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  • Overriding content_type for Rails Paperclip plugin

    - by Fotios
    I think I have a bit of a chicken and egg problem. I would like to set the content_type of a file uploaded via Paperclip. The problem is that the default content_type is only based on extension, but I'd like to base it on another module. I seem to be able to set the content_type with the before_post_process class Upload < ActiveRecord::Base has_attached_file :upload before_post_process :foo def foo logger.debug "Changing content_type" #This works self.upload.instance_write(:content_type,"foobar") # This fails because the file does not actually exist yet self.upload.instance_write(:content_type,file_type(self.upload.path) end # Returns the filetype based on file command (assume it works) def file_type(path) return `file -ib '#{path}'`.split(/;/)[0] end end But...I cannot base the content type on the file because Paperclip doesn't write the file until after_create. And I cannot seem to set the content_type after it has been saved or with the after_create callback (even back in the controller) So I would like to know if I can somehow get access to the actual file object (assume there are no processors doing anything to the original file) before it is saved, so that I can run the file_type command on that. Or is there a way to modify the content_type after the objects have been created.

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  • Virtual destructor - How does it work?

    - by Prabhu
    Hello All, Few hours back I was fiddling with a Memory Leak issue and it turned out that I really got some basic stuff about virtual destructor wrong!! Let me put explain my class design. class Base { virtual push_elements()<br>{}<br> }; class Derived:public Base { vector<int> x; public: void push_elements(){ for(int i=0;i <5;i++) x.push_back(i); } }; void main() { Base* b = new Derived(); b->push_elements(); delete b; } The bounds checker tool reported a memory leak in the derived class vector. And I figured out that the destructor is not virtual and the derived class destructor is not called.And it surprisingly got fixed when I made the destructor virtual. But my question is "isn't the vector deallocated automatically even if the derived class destructor is not called"? Is that a quirk in BoundsChecker tool or is my understanding of virtual destructor is wrong:)

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  • WCF code generation for large/complex schema (HR-XML/OAGIS) - is there an alternative?

    - by Sasha Borodin
    Hello, and thank you for reading. I am implementing a WCF Service based on a predefined specification (HR-XML 3.0). As such, I am starting with the schema, and working my way back to code. There are a number of large Schema documents (which import yet more Schema documents) related to my implementation, provided by this specification. I am able to generate code using xsd.exe, by supplying the "main" and "supporting" xsd files as arguments. But there are several issues, and I am wondering if this is the right approach. there are litterally hundreds of classes - the code file is half a meg in size duplicate classes (ex. Type, Type1 - which both represent the same type) there are classes declared as inheriting from a base class, but that base class is not generated/defined I understand that there are limitations to the types of Schema supported by svcutil.exe/xsd.exe when targeting the DataContractSerializer and even XmlSerializer. My question is two-fold: Are code generation "issues" fairly common when dealing with larger, modular xsd files? Has anyone had success with generating data contracts from OAGIS or HR-XML schema? Given the above issues, are there better approaches to this task, avoiding generating code and working with concrete objects? Does it make better sence to read and compose a SOAP message directly, while still taking advantage of the rest of the WCF framework? I understand that I am loosing the convenience of working with .NET objects, and the framekwork-provided (de)serialization; given these losses, would it still be advantageous to base my Service on WCF? Is there some "middle ground" between working with .NET types and pure XML? Thank you very much! -Sasha Borodin DFWHC.org

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  • Saving an active record, in what order are the associated objects saved?

    - by Bryan
    In rails, when saving an active_record object, its associated objects will be saved as well. But has_one and has_many association have different order in saving objects. I have three simplified models: class Team < ActiveRecord::Base has_many :players has_one :coach end class Player < ActiveRecord::Base belongs_to :team validates_presence_of :team_id end class Coach < ActiveRecord::Base belongs_to :team validates_presence_of :team_id end I expected that when team.save is called, team should be saved before its associated coach and players. I use the following code to test these models: t = Team.new team.coach = Coach.new team.save! team.save! returns true. But in another test: t = Team.new team.players << Player.new team.save! team.save! gives the following error: > ActiveRecord::RecordInvalid: > Validation failed: Players is invalid I figured out that team.save! saves objects in the following order: 1) players, 2) team, and 3) coach. This is why I got the error: When a player is saved, team doesn't yet have a id, so validates_presence_of :team_id fails in player. Can someone explain to me why objects are saved in this order? This seems not logical to me.

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  • web service client authentication

    - by Jack
    I want to consume Java based web service with c#.net client. The problem is, I couldnt authenticate to the service. it didnt work with this: mywebservice.Credentials = new System.Net.NetworkCredential(userid, userpass); I tried to write base class for my client method. public class ClientProtocols : SoapHttpClientProtocol { protected override WebRequest GetWebRequest(Uri uri) { System.Net.WebRequest request = base.GetWebRequest(uri); if (null != Credentials) request.Headers.Add("Authorization", GetAuthHeader()); return request; } protected override WebResponse GetWebResponse(WebRequest request) { WebResponse response = base.GetWebResponse(request); return response; } private string GetAuthHeader() { StringBuilder sb = new StringBuilder(); sb.Append("Basic "); NetworkCredential cred = Credentials.GetCredential(new Uri(Url), "Basic"); string s = string.Format("{0}:{1}", cred.UserName, cred.Password); sb.Append(Convert.ToBase64String(Encoding.ASCII.GetBytes(s))); return sb.ToString(); } } How can I use this class and authorize to the web service? Thanks.

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  • NHibernate / Fluent - Mapping multiple objects to single lookup table

    - by Al
    Hi all I am struggling a little in getting my mapping right. What I have is a single self joined table of look up values of certain types. Each lookup can have a parent, which can be of a different type. For simplicities sake lets take the Country and State example. So the lookup table would look like this: Lookups Id Key Value LookupType ParentId - self joining to Id base class public class Lookup : BaseEntity { public Lookup() {} public Lookup(string key, string value) { Key = key; Value = value; } public virtual Lookup Parent { get; set; } [DomainSignature] [NotNullNotEmpty] public virtual LookupType LookupType { get; set; } [NotNullNotEmpty] public virtual string Key { get; set; } [NotNullNotEmpty] public virtual string Value { get; set; } } The lookup map public class LookupMap : IAutoMappingOverride<DBLookup> { public void Override(AutoMapping<Lookup> map) { map.Table("Lookups"); map.References(x => x.Parent, "ParentId").ForeignKey("Id"); map.DiscriminateSubClassesOnColumn<string>("LookupType").CustomType(typeof(LookupType)); } } BASE SubClass map for subclasses public class BaseLookupMap : SubclassMap where T : DBLookup { protected BaseLookupMap() { } protected BaseLookupMap(LookupType lookupType) { DiscriminatorValue(lookupType); Table("Lookups"); } } Example subclass map public class StateMap : BaseLookupMap<State> { protected StateMap() : base(LookupType.State) { } } Now I've almost got my mappings set, however the mapping is still expecting a table-per-class setup, so is expecting a 'State' table to exist with a reference to the states Id in the Lookup table. I hope this makes sense. This doesn't seem like an uncommon approach when wanting to keep lookup-type values configurable. Thanks in advance. Al

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  • Accepts Nested Attributes For - edit form displays incorrect number of items ( + !map:ActiveSupport:

    - by Brightbyte8
    Hi, I have a teacher profile model which has many subjects (separate model). I want to add subjects to the profile on the same form for creating/editing a profile. I'm using accepts_nested_attributes for and this works fine for creation. However on the edit page I am getting a very strange error - instead of seeing 3 subjects (I added three at create and a look into the console confirms this), I see 12 subjects(!). #Profile model class Profile < ActiveRecord::Base has_many :subjects accepts_nested_attributes_for :subjects end #Subject Model class Subject < ActiveRecord::Base belongs_to :profile end #Profile Controller (only showing deviations from normal RESTFUL setup) def new @profile = Profile.new 3.times do @profile.subjects.build end end #Here's 1 of three parts of the subject output of = debug @profile errors: !ruby/object:ActiveRecord::Errors base: *id004 errors: !map:ActiveSupport::OrderedHash {} subjects: - &id001 !ruby/object:Subject attributes: exam: Either name: "7" created_at: 2010-04-15 10:38:13 updated_at: 2010-04-15 10:38:13 level: Either id: "31" profile_id: "3" attributes_cache: {} # Note that 3 of these attributes are displayed despite me seeing 12 subjects on screen Other info in case it's relevant. Rails: 2.3.5 Ruby 1.8.7 p149 HAML I've never had so much difficulty with a bug before - I've already lost about 8 hours to it. Would really appreciate any help! Thanks to any courageous takers Jack

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  • CONSOLE appender was turned off. But JBoss still writes some traces to STDOUT

    - by Vladimir Bezugliy
    CONSOLE appender was turned off. But JBoss still writes some traces to STDOUT during startup. Why? C:\as\jboss-5.1.0.GA\bin>start.cmd Calling C:\as\jboss-5.1.0.GA\bin\run.conf.bat =============================================================================== JBoss Bootstrap Environment JBOSS_HOME: C:\as\jboss-5.1.0.GA JAVA: C:\as\jdk1.6.0_07\bin\java JAVA_OPTS: -Dprogram.name=run.bat -Xms512M -Xmx758M -XX:MaxPermSize=256M -server CLASSPATH: C:\as\jboss-5.1.0.GA\bin\run.jar =============================================================================== 13:11:25,080 INFO [ServerImpl] Starting JBoss (Microcontainer)... 13:11:25,080 INFO [ServerImpl] Release ID: JBoss [The Oracle] 5.1.0.GA (build: SVNTag=JBoss_5_1_0_GA date=200905221053) 13:11:25,080 INFO [ServerImpl] Bootstrap URL: null 13:11:25,080 INFO [ServerImpl] Home Dir: C:\as\jboss-5.1.0.GA 13:11:25,080 INFO [ServerImpl] Home URL: file:/C:/as/jboss-5.1.0.GA/ 13:11:25,080 INFO [ServerImpl] Library URL: file:/C:/as/jboss-5.1.0.GA/lib/ 13:11:25,080 INFO [ServerImpl] Patch URL: null 13:11:25,080 INFO [ServerImpl] Common Base URL: file:/C:/as/jboss-5.1.0.GA/common/ 13:11:25,080 INFO [ServerImpl] Common Library URL: file:/C:/as/jboss-5.1.0.GA/common/lib/ 13:11:25,080 INFO [ServerImpl] Server Name: web 13:11:25,080 INFO [ServerImpl] Server Base Dir: C:\as\jboss-5.1.0.GA\server 13:11:25,080 INFO [ServerImpl] Server Base URL: file:/C:/as/jboss-5.1.0.GA/server/ 13:11:25,080 INFO [ServerImpl] Server Config URL: file:/C:/as/jboss-5.1.0.GA/server/web/conf/ 13:11:25,080 INFO [ServerImpl] Server Home Dir: C:\as\jboss-5.1.0.GA\server\web 13:11:25,080 INFO [ServerImpl] Server Home URL: file:/C:/as/jboss-5.1.0.GA/server/web/ 13:11:25,080 INFO [ServerImpl] Server Data Dir: C:\as\jboss-5.1.0.GA\server\web\data ...

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  • How do I add code automatically to a derived function in C++

    - by Ian
    I have code that's meant to manage operations on both a networked client and a server, since there is significant overlap between the two. However, there are a few functions here and there that are meant to be exclusively called by the client or server, and accidentally calling a client function on the server (or vice versa) is a significant source of bugs. To reduce these sorts of programming errors, I'm trying to tag functions so that they'll raise a ruckus if they're misused. My current solution is a simple macro at the start of each function that calls an assert if the client or server accesses members they shouldn't. However, this runs into problems when there are multiple derived instances of classes, in that I have to tag the implementation as client or server side in EVERY child class. What I'd like to be able to do is put a tag in the virtual member's signature in the base class, so that I only have to tag it once and not run into errors by forgetting to do it repeatedly. I've considered putting a check in a base class implementation and then referring to it with something like base::functionName, but that runs into the same issue as far as needing to manually add the function call to every implementation. Ideally, I'd be able to have parent versions of the function called automatically like default constructors do. Does anybody know how to achieve something like this in C++? Is there an alternate approach I should be considering? Thanks!

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  • Rails database relationships

    - by Danny McClelland
    Hi Everyone, I have three models that I want to interact with each other. Kase, Person and and Company. I have (I think) setup the relationships correctly: class Kase < ActiveRecord::Base #HAS ONE COMPANY has_one :company #HAS MANY PERSONS has_many :persons class Person < ActiveRecord::Base belongs_to :company class Company < ActiveRecord::Base has_many :persons def to_s; companyname; end I have put the select field on the create new Kase view, and the create new Person view as follows: <li>Company<span><%= f.select :company_id, Company.all %> </span></li> All of the above successfully shows a drop down menu dynamically populated with the company names within Companies. What I am trying to do is display the contact of the Company record within the kase and person show.html.erb. For example, If I have a company called "Acme, Inc." and create a new Kase called "Random Case" and choose within the create new case page "Acme, Inc." from the companies drop down menu. I would then want to display "Acme, Inc" along with "Acme, Inc. Mobile" etc. on the "Random Case" show.html.erb. I hope this makes sense to somebody! Thanks, Danny

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  • Conditional column values in NSTableView?

    - by velocityb0y
    I have an NSTableView that binds via an NSArrayController to an NSMutableArray. What's in the array are derived classes; the first few columns of the table are bound to properties that exist on the base class. That all works fine. Where I'm running into problem is a column that should only be populated if the row maps to one specific subclass. The property that column is meant to display only exists in that subclass, since it makes no sense in terms of the base class. The user will know, from the first two columns, why the third column's cell is populated/editable or not. The binding on the third column's value is on arrangedObjects, with a model path of something like "foo.name" where foo is the property on the subclass. However, this doesn't work, as the other subclasses in the hierarchy are not key-value compliant for foo. It seems like my only choice is to have foo be a property on the base class so everybody responds to it, but this clutters up the interfaces of the model objects. Has anyone come up with a clean design for this situation? It can't be uncommon (I'm a relative newcomer to Cocoa and I'm just learning the ins and outs of bindings.)

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  • Applying the Decorator Pattern to Forms

    - by devoured elysium
    I am trying to apply the Decorator Design Pattern to the following situation: I have 3 different kind of forms: Green, Yellow, Red. Now, each of those forms can have different set of attributes. They can have a minimize box disabled, a maximized box disabled and they can be always on top. I tried to model this the following way: Form <---------------------------------------FormDecorator /\ /\ |---------|-----------| |----------------------|-----------------| GreenForm YellowForm RedForm MinimizeButtonDisabled MaximizedButtonDisabled AlwaysOnTop Here is my GreenForm code: public class GreenForm : Form { public GreenForm() { this.BackColor = Color.GreenYellow; } public override sealed Color BackColor { get { return base.BackColor; } set { base.BackColor = value; } } } FormDecorator: public abstract class FormDecorator : Form { private Form _decoratorForm; protected FormDecorator(Form decoratorForm) { this._decoratorForm = decoratorForm; } } and finally NoMaximizeDecorator: public class NoMaximizeDecorator : FormDecorator { public NoMaximizeDecorator(Form decoratorForm) : base(decoratorForm) { this.MaximizeBox = false; } } So here is the running code: static void Main() { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); Application.Run(CreateForm()); } static Form CreateForm() { Form form = new GreenForm(); form = new NoMaximizeDecorator(form); form = new NoMinimizeDecorator(form); return form; } The problem is that I get a form that isn't green and that still allows me to maximize it. It is only taking in consideration the NoMinimizeDecorator form. I do comprehend why this happens but I'm having trouble understanding how to make this work with this Pattern. I know probably there are better ways of achieving what I want. I made this example as an attempt to apply the Decorator Pattern to something. Maybe this wasn't the best pattern I could have used(if one, at all) to this kind of scenario. Is there any other pattern more suitable than the Decorator to accomplish this? Am I doing something wrong when trying to implement the Decorator Pattern? Thanks

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  • Refactoring or Rewriting Monolithic PHP Spaghetti Codebase

    - by nategood
    I've inherited a really poorly designed PHP spaghetti code project. It's been gaining a good bit of traffic recently and is starting to have performance issues on top of the poor monolithic code base. Its maxing out performance on a chunky 16GB dedicated machine when it really shouldn't be. I'm planning on doing some performance tweaks right off the bat to help the performance issue, but this still won't really help the horrible code base. The team is small but expecting to grow very soon. I've read Joel's article on the troubles of doing a complete rewrite and see the concerns. But how bad does the code base have to be before you consider a rewrite? There is PHP handling logic interjected into what one would usually consider a "view". Even worse, in some places SQL statements are in these same files! The only real separation of presentation and logic are a few PHP scripts that serve as function libraries. These scripts do most of the ORM stuff... if you can even call it that. Trying to slowly refractor this seems like a nightmare. Open to your thoughts and opinions... however not interested in hearing, "Run away, Run away!".

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  • How should I handle multiple links ot the same page with different Query Strings

    - by RandomBen
    In the website I am working on, there is a product page with 8 tabs on it, showing different aspects of the product. There are quick links on other pages within the site that take you to the page and to a specific link specified by a query string. For example the base page would be www.example.com/Product1. And then there are links like this: www.example.com/Product1?tab=CADDrawing www.example.com/Product1?tab=Schematics www.example.com/Product1?tab=Reviews My concern is that Google sees each of these links as a different URL but they aren't and the data on the page is 100% the same. Is there any easy way to make it so Google either knows that www.example.com/Product1 is the base page or doesn't follow the links with Query Strings? I thought about using rel="nofollow" but that seems like it would actually hurt my page ranking. Most of the websites, including Googles on webmaster pages, is unclear. The other option is to add the rel="canonical" to the pages that have a query string but not to the base page. Does that succeed in stopping all of the noisy links?

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  • How are declared private ivars different from synthesized ivars?

    - by lemnar
    I know that the modern Objective-C runtime can synthesize ivars. I thought that synthesized ivars behaved exactly like declared ivars that are marked @private, but they don't. As a result, come code compiles only under the modern runtime that I expected would work on either. For example, a superclass: @interface A : NSObject { #if !__OBJC2__ @private NSString *_c; #endif } @property (nonatomic, copy) NSString *d; @end @implementation A @synthesize d=_c; - (void)dealloc { [_c release]; [super dealloc]; } @end and a subclass: @interface B : A { #if !__OBJC2__ @private NSString *_c; #endif } @property (nonatomic, copy) NSString *e; @end @implementation B @synthesize e=_c; - (void)dealloc { [_c release]; [super dealloc]; } @end A subclass can't have a declared ivar with the same name as one of its superclass's declared ivars, even if the superclass's ivar is private. This seems to me like a violation of the meaning of @private, since the subclass is affected by the superclass's choice of something private. What I'm more concerned about, however, is how should I think about synthesized ivars. I thought they acted like declared private ivars, but without the fragile base class problem. Maybe that's right, and I just don't understand the fragile base class problem. Why does the above code compile only in the modern runtime? Does the fragile base class problem exist when all superclass instance variables are private?

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  • Display: table-cell problems in chrome

    - by F21
    I have 3 divs that I would like to display as table cells: <div class="field"> <div class="row"> <label for="name">Subdomain</label> <input type="text" id="name" name="name"> <div class="subdomain-base ">test</div> </div> </div> This is the CSS that I am using: body{ font-size: 13px; } .field { width:450px; display: table; } .row { display: table-row; width: 100%; } .row > * { display: table-cell; border: 1px solid red; } label { width: 125px; height: 18px; } input { max-width: none; min-width: 0; overflow: auto; height: 18px; width: 100%; } .subdomain-base { height: 18px; width: 1px; } .subdomain-base { color: blue; font-size: 13px; } It works perfectly in Firefox 24: However, it has a height problem in Chrome 30 (latest): I have been trying all sorts of things to fix the problem with Chrome, but it seems like nothing works. Why is chrome getting that extra height? Jsfiddle: http://jsfiddle.net/ahLMH/

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  • HTML relative links with URL Rewrite

    - by Adam Kiss
    I have quickie: When you code/develop themes, how do you link to various files in your html/css code? Example: We at our firm use mostly <base target="http://whatever"> in our main template and then just <img src="./images/file.png"> in our html, "/category/page" as links and something alike in our css. However, when testing on different machines, we use ip address rather than localhost on main dev station of coder, so all base links don't work (because localhost goes to viewing machine, not coder's, in our network). Same thing happens when updating pages - on dev server, we have to edit base target, so browsing site won't take us to live site - this part is actually rather simple PHP (if ... echo else echo something else), but it still not solve problem of more coding-testing problems. So, my question is, how do YOU solve it? How do you use relative links, which basically don't care for what domain is the page on and don't care for url rewrite? (because ../images/ is different for / and different for /something/somethingElse/page)?

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  • gcc -finline-functions behaviour?

    - by user176168
    I'm using gcc with the -finline-functions optimization for release builds. In order to combat code bloat because I work on an embedded system I want to say don't inline particular functions. The obvious way to do this would be through function attributes ie attribute(noinline). The problem is this doesn't seem to work when I switch on the global -finline-functions optimisation which is part of the -O3 switch. It also has something to do with it being templated as a non templated version of the same function doesn't get inlined which is as expected. Has anybody any idea of how to control inlining when this global switch is on? Here's the code: #include <cstdlib> #include <iostream> using namespace std; class Base { public: template<typename _Type_> static _Type_ fooT( _Type_ x, _Type_ y ) __attribute__ (( noinline )); }; template<typename _Type_> _Type_ Base::fooT( _Type_ x, _Type_ y ) { asm(""); return x + y; } int main(int argc, char *argv[]) { int test = Base::fooT( 1, 2 ); printf( "test = %d\n", test ); system("PAUSE"); return EXIT_SUCCESS; }

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  • How to add a new entry to a multiple has_many association?

    - by siulamvictor
    I am not sure am I doing these correct. I have 3 models, Account, User, and Event. Account contains a group of Users. Each User have its own username and password for login, but they can access the same Account data under the same Account. Events is create by a User, which other Users in the same Account can also read or edit it. I created the following migrations and models. User migration class CreateUsers < ActiveRecord::Migration def self.up create_table :users do |t| t.integer :account_id t.string :username t.string :password t.timestamps end end def self.down drop_table :users end end Account migration class CreateAccounts < ActiveRecord::Migration def self.up create_table :accounts do |t| t.string :name t.timestamps end end def self.down drop_table :accounts end end Event migration class CreateEvents < ActiveRecord::Migration def self.up create_table :events do |t| t.integer :account_id t.integer :user_id t.string :name t.string :location t.timestamps end end def self.down drop_table :events end end Account model class Account < ActiveRecord::Base has_many :users has_many :events end User model class User < ActiveRecord::Base belongs_to :account end Event model class Event < ActiveRecord::Base belongs_to :account belongs_to :user end so.... Is this setting correct? Every time when a user create a new account, the system will ask for the user information, e.g. username and password. How can I add them into correct tables? How can I add a new event? I am sorry for such a long question. I am not very understand the rails way in handling such data structure. Thank you guys for answering me. :)

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  • HTML relative links on various domains

    - by Adam Kiss
    I have quickie: When you code/develop themes, how do you link to various files in your html/css code? Example: We at our firm use mostly <base target="http://whatever"> in our main template and then just <img src="./images/file.png"> in our html, "/category/page" as links and something alike in our css. However, when testing on different machines, we use ip address rather than localhost on main dev station of coder, so all base links don't work (because localhost goes to viewing machine, not coder's, in our network). Same thing happens when updating pages - on dev server, we have to edit base target, so browsing site won't take us to live site - this part is actually rather simple PHP (if ... echo else echo something else), but it still not solve problem of more coding-testing problems. So, my question is, how do YOU solve it? How do you use relative links, which basically don't care for what domain is the page on and don't care for url rewrite? (because ../images/ is different for / and different for /something/somethingElse/page)?

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  • How can variadic char template arguments from user defined literals be converted back into numeric types?

    - by Pubby
    This question is being asked because of this one. C++11 allows you to define literals like this for numeric literals: template<char...> OutputType operator "" _suffix(); Which means that 503_suffix would become <'5','0','3'> This is nice, although it isn't very useful in the form it's in. How can I transform this back into a numeric type? This would turn <'5','0','3'> into a constexpr 503. Additionally, it must also work on floating point literals. <'5','.','3> would turn into int 5 or float 5.3 A partial solution was found in the previous question, but it doesn't work on non-integers: template <typename t> constexpr t pow(t base, int exp) { return (exp > 0) ? base * pow(base, exp-1) : 1; }; template <char...> struct literal; template <> struct literal<> { static const unsigned int to_int = 0; }; template <char c, char ...cv> struct literal<c, cv...> { static const unsigned int to_int = (c - '0') * pow(10, sizeof...(cv)) + literal<cv...>::to_int; }; // use: literal<...>::to_int // literal<'1','.','5'>::to_int doesn't work // literal<'1','.','5'>::to_float not implemented

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  • Why it's important to specify the complete class name in your association when using namespaces

    - by Carmine Paolino
    In my Rails application there is a model that has some has_one associations (this is a fabricated example): class Person::Admin < ActiveRecord::Base has_one :person_monthly_revenue has_one :dude_monthly_niceness accepts_nested_attributes_for :person_monthly_revenue, :dude_monthly_niceness end class Person::MonthlyRevenue < ActiveRecord::Base belongs_to :person_admin end class Dude::MonthlyNiceness < ActiveRecord::Base belongs_to :person_admin end The application talks to a backend that computes some data and returns a piece of JSON like this: { "dude_monthly_niceness": { "february": 1.1153232569518972, "october": 1.1250217200558268, "march": 1.3965786869658541, "august": 1.6293418014601631, "september": 1.4062771500697835, "may": 1.7166279693955291, "january": 1.0086401628086725, "june": 1.5711510228365859, "april": 1.5614525597326563, "december": 0.99894169970474289, "july": 1.7263264324994585, "november": 0.95044938418509506 }, "person_monthly_revenue": { "february": 10.585596551505297, "october": 10.574823016656749, "march": 9.9125274764852787, "august": 9.2111604702328922, "september": 9.7905249446675153, "may": 9.1329712474607962, "january": 10.479614016604238, "june": 9.3710235926961936, "april": 9.5897372624830304, "december": 10.052587677671438, "july": 8.9508877843925561, "november": 10.925339756096172 }, } To deserialize it, I use ActiveRecord's from_json, but instead of a Person::Admin object with all the associations in place, I get this error: >> Person::Admin.new.from_json(json) NameError: uninitialized constant Person::Admin::DudeMonthlyNiceness Am I doing something wrong? Is there a better way to deserialize data? (I can modify the backend easily) UPDATE: the original title was "How to deserialize from json to ActiveRecord objects with associations?" but it ended up being my mistake in specifying associations so I changed the title.

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  • How do virtual destructors work?

    - by Prabhu
    Few hours back I was fiddling with a Memory Leak issue and it turned out that I really got some basic stuff about virtual destructors wrong! Let me put explain my class design. class Base { virtual push_elements() {} }; class Derived:public Base { vector<int> x; public: void push_elements(){ for(int i=0;i <5;i++) x.push_back(i); } }; void main() { Base* b = new Derived(); b->push_elements(); delete b; } The bounds checker tool reported a memory leak in the derived class vector. And I figured out that the destructor is not virtual and the derived class destructor is not called. And it surprisingly got fixed when I made the destructor virtual. Isn't the vector deallocated automatically even if the derived class destructor is not called? Is that a quirk in BoundsChecker tool or is my understanding of virtual destructor wrong?

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  • Is boost shared_ptr <XXX> thread safe?

    - by sxingfeng
    I have a question about boost :: shared_ptr. There are lots of thread. class CResource { xxxxxx } class CResourceBase { public: void SetResource(shared_ptr<CResource> res) { m_Res = res; } shared_ptr<CResource> GetResource() { return m_Res; } private: shared_ptr<CResource> m_Res; } CResourceBase base; //---------------------------------------------- Thread A: while (true) { ...... shared_ptr<CResource> nowResource = base.GetResource(); nowResource.doSomeThing(); ... } Thread B: shared_ptr<CResource> nowResource; base.SetResource(nowResource); ... //----------------------------------------------------------- If thread A do not care the nowResource is the newest . Will this part of code have problem? I mean when ThreadB do not SetResource completely, Thread A get a wrong smart point by GetResource? Another question : what does thread-safe mean? If I do not care about whether the resource is newest, will the shared_ptr nowResource crash the program when the nowResource is released or will the problem destroy the shared_point?

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  • Backbone.js routes not firing

    - by drale2k
    I have a Base Router where i define some functions that need to be run everywhere. Every Router extends this Router. Now my problem is, that none of my routes defined in this Base router, actually fire. Every other route in other Routers work fine. I have created a test route called 'a' which calls method 'b', which should fire an alert but nothing happens. Here is the code: (This is Coffeescript, don't pay attention to the indentation, it's fine in my file) class Etaxi.Routers.Base extends Backbone.Router routes: 'register' : 'registerDevice' 'a' : 'b' b: -> alert "a" initialize: -> @registerDevice() unless localStorage.device_id? @getGeolocation() registerDevice: -> @collection = new Etaxi.Collections.Devices() @collection.fetch() view = new Etaxi.Views.RegisterDevice(collection: @collection) $('#wrapper').append(view.render().el) getGeolocation: -> navigator.geolocation.getCurrentPosition (position) -> lat = position.coords.latitude lng = position.coords.longitude #$('#apphead').tap -> # alert 'Position: ' + lat + " ," + lng So when i visit '/register' or '/a' it should fire the appropriate method but it does not. I wonder if it has something to do with the fact that other Router extend from this Router? Would be wired but it is the only thing i can think of because every other Router works fine.

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