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  • I've got two technical degrees but little in the way of experience. How do I get into programming? [closed]

    - by Neonfirelights
    I'm looking for a job, I want to break into programming. I'm looking for the right sort of role and the right place to look for it; I would really appreciate input from someone with industry experience. I've got an excellent academic record: BSc Physics (2:1), MSc Computer Graphics, Vision and Imaging (expecting Merit) from two world ranking universities. I have advanced technical knowledge of C/C++ and Matlab and experience working with C# and VB.NET. Unfortunately I don't have much in the way of commercial experience; unlike a lot of people I know my under-graduate didn't come with a sandwich placement. Where can I go to break into the software industry?

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  • Tasks not appearing in Mac Outlook 2011

    - by Tama
    My current workplace uses Macs and my old workplaces used Windows. In my old workplaces I heavily used Outlook's Task functionality to manage my workload. I understand that the Task functionality in Outlook 2011 for Mac is heavily limited so I was very pleased to find this useful "how-to" on making the most of Tasks. My problem is that my tasks don't appear in the Task folder, or anywhere else for that matter. Even if I search for a the title of a task I've recently found I still can't find them. After some Googling I found this forum thread that suggests it may be a problem with the Outlook database, which points to a Microsoft KB. So I went through all of the recommended steps on rebuilding/ adding a new identity using the "Microsoft Database Utility" - the theory being that if I create a new identity I can test the task creation using a "blank slate" identity. When I change the default identity to my newly created identity using the Microsoft Database Utility (have to restart the computer) Task creation still doesn't work. Any ideas appreciated, I really miss the task functionality in Outlook 2010 for Windows.

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  • Updating PHP on Linux - "No Packages marked for Update"?

    - by Aristotle
    I'm very new to server-administration, but I was thinking the task of updating PHP to 5.2+ should be relatively simple. Online I found that the following was allegedly sufficient to do this: yum update php But when I run this, the following is output: [root@ip-XXX-XXX-XXX-XXX /]# php -v PHP 5.1.6 (cli) (built: Jan 13 2010 17:13:05) Copyright (c) 1997-2006 The PHP Group Zend Engine v2.1.0, Copyright (c) 1998-2006 Zend Technologies [root@ip-XXX-XXX-XXX-XXX /]# yum update php Loaded plugins: fastestmirror Determining fastest mirrors * addons: p3plmirror02.prod.phx3.secureserver.net * base: p3plmirror02.prod.phx3.secureserver.net * extras: p3plmirror02.prod.phx3.secureserver.net * turbopanel-base: p3plmirror02.prod.phx3.secureserver.net * turbopanel-centos5: p3plmirror02.prod.phx3.secureserver.net * update: p3plmirror02.prod.phx3.secureserver.net addons | 951 B 00:00 addons/primary | 201 B 00:00 base | 2.1 kB 00:00 base/primary_db | 1.6 MB 00:00 extras | 1.1 kB 00:00 extras/primary | 107 kB 00:00 extras 325/325 turbopanel-base | 951 B 00:00 turbopanel-base/primary | 72 kB 00:00 turbopanel-base 494/494 turbopanel-centos5 | 951 B 00:00 turbopanel-centos5/primary | 2.1 kB 00:00 turbopanel-centos5 8/8 update | 1.9 kB 00:00 update/primary_db | 463 kB 00:00 Setting up Update Process No Packages marked for Update [root@ip-XXX-XXX-XXX-XXX /]# php -v PHP 5.1.6 (cli) (built: Jan 13 2010 17:13:05) Copyright (c) 1997-2006 The PHP Group Zend Engine v2.1.0, Copyright (c) 1998-2006 Zend Technolog [root@ip-XXX-XXX-XXX-XXX /]# No Packages marked for Update [root@ip-XXX-XXX-XXX-XXX /]# php -v bash: No: command not found [root@ip-XXX-XXX-XXX-XXX /]# [root@ip-XXX-XXX-XXX-XXX /]# php -v bash: [root@ip-XXX-XXX-XXX-XXX: command not found [root@ip-XXX-XXX-XXX-XXX /]# PHP 5.1.6 (cli) (built: Jan 13 2010 17:13:05) bash: syntax error near unexpected token `(' [root@ip-XXX-XXX-XXX-XXX /]# Copyright (c) 1997-2006 The PHP Group bash: syntax error near unexpected token `c' [root@ip-XXX-XXX-XXX-XXX /]# Zend Engine v2.1.0, Copyright (c) 1998-2006 Zend Technologies bash: syntax error near unexpected token `(' [root@ip-XXX-XXX-XXX-XXX /]# My PHP version is 5.1.6 before, and after running the command. Am I being too naive here with this update process? Is there a more verbose route that is necessary for me to take?

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  • CentOs 6.3 can't install Git

    - by drivard
    I am trying to install git on an OpenVZ container using the CentOs 6.3 precreated template. When I try the command line yum install git I get the message: Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: www.cubiculestudio.com * epel: mirror.csclub.uwaterloo.ca * extras: www.cubiculestudio.com * rpmforge: mirror.us.leaseweb.net * updates: www.cubiculestudio.com Setting up Install Process No package git available. Error: Nothing to do As I understand, the git package should be in the centos6 base repository: http://pkgs.org/centos-6-rhel-6/centos-rhel-x86_64/git-1.7.1-2.el6_0.1.x86_64.rpm.html But it doesn't find it, I even have the EPEL and RPMForge repo enabled, but still can't find the git package. yum repolist Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: www.cubiculestudio.com * epel: mirror.csclub.uwaterloo.ca * extras: www.cubiculestudio.com * rpmforge: mirror.us.leaseweb.net * updates: www.cubiculestudio.com repo id repo name status base CentOS-6 - Base 4,776 epel Extra Packages for Enterprise Linux 6 - i386 6,523 extras CentOS-6 - Extras 4 rpmforge RHEL 6 - RPMforge.net - dag 4,501 updates CentOS-6 - Updates 596 vz-base vz-base 3 vz-updates vz-updates 0 repolist: 16,403 The weirdest thing is that my OpenVZ server is running on CentOs 6.3 and I was able to install git without any issue. Can you help me understanding why it doesn't find the package? Thank you in advance.

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  • How do I enable additional debugging output from Ansible and Vagrant?

    - by Brian Lyttle
    I'm investigating Ansible for server and application provisioning. My application is currently provisioned with shell scripts in Vagrant. Rather than rewrite my scripts I've taken a sample and attempted to deploy it. It appears to deploy fine, but I've seeing a failure message after what looks like a series of successful steps: » vagrant provision ~/vm/blvagrant 1 ? [default] Running provisioner: ansible... PLAY [web-servers] ************************************************************ GATHERING FACTS *************************************************************** ok: [192.168.9.149] TASK: [install python-software-properties] ************************************ ok: [192.168.9.149] => {"changed": false, "item": ""} TASK: [add nginx ppa if it ubuntu 10.04 and up] ******************************* ok: [192.168.9.149] => {"changed": false, "item": "", "repo": "ppa:nginx/stable", "state": "present"} TASK: [update apt repo] ******************************************************* ok: [192.168.9.149] => {"changed": false, "item": ""} TASK: [install nginx] ********************************************************* ok: [192.168.9.149] => {"changed": false, "item": ""} TASK: [copy fixed init for nginx] ********************************************* ok: [192.168.9.149] => {"changed": false, "gid": 0, "group": "root", "item": "", "mode": "0755", "owner": "root", "path": "/etc/init.d/nginx", "size": 2321, "state": "file", "uid": 0} TASK: [service nginx] ********************************************************* ok: [192.168.9.149] => {"changed": false, "item": "", "name": "nginx", "state": "started"} TASK: [write nginx.conf] ****************************************************** ok: [192.168.9.149] => {"changed": false, "gid": 0, "group": "root", "item": "", "mode": "0644", "owner": "root", "path": "/etc/nginx/nginx.conf", "size": 1067, "state": "file", "uid": 0} PLAY RECAP ******************************************************************** 192.168.9.149 : ok=8 changed=0 unreachable=0 failed=0 Ansible failed to complete successfully. Any error output should be visible above. Please fix these errors and try again. How do I go about getting additional debug information? I've already added ansible.verbose = true to my vagrant config which results in the dictionaries being displayed within the output above.

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  • Apache forwarding without redirecting (application won't follow redirects)

    - by DrewVS
    Recently we had to move /task to /public/task, and I'd like to configure Apache to redirect accordingly. However, using mod_rewrite, though it works in the browser, seems to break applications making api calls to the above location. What happens is the application returns a page with the message saying the page was moved, but the app doesn't follow the redirect. So, is there a way to simply forward any traffic to /task to /public/task without 'redirecting', i.e, returning a redirect status code? EDIT: Here's a little more information. I've found a simple test to clarify what I'm trying to fix. Here is the URL path that needs forwarding: https://mydomain.com/task Needs to go to: https://mydomain.com/public/task If I use curl against the original domain, it just returns a redirect page notice. If I add the -L flag, which tells curl to follow redirects, it then follows the redirect successfully. I assume something very similar is happening in the application (which I don't have access to) that makes calls to the /task URL path. Since I cannot modify the application to make it follow redirects properly, I'm looking for a solution I can implement in Apache.

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  • Error in requiring Sinatra gem

    - by Dan
    I'm having a hard time getting Sinatra running on my local setup, Ubuntu Karmic 9.10. The error getting thrown when I have require 'sinatra' is: NoMethodError: undefined method `[]' for nil:NilClass from /usr/local/lib/ruby/gems/1.8/gems/sinatra-1.0/lib/sinatra/base.rb:891:in `compile' from /usr/local/lib/ruby/gems/1.8/gems/sinatra-1.0/lib/sinatra/base.rb:883:in `gsub' from /usr/local/lib/ruby/gems/1.8/gems/sinatra-1.0/lib/sinatra/base.rb:883:in `compile' from /usr/local/lib/ruby/gems/1.8/gems/sinatra-1.0/lib/sinatra/base.rb:856:in `route' from /usr/local/lib/ruby/gems/1.8/gems/sinatra-1.0/lib/sinatra/base.rb:838:in `get' from /usr/local/lib/ruby/gems/1.8/gems/sinatra-1.0/lib/sinatra/base.rb:1077 from /usr/local/lib/ruby/gems/1.8/gems/sinatra-1.0/lib/sinatra/base.rb:929:in `configure' from /usr/local/lib/ruby/gems/1.8/gems/sinatra-1.0/lib/sinatra/base.rb:1076 from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require' from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require' from /usr/local/lib/ruby/gems/1.8/gems/sinatra-1.0/lib/sinatra.rb:4 from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:36:in `gem_original_require' from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:36:in `require' from (irb):2 from :0 I've tried: Uninstalling/reinstalling Sinatra Updating all gems Ensuring all dependencies exist (rack) Any ideas? Your time and help is greatly appreciated!

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  • raw_id_fields for modelforms

    - by nbv4
    I have a modelform which has one field that is a ForeignKey value to a model which as 40,000 rows. The default modelform tries to create a select box with 40,000 options, which, to say the least is not ideal. Even more so when this modelform is used in a formset factory! In the admin, this is easiely avoidable by using "raw_id_fields", but there doesn't seem to be a modelform equivalent. How can I do this? Here is my modelform: class OpBaseForm(ModelForm): base = forms.CharField() class Meta: model = OpBase exclude = ['operation', 'routes'] extra = 0 raw_id_fields = ('base', ) #does nothing The first bolded line works by not creating the huge unwieldy selectbox, but when I try to save a fieldset of this form, I get the error: "OpBase.base" must be a "Base" instance. In order for the modelform to be saved, 'base' needs to be a Base instance. Apparently, a string representation of a Base primary key isn't enough (at least not automatically). I need some kind of mechanism to change the string that is given my the form, to a Base instance. And this mechanism has to work in a formset. Any ideas? If only raw_id_fields would work, this would be easy as cake. But as far as I can tell, it only is available in the admin.

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  • Trying to Use LoadMoreElement in Monotouch.Dialog

    - by user1487581
    I am using Monotouch to write an Ipad app. The app uses tables to browse down through a directory tree and then select a file. I have used Monotouch.Dialog to browse the directories and I set up the directory tables as the app starts.However there are too many files to set up in a table as the app starts and so I want to set up the 'file table' as the file is selected from the lowest level directory table. I am trying to use LoadMoreElement to do this but I cannot make it work or find any examples online. I have coded the 'Elements API Walkthrough' in the Xamarin tutorial at:- http://docs.xamarin.com/ios/tutorials/MonoTouch.Dialog I then add a new section to the code:- _addButton.Clicked += (sender, e) => { ++n; var task = new Task{Name = "task " + n, DueDate = DateTime.Now}; var taskElement = new RootElement (task.Name){ new Section () { new EntryElement (task.Name, "Enter task description", task.Description) }, new Section () { new DateElement ("Due Date", task.DueDate) }, new Section() { new LoadMoreElement("Passive","Active", delegate {MyAction();}) } }; _rootElement [0].Add (taskElement); Where MyAction is:- public void MyAction() { Console.WriteLine ("we have been actioned"); } The problem is that MyAction is triggered and Console.Writeline writes the message but the table stays in the active state and never returns to passive. the documentation says:- Once your code in the NSAction is finished, the UIActivity indicator stops animating and the normal caption is displayed again. What am I missing? Ian

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  • Hazelcast Distributed Executor Service KeyOwner

    - by János Veres
    I have problem understanding the concept of Hazelcast Distributed Execution. It is said to be able to perform the execution on the owner instance of a specific key. From Documentation: <T> Future<T> submitToKeyOwner(Callable<T> task, Object key) Submits task to owner of the specified key and returns a Future representing that task. Parameters: task - task key - key Returns: a Future representing pending completion of the task I believe that I'm not alone to have a cluster built with multiple maps which might actually use the same key for different purposes, holding different objects (e.g. something along the following setup): IMap<String, ObjectTypeA> firstMap = HazelcastInstance.getMap("firstMap"); IMap<String, ObjectTypeA_AppendixClass> secondMap = HazelcastInstance.getMap("secondMap"); To me it seems quite confusing what documentation says about the owner of a key. My real frustration is that I don't know WHICH - in which map - key does it refer to? The documentation also gives a "demo" of this approach: import com.hazelcast.core.Member; import com.hazelcast.core.Hazelcast; import com.hazelcast.core.IExecutorService; import java.util.concurrent.Callable; import java.util.concurrent.Future; import java.util.Set; import com.hazelcast.config.Config; public void echoOnTheMemberOwningTheKey(String input, Object key) throws Exception { Callable<String> task = new Echo(input); HazelcastInstance hz = Hazelcast.newHazelcastInstance(); IExecutorService executorService = hz.getExecutorService("default"); Future<String> future = executorService.submitToKeyOwner(task, key); String echoResult = future.get(); } Here's a link to the documentation site: Hazelcast MultiHTML Documentation 3.0 - Distributed Execution Did any of you guys figure out in the past what key does it want?

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  • Emulating Dynamic Dispatch in C++ based on Template Parameters

    - by Jon Purdy
    This is heavily simplified for the sake of the question. Say I have a hierarchy: struct Base { virtual int precision() const = 0; }; template<int Precision> struct Derived : public Base { typedef Traits<Precision>::Type Type; Derived(Type data) : value(data) {} virtual int precision() const { return Precision; } Type value; }; I want a function like: Base* function(const Base& a, const Base& b); Where the specific type of the result of the function is the same type as whichever of first and second has the greater Precision; something like the following pseudocode: template<class T> T* operation(const T& a, const T& b) { return new T(a.value + b.value); } Base* function(const Base& a, const Base& b) { if (a.precision() > b.precision()) return operation((A&)a, A(b.value)); else if (a.precision() < b.precision()) return operation(B(a.value), (B&)b); else return operation((A&)a, (A&)b); } Where A and B are the specific types of a and b, respectively. I want f to operate independently of how many instantiations of Derived there are. I'd like to avoid a massive table of typeid() comparisons, though RTTI is fine in answers. Any ideas?

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  • WM_NOTIFY and superclass chaining issue in Win32

    - by DasMonkeyman
    For reference I'm using the window superclass method outlined in this article. The specific issue occurs if I want to handle WM_NOTIFY messages (i.e. for custom drawing) from the base control in the superclass I either need to reflect them back from the parent window or set my own window as the parent (passed inside CREATESTRUCT for WM_(NC)CREATE to the base class). This method works fine if I have a single superclass. If I superclass my superclass then I run into a problem. Now 3 WindowProcs are operating in the same HWND, and when I reflect WM_NOTIFY messages (or have them sent to myself from the parent trick above) they always go to the outermost (most derived) WindowProc. I have no way to tell if they're messages intended for the inner superclass (base messages are supposed to go to the first superclass) or messages intended for the outer superclass (messages from the inner superclass are intended for the outer superclass). These messages are indistinguishable because they all come from the same HWND with the same control ID. Is there any way to resolve this without creating a new window to encapsulate each level of inheritance? Sorry about the wall of text. It's a difficult concept to explain. Here's a diagram. single superclass: SuperA::WindowProc() - Base::WindowProc()---\ ^--------WM_NOTIFY(Base)--------/ superclass of a superclass: SuperB::WindowProc() - SuperA::WindowProc() - Base::WindowProc()---\ ^--------WM_NOTIFY(Base)--------+-----------------------/ ^--------WM_NOTIFY(A)-----------/ The WM_NOTIFY messages in the second case all come from the same HWND and control ID, so I cannot distinguish between the messages intended for SuperA (from Base) and messages intended for SuperB (from SuperA). Any ideas?

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  • What is the right pattern for a async data fetching method in .net async/await

    - by s093294
    Given a class with a method GetData. A few other clients call GetData, and instead of it fetching data each time, i would like to create a pattern where the first call starts the task to get the data, and the rest of the calls wait for the task to complete. private Task<string> _data; private async Task<string> _getdata() { return "my random data from the net"; //get_data_from_net() } public string GetData() { if(_data==null) _data=_getdata(); _data.wait(); //are there not a problem here. cant wait a task that is already completed ? if(_data.status != rantocompletion) _data.wait() is not any better, it might complete between the check and the _data.wait? return _data.Result; } How would i do the pattern correctly? (Solution) private static object _servertime_lock = new object(); private static Task<string> _servertime; private static async Task<string> servertime() { try { var thetvdb = new HttpClient(); thetvdb.Timeout = TimeSpan.FromSeconds(5); // var st = await thetvdb.GetStreamAsync("http://www.thetvdb.com/api/Updates.php?type=none"); var response = await thetvdb.GetAsync("http://www.thetvdb.com/api/Updates.php?type=none"); response.EnsureSuccessStatusCode(); Stream stream = await response.Content.ReadAsStreamAsync(); XDocument xdoc = XDocument.Load(stream); return xdoc.Descendants("Time").First().Value; } catch { return null; } } public static async Task<string> GetServerTime() { lock (_servertime_lock) { if (_servertime == null) _servertime = servertime(); } var time = await _servertime; if (time == null) _servertime = null; return time; }

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  • How do I make my program run with different privileges at Windows 7 startup?

    - by iira
    Hi, I am trying to add my program run in Windows 7 startup, but it doesn't work. My program has an embedded UAC manifest. My current way is by adding a string value at HKCU..\Run. I found a manual solution for Vista from http://social.technet.microsoft.com/Forums/en/w7itprosecurity/thread/81c3c1f2-0169-493a-8f87-d300ea708ecf Click Start, right click on Computer and choose “Manage”. Click “Task Scheduler” on the left panel. Click “Create Task” on the right panel. Type a name for the task. Check “Run with highest privileges”. Click Actions tab. Click “New…”. Browse to the program in the “Program/script” box. Click OK. On desktop, right click, choose New and click “Shortcut”. In the box type: schtasks.exe /run /tn TaskName where TaskName is the name of task you put in on the basics tab and click next. Type a name for the shortcut and click Finish. Additionally, you need to run the saved scheduled task shortcut to run the program instead of running the application shortcut to ignore the IAC prompt. When startup the system will run the program via the original shortcut. Therefore you need to change the location to run the saved task. Please: Open Regedit. Find the entry of the startup item in Registry. It will be stored in one of the following branches. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run HKEY_USERS.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Run HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run Double-click on the correct key, change the path to the saved scheduled task you created. Is there any free code to add item with privileges option in scheduled task? I haven't found the free one in torry.net. Thanks a lot.

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  • Trying to make a plugin system in C++/Qt

    - by Pirate for Profit
    I'm making a task-based program that needs to have plugins. Tasks need to have properties which can be easily edited, I think this can be done with Qt's Meta-Object Compiler reflection capabilities (I could be wrong, but I should be able to stick this in a QtPropertyBrowser?) So here's the base: class Task : public QObject { Q_OBJECT public: explicit Task(QObject *parent = 0) : QObject(parent){} virtual void run() = 0; signals: void taskFinished(bool success = true); } Then a plugin might have this task: class PrinterTask : public Task { Q_OBJECT public: explicit PrinterTask(QObject *parent = 0) : Task(parent) {} void run() { Printer::getInstance()->Print(this->getData()); // fictional emit taskFinished(true); } inline const QString &getData() const; inline void setData(QString data); Q_PROPERTY(QString data READ getData WRITE setData) // for reflection } In a nutshell, here's what I want to do: // load plugin // find all the Tasks interface implementations in it // have user able to choose a Task and edit its specific Q_PROPERTY's // run the TASK It's important that one .dll has multiple tasks, because I want them to be associated by their module. For instance, "FileTasks.dll" could have tasks for deleting files, making files, etc. The only problem with Qt's plugin setup is I want to store X amount of Tasks in one .dll module. As far as I can tell, you can only load one interface per plugin (I could be wrong?). If so, the only possible way to do accomplish what I want is to create a FactoryInterface with string based keys which return the objects (as in Qt's Plug-And-Paint example), which is a terrible boilerplate that I would like to avoid. Anyone know a cleaner C++ plugin architecture than Qt's to do what I want? Also, am I safely assuming Qt's reflection capabilities will do what I want (i.e. able to edit an unknown dynamically loaded tasks' properties with the QtPropertyBrowser before dispatching)?

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  • Trying to make a plugin system in C++

    - by Pirate for Profit
    I'm making a task-based program that needs to have plugins. Tasks need to have properties which can be easily edited, I think this can be done with Qt's Meta-Object Compiler reflection capabilities (I could be wrong, but I should be able to stick this in a QtPropertyBrowser?) So here's the base: class Task : public QObject { Q_OBJECT public: explicit Task(QObject *parent = 0) : QObject(parent){} virtual void run() = 0; signals: void taskFinished(bool success = true); } Then a plugin might have this task: class PrinterTask : public Task { Q_OBJECT public: explicit PrinterTask(QObject *parent = 0) : Task(parent) {} void run() { Printer::getInstance()->Print(this->getData()); // fictional emit taskFinished(true); } inline const QString &getData() const; inline void setData(QString data); Q_PROPERTY(QString data READ getData WRITE setData) // for reflection } In a nutshell, here's what I want to do: // load plugin // find all the Tasks interface implementations in it // have user able to choose a Task and edit its specific Q_PROPERTY's // run the TASK It's important that one .dll has multiple tasks, because I want them to be associated by their module. For instance, "FileTasks.dll" could have tasks for deleting files, making files, etc. The only problem with Qt's plugin setup is I want to store X amount of Tasks in one .dll module. As far as I can tell, you can only load one interface per plugin (I could be wrong?). If so, the only possible way to do accomplish what I want is to create a FactoryInterface with string based keys which return the objects (as in Qt's Plug-And-Paint example), which is a terrible boilerplate that I would like to avoid. Anyone know a cleaner C++ plugin architecture than Qt's to do what I want? Also, am I safely assuming Qt's reflection capabilities will do what I want (i.e. able to edit an unknown dynamically loaded tasks' properties with the QtPropertyBrowser before dispatching)?

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  • C++ polymorphism and slicing

    - by Draco Ater
    The following code, prints out Derived Base Base But I need every Derived object put into User::items, call its own print function, but not the base class one. Can I achieve that without using pointers? If it is not possible, how should I write the function that deletes User::items one by one and frees memory, so that there should not be any memory leaks? #include <iostream> #include <vector> #include <algorithm> using namespace std; class Base{ public: virtual void print(){ cout << "Base" << endl;} }; class Derived: public Base{ public: void print(){ cout << "Derived" << endl;} }; class User{ public: vector<Base> items; void add_item( Base& item ){ item.print(); items.push_back( item ); items.back().print(); } }; void fill_items( User& u ){ Derived d; u.add_item( d ); } int main(){ User u; fill_items( u ); u.items[0].print(); }

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  • implementing a read/write field for an interface that only defines read

    - by PaulH
    I have a C# 2.0 application where a base interface allows read-only access to a value in a concrete class. But, within the concrete class, I'd like to have read/write access to that value. So, I have an implementation like this: public abstract class Base { public abstract DateTime StartTime { get; } } public class Foo : Base { DateTime start_time_; public override DateTime StartTime { get { return start_time_; } internal set { start_time_ = value; } } } But, this gives me the error: Foo.cs(200,22): error CS0546: 'Foo.StartTime.set': cannot override because 'Base.StartTime' does not have an overridable set accessor I don't want the base class to have write access. But, I do want the concrete class to provide read/write access. Is there a way to make this work? Thanks, PaulH Unfortunately, Base can't be changed to an interface as it contains non-abstract functionality also. Something I should have thought to put in the original problem description. public abstract class Base { public abstract DateTime StartTime { get; } public void Buzz() { // do something interesting... } } My solution is to do this: public class Foo : Base { DateTime start_time_; public override DateTime StartTime { get { return start_time_; } } internal void SetStartTime { start_time_ = value; } } It's not as nice as I'd like, but it works.

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  • How to add a has_many association on all models

    - by joshsz
    Right now I have an initializer that does this: ActiveRecord::Base.send :has_many, :notes, :as => :notable ActiveRecord::Base.send :accepts_nested_attributes_for, :notes It builds the association just fine, except when I load a view that uses it, the second load gives me: can't dup NilClass from: /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:2184:in `dup' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:2184:in `scoped_methods' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:2188:in `current_scoped_methods' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:2171:in `scoped?' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:2439:in `send' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:2439:in `initialize' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/reflection.rb:162:in `new' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/reflection.rb:162:in `build_association' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/associations/association_collection.rb:423:in `build_record' /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/associations/association_collection.rb:102:in `build' (my app)/controllers/manifests_controller.rb:21:in `show' Any ideas? Am I doing this the wrong way? Interestingly if I move the association onto just the model I'm working with at the moment, I don't get this error. I figure I must be building the global association incorrectly.

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  • The best way to write a jQuery plugin - If there is such a way?

    - by Nick Lowman
    There are quite a few ways to write plugins i.e. here's a nice example and what I've seen quite a lot of lately is the following code pattern and it's used by Doug Neiner here; (function($){ $.formatLink = function(el, options){ var base = this; base.$el = $(el); base.el = el; base.$el.data("formatLink", base); base.init = function(){ base.options = $.extend({}, $.formatLink.defaultOptions, options); //code here } base.init(); }; $.formatLink.defaultOptions = { }; $.fn.formatLink = function(options){ return this.each(function(){ (new $.formatLink(this, options)); }); }; })(jQuery); So, can anyone tell me the benefits of using the pattern above rather than the one below. I can't see the point in calling the $.extend function for every element in the jQuery stack (above), where the example below only does this once and then works on the stack. To test it I created two plugins, using both patterns, which applied styles to about 5000 li elements and the code below took about 1 second whereas the pattern above took about 1.3 seconds. (function($){ $.fn.formatLink = function(options){ var options = $.extend({}, $.fn.formatLink.defaultOptions, options || {}); return this.each(function(){ //code here }); }); $.fn.formatLink.defaultOptions ={} })(jQuery);

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  • Sencha 2 : Sync models with hasMany associations in LocalStorage

    - by Alytrem
    After hours and hours trying to do this, I need your help. I have to models : Project and Task. A project hasMany tasks and a task belong to a project. Everyting works well if you don't use a store to save these models. I want to save both tasks and projects in two stores (TaskStore and ProjectStore). These stores use a LocalStorage proxy. I tried many things, and the most logical is : Ext.define('MyApp.model.Task', { extend: 'Ext.data.Model', config: { fields: [ { name: 'name', type: 'string' }, { dateFormat: 'd/m/Y g:i', name: 'start', type: 'date' }, { dateFormat: 'd/m/Y g:i', name: 'end', type: 'date' }, { name: 'status', type: 'string' } ], belongsTo: { model: 'MyApp.model.Project' } } }); Ext.define('MyApp.model.Project', { extend: 'Ext.data.Model', alias: 'model.Project', config: { hasMany: { associationKey: 'tasks', model: 'MyApp.model.Task', autoLoad: true, foreignKey: 'project_id', name: 'tasks', store: {storeId: "TaskStore"} }, fields: [ { name: 'name', type: 'string' }, { dateFormat: 'd/m/Y', name: 'start', type: 'date' }, { dateFormat: 'd/m/Y', name: 'end', type: 'date' } ] } }); This is my "main" : var project = Ext.create("MyApp.model.Project", {name: "mojo", start: "17/03/2011", end: "17/03/2012", status: "termine"}); var task = Ext.create("MyApp.model.Task", {name: "todo", start: "17/03/2011 10:00", end: "17/03/2012 19:00", status: "termine"}); project.tasks().add(task); Ext.getStore("ProjectStore").add(project); The project is added to the store, but task is not. Why ?!

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  • Will this cause a problem with different runtimes with DLL?

    - by Milo
    My gui application supports polymorphic timed events so that means that the user calls new, and the gui calls delete. This can create a problem if the runtimes are incompatible. So I was told a proposed solution would be this: class base; class Deallocator { void operator()(base* ptr) { delete ptr; } } class base { public: base(Deallocator dealloc) { m_deleteFunc = dealloc; } ~base() { m_deleteFunc(this); } private: Deallocator m_deleteFunc; } int main { Deallocator deletefunc; base baseObj(deletefunc); } While this is a good solution, it does demand that the user create a Deallocator object which I do not want. I was however wondering if I provided a Deallocator to each derived class: eg class derived : public base { Deallocator dealloc; public: Derived() : base(dealloc); { } }; I think this still does not work though. The constraint is that: The addTimedEvent() function is part of the Widget class which is also in the dll, but it is instanced by the user. The other constraint is that some classes which derive from Widget call this function with their own timed event classes. Given that "he who called new must call delete" what could work given these constraints? Thanks

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  • dynamic inheritance without touching classes

    - by Jasper
    I feel like the answer to this question is really simple, but I really am having trouble finding it. So here goes: Suppose you have the following classes: class Base; class Child : public Base; class Displayer { public: Displayer(Base* element); Displayer(Child* element); } Additionally, I have a Base* object which might point to either an instance of the class Base or an instance of the class Child. Now I want to create a Displayer based on the element pointed to by object, however, I want to pick the right version of the constructor. As I currently have it, this would accomplish just that (I am being a bit fuzzy with my C++ here, but I think this the clearest way) object->createDisplayer(); virtual void Base::createDisplayer() { new Displayer(this); } virtual void Child::createDisplayer() { new Displayer(this); } This works, however, there is a problem with this: Base and Child are part of the application system, while Displayer is part of the GUI system. I want to build the GUI system independently of the Application system, so that it is easy to replace the GUI. This means that Base and Child should not know about Displayer. However, I do not know how I can achieve this without letting the Application classes know about the GUI. Am I missing something very obvious or am I trying something that is not possible?

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  • calling a function from a set of overloads depending on the dynamic type of an object

    - by Jasper
    I feel like the answer to this question is really simple, but I really am having trouble finding it. So here goes: Suppose you have the following classes: class Base; class Child : public Base; class Displayer { public: Displayer(Base* element); Displayer(Child* element); } Additionally, I have a Base* object which might point to either an instance of the class Base or an instance of the class Child. Now I want to create a Displayer based on the element pointed to by object, however, I want to pick the right version of the constructor. As I currently have it, this would accomplish just that (I am being a bit fuzzy with my C++ here, but I think this the clearest way) object->createDisplayer(); virtual void Base::createDisplayer() { new Displayer(this); } virtual void Child::createDisplayer() { new Displayer(this); } This works, however, there is a problem with this: Base and Child are part of the application system, while Displayer is part of the GUI system. I want to build the GUI system independently of the Application system, so that it is easy to replace the GUI. This means that Base and Child should not know about Displayer. However, I do not know how I can achieve this without letting the Application classes know about the GUI. Am I missing something very obvious or am I trying something that is not possible?

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  • How do I want untill is finished in C#?

    - by Grienders
    Let's say, I want to send a request to a server and get a result from it: private static string Send(int id) { Task<HttpResponseMessage> responseTask = client.GetAsync("aaaaa"); string result = string.Empty; responseTask.ContinueWith(x => result = Print(x)); responseTask.Wait(); // it doesn't wait for complemeting of response task return result; } private static string Print(Task<HttpResponseMessage> httpTask) { Task<string> task = httpTask.Result.Content.ReadAsStringAsync(); string result = string.Empty; task.ContinueWith(t => { Console.WriteLine("Result: " + t.Result); result = t.Result; }); task.Wait(); // it does wait return result; } Am I using task correct? I don't think so because Send() method return string.Empty all the time, while Print returns the correct value. What am I doing wrong? How do I get a result from a server?

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