I am having an UI component which is reusable in multiple places. Therefore I have to duplicate the same css sections over several css files. Is it ok to create a directive for this scenario ? The directive will not process any js specific operations, it is there only for handling the UI component and avoid the duplication.
NOTE: You've specified “Angular” in the question title, but angularjs as a tag. This answer assumes you're coding for Angular, not AngularJS. Consider editing the tag or the question title to remove this ambiguity. (What’s the difference between AngularJS and Angular?)
Angular can bundle style information with components. You can specify the CSS:
inline using the styles attribute of the #Component decorator, or
in an external file using the styleUrls attribute of the #Component decorator.
See the Component Styles section of the Angular docs for examples & more info.
While you could technically write an attribute directive to style your component, why you would choose to do this instead of using the styling functionality provided by components is unclear. Expanding your question with an example or two of what you're trying to achieve may bring you a better answer.
Related
Some (advanced?) angular is making my head hurt.
The goal is to extend a WYSIWYG HTML editor to allow users to insert certain angular directives into arbitrary HTML content. I have chosen medium-editor and its angular-medium-editor wrapper (but I'm not wedded to that if there are better solutions).
This Plunk shows how the editor directive is instantiated and activated (using an editable attribute). The toolbar is customised to include a button which adds a custom directive around selected text: <my-custom-directive class="bg-info"> ... </my-custom-directive>. (For demonstration, the custom directive wraps (transcludes) its contents in a button which triggers an alert when clicked).
I'm having problems with (re-)compiling the editor's content so that the directives inside the editor compile. Using $compile(element.contents())(scope) throws ngTransclusion:orphan errors for directives which uses transclusion. (I understand this is due to angular already having made the transclusion by the time the editor's link function is called.)
I cannot refactor all potential custom directives to not use transclusion.
What pattern can I use to successfully compile arbitrary editor content (which may include many different directives), ideally whenever that content changes, or at least when the editing is finished? Is this one of the "fringe cases" where the use of $compile is justified? If so, how do I use it?
This question and answer made me realise that the way to do this is to $compile only the inserted element when it is inserted, rather than recompiling the whole section.
Handily, rangy's classApplier module allows for an onElementCreate callback which can be used to compile the custom directive as it is added.
Here's the working plunker.
Is there a way to tell Angular to not compile contents of certain elements?
Use case:
Angular CMS contains textarea elements that have CKEditor attached. The CKEditor is using the divarea plugin instead of the default iframe plugin. The textareas contain HTML templates. These templates are exported on demand and fed to a Angular webapp.
The templates are simple enough: plain text, ordered lists, the occasional predefined class attribute applied on the plain text; but the plain text can contain placeholders for the Angular webapp to interpolate. I do not want to let the Angular in the CMS interpolate these at all.
Currently my problem is that the Angular in the CMS interpolates these placeholders and, since they don't refer to anything, removes them. I would rather not just change the delimiters to '{[', ']}', as while this might fix this in the short term, the chance of directive and text copy collision increases as the project goes on, and I'd like to avoid it.
Is there any directive or other way to tell Angular to keep away from the content of specially marked elements?
Use ng-non-bindable directive on the element:
The ngNonBindable directive tells Angular not to compile or bind the
contents of the current DOM element. This is useful if the element
contains what appears to be Angular directives and bindings but which
should be ignored by Angular.
Or use your own directive with terminal: true property to match the layout better, because it is the only thing that ng-non-bindable directive does.
So I'm a bit new to Angular, and I'm wondering what best practice would be if I wanted to be able to toggle content completely away. So you would be able to view it, or toggle off to hide it. Sorta clean things up. Should I use a if statement, or maybe give the content two sides (one being empty) and be able to switch between them? What would be best?
View switching in angular can be done in a multitude of ways. In order to do route based switching (switching based on the hash in the url). Use a combination of the ngRoute module which helps you to configure routes through the use of the $routeProvider and the ngView directive.
$routeProvider docs:
https://docs.angularjs.org/api/ngRoute/provider/$routeProvider
ngView docs:
https://docs.angularjs.org/api/ngRoute/directive/ngView
Also you can hide/show, add/remove content via these directives
ngIf - will completely remove and destroy the scope of the content
https://docs.angularjs.org/api/ng/directive/ngIf
ngSwitch - will work similar to a switch statement in javascript. This is used in conjunction with ngSwitchWhen and ngSwitchDefault. Like the ngIf directive this will also remove and destroy the scope of the content.
ngSwitch/ngSwitchWhen/ngSwitchDefault
https://docs.angularjs.org/api/ng/directive/ngSwitch
ngHide/ngShow - per the name these directives will simply toggle the classes ng-hide and ng-show respectively. ng-hide has a css property of display: none.
ngShow:
https://docs.angularjs.org/api/ng/directive/ngShow
ngHide:
https://docs.angularjs.org/api/ng/directive/ngHide
The directives that completely remove the contents can be better for performance since the number of watchers in your app can accumulate fairly quickly. In most cases I'd suggest using the removal based directives for anything that has an evaluation of the scope beneath it and use the hide/show directives for simple static content display.
There are example usages of each of these directives on all the documentation links I've included. Feel free to comment with questions.
I am using angular formly. I read the documentation,but they didn't mention how to apply css classes from options.
I am trying to apply kendo ui classes to form fields but of no use.
Can anyone help me?
here is my jsbin
http://jsbin.com/golehimize/edit?html,output
Here's how you apply a custom class to the formly-field element: https://jsbin.com/foqixe/edit?html,js,output
I'm not sure what classes you're wanting to apply, but this would be the way to do it (see the email field configuration).
I'm working with angular js and there's one thing I didn't fully understand yet. I know what directives are: they are "additional features" that we add to HTML that can be used as elements, attributes, comments or classes and that can change completely the markup there by some other thing rendered by angular or can add functionality with the link function.
That's fine, but when to use directives? I know that if we want to represent on screen some domain specific object then this is one possible candidate for a directive, or when we want to add functionality to some HTML element (like slider functionality to an input) then we use a directive. But what about other cases? What about when we want to manipulate the DOM to, for instance, activate the functionality of a sidebar or thing like that? Directives are used for this to?
How do when know when to use a directive in angular?
I think about directives when I face one of this two scenarios:
Custom control: I need to implement a custom control, that probably I will reuse in other parts of my app or even other projects.
Custom Validations: AngularJS provides a limited set of validations (e.g. ngRequired, RegEx...), but for sure you will need to implement your custom logic validations. I prefer to implement that validations in directives (reuse, SRP, easy to be tested isolated) rather to overload the controller with that logic.
Some directive rules of thumbs:
If you plan on adding the same markup-based functionality more than once, create a directive (but if it's simple enough, just use ng-include).
If you need to modify the way an ng-modeled input field validates, formats, or parses, create a directive that requires ngModel.
If you want to make writing unit tests easier for a specific piece of markup, write a directive.
If you come from a jQuery background and instinctively feel like using $('.jquery-style-selectors') from your controller, instead write a group of directives where the child directive(s) require the parent directive(s) and communicate via the directive controller(s).