I have top menu in my app, and I would like to have different content there depending on controller. In Rails it is easy with content_for, but how to achieve it with angular? I already know this solution: AngularJS: How can I pass variables between controllers? but maybe there is better way to do this?
One of the fun things about Angular is there is, often, no "better way" without understanding the context of your application. There are, "other" ways, which is best depends tremendously. I guess more info might help to customise or recommend a particular answer, too.
However here's my thought stream on this topic:
First thoughts
More defined service
The answer you found is not bad, though I would probably take it a little further and have some sort of 'menu service' rather than a highly generic 'property' store. This menu service could be manipulated by the controllers that ng-view instantiates.
Via the route mappings
Taking it even further, it would be possible to include menu information within the route provider declarations and then, on $routeChangeSuccess or $routeChangeStart have the menu controller update itself based on the data from the routes (perhaps maintaining the service as well so that controllers can contribute "special" menu options, thereby allowing a degree of customisation).
A few more options
If shared services (a Angular best practice, fyi) aren't to your liking or setup and playing with the routes isn't, either (could be tricky) then I can see a few more options:
$rootScope
One is to inject $rootScope (the great grand-daddy of all scopes) and have a collection on there that is your menu items; each controller could then just update that manually.
Custom events
Here $rootScope.$emit() is your friend - you could emit some sort of event and supply menu configuration data. A controller would then be listening ($rootScope.$on()) for the event and update/clear-out/replace it's own list of menu items with the newly-emitted menu list.
Advanced routing
Getting even funkier, you could even try and see if including functions in the resolve part of the routes would do the trick.
References
Info on playing with the scope is on Angular's documentation: http://docs.angularjs.org/api/ng.$rootScope.Scope
Info on complex routing is here: http://www.yearofmoo.com/2012/10/more-angularjs-magic-to-supercharge-your-webapp.html#additional-features-of-controllers-and-routes (yearofmoo are Rails fans, so their opinions might match your own)
For a similar task I wrote an angular js directive that mimics rails content_for
Sorry for CoffeeScript:
App.directive "contentFor", ["$sce", ($sce) ->
compile: (e, attrs, transclude) ->
pre: (scope, iElement, iAttrs, controller) ->
varname = iAttrs["contentFor"]
# Looks for the closest scope where 'varname' is defined
# or pick the top one
targetScope = scope
while targetScope.$parent
if ( if targetScope.hasOwnProperty then targetScope.hasOwnProperty(varname) else targetScope[varname] )
break
else
targetScope = targetScope.$parent
# Store html inside varname
html = iElement.html()
targetScope[varname] = $sce.trustAsHtml(html)
# remove the directive element
iElement.remove()
]
You can use it like this
<span content-for="menuHtml">
<ul>
<li>Menu Item 1</li>
<li>Menu Item 2</li>
<li>Menu Item 3</li>
</ul>
</span>
And here is the equivalent of <%= yield(:menuHtml) %>:
<nav ng-bind-html="menuHtml"></nav>
In the end you could reset menu to a default binding to $routeChangeSuccess event in your controller:
$scope.$on '$routeChangeSuccess', ->
$scope.menuHtml = $sce.trustAsHtml("<ul>...</ul>")
Bind your top level menu to an object in top level scope. Create a method in that controller to set that variable. Within your child controllers call the method to set the appropriate variable that will change the menu based on your controller.
You can leverage services to store menu items if they are not coming from the server.
I think making a direct reference to the div which will be replaced instead of using angular's scopes as in mcasimir's answer is much simpler. Also it has the added benefit of allowing angular to compile the directives which in the other answer will give you an 'untrusted' error. This is what the directive looks like:
.directive('appContentFor', ($compile) -> {
replace: true,
compile: (element,attr,transclude)->
return (scope, element, attrs)->
element.remove()
node = $(attrs.node)
$(node[0]).replaceWith($compile(element.html())(scope))})
By injecting the $compile service angular can do it's job on the html before inserting it where it belongs. Now you can use this directive like this:
<div app-content-for node="div#awesomeContentFor">
<ul id="awesome_inserted_list">
<li>{{1+2}}</li>
<li>{{something_on_current_scope}}</li>
</ul>
</div>
then somewhere else just add the div with id awesomeContentFor:
<div id="awesomecontentfor"></div>
Related
Here's a plunker example you can see: http://plnkr.co/edit/NQT8oUv9iunz2hD2pf8H
I have a directive that I would like to turn into a web component. I've thought of several ways as to how I can achieve that with AngularJS but am having difficulty with a piece of it. I'm hoping someone can explain my misstep rather than tell me a different way to do it.
Imagine you have a directive component that sets up some shell with css classes maybe some sub components, etc.. but lets the user define the main content of the component. Something like the following:
<my-list items="ctrl.stuff">
<div>List Item: {{ item.name }}</div>
</my-list>
The HTML for the list directive could be something like the following (with OOCSS):
<ul class="mas pam bas border--color-2">
<li ng-repeat="items in item track by item.id" ng-transclude></li>
</ul>
Normally this can be solved in the link function by linking the directives scope to the new content. And it does work for other components. However introducing the ng-repeat seems to break that portion of the control. From what I can tell, the appropriate place might be the compile function but the documentation says the transcludeFn parameter will be deprecated so I'm not sure how to proceed.
I should also note that when using the beta AngularJS, there is either a bug or a new paradigm coming, because this is no longer a problem. It seems like the transcluded content always gets access to the directives scope as well as the outer controllers scope.
I really appreciate any enlightenment on this.
It's by design that content added via ng-transclude will bind with an outer controller scope, not a scope of the current element that ng-transclude is on.
You could solve the problem by copy the ng-transclude's code and modify it a bit to give a correct scope:
.directive('myTransclude', function () {
return {
restrict: 'EAC',
link: function(scope, element, attrs, controllers, transcludeFn) {
transcludeFn(scope, function(nodes) {
element.empty();
element.append(nodes);
});
}
};
});
And replace the ng-transclude with my-transclude in your directive template.
Example Plunker: http://plnkr.co/edit/i7ohGeRiO3m5kfxOehC1?p=preview
I have code in a directive relating to a "highlightable image." The goal is to be able to create highlights on an image and attach a comment to it. So when you click on the image, it creates an annotation.
I have code in the controller for a tooltip toolbar, which you can use to attach a comment to the annotation. Currently, when the 'comment' button on this toolbar is pressed, the information is stored into the database. If you click 'cancel' on the toolbar, the highlight should be deleted.
My dilemma is that I'm not sure how to structure things to conform to the MVC design pattern. Specifically, clicking cancel occurs in the toolbar, but must affect the highlights (which are managed by the directive). And clicking comment must make a call to a service to modify the database.
I've considered moving the toolbar code into the directive, but decided otherwise because directives shouldn't be dealing with backend. And ideally, the toolbar should be in its own directive. I'd like to know what you think the 'correct' way of doing it is.
Based on the functionality that you described,
Create a service:
highlightImageService (this will use the $http service to persist data to the database)
addHighlightToImage(image, highlight)
attachComment(highlight, comment)
deleteHighlight(highlight)
Create a controller:
highlightImageController
createHighlight()
attachComment()
deleteHighlight()
In your directive, specify your controller and inject your service:
.directive('imageHighlighter', function(highlightImageService) {
restrict: ...
scope: ...
controller: highlightImageController,
link: function(scope, element, attr, controller) ...
})
Tie everything together in a module:
var module = angular.module('imageHighlighter', [...]);
module.controller(highlightImageController);
module.directive(imageHighlighter)
module.factory(highlightImageService);
Since everything is self-contained in a module (directives, controllers, services), all one has to do to use your module is add it as a module dependency and add directives to your page:
Script:
var app = angular.module('app', ['imageHighlighter']);
Html:
<body ng-app="app">
<div image-highlighter></div>
</body>
There's another way to structure this.
Create directive Toolbar
Create directive Highlighter
Create service DataService
Create callback functions in your controller's scope
Pass these functions as attributes to your directive
After dealing with all UI related issues, your directive will execute the appropriate callbacks
The callbacks in the controller's scope will call DataService to take the appropriate action such as: Delete the comment, Save the comment
This way you can avoid calling the service directly from the directive and have it only deal with UI issues.
Here's how to pass a function to the directive: Passing a function as an attribute to a directive
I am not building a single-page application, but rather a "traditional" site that uses AngularJS in places. I've hit the following problem (using 1.3.0-beta.6):
Standard, working anchor links:
Link text
... [page content]
<a id="foo"></a>
<h1>Headline</h1>
[more content]
That works fine. Now I introduce a template partial somewhere:
<script type="text/ng-template" id="test-include.html">
<p>This text is in a separate partial and inlcuded via ng-include.</p>
</script>
which is invoked via:
<div ng-include="'test-include.html'"></div>
The partial is included properly, but the anchor link no longer works. Clicking on "Link text" now changes the displayed URL to /#/foo rather than /#foo and the page position does not change.
My understanding is that using ng-include implicitly tells Angular that I want to use the routes system and overrides the browser's native anchor link behavior. I've seen recommendations to work around this by changing my html anchor links to #/#foo, but I can't do that for other reasons.
I don't intend to use the routes system - I just want to use ng-include without it messing with browser behavior. Is this possible?
The reason is that angular overrides the behavior of standard HTML tags which include <a> also. I'm not sure when this change happened because angular v1.0.1 works fine with this.
You should replace the href attribute with ngClick as:
<a ng-click="scroll()">Link text</a>
And in a controller so:
function MyCtrl($scope, $location, $anchorScroll) {
$scope.scroll = function() {
$location.hash('foo');
$anchorScroll();
};
};
Demo: http://jsfiddle.net/HB7LU/3261/show/
Or simply use double hash as:
<a href='##foo'>Link text</a>
Demo: http://jsfiddle.net/HB7LU/3262/show/
Update: I did not know that you want no modification in HREF. But you can still achieve the desired result by overriding the existing a directive as:
myApp.directive('a', function() {
return {
restrict: 'E',
link: function(scope, element) {
element.attr('href', '#' + element.attr('href'));
}
};
});
Demo: http://jsfiddle.net/HB7LU/3263/
My understanding is that using ng-include implicitly tells Angular
that I want to use the routes system and overrides the browser's
native anchor link behavior. I've seen recommendations to work around
this by changing my html anchor links to #/#foo, but I can't do that
for other reasons.
Routing system is defined in a separate module ngRoute, so if you did not injected it on your own - and I am pretty sure you did not - it is not accessible at all.
The issue is somehow different here.
ng-include depends on: $http, $templateCache, $anchorScroll, $animate, $sce. So make use of ng-include initiate all these services.
The most natural candidate to investigate would be $anchorScroll. The code of $anchorScroll does not seem to do any harm, but the service depends on $window, $location, $rootScope. The line 616 of $location says:
baseHref = $browser.baseHref(), // if base[href] is undefined, it defaults to ''
So basically the base href is set to '', if it was no set before.
Now look HERE - from BalusC answer :
As to using named anchors like , with the tag
you're basically declaring all relative links relative to it,
including named anchors. None of the relative links are relative to
the current request URI anymore (as would happen without the
tag).
How to mitigate the issue?
I do not have much time today, so cannot test it myself, but what I would try to check as the first option is to hook up to '$locationChangeStart' event and if the new url is of #xxxxxx type just prevent the default behaviour and scroll with $anchorScroll native methods instead.
Update
I think this code should do the work:
$scope.$on("$locationChangeStart", function (event, next, current) {
var el, elId;
if (next.indexOf("#")>-1) {
elId = next.split("#")[1];
el = document.getElementById(elId);
if(el){
// el.scrollIntoView(); do not think we need it
window.location.hash = "#" + elId;
event.preventDefault();
}
}
});
This is the best solution, and works in recent versions of Angular:
Turn off URL manipulation in AngularJS
A lot late to the party but I found that adding a simple target="_self" fixes it.
Link
Rather than applying the angular application to the entire page, you can isolate the application to just the places you want to perform an ng-include. This will allow links outside the scope of the application to retain their normal functionality, while allowing links within the application to be handled as desired.
See this plunkr:
http://plnkr.co/edit/hOB7ixRM39YZEhaz0tfr?p=preview
The plunkr shows a link outside the app that functions as normal, and a link within the app that is handled using an overriding a directive to restore normal functionality. HTML5 mode is enabled to retain 'standard' URLs (rather than 'hashbang' [without the bang!] URLs).
You could equally run the whole of the page within the app, but I thought it would be worth demonstrating how to isolate angular to certain parts of the page in any case.
I've been researching this for a few hours now.
Let's say I have a jQuery selector of $('#bottom .downloads .links a').click.....
How can I do the same type of thing in an Angular directive?
This is what I have so far and it works, but for all tags on the page.
angular.module('directives', []).directive('a', function(mongoDB){ //Don't need ['customServices'], it can just be [] to use mongoDB
return {
restrict : 'E',
link : function(scope, element, attrs){
element.on('click', function(){
//But this gets called for all links on the page
//I just want it to be links within the #bottom .downloads .links div
//I wanted to use a directive instead of ng-click="someMethod()"
});
}
});
Is there a way to target this directive to only a certain div? I guess I could change the restrict to 'C' or 'A' and add an attribute to the links, but I was wondering if I could still layout the front end like I currently am used to with my jQuery selectors.
There is a pretty significant philosophical difference between AngularJS and jQuery. In jQuery, everything is in the DOM - including your data - and you do everything through DOM transformations. AngularJS, on the other hand, has separation of concerns built in: models, views, controllers, services, etc., are all separate. We use controllers to glue code together, but each component knows nothing about the other components.
So whereas in jQuery, one might use a selector to find all links matching a certain pattern and then add a certain functionality to it (say a click handler), in AngularJS, the HTML is the "offical record". Instead of abstracting away the attachment of a click handler into a JavaScript function, it is put right into the markup:
<a ng-click="doWhatever()">Click me!</a>
In this case, doWhatever is a method on the scope for that part of the page, probably set in your controller:
$scope.doWhatever = function () {
console.log("Hello!");
}
So the way you are approaching the problem is not going to work in AngularJS. Instead, you need to look at directives not like jQuery selectors with a function, but as an extension of HTML. You ask yourself, "what does HTML not do out of the box that I need it to?" Your answer is your directive.
But AngularJS already has a built-in directive for click handlers (the ngClick used above).
Angular already has an a directive, so you probably shouldn't create your own.
In an Angular world, to "target only a certain div" (well, <a> within the div) we declaratively target that <a> with a directive, rather than use CSS-like selectors. So yes, restrict to 'A' and add an attribute to the <a> would be best:
<a ... target-this-one>...</a>
I personally think this reads better. Looking at the HTML it is clear which <a>s have special/additional functionality.
As #Josh pointed out, you would only need to do this if ng-click isn't sufficient for your needs.
I want to write 'edit in place' directive in angularjs.
I want that directive is reusable, therefore I have following requirements on the directive:
it must be an attirbute that can deocorate any element, that makes sense (div,span,li)
it must support edit button, clicking on that will change set ot displayd elements into input fileds. Typically properties of one object, e.g. contact (number, name)
I disocvere trickery behaviour of scope visibility in the directive that can be seen in this fiddle http://jsfiddle.net/honzajde/ZgNbU/1/.
Comenting out in the directive: template and scope -> contact.number and contact.name are displayed
Comenting out in the directive: scope -> contact.number only is displayed
Not commenting out anything -> nothing is displayed
=> when both are commented out just adding template to the directive makes it render contact.number even though template is not used.
I am asking what are the rules of the game?
<div>
<div ng-controller="ContactsCtrl">
<h2>Contacts</h2>
<br />
<ul>
<li ng-repeat="contact in contacts">
<span edit-in-place="" ng-bind="contact.number"></span> |
<span edit-in-place="" >{{contact.name}}</span>
</li>
</ul>
<br />
<p>Here we repeat the contacts to ensure bindings work:</p>
<br />
<ul>
<li ng-repeat="contact in contacts">
{{contact.number}} | {{contact.name}}
</li>
</ul>
</div>
</div>
var app = angular.module( 'myApp', [] );
app.directive( 'editInPlace', function() {
return {
restrict: 'A',
//scope: { contact:"=" },
template: '<span ng-click="edit()" ng-bind="value"></span><input ng-model="value"></input>',
link: function ( $scope, element, attrs ) {
// Let's get a reference to the input element, as we'll want to reference it.
var inputElement = angular.element( element.children()[1] );
// This directive should have a set class so we can style it.
element.addClass( 'edit-in-place' );
// Initially, we're not editing.
$scope.editing = false;
// ng-click handler to activate edit-in-place
$scope.edit = function () {
$scope.editing = true;
// We control display through a class on the directive itself. See the CSS.
element.addClass( 'active' );
// And we must focus the element.
// `angular.element()` provides a chainable array, like jQuery so to access a native DOM function,
// we have to reference the first element in the array.
inputElement[0].focus();
};
// When we leave the input, we're done editing.
inputElement.prop( 'onblur', function() {
$scope.editing = false;
element.removeClass( 'active' );
});
}
};
});
app.controller('ContactsCtrl', function ( $scope ) {
$scope.contacts = [
{ number: '+25480989333', name: 'sharon'},
{ number: '+42079872232', name: 'steve'}
];
});
You are running into problems because you are misusing angular.
First, a directive should be self-contained, but you are pulling functionality out of it, which makes it less universal and less reusable. In your code, you have functionality in the DOM and in the controller that belongs in the directive. Why?
Second, it's also unclear from your markup and javascript specifically want you want to accomplish when all these pieces are strung together.
Third, in most cases, directives should have their own isolated scope, which is done by declaring a scope object with attributes it should bind. You shouldn't be passing an expression (i.e. {{contact.name}}) inside the directive as it will break the binding and your contact will not be updated when the edit-in-place finishes. The proper way is to establish bi-directional binding through an = property on the scope. ng-bind isn't what you want here: that's scope-specific, so we use it inside the directive's scope. As Valentyn suggested, you could do some magic to get around this, but it's not a good idea and it's super-simple to set it up the right way. What's the issue with doing this by an attribute?
This is all bad Ju-ju.
As I pointed out in your other question on this same topic, you must make your directive self-contained and work with angular, rather than against it. Here's an attribute-based version of the fiddle I gave you previously, meeting the first of your requirements. Please let me know what is wrong specifically with this implementation and we can talk about the angular way of fixing it.
Lastly, if you provide further context on what you need in terms of a "button", I'll incorporate that into the fiddle too.
[update]
It is possible to make the directives work your way, but you will run into problems eventually (or right now, it would seem). All components in an angular app (or any app for that matter) should be as self-contained as is feasible. It's not a "rule" or limitation; it's a "best practice". Similarly, communication between directive components can occur through a controller, but it shouldn't. Ideally, you shouldn't reference the DOM in a controller at all - that's what directives are for.
If your specific purpose is a row that is editable, then that is your directive. It's okay to have a lower-level generic edit-in-place directive that the larger directive uses, but there is still the higher-level directive too. The higher-level directive encapsulates the logic between them. This higher-level component would then require a contact object.
Lastly, no, there isn't necessarily a big difference between ng-bind="var" and {{var}}. But that's not the issue; the issue was where that binding takes place. In your example, a value was passed to the directive instead of a bi-directionally-bound variable. My point was that the directive needs access to the variable so it can change it.
Summary: You are coding in a very jQuery-style way. That's great for coding in jQuery, but it doesn't work so well when coding in Angular. In fact, it causes a lot of problems, like the ones you're experiencing. In jQuery, you would, for example, dynamically insert DOM elements, declare and handle events, and manually bind variables all within a single code block, all manually. In Angular, there is a clean separation of concerns and most of the binding is automatic. In most cases, it leads to javascript code at least two-thirds smaller than the jQuery alternative. This is one of those cases.
That said, I have created a Plunker that contains a more sophisticated version of both the edit-in-place as well as a new higher-level directive to incorporate additional features: http://plnkr.co/edit/LVUIQD?p=preview.
I hope this helps.
[update 2]
These are the answers to your new round of questions. They may be good for your edification, but I already gave you the "angular way" to fix your problem. You will also find that I already addressed these questions (in broader strokes) earlier in my original answer as well as in my update. Hopefully, this makes it more apparent.
Question: "Comenting out in the directive: template and scope -> contact.number and contact.name are displayed"
My Reply: When you do not specify a scope, the directive inherits its parent scope. You bound and interpolated the name and number within the context of the parent, so it "works". Because the directive will alter the value, however, this is not a good way way to solve it. It really should have its own scope.
Question: "Comenting out in the directive: scope -> contact.number only is displayed"
My Reply: You bound a scope property of the parent to the "contact.number" directive, so it will get placed inside during the $digest loop - after the directive has been processed. On the "contact.name", you put it inside the directive, which can only work if the directive codes for transclusion.
Question: "Not commenting out anything -> nothing is displayed"
My Reply: Right. If the directive has its own scope (and this one definitely should), then you must use a defined directive scope property to communicate values, as my several code samples demonstrate. Your code, however, tries to use the parent scope in the directive when we explicitly forbid that by using the scope property in its definition.
Summary: While this second update may be informative (and I hope that it is), it doesn't answer the question beneath your questions: how do I use angular components correctly so that the scope I'm using is always what I think it is? My first post and the subsequent update, answer that question.
Here is little bit updated your fiddle, but it need further improvements to meet full list of your requirements: http://jsfiddle.net/5VRFE/
Key point is:
scope: { value:"=editInPlace" },
Some notes: its better to use ng-show ng-hide directivies for visual appearing-hiding instead of changing css classes. Also its better to spread functionality into different directives to have better separation of concerns (check ngBlur directive)
About your confusion of scope check guide about scopes paragraph "Understanding Transclusion and Scopes": Each directive have separate isolated scopes, if you want to have access from directive's template to controller's scope use directive scope binging ("scope" field of directive definition object). And also transcluded elements have a scope of from where you defined transcluding template.
From the first view those isolated scope sounds little bit strange, but when you have good structured directives (note also that one directive can require another and share bindings) you can find it extremly usefull.