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• why does django-registration use an "activation window" for activating accounts?

  - by bharal

  i'm using django-registration, which is a django lib that helps with users registering on a django-built website. All well and dandy, except that it insists i have an "activation email" associated with all new users. It defaults to a 7 day window, after which, if someone signed up (and we then sent an email to confirm their email address) but didn't click on the link in the sent email within the 7 days, then they cannot sign up. Instead, they need to do the whole process all over again. I'm sure this is a concept that exists generally in web design, because why would django-registration make its own arbitrary signup process up? Anyway, the question is why? What do i gain by having the peace of mind knowing that all the users of my site are the kind of go-getters that click on registration emails with 7 days of receiving them? Why should i sleep easier knowing that my database isn't filled with users who, for whatever reason, clicked through to sign up but didn't actually want to sign up? cheers!

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• How do I center align horizontal <UL> menu?

  - by Steven

  I need to centre align a horizontal menu. I've tried various solutions, including the mix of inline-block / block / center-align etc., but not being successful. Can someone help me please? :) Here is my code: <div class="topmenu-design"> <!-- Top menu content: START --> <ul id="topmenu firstlevel"> <li class="firstli" id="node_id_64"><div><a href="#"><span>Om kampanjen</span></a></div></li> <li id="node_id_65"><div><a href="#"><span>Fakta om inneklima</span></a></div></li> <li class="lastli" id="node_id_66"><div><a href="#"><span>Statistikk</span></a></div></li> </ul> <!-- Top menu content: END --> </div> UPDATE I know how to center align the UL within the DIV. That can be accomplished using Sarfraz's suggestion. But the list items are still floated left within the UL. Do I smell javascript to accomplish this?

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• Are reads and (transactional) writes faster for entities of the same group than otherwise?

  - by indiehacker

  What advantage is there to designing child-parent relationships, which allow us to do writes in transactions, when there is never a real concern for consistency and contention and those sort of more complex issues? Does it make writes and reads faster? Consider my situation where there are many .png images that are referenced to one mosaic layer, and these .png images are written just once by a single user. The user can design many mosaic layers and her mosaic layers and referenced image entities are never changed/updated, they are just deleted some time in the future. Other users can come to the web project site and interactively view the mosaic layer as different layouts/configurations of the images as they play (query) with different criteria. So reads should be very fast. So there is no real worry of contention, or users conflicting with one another with writing new image entities. And because of that I am assuming there is no "requirement" for the .png image entities to be grouped by their same mosaic layer in child-parent relationship. However, perhaps, since the documentation says they are stored close to one another, if the many image entities were grouped as children to a single mosaic layer parent than this has the advantage that the writing (in transaction) and reading will happen much faster?

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• Javascript Application Book

  - by Jormundir

  Can anyone recommend a good book on Javascript module/application development. I'm a Software Engineer, so I don't need all the intro to programming stuff. What I'm really looking for is: How do you bundle the html/css/javascript together so that you can make one include that will load the whole application. I.e.: <div id="myapplication"></div> ... ... <script src="myapplication.js"> Design patterns are always welcome. I've already read Javascript the good parts, and online guides, but it's hard to find a comprehensive guide/tutorial for specifically this. There's a lot of good "this is a javascript application" and "this is a scalable framework", but I haven't had any luck with "This is how you build a javascript application, including the html and css, and this is how you deliver it nicely". I'm building a small application to start, so I'm not interested in scalability and large-scale development practices, just a nice and comprehensive guide to get me off the ground.

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• Codeigniter - Active record - sql - complex join

  - by Jack

  I have a function that retrieves all tags from a table: function global_popular_tags() { $this->db->select('tags.*, COUNT(tags.id) AS count'); $this->db->from('tags'); $this->db->join('tags_to_work', 'tags.id = tags_to_work.tag_id'); $this->db->group_by('tags.id'); $this->db->order_by('count', 'desc'); $query = $this->db->get()->result_array(); return $query; } I have another table called 'work'. The 'work' table has a 'draft' column with values of either 1 or 0. I want the COUNT(tags.id) to take into account whether the work with the specific tag is in draft mode (1) or not. Say there are 10 pieces of work tagged with, for example, 'design'. The COUNT will be 10. But 2 of these pieces of work are in draft mode, so the COUNT should really be 8. How do I manage this?

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• Detecting what the target object is when NullReferenceException is thrown.

  - by StingyJack

  I'm sure we all have received the wonderfully vague "Object reference not set to instance of an Object" exception at some time or another. Identifying the object that is the problem is often a tedious task of setting breakpoints and inspecting all members in each statement. Does anyone have any tricks to easily and efficiently identify the object that causes the exception, either via programmatical means or otherwise? --edit It seems I was vague like the exception =). The point is to _not have to debug the app to find the errant object. The compiler/runtime does know that the object has been allocated, and that the object has not yet been instantiated. Is there a way to extract / identify those details in a caught exception @ W. Craig Trader Your explanation that it is a result of a design problem is probably the best answer I could get. I am fairly compulsive with defensive coding and have managed to get rid of most of these errors after fixing my habits over time. The remaining ones just tweak me to no end, and lead me to posting this question to the community. Thanks for everyone's suggestions.

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• C# MVVM Calculating Total

  - by LnDCobra

  I need to calculate a trade value based on the selected price and quantity. How can The following is my ViewModel: class ViewModel : ViewModelBase { public Trade Trade { get { return _trade; } set { SetField(ref _trade, value, () => Trade); } } private Trade _trade; public decimal TradeValue { get { return Trade.Amount * Trade.Price; } } } ViewModelBase inherits INotifyPropertyChanged and contains SetField() The Following is the Trade class: public class Trade : INotifyPropertyChaged { public virtual Decimal Amount { get { return _amount; } set { SetField(ref _amount, value, () => Amount); } } private Decimal _amount; public virtual Decimal Price { get { return _price; } set { SetField(ref _price, value, () => Price); } } private Decimal _price; ...... } I know due to the design my TradeValue only gets calculated once (when its first requested) and UI doesn't get updated when amount/price changes. What is the best way of achieving this? Any help greatly appreciated.

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• Localization of DisplayNameAttribute

  - by PowerKiKi

  Hi, I am looking for a way to localize properties names displayed in a PropertyGrid. The property's name may be "overriden" using the DisplayNameAttribute attribute. Unfortunately attributes can not have non constant expressions. So I can not use strongly typed resources such as: class Foo { [DisplayAttribute(Resources.MyPropertyNameLocalized)] // do not compile string MyProperty {get; set;} } I had a look around and found some suggestion to inherit from DisplayNameAttribute to be able to use resource. I would end up up with code like: class Foo { [MyLocalizedDisplayAttribute("MyPropertyNameLocalized")] // not strongly typed string MyProperty {get; set;} } However I lose strongly typed resource benefits which is definitely not a good thing. Then I came across DisplayNameResourceAttribute which may be what I'm looking for. But it's supposed to be in Microsoft.VisualStudio.Modeling.Design namespace and I can't find what reference I am supposed to add for this namespace. Anybody know if there's a easier way to achieve DisplayName localization in a good way ? or if there is as way to use what Microsoft seems to be using for Visual Studio ?

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• To NOLOCK or NOT to NOLOCK, that is the question

  - by Limey

  Hi all, This is really more of a discussion than a specific question about nolock. I took over an app recently that almost every query (and there are lots of them) has the nolock option on them. Now I am pretty new to SQL server (used Oracle for 10 years) but yet I find this pretty disturbing. So this weekend I was talking with one of my friends who runs a rather large ecommerce site (name will be withheld to protect the guilty) and he says he has to do this with all of his SQL servers cause he will always end in deadlocks. Is this just a huge short fall with SQL server? Is this just a failure in the DB design (mine is not 3rd level, but its close) Is anybody out there running an SQL server app without nolocks? These are issues that Oracle handles better with more grandulare recordlocks. Is SQL server just not able to handle big loads? Is there some better workaround than reading uncommited data? I would love to hear what people think. Thanks

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• "Find all tiles connected to this one" project

  - by Omega

  Remember MS Paint? The bucket tool? If you used it and clicked on a pixel, all pixels connected to this pixel that are the same are affected. The theory is, I suppose, to check if there is any pixel adjacent to the selected one. If such pixel is the same type as the selected one, check for more adjacent pixels in this one, and so on. I want to implement something similar in VB.NET. Basically I have a 2D array map which represents the map. Let's assume there are only two types of tile: 0 and 1. Now, I got pretty much everything ready: I got my 2d map and I can tell which tile is clicked and tell what array indexes are the ones that represent such tile. Now for the "painting" process. Whenever I think about it, I can't figure a convenient way to execute such iteration. Can someone help me choosing a correct design/way/tip to achieve this?

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• Safari & Frames in html

  - by user575838

  Hi, I am using Windows Expression web to design a embedded quicktime player that plays 4 separate videos in a main frame. Yes, I am using frames. Header Frame, Left Bar frame, Footer & Main centre frame. Everything works in Explorer as it should. See the picture ![Web Frames preview in Explorer, links work, link plays dif videos when clicked.][1] <html> Untitled 1 <div style="position: absolute; width: 100px; height: 100px; z-index: 1" id="layer1"> </div> <p>This page uses frames, but your browser doesn&#39;t support them.</p> </body> </noframes> When I check it in Safari, the video is misaligned in the frame & the background color is black, which I want it white. All the links work, it's just the misalignment & background color. See the picture. ![Safari Preview][2] Firefox also works. Here's the code, page source from the Safari browser. Heres a pic of Safari misalignment. Heres the Safari Code code Please help. It may be simple but I'm a newb. I appreciate any advice from you pro's.

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• C# property exactly the same, defined in two places

  - by Sarah Vessels

  I have the following classes: Defect - represents a type of data that can be found in a database FilterQuery - provides a way of querying the database by setting simple Boolean filters Both Defect and FilterQuery implement the same interface: IDefectProperties. This interface specifies particular fields that are in the database. Different classes have methods that return lists of Defect instances. With FilterQuery, you specify some filters for the particular properties implemented as part of IDefectProperties, and then you run the query and get back a list of Defect instances. My problem is that I end up implementing some properties exactly the same in FilterQuery and Defect. The two are inherently different classes, they just share some of the same properties. For example: public DateTime SubmitDateAsDate { get { return DateTime.Parse(SubmitDate); } set { SubmitDate = value.ToString(); } } This is a property required by IDefectProperties that depends on a different property, SubmitDate, which returns a string instead of a DateTime. Now SubmitDate is implemented differently in Defect and FilterQuery, but SubmitDateAsDate is exactly the same. Is there a way that I can define SubmitDateAsDate in only place, but both Defect and FilterQuery provide it as a property? FilterQuery and Defect already inherit from two different classes, and it wouldn't make sense for them to share an ancestor anyway, I think. I am open to suggestions as to my design here as well.

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• Ordering z-indexes in an array

  - by Tom Gullen

  I have an array which looks something along the lines of resourceData[0][0] = "pic1.jpg"; resourceData[0][1] = 5; resourceData[1][0] = "pic2.jpg"; resourceData[1][1] = 2; resourceData[2][0] = "pic3.jpg"; resourceData[2][1] = 900; resourceData[3][0] = "pic4.jpg"; resourceData[3][1] = 1; The numeric represents the z-index of the image. Minimum z-index value is 1. Maximum (not really important) is 2000. I have all the rendering and setting z-indexes done fine. My question is, I want to have four functions: // Brings image to z front function bringToFront(resourceIndex) { // Set z-index to max + 1 resourceData[resourceIndex][1] = getBiggestZindex() + 1; // Change CSS property of image to bring to front $('#imgD' + resourceIndex).css("z-index", resourceData[resourceIndex][1]); } function bringUpOne(resourceIndex) { } function bringDownOne(resourceIndex) { } // Send to back z function sendToBack(resourceIndex) { } So given then index [3] (900 z): If we send it to the back, it will take the value 1, and [3] will have to go to 2, but that conflicts with [1] who has a 2 z-index so they need to go to three etc. Is there an easy programatical way of doing this because as soon as I start doing this it's going to get messy. It's important that the indexes of the array don't change. We can't sort the array unfortunately due to design. Update Thanks for answers, I'll post the functions here once they are written incase anyone comes across this in the future (note this code has zindex listed in [6]) // Send to back z function sendToBack(resourceIndex) { resourceData[resourceIndex][6] = 1; $('#imgD' + resourceIndex).css("z-index", 1); for (i = 0; i < resourceData.length; i++) { if (i != resourceIndex) { resourceData[i][6]++; $('#imgD' + i).css("z-index", resourceData[i][6]); } } }

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• Handling text menu in Python

  - by PulpFiction

  Hi all. I am trying to create a text based menu in Python. Here is the code: #!/usr/bin/env python def testcaseOutput(): print '1. Add. 2. Subtract. 3. Divide. 4. Multiply' try: answer = int(raw_input('Enter a value (1 - 4) >. ')) except ValueError: print 'Invalid input. Enter a value between 1 -4 .' testcaseOutput() if answer in range(1, 5): return answer else: print 'Invalid input. Enter a value between 1 - 4.' testcaseOutput() My question: When the user enters an invalid input, i.e. not a number, I want this function to get called again. So I used the recursive approach which I think is bad design. I use that approach again in the if answer in range(1, 5). Is there any other way to handle this? I need the prompt called again when there is an invalid input. Also, is there any way I can club the two constraints: check whether input is a number and check whether the number is in the range(1,5) together? As you can see, I am checking that individually.

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• git + partly shared files between branches/repositories. Is it possible?

  - by Maxym

  One team in company I work for has the following problem. They develop an application, which will have different builds (e.g. different design depending on customer). so they have some code shared between builds, and some specific to build. E.g. first build has (example is meaningless about files, it is just to understand the problem; I don't know exactly which code differs) /src/class1.java /src/class2.java /res/image1.png /res/image2.png second project contains /src/class1.java /src/class3.java /res/image1.png /res/image3.png as you see, both have class1.java and image1.png. Evething else is different. The project is much more complex of course, so to contain everything in one project is not comfortable... But also to make different branches and commit the same code to all of them is not comfortable... probably I picked wrong direction thinking about this problem, but I just took a look at git (we use svn), and it allows separated repositories. The question is: is it possible to make different branches in git, but tell it that "these files should be shared between them" and other files should be only in those branches. Then when developer commits class1.java git synchronizes it in all branches/repositorias etc. Maybe there is another solution which can be easy taken?

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• Add a banner at the top on unknown HTML page on the fly; Send a note to network user

  - by Vi

  I want to be able to send messages to users of network that my computer routes to. Modifying requested pages, by adding messages like Warning: this access point is going down soon" or Network quota exhausted or You are overusing the network connection and may be banned or Security notice: this is unencrypted network, so everybody around can see this page too It seems the only good solution (as there is no general "Send notice to users of my access point" thing). All traffic is already routed through -j REDIRECT, socat and remote SOCSK5 server, so intercepting unencrypted content should be easy. How it's better to add a message? Just inserting <div style="color:white; background-color:red">Sorry, connect_me access point is going down soon...</div> as the first element of <body> breaks design of some pages (f.e. Wikipedia). Should I also add some "Cache-control" directive to prevent persisting such messages? /* smdclient messages are poor solution, as them are Windows-only and can disturb users not using the network */

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• has_many :through default values

  - by David Lyod

  I have a need to design a system to track users memberships to groups with varying roles (currently three). class Group < ActiveRecord::Base has_many :memberships has_many :users, :through => :memberships end class Role < ActiveRecord::Base has_many :memberships has_many :users, :through => :memberships end class Membership < ActiveRecord::Base belongs_to :user belongs_to :role belongs_to :group end class User < ActiveRecord::Base has_many :memberships has_many :groups, :through => :memberships end Ideally what I want is to simply set @group.users << @user and have the membership have the correct role. I can use :conditions to select data that has been manually inserted as such : :conditions => ["memberships.grouprole_id= ? ", Grouprole.find_by_name('user')] But when creating the membership to the group the grouprole_id is not being set. Is there a way to do this as at present I have a somewhat repetitive piece of code for each user role in my Group model.

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• jQuery .ready() automatically assigning variables for each element with ID in DOM

  - by Greg

  I have noticed some unexpected behaviour when using the jQuery .ready() function, whereby afterwards you can reference an element in the DOM simply by using its ID without prior declaration or assignment: <html> <script src="jquery.js"></script> <script> $(document).ready(function() { myowndiv.innerHTML = 'wow!' }); </script> <body> <div id="myowndiv"></div> </body> </html> I would have expected to have to declare and assign myowndiv with document.getElementById("myowndiv"); or $("#myowndiv"); before I could call innerHTML or anything else on it? Is this behaviour by design? Can anyone explain why? My fear is that if I refactor and end up not using .ready() or even using jQuery at all then my code will fail to execute. Cheers!

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• is there a simple timed lock algorithm avoiding deadlock on multiple mutexes?

  - by Vicente Botet Escriba

  C++0x thread library or Boost.thread define a non-member variadic template function that locks all mutex at once that helps to avoid deadlock. template <class L1, class L2, class... L3> void lock(L1&, L2&, L3&...); The same can be applied to a non-member variadic template function try_lock_until, which locks all the mutex until a given time is reached that helps to avoid deadlock like lock(...). template <class Clock, class Duration, class L1, class L2, class... L3> void try_lock_until( const chrono::time_point<Clock,Duration>& abs_time, L1&, L2&, L3&...); I have an implementation that follows the same design as the Boost function boost::lock(...). But this is quite complex. As I can be missing something evident I wanted to know if: is there a simple timed lock algorithm avoiding deadlock on multiple mutexes? If no simple implementation exists, can this justify a proposal to Boost? P.S. Please avoid posting complex solutions.

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• Execute client & server side code with one click?

  - by Abu Hamzah

  i am not sure if my design have flaw but would like to know what others have to say, i am in a situation where i am trying to acheive two things in one click. using : asp.net web form i have a web form with few textbox and a gridview control and a button. if i click on the button i am executing two things 1) asynchronously get data from server to client (working great) and able to display the data in the textboxes. 2) same click i want to bind the gridview. <asp:Content ID="Content2" ContentPlaceHolderID="cphMaster" runat="server"> <asp:Label runat="server" ID='Label1' >Id:</asp:Label> <asp:TextBox ID="txtId" runat='server'></asp:TextBox> <asp:Button ID="btnSubmit" OnClientClick="LoadDataById();" runat="server" Text="Submit" onclick="btnSubmit_Click" /> <br /> <br /> <asp:TextBox ID="txtName" runat='server'></asp:TextBox> <br /> <asp:TextBox ID="txtPurpose" runat='server'></asp:TextBox> <br /> <br /> <asp:GridView ID="GridView1" runat="server"> </asp:GridView> </asp:Content> server side protected void btnSubmit_Click(object sender, EventArgs e) { GridView1.DataSource = laodData(int.Parse(txtId.Text)); GridView1.DataBind(); } Jquery: function LoadVisitBasicByVisitId() { ContactServiceProxy.invoke({ serviceMethod: "GetDataById", data: { request: request }, callback: function(response) { processCompletedContactStore(response); }, error: function(xhr, errorMsg, thrown) { postErrorAndUnBlockUI(xhr, errorMsg, thrown); } }); return false; } recap: 1) jquery script execute asynchronously to get data from server to client and display in the textboxes 2) server side code to bind the gridview.

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• What choices do I have for a future in software development?

  - by user354892

  After graduating from college with a degree in mathematics and a minor in computer science, I took over a year to find my first programming job. I very much enjoy my work environment, but sometimes I feel like I'm not developing professionally as quickly as I am capable of. My company does mostly web programming. The project that I work on is basically a front-end for a SQL database. The entire project is (AFAIK) coded is VB.NET. I've been working on the back-end logic of the program. After some time on the job, we decided that designing web pages is not my cup of tea. It seems like the thing that I spend more time on than anything else is searching the web and SO for information about poorly documented .net and web APIs. This does not make me happy; is this normal for a programming job; I don't think it is. It really hit me the other day when i saw a question about math asked here and I didn't know the answer; I feel like my knowledge is going stale! I was previously almost hired by another company where they design graphic-intensive battle simulations for the military. I sometimes wonder what my life might be like if I had that job. I feel like my math and problem solving skills might have been a better fit at this other company. Within the wide field of software development, there are a number of directions in which to go as evidenced by the huge variety of topics discussed here on StackOverflow. I would like to feel like I'm going in the direction where I will make the most of my skills and have a satisfying career. Let me word this question as clearly as possible: given the wide breadth of the field of software development, how does it break down into sub-fields and what are the considerations for developing a software development career. I do not want to manage my career by default.

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• Dojo's nested BorderContainer disappear in IE

  - by h4b0

  I have this terrible problem with IE 7/8/9. I wrote an app using Dojo toolkit 1.8.0 and Play! framework. It works fine in all browser except for IE. Its 'developers tools' show no error, so does firebug. The problematic code section is here: <div data-dojo-type="dijit.layout.BorderContainer" data-dojo-props="design: 'headline'"> <div data-dojo-type="dijit.layout.ContentPane" id="head" region="top"> </div> <div data-dojo-type="dijit.layout.BorderContainer" data-dojo-props="region: 'center'"> <div data-dojo-type="dijit.layout.ContentPane" id="menu" region="left"> </div> <div data-dojo-type="dijit.layout.BorderContainer" data-dojo-props="region: 'center'"> <div data-dojo-type="dijit.layout.ContentPane" id="content_1" region="top"> </div> <div data-dojo-type="dijit.layout.ContentPane" id="content_2" region="bottom"> </div> </div> </div> <div data-dojo-type="dijit.layout.ContentPane" id="foot" region="bottom"> </div> </div> The result, in all browsers except for IE is like that: But in IE it is shown like that: Can anyone explain why there are such differences? At first I thought that in IE content is hidden, so I set overflow: auto, but no scrollbar appeared after page load.

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• Would like some modelling tips for dependent values

  - by orjan

  I'm working on a model for a simple fishing competition and I have some issues with my design. The main class for the fishing game is Capture and it looks like this: public class Capture : Entity { public virtual int Weight { get; set; } public virtual int Length { get; set; } public virtual DateTime DateForCapture { get; set; } public virtual User CapturedBy { get; set; } public virtual Species Species { get; set; } } So far there´s no problem but I'm not really sure how to model the game. Every Species is connected to a reference weight that changes from year to year The number of point for a capture is its Weight divided by the current reference weight for the species. One way to solve the problem is to connect a capture to SpeciesReferenceWeight instead of Species public class SpeciesReferenceWeight : Entity { public virtual Species Species { get; set; } public virtual int ReferenceWeight { get; set; } public virtual int Year { get; set; } } But in that way that Capture is connected to the implementation details of the game and from my point of view a capture is still a capture even if it's not included in a game. The result I'm aiming for is like: http://hornalen.net/fishbonkern/2007/ that I wrote a couple of years ago with brute force sql and no domain model. I would be very happy for all kinds of feeback on this issue.

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• How to get results efficiently out of an Octree/Quadtree?

  - by Reveazure

  I am working on a piece of 3D software that has sometimes has to perform intersections between massive numbers of curves (sometimes ~100,000). The most natural way to do this is to do an N^2 bounding box check, and then those curves whose bounding boxes overlap get intersected. I heard good things about octrees, so I decided to try implementing one to see if I would get improved performance. Here's my design: Each octree node is implemented as a class with a list of subnodes and an ordered list of object indices. When an object is being added, it's added to the lowest node that entirely contains the object, or some of that node's children if the object doesn't fill all of the children. Now, what I want to do is retrieve all objects that share a tree node with a given object. To do this, I traverse all tree nodes, and if they contain the given index, I add all of their other indices to an ordered list. This is efficient because the indices within each node are already ordered, so finding out if each index is already in the list is fast. However, the list ends up having to be resized, and this takes up most of the time in the algorithm. So what I need is some kind of tree-like data structure that will allow me to efficiently add ordered data, and also be efficient in memory. Any suggestions?

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• Comparing lists of field-hashes with equivalent AR-objects.

  - by Tim Snowhite

  I have a list of hashes, as such: incoming_links = [ {:title => 'blah1', :url => "http://blah.com/post/1"}, {:title => 'blah2', :url => "http://blah.com/post/2"}, {:title => 'blah3', :url => "http://blah.com/post/3"}] And an ActiveRecord model which has fields in the database with some matching rows, say: Link.all => [<Link#2 @title='blah2' @url='...post/2'>, <Link#3 @title='blah3' @url='...post/3'>, <Link#4 @title='blah4' @url='...post/4'>] I'd like to do set operations on Link.all with incoming_links so that I can figure out that <Link#4 ...> is not in the set of incoming_links, and {:title => 'blah1', :url =>'http://blah.com/post/1'} is not in the Link.all set, like so: #pseudocode #incoming_links = as above links = Link.all expired_links = links - incoming_links missing_links = incoming_links - links expired_links.destroy missing_links.each{|link| Link.create(link)} One route I've tried: I'd rather not rewrite Array#- and such, and I'm okay with converting incoming_links to a set of unsaved Link objects; so I've tried overwriting hash eql? and so on in Link so that it ignored the id equality that AR::Base provides by default. But this is the only place this sort of equality should be considered in the application - in other places the Link#id default identity is required. Is there some way I could subclass Link and apply the hash, eql?, etc overwriting there? The other route I've tried is to pull out the attributes hash for each Link and doing a .slice('id',...etc) to prune the hashes down. But this requires writing seperate methods for keeping track of the Link objects while doing set operations on the hashes, or writing seperate Collection classes to wrap the incoming_links hash-list and Link-list which seems a bit overkill. What is the best way to design this interaction? Extra credit for cleanliness.

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