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• Open Source CMS (.Net vs Java)

  - by CmsAndDotNetKindaGuy

  I must say up-front that this is not a strictly programming-related question and a very opinionated one. I am the lead developer of the dominant .Net CMS in my country and I don't like my own product :). Managerial decisions over what is important or not and large chunks of legacy code done before I joined gives me headache every day I go for work. Anyway, having a vast amount of experience in web industry and a very good grasp of C# and programming practices I'm designing my own CMS the past few months. Now the problem is that I'm an open source kinda guy so I have a dilemma. Should I use C# and .Net which has crippled multi-platform support or should I drop .Net entirely and start learning Java where I can create a truly open-source and cross-platform CMS? Please don't answer that I should contribute to an existing open source CMS. I ruled that out after spending a great deal of time searching for something similar in structure to what I have in mind. I am not a native speaker, so feel free to correct my syntax or rephrase my question.

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• Speed of CSS

  - by Ólafur Waage

  This is just a question to help me understand CSS rendering better. Lets say we have a million lines of this. <div class="first"> <div class="second"> <span class="third">Hello World</span> </div> </div> Which would be the fastest way to change the font of Hello World to red? .third { color: red; } div.third { color: red; } div.second div.third { color: red; } div.first div.second div.third { color: red; } Also, what if there was at tag in the middle that had a unique id of "foo". Which one of the CSS methods above would be the fastest. I know why these methods are used etc, im just trying to grasp better the rendering technique of the browsers and i have no idea how to make a test that times it. UPDATE: Nice answer Gumbo. From the looks of it then it would be quicker in a regular site to do the full definition of a tag. Since it finds the parents and narrows the search for every parent found. That could be bad in the sense you'd have a pretty large CSS file though.

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• Can't contravariance be solved with interfaces?

  - by Sir Psycho

  Hi, I'm at the point where I'm starting to grasp contravariance, although I'm trying to work out what the advantage is when an interface can be used instead. Obviously I'm missing something. Here is the c#4 example class Dog : Animal { public Dog(string name) : base(name) { } } class Animal { string _name; public Animal(string name) { _name = name; } public void Walk() { Console.WriteLine(_name + " is walking"); } } Action<Animal> MakeItMove = (ani) => { ani.Walk(); }; Action<Dog> MakeItWalk = MakeItMove; MakeItWalk(new Dog("Sandy")); Same example which works in earlier versions on c# class Dog : Animal { public Dog(string name) : base(name) { } } class Animal : IAnimal { string _name; public Animal(string name) { _name = name; } public void Walk() { Console.WriteLine(_name + " is walking"); } } interface IAnimal { void Walk(); } Action<IAnimal> MakeItMove = (ani) => { ani.Walk(); }; Action<IAnimal> MakeItWalk = MakeItMove; MakeItWalk(new Dog("Sandy")); These may not be the best examples, but I still can't seem to 'get it'. Is the in keywork defined on the action delegate simply a short hand syntax way like lamda is to delegates?

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• Find and Replace RegEx with wildcard search and addition of value

  - by fraXis

  The below code is from my other questions that I have asked here on SO. Everyone has been so helpful and I almost have a grasp with regards to RegEx but I ran into another hurdle. This is what I basically need to do in a nutshell. I need to take this line that is in a text file that I load into my content variable: X17.8Y-1.Z0.1G0H1E1 I need to do a wildcard search for the X value, Y value, Z value, and H value. When I am done, I need this written back to my text file (I know how to create the text file so that is not the problem). X17.8Y-1.G54G0T2 G43Z0.1H1M08 I have code that the kind users here have given me, except I need to create the T value at the end of the first line, and use the value from the H and increment it by 1 for the T value. For example: X17.8Y-1.Z0.1G0H5E1 would translate as: X17.8Y-1.G54G0T6 G43Z0.1H5M08 The T value is 6 because the H value is 5. I have code that does everything (does two RegEx functions and separates the line of code into two new lines and adds some new G values). But I don't know how to add the T value back into the first line and increment it by 1 of the H value. Here is my code: StreamReader reader = new StreamReader(fDialog.FileName.ToString()); string content = reader.ReadToEnd(); reader.Close(); content = Regex.Replace(content, @"X[-\d.]+Y[-\d.]+", "$0G54G0"); content = Regex.Replace(content, @"(Z(?:\d*\.)?\d+)[^H]*G0(H(?:\d*\.)?\d+)\w*", "\nG43$1$2M08"); //This must be created on a new line This code works great at taking: X17.8Y-1.Z0.1G0H5E1 and turning it into: X17.8Y-1.G54G0 G43Z0.1H5M08 but I need it turned into this: X17.8Y-1.G54G0T6 G43Z0.1H5M08 (notice the T value is added to the first line, which is the H value +1 (T = H + 1). Can someone please modify my RegEx statement so I can do this automatically? I tried to combine my two RegEx statements into one line but I failed miserably.

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• advanced Visual Studio kung-fu test -- Calling functions from the Immediate Window during debugging

  - by kizzx2

  I see some related questions have been asked, but they're either too advanced for me to grasp or lacking a step-by-step guide from start to finish (most of them end up being insider talk of their own experiment results). OK here it is, given this simple program: #include <stdio.h> #include <string.h> int main() { FILE * f; char buffer[100]; memset(buffer, 0, 100); fun(); f = fopen("main.cpp", "r"); fread(buffer, 1, 99, f); printf(buffer); fclose(f); return 0; } What it does is basically print itself (assume file name is main.cpp). Question How can I have it print another file, say foobar.txt without modifying the source code? It has something to do with running it through VS's, stepping through the functions and hijacking the FILE pointer right before fread() is called. No need to worry about leaking resources by calling fclose(). I tried the simple f = fopen("foobar.txt", "r") which gave CXX0017: Error: symbol "fopen" not found Any ideas? Edit I found out the solution accidentally on Debugging Mozilla on Windows FAQ. The correct command to put into the Immediate Window is f = {,,MSVCR100D}fopen("foo.txt", "r") However, it doesn't really answer this question: I still don't understand what is going on here. How to systematically find out the {,,MSVCR100D} part for any given method? I know the MSVCR version changes from system to system. How can I find that out? Could anyone explain the curly brace syntax, especially, what are those two commas doing there? Are there more hidden gems using this syntax?

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• Common practice for higher-order-polymorphism in scala

  - by raichoo

  Hi, I'm trying to grasp higher-order-polymophism in scala by implementing a very basic interface that describes a monad but I come across a problem that I don't really understand. I implemented the same with C++ and the code looks like this: #include <iostream> template <typename T> class Value { private: T value; public: Value(const T& t) { this->value = t; } T get() { return this->value; } }; template < template <typename> class Container > class Monad { public: template <typename A> Container<A> pure(const A& a); }; template <template <typename> class Container> template <typename A> Container<A> Monad<Container>::pure(const A& a) { return Container<A>(a); } int main() { Monad<Value> m; std::cout << m.pure(1).get() << std::endl; return 0; } When trying to do the same with scala I fail: class Value[T](val value: T) class Monad[Container[T]] { def pure[A](a: A): Container[A] = Container[A](a) } object Main { def main(args: Array[String]): Unit = { val m = new Monad[Value] m.pure(1) } } The compiler complains about: [raichoo@lain:Scala]:434> scalac highorder.scala highorder.scala:5: error: not found: value Container Container[A](a) ^ one error found What am I doing wrong here? There seems to be a fundamental concept I don't seem to understand about scala typeconstructors. Regards, raichoo

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• Rails preventing duplicates in polymorphic has_many :through associations

  - by seaneshbaugh

  Is there an easy or at least elegant way to prevent duplicate entries in polymorphic has_many through associations? I've got two models, stories and links that can be tagged. I'm making a conscious decision to not use a plugin here. I want to actually understand everything that's going on and not be dependent on someone else's code that I don't fully grasp. To see what my question is getting at, if I run the following in the console (assuming the story and tag objects exist in the database already) s = Story.find_by_id(1) t = Tag.find_by_id(1) s.tags << t s.tags << t My taggings join table will have two entries added to it, each with the same exact data (tag_id = 1, taggable_id = 1, taggable_type = "Story"). That just doesn't seem very proper to me. So in an attempt to prevent this from happening I added the following to my Tagging model: before_validation :validate_uniqueness def validate_uniqueness taggings = Tagging.find(:all, :conditions => { :tag_id => self.tag_id, :taggable_id => self.taggable_id, :taggable_type => self.taggable_type }) if !taggings.empty? return false end return true end And it works almost as intended, but if I attempt to add a duplicate tag to a story or link I get an ActiveRecord::RecordInvalid: Validation failed exception. It seems that when you add an association to a list it calls the save! (rather than save sans !) method which raises exceptions if something goes wrong rather than just returning false. That isn't quite what I want to happen. I suppose I can surround any attempts to add new tags with a try/catch but that goes against the idea that you shouldn't expect your exceptions and this is something I fully expect to happen. Is there a better way of doing this that won't raise exceptions when all I want to do is just silently not save the object to the database because a duplicate exists?

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• How do I get an overview and a methodology for programming in Python

  - by Peter Nielsen

  I've started to learn Python and programming from scratch. I have not programmed before so it's a new experience. I do seem to grasp most of the concepts, from variables to definitions and modules. I still need to learn a lot more about what the different libraries and modules do and also I lack knowledge on OOP and classes in Python. I see people who just program in Python like that's all they have ever done and I am still just coming to grips with it. Is there a way, some tools, a logical methodology that would give me an overview or a good hold of how to handle programming problems ? For instance, I'm trying to create a parser which we need at the office . I also need to create a spider that would collect links from various websites. Is there a formidable way of studying the various modules to see what is needed ? Or is it just nose to the grind stone and understand what the documentation says ? Sorry for the lengthy question..

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• How large a role does subjectiveness play in programming?

  - by Bob

  I often read about the importance of readability and maintainability. Or, I read very strong opinions about which syntax features are bad or good. Or discussions about the values of certain paradigms, like OOP. Aside from that, this same question floats about in my mind whenever I read debates on SO or Meta about subjective questions. Or read questions about best practices and sometimes find myself or others disagreeing. What role does subjectiveness play within the programming realm? Sometimes I think it plays a large role. Software developers are engineers in a way, but also people. A large part of programming is dealing with code that's human readable. This is very different from Math or Physics or other disciplines with very exact and structured rules. Here the exact structure and rules are largely up in the air, changeable on a whim, and hence the amount of languages in existence. And one person may find one language very readable, and another person may find their own language the most comforting. The same with practices. One person may not like certain accepted practices. I myself find splitting classes into different files very unreadable, for instance. But, I can't say rules haven't helped in general. Certain practices have and do make life easier. And new languages have given rise to syntax and structure that make life easier. There's certainly been a progression towards code that is easier to read and maintain even given a largely diverse group of people. So maybe these things aren't as subjective as I thought. It reminds me, in a way, of UI design. Certainly it's subjective, but then there's an entire discipline involved in crafting good UI and it tends to work. Is there something non-subjective about the ideas behind maintainability, readability, and other best practices? Is there something tangible to grasp when one develops a new language or thinks of new practices?

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• Simple multilingual CMS?

  - by Christoffer

  Hi, I have been searching for a while now for a dead simple CMS with multi-language support. The ideal candidate is very lean and offers the possibility to set up different languages for different domains. It's OK if the language support is provided by a plugin/extension. For example I want example.com to point to English and example.fr should be French. With different URI-mappings for SEO. It can be developed in either of PHP, Ruby or Python and has to be open source. Any tips? Thank you EDIT / MORE DETAILS What I want is a CMS that is as simple to use and grasp for a client as Radiant is, but with tabs on each resource that can translate articles to different languages. Languages have to be able to use multiple domains, one for each language. I want to easily use the same article for more than one language as well as have articles (e.g. blog posts or news stories) that are only connected to one language. The CMS should be very light in core functionality (like Radiant, unlike Drupal/Joomla) but be easily extendable with plugins.

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• Beyond core java

  - by Paul

  Coming to the end of the first year of my CS degree, we've done some Java but just the core stuff; manipulating strings and arrays, inheritance, implementing logic etc. I visit this website daily and I see so much stuff that is beyond me; using frameworks; managing databases etc. It makes me feel like I've just learned the syntax of Java, and there is so much more to do with it. My question is though, how do I get there? I don't think I'm advanced enough to join an open source project, which seems to be suggested often (though I'd love to) and I've looked at other similar questions on here (like this one) but even then I don't think that'd work for me.. firstly, could somebody try give me some commonly used frameworks etc and how and what they are used for? Where would be a good place to start? How did you get started in using the things you do? Or perhaps you think I'm going down the wrong route. Should I learn another language, and just wait until the moment occurs where it's clear what I should be doing? I'm only in the first year of my degree, so far we've lightly covered Haskell and Java, and I've done a little HTML and CSS in my free time. I know that next year we cover python, so perhaps I should just wait till then and see if I prefer that? I feel like I also risk learning something in depth and then never using it... I suppose I'm also asking for personal experiences; was there a point where you felt you'd exceeded the basic grasp of a language (does not necessarily have to be Java related) and reach a more "advanced" level? I guess I'll put subjective tag on this, but really I just want to know how to get beyond the basic understanding of a language.

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• Calling functions from the Immediate Window during debugging -- advanced Visual Studio kung-fu test

  - by kizzx2

  I see some related questions have been asked, but they're either too advanced for me to grasp or lacking a step-by-step guide from start to finish (most of them end up being insider talk of their own experiment results). OK here it is, given this simple program: #include <stdio.h> #include <string.h> int main() { FILE * f; char buffer[100]; memset(buffer, 0, 100); fun(); f = fopen("main.cpp", "r"); fread(buffer, 1, 99, f); printf(buffer); fclose(f); return 0; } What it does is basically print itself (assume file name is main.cpp). Question How can I have it print another file, say foobar.txt without modifying the source code? It has something to do with running it through VS's, stepping through the functions and hijacking the FILE pointer right before fread() is called. No need to worry about leaking resources by calling fclose(). I tried the simple f = fopen("foobar.txt", "r") which gave CXX0017: Error: symbol "fopen" not found Any ideas?

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• How does the PHP IteratorIterator class work?

  - by WilliamMartin

  Try as I might I cannot get my head around what the IteratorIterator class actually does. I understand that classes can implement Traversable so the engine knows it can loop using foreach and I realise that IteratorIterator is supposed to convert anything that is Traversable into an Iterator but I cannot for the life of me understand how. Take for example, the PDOStatement class; how would the standard Iterator methods (next, key, rewind, etc) be implemented to allow iteration over a PDOStatement? Sorry if my question is unclear, I am just struggling to grasp the exact reason for this class and the documentation on it is scant. Thanks, Will Update: Going through the phpt files, I found one test which uses IteratorIterator: <?php $root = simplexml_load_string('<?xml version="1.0"?> <root> <child>Hello</child> <child>World</child> </root> '); foreach (new IteratorIterator($root->child) as $child) { echo $child."\n"; } ?> The expected output is: Hello World I don't really follow how the IteratorIterator construct takes $root-child as an argument and how it manages to iterate over the child elements.

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• Silverlight Data Binding for Collection in Stack Panel

  - by Blake Blackwell

  I'm new to Silverlight, so I don't have a complete grasp of all the controls at my disposal. What I would like to do is use databinding and a view model to maintain a collection of items. Here is some mock code for what I'd like to do: Model public class MyItem { public string DisplayText { get; set; } public bool Enabled { get; set; } } ViewModel public class MyViewModel : INotifyPropertyChanged { private ObservableCollection<MyItem> _myItems = new ObservableCollection<MyItem>(); public ObservableCollection<MyItem> MyItems { get { return _myItems; } set { _myItems = value NotifyPropertyChanged(this, "MyItems"); } } } View <Grid x:Name="LayoutRoot" Background="White"> <StackPanel ItemsSource="{Binding MyItems}"> <StackPanel Orientation="Horizontal"> <CheckBox "{Binding Enabled, Mode=TwoWay}"></CheckBox> <TextBlock Text="{Binding DisplayText, Mode=TwoWay}" /> </StackPanel> </StackPanel> </Grid> So my end goal would be that every time I add another MyItem to the MyItems collection it would create a new StackPanel with checkbox and textblock. I don't have to use a stack panel but just thought I'd use that for this sample.

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• Testing ActionFilterAttributes with MSpec

  - by Tomas Lycken

  I'm currently trying to grasp MSpec, mainly to learn new ways of (T/B)DD to be able to make an educated decision on which technology to use. Previously, I've mostly (read: only) used the built-in MSTest framework with Moq, so BDD is quite new for me. I'm writing an ASP.NET MVC app, and I want to implement PRG. Last time I did this, I used action filters to export and import ModelState via TempData, so that I could return a RedirectResult and the validation errors would still be there when the user got the view. I tested that scenario by verifying two things: a) That the ExportModelStateAttribute I had written was applied (among tests for my controller) b) That the attribute worked (among tests for action filter attributes) However, in BDD I've understood I should be even more concerned with behavior, and even less with implementation. This means I should probably just verify that the model state is in tempdata when the action has finished executing - not necessarily that it's done via an attribute. To further complicate things, attributes are not run when calling the action directly in the test, so I can't just call the action and see if the job's been done. How should I spec/test this in MSpec?

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• Which Stroustrup book should I use?

  - by Chris Simmons

  I'm a C# programmer that is looking to branch out. I'm bored of writing business software and want to start getting into graphics programming and games/simulators. So I figured, although writing that stuff isn't impossible in managed code, the "right" way to do that would be to look to C++, of course focussing on the language first, then getting into OpenGL or DirectX (or whatever). Way way back ('98? '99?) I had tried and failed to really grasp Stroustrup's The C++ Programming Language. I know that this book is often not recommended for the beginner. Anyway, I picked it back up (in a much more recent printing) and I'm actually getting it and enjoying it. I also have a copy of his textbook, Programming: Principles and Practice Using C++, which, as I understand it, is really geared toward teaching programming, not necessarily C++. I'm certainly not arrogant enough to claim I don't have anything more to learn about programming, data structures, algoriths, etc., however I'm not a novice there either. So my question is, with the goal of gaining the broader and more real-world-useful understanding of C++ and given my background, on which should I focus? The denser (as I perceive it) TCPPPL or the gentler Programming? EDIT: I thank everyone for the responses. However, I've got a personal choice here to make between these two books. Granted there are other very good books out there, but I'm already a good length into both of the books I mention and I'd like to finish one. So, can anyone respond on which would be the better and why? Time is not an issue; I'm not looking (at this point) at an "accelerated" read.

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• lots of backbone views - performance issues?

  - by ksol

  tl;dr: I wonder if having lots (100+ for the moment, potentially up to 1000/2000 or more) of backbone views (as a cell of a table) is too heavy or not The project I'm working on revolves around a planning view. There one row per user that covers 6 hours of a day, each hour splitted in 4 slots of 15mn. This planning is used to add "reservations" when clicking on a slot, and should handle hovering of the correct slots, and also handle when it is NOT possible to make a reservation - ie. prevent user click on an "unavailable" slot. There is many reasons why a slot can't be clicked on: the user is not available at this time, or the user is in a reservation; or the app needs to "force" a delay slot between two reservations. Reservations (a div) are rendered in a slot (a cell of a table), and by toying with dimensions, hovers the right number of slots. All this screen is handled with backbone. So For each slot I'm hovering on, I need to check wether I can do a reservation here or not. As of this moment, I use this by toying with the data attributes on the slots : when a reservation object is added, the slots covered are "enhanced with (among others) the reservation object (the backbone view object). But in some cases I don't quite have a grasp on now, it mixes up, and when the reservation view is removed, the slots are not "cleaned up" : the previous class is not reset correctly. It is probably something I've done wrong or badly, but this is only going to get heavier; I think I should use another class of Backbone views here, but I'm afraid the number of slots and thereof of views objects will be high and cause performance issue. I don't know mush about js perf so I'd like to have some feedback before jumping on that train. Any other advice on how to do this would be quite welcomed too. Thanks for your time. If this is not clear enough, tell me, I'll try and rephrase it.

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• Visual Studio macro to navigate to T4MVC link

  - by shannon

  I use T4MVC and I'm happy with it and want to keep it - it keeps down run time defects. Unfortunately, it makes it harder to navigate to views and content (a.k.a. Views and Links in T4MVC) though. Even using Resharper, I can't navigate to the referenced item: T4MVC and Resharper Navigation Can I get a hand building a macro to do this? Never having built a VS IDE macro before, I don't have a grasp on how to get at some things, like the internal results of the "Go To Definition" process, if that's even possible. If you aren't familiar with T4MVC, here's generally what the macro might do to help: Given the token: Links.Content.Scripts.jQuery_js in the file MyView.cshtml, '(F12) Go To Definition'. This behaves properly. Having arrived at the the related assignment: public readonly string jQuery_js = "~/Content/Scripts/jQuery.js"; in a file generated by T4MVC (which is very nice, thank you David, but we really don't ever need to see), capture the string assigned and close the file. Navigate in Solution Explorer to the PhysicalPath represented by the captured string. This process would also work for views/layouts/master-pages/partials, etc. If you provide a macro or link to a macro to do this, or have another solution, wonderful. Otherwise, hints on how to do step 3 simply in a VS macro would be especially appreciated and receive upvote from me. I'd post the macro back here as an answer when done. Thanks!

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• How do I use price data in one table for a calculation that is stored in another table?

  - by shane

  I'm still leanring PHP/MySQL but have learned quite a bit thanks to codies on StackOverflow. I'm trying to setup a sort of room reservations system using two tables: SETUP: Room price table: Has, prices for a type room a client may want to rent as well as the dates (day of week) they wish to use it. Pricing varies based on day of the week and per room. I've setup a different table for each room type as each room type carries different pricing for each day of the week. So, There is an Alpha room table, Bravo room, etc. Within Alpha table are headers for the days of the week with pricing pre-entered into the rows. Client info table: Has the name, address, date of room use, etc data for the specific client. EXAMPLE: Alpha-room price table: Sun = $100; Mon = $200; Tue=$300 and so on. Bravo-room price table: Sun = $100; Mon = $200; Tue=$300 and so on. Client data table: ClientName; date-of-room-use; address; day_subtotal; grand_total. QUESTION: I'm trying to find PHP code that will: look at the date of room use in the client data table, look up the associated cost for that date in the specific room pricing table, record that unit cost in the day subtotal of the client data table and sum a grand total in the grand total row of the client data table (assuming the room may be used more than one day by the customer). I know there's something to do with join but I'm finding it difficult to grasp the concept and, if someone can demonstrate using this example, I think I will have a better understanding of how to work this sort of transaction. Thank you ALL in advance for your suggestions or alternatvie approaches.

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• what is file verification system for php project or licence checking the configuration files

  - by Jayapal Chandran

  Hi, My colleague asked me a question like "license check to config file". when i searched i got this http://www.google.com/search?q=file+verification+system&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a and in the result i got this http://integrit.sourceforge.net/texinfo/integrit.html but could not grasp much of its idea. Here is my thoughts... Our project is written in codeigniter. The project owner is providing it to their customer. The owner is a business partner with that concept. Besides, the owner needs control of the project code so that the customer will not break rules with him like changing the code or moving it go another server or validity. So the owner needs a system to enable disable the site. Let me give an example... owner.com will have an admin panel where he can either disable or enable the client.com. when he disables the client.com should display a custom message instead of loading the files. client.com is written i a way that i will process requests from owner.com and also the other way round. so, here i want a list of the concepts with which we can implement the ownership and control over client.com any suggestions, links, references, answers will be helpful. If i am missing something in my question i will update my question according to your comments if any so that the users can give in their idea without confusing of what i had asked. THX

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• Ruby and public_method_defined? : strange behaviour

  - by aXon

  Hi there Whilst reading through the book "The well grounded Rubyist", I came across some strange behaviour. The idea behind the code is using one's own method_missing method. The only thing I am not able to grasp is, why this code gets executed, as I do not have any Person.all_with_* class methods defined, which in turn means that the self.public_method_defined?(attr) returns true (attr is friends and then hobbies). #!/usr/bin/env ruby1.9 class Person PEOPLE = [] attr_reader :name, :hobbies, :friends def initialize(mame) @name = name @hobbies = [] @friends = [] PEOPLE << self end def has_hobby(hobby) @hobbies << hobby end def has_friend(friend) @friends << friend end def self.method_missing(m,*args) method = m.to_s if method.start_with?("all_with_") attr = method[9..-1] if self.public_method_defined?(attr) PEOPLE.find_all do |person| person.send(attr).include?(args[0]) end else raise ArgumentError, "Can't find #{attr}" end else super end end end j = Person.new("John") p = Person.new("Paul") g = Person.new("George") r = Person.new("Ringo") j.has_friend(p) j.has_friend(g) g.has_friend(p) r.has_hobby("rings") Person.all_with_friends(p).each do |person| puts "#{person.name} is friends with #{p.name}" end Person.all_with_hobbies("rings").each do |person| puts "#{person.name} is into rings" end The output is is friends with is friends with is into rings which is really understandable, as there is nothing to be executed.

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• IE6 transparency+radio button can't be clicked

  - by Jonas Byström

  IE6: when I place a partially transparent image in a div, the radio buttons in that div that overlap the non-transparent pixels of the image become unclickable. Example: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <style media="screen" type="text/css"> div { position: relative; width: 500px; height: 300px; _filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src=http://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Olympic_flag_transparent.svg/200px-Olympic_flag_transparent.svg.png, sizingMethod='crop'); } input { position: absolute; top: 40px; left: 60px; } </style> </head> <body> <div> <input type="radio" value="1" name="1"/> </div> </body> </html> If you test the code, you can also try moving the button from (60, 40) to (40, 40) where the image is transparent, and voilà - the clicking is back in business again. This bug might, or might not, be related to the IE6 links transparency bug, but I'm not knowledgable enough to grasp any resemblence. Have I done something wrong? Or how can I circumvent? Is there some other option apart from removing the _filter:progid?

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• Should I use a regular server instead of AWS?

  - by Jon Ramvi

  Reading about and using the Amazon Web Services, I'm not really able to grasp how to use it correctly. Sorry about the long question: I have a EC2 instance which mostly does the work of a web server (apache for file sharing and Tomcat with Play Framework for the web app). As it's a web server, the instance is running 24/7. It just came to my attention that the data on the EC2 instance is non persistent. This means I lose my database and files if it's stopped. But I guess it also means my server settings and installed applications are lost as they are just files in the same way as the other data. This means that I will either have to rewrite the whole app to use amazon CloudDB or write some code which stores the db on S3 and make my own AMI with the correct applications installed and configured. Or can this be quick-fixed by using EBS somehow? My question is 1. is my understanding of aws is correct? and 2. is it's worth it? It could be a possibility to just set up a regular dedicated server where everything is persistent, as you would expect. Would love to have the scaleability of aws though..

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• How safe and reliable are C++ String Literals?

  - by DoctorT

  So, I'm wanting to get a better grasp on how string literals in C++ work. I'm mostly concerned with situations where you're assigning the address of a string literal to a pointer, and passing it around. For example: char* advice = "Don't stick your hands in the toaster."; Now lets say I just pass this string around by copying pointers for the duration of the program. Sure, it's probably not a good idea, but I'm curious what would actually be going on behind the scenes. For another example, let's say we make a function that returns a string literal: char* foo() { // function does does stuff return "Yikes!"; // somebody's feeble attempt at an error message } Now lets say this function is called very often, and the string literal is only used about half the time it's called: // situation #1: it's just randomly called without heed to the return value foo(); // situation #2: the returned string is kept and used for who knows how long char* retVal = foo(); In the first situation, what's actually happening? Is the string just created but not used, and never deallocated? In the second situation, is the string going to be maintained as long as the user finds need for it? What happens when it isn't needed anymore... will that memory be freed up then (assuming nothing points to that space anymore)? Don't get me wrong, I'm not planning on using string literals like this. I'm planning on using a container to keep my strings in check (probably std::string). I'm mostly just wanting to know if these situations could cause problems either for memory management or corrupted data.

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• How to access child div elements under a given condition with javascript?

  - by hlovdal

  My main question is to calculate the last alert message, but any other information is also welcome. I am trying to learn javascript (to use with greasemonkey later), but I am struggling a bit to grasp the DOM and how to process it. <html> <head> <script type="text/javascript"> function my_test() { var elements = document.getElementsByTagName("div"); // prints "found [object HTMLCollection] with length 8" alert("found " + elements + " with length " + elements.length); // prints "0:[object HTMLDivElement]" alert("0:" + elements[0]); // how to calculate the following? alert("for intereting one is AAAA and three is CCCC"); } </script> </head> <body> <div class="interesing"> <div class="one">AAAA</div> <div class="two">BBBB</div> <div class="three">CCCC</div> </div> <div class="boring"> <div class="one">1111</div> <div class="two">2222</div> <div class="three">3333</div> </div> <input type="button" onclick="my_test()" value="my test" </body> </html> So elements is now an array of elements and I can access each of them individually. But where can I find what methods/properties these elements have?

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