Gtk::StyleContext has methods for adding and removing a CSS class. Can I change the property of this class programmatically?
Yes, sort of; you can load another CSS file in the style context's CSS provider, that has different rules for that CSS class.
I suspect you might be asking about how to go into the rules directly and edit them programmatically; you can't do that.
In my ember js project I have a style sheet where it should only available inside the given template how do I achieve that properly? I mean where to put that style sheet?
And how do I reference it to my template?
Create css file under styles/style1.css and include that file in styles/app.css like #import 'style1.css';.
If you would like to specify component specific css stylesheets then you can try ember-component-css addon.
I could not find any info on overriding a Joomla plugin in my template.
Some forums claimed there was no plugin override, and the Joomla documentation (being the menacing forest that it is) either has nothing on the subject, or the page is hard to find.
So how can we override the output of a Joomla plugin in the same was we override the output of com_content or mod_contact?
I have found a way to do this:
Navigate to <joomla_homefolder>/administrator/language/<your_language>/
Search for the plugin's corresponding language file.
Copy the file name, EXCLUDING the language prefix (ie en-GB.) and the .ini suffix.
In your template create a folder named html (a common practice for template overrides).
In the html folder create a subfolder and name with the language file name as you copied it in step 3.
Navigate to the tmpl subfolder in the plugin's path: <joomla_homefolder>/plugins/<plugin_type>/<plugin_name>/tmpl
Copy the view file you wish to override into the folder you've created in step 5.
Modify the copied file to override the plugins output.
For example -
To change the page navigation buttons - modify the output of <joomla_homefolder>/plugins/content/pagenavigation:
Go into <joomla_homefolder>/administrator/language/en-GB/ and find the file named en-GB.plg_content_pagenavigation.ini.
From the filename copy only plg_content_pagenavigation.
Create a folder named html (If it does not exist already) in your theme, inside it create a subfolder and name it plg_content_pagenavigation.
Copy the view file <joomla_homefolder>/plugins/content/pagenavigation/tmpl/default.php into the plg_content_pagenavigation folder you just created.
Modify the file.
Note: I have tried it only with Joomla 3.1.
The method may not work with some plugins.
Good Luck.
In joomla 3 you can override plugins output only, that's why the origin plugin must be implemented with a tmpl.
The naming convention of the folder in you [template]/html is
plg_[type*]_[pluginElement]
Template overridden native joomla plugins is only the pagenavigation.
type* : obviously there's no sense to be other than content but if it's custom plugin no one can stop you.
On a Joomla 3.1 install, I am using the Simple Image Gallery plugin and I felt the need to override it in order to add extra functionality to each thumbnail of the gallery.
I copied all of the contents of <joomla_homefolder>/plugins/content/jw_sig/jw_sig/tmpl/ into the folder <joomla_homefolder>/templates/protostar/html/jw_sig/ and I was then able to modify both the default.php file for output modifications, and the accompanying template.css file for styling modifications. This successfully overrides the plugin's output without risking issues during future updates.
Of course, this will not work with all plugins, but it offers another alternative if you have a plugin that was nice enough to be developed with a tmpl folder.
No you can't override the same way because there is not tmpl folder because plugins really should not be rendering though of course a lot do. You probably need to clone the plugin and make a the layout your want possibly using a jlayout to make it easier to manage.
Elin's answer is not quite correct for Joomla 2.5-3.x. Some plugins do render screen output and have /tmpl folders that you may be able to override. See http://docs.joomla.org/Layout_Overrides_in_Joomla
In some cases you may need to create alternative views within the plugin /tmpl folder. For example, some of the simple, newer custom content components that use JForms let you add fields to com_content articles and select a view template for each field. Then overrides for com_content are generated dynamically to display the custom fields. Each field type can be displayed in the component area through plugins, or in a module, or within the template code, but it will use the /tmpl file you selected for the field in the CCK component. If there is a way to override the different field views from within the template folder, it must require an arcane menu structure I haven't been able to discover.
How these application allow users to upload their own templates? How is this possible?
Do they have some kind of a their own template engine or..?
Tumblr gives you two options to include your own theme:
If it is just for personal use: by changing the html of the theme. If you go to your tumblr-website and click on the customize button, you can edit the html. In the header file the content of your .css must be pasted between the <style type="text/css"> </style> tags. And you can add some javascript there. For the html I suggest to read the manual that Mirko Adari suggested: Tumblr Theme manual
If you want it to be a theme on itself: submit your theme to the Theme Garden: Tumblr Theme Garden
Blogger is a bit more rigid. Also there you can change your html file. Keep in mind that it's markup for posts is different then Tumblr. Also custom CSS files can be added (more information on that). If you are less familiar with css and html Blogger offers some buttons so that you can change the basics to your own needs. Blogger also offers a way to backup and restore your theme. A more detailed explanation can be found here. This template file must be an .xml file. More information on the markup of this xml-template can be found here.
Django-CMS custom plugins and navigation extenders allow to create any content HTML in some part of the HTML . However I frequently have some JavaScripts required for some specific plugins, like a photo album viewer plugin that requires a JS in the .
My current solution is to let the user specify a specific template for that. I could do some checking in the template render() to use a specific placeholder or use placeholder restrictions but that doesn't seem right: It's still in the "body" placeholder.
Any suggestion?
Nothing wrong with including Javascript in the body - in fact, some consider it best practice.