    What are the linux developper tools to do the things i do with .NET in my windows environnement : I would like to port my client server application that runs under winform/nhibernate/sql server. Language c# Database SQL server ORM Nhibernate Source control SVN / Tortoise Unit testing Nunit Continuous integration Cruise Control Should i go java and eclipse ? Python and ??? Ruby and ??? Is there some IDE that allow me to manage all these processes under linux ?

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  • Global and local variables in my script

    - by Acorn
    I'm starting out learning javascript, and tried to write a little script that would make a grid of divs on a page. Here's the script: var tileWidth=50; var tileHeight=100; var leftPos=10; var topPos=10; var columns=10; var rows=10; var spacing=5; $('document').ready(function() { placeTiles(); }); function makeRow() { for (var i=0; i<columns; i++) { $('#canvas').append('<div class="tile" style="left:' + leftPos + 'px;top:' + topPos + 'px;"></div>'); var leftPos = leftPos + tileWidth + spacing; } } function placeTiles() { for (var i=0; i<rows; i++) { makeRow(); var topPos = topPos + tileHeight + spacing; } } At the moment, 100 <div>s get created, all with a top position of 10px and a left position of undefined (for the first <div> in the row) or NaN. What should I be doing differently? Why can't makerow() see my global leftPos variable (and all the other variables for that matter)? Thanks.

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  • How does jQuery .data() work?

    - by kazanaki
    My Javascript knowledge is pretty limited. Instead of asking several javascript questions I got the "message" from Stack overflow and started using jQuery right away in order to save me some time. However several times I do not undestand the "magic" behind jQuery and I would love to learn the details. I want to use .data() in my application. The examples are very helpful. I do not understand however WHERE these values are stored. I inspect the webpage with Firebug and as soon as .data() saves an object to a dom element, I do not see any change in Firebug (either HTML or Dom tabs). I tried to look at jQuery source, but it is very advanced for my Javascript knowledge and I lost myself. So the question is: Where do the values stored by jQuery.data() actually go? Can I inspect/locate/list/debug them using a tool?

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  • Problem with Delete Link?

    - by Kevin
    When I click on the delete link I created, it doesn't do anything (even the flash[:notice] part) in the controller. Am I not calling the .delete? part correctly? The POST part works as I can add tips. Link: <%= link_to "Delete", :controller => "/admin", :action => "tips", :id => t.id, :method => :delete, :confirm => "Are you sure?" %> Admin Controller def tips @tips = Tip.all if request.post? tip = Tip.new(params[:geek_tips]) if tip.save flash[:notice] = "Saved!" redirect_to :action => "tips" else flash[:notice] = "Error!" end elsif request.delete? tip = Tip.find_by_id(params[:id]) tip.delete! flash[:notice] = "Delete Message" redirect_to :action => "tips" end end

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