FAQ
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Related: Dev Guide: Best Practices, Dev Guide: Anti-Patterns
Editors: put 2 spaces at the end of a question to create a <br>
-
Why does it think the jQuery plugin is missing?
Remember: load jQuery before AngularJS if you are using jQuery plugins! -
How do I access the DOM from a controller?
DO NOT perform DOM selection/traversal from the controller. The HTML hasn't rendered yet. Look up 'directives'. -
Why does angular say my controllers/directives/etc are missing?
Callingangular.module('myApp', [])
will ALWAYS create a new module (and wipe out your existing one). Instead, make sure to callangular.module('myApp')
with only 1 parameter to refer to an already created module. -
How to render unescaped data?
$sce.trustAsHtml -
How can I watch when an array/object/$resource-result is modified?
$scope.$watch
has a third parameter to monitor changes by value (and not by reference). -
How can I serialize form data for submitting?
Don't. Don't try to collect input values manually. Just attachng-model="data.myField"
onto every form input and take a look at$scope.data
when you finally need it. -
Always have a '.' in your ng-models.
Misko best practice. -
How should I access the scope from services?
$rootScope
is equivalent to theng-app
tag and can be injected into your bootstrap or services to add functions and values accessible on all scopes.
NOTE: avoid doing this - it's the equivalent to defining global variables -
What is the difference between
module().factory()
andmodule().service()
?
Checkout this discussion thread. -
How do I prevent Flash Of Unstyled Content (FOUC) (and curly braces)?
Leverageng-bind
instead of{{...}}
andng-cloak
in a few places -
Why isn't
<a ng-click="go({{myVal}})">
working?
The onlyng-*
attributes that require{{...}}
isng-src
andng-href
because the final result must be a string, not an expression. All others will work without. -
Nested Routes / Views?
Maybe... -
Can I specify templates or partials inline?
Yes! You can always do<script id="some/partial.html" type="text/ng-template">
and angular will use it instead! -
How do I use a port in my
ngResource
url?
Escape it:$resource('example.com\\:8080')
-
Why do plugins that trigger the
change
event not seem to work?
Angular watches the input event, not the 'change' event. -
Don't use jQuery to toggle crap. Just use a lot of variable flags inline
<a ng-click="flags.open=!flags.open">...<div ng-class="{active:flags.open}">
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How can I view the scope from the DOM inspector?
Google Chrome: install the Batarang extension, inspect a DOM element, then type$scope
in the console
Firefox / Firebug: inspect a DOM element, then typeangular.element($0).scope()
(or$($0).scope()
) in the console
IE 10+: Using the F12 tool, inspect a DOM element, then typeangular.element($0).scope()
(or$($0).scope()
) in the console. -
Do you have any good directive samples / libraries?
AngularUI is an awesome collection of AngularJS tools (and even BETTER example code). -
Internet Explorer!?!
For IE v8.0 or earlier you may want to read this and use this. -
Do I have to use the
#
for the router?
$locationProvider
-
You should try using the AngularUI Passthru Directive (uiJq) before trying to roll your own jQuery plugin wrapper directive.
-
Why is my
$scope.$watch()
firing recursively?
If you changenewVal
inside your$scope.$watch(newVal, oldVal)
it could fire again (recursively?). After a$watch()
is runs, the$scope
is re-evaluated and relevant watchers will be re-triggered. -
When should I use
$scope.$apply()
?
You should ONLY use$scope.$apply
in non-angular events/callbacks. It usually doesn't belong anywhere else. -
With
html5mode
enabled, how do I get the default<a href>
behavior back?
If you want a link to cause a full page refresh then addtarget="_self"
to your<a>
tag -
How do I
.preventDefault()
or.stopPropagation()
?
Allng-click
and related bindings inject a$event
object that you can call things like.preventDefault()
or even pass the object to your methods -
AngularJS isn't working in my Chrome extension!
You want to useng-csp
-
How do I cachebust $http and html partials?
myAppModule.config(function($routeProvider, $provide) {
$provide.decorator('$http', function($delegate){
var get = $delegate.get;
$delegate.get = function(url, config){
url += (url.indexOf('?') !== -1) ? '?' : '&';
url += 'v=' + cacheBustVersion;
return get(url, config);
};
return $delegate;
});
});
Testing
-
Rejecting / Resolving a
$q.defer()
doesn't go through
You must add a$scope.$apply()
for these to process -
Jasmine
spyOn()
is not executing the spy'd function
Not necessarily an AngularJS question, but you need to append.andCallThrough()
-
How do I test async code?
Focus on creating mocks (fake objects / functions) that let you flush the async stuff synchronously.$timeout
has a.flush()
method specifically for this reason, just remember to add a$scope.$apply()
too. If that still doesn't work, look up Jasmine'sruns()
andwaits()
functions. -
How does
module()
andinject()
work?
You can callmodule()
as many times as you want, and spin up as many unrelated modules as you want at time BEFORE your very firstinject()
is called. All subsequent calls tomodule()
afterwards will either behave incorrectly or fail. If you load modules that contain assets with the same name, the last module to have loaded for that specific test will take precedence. This is a useful and simplistic way to load mock assets. -
How can I mock or modify services?
Callmodule()
and pass$provide
to a callback. Use$provide.decorator()
as an easy way to manipulate or replace services before they get injected into other services! Alternatively, you could just createmyApp.mocks.myService
modules that contain mock services with the identical names to their originals and load it on-demand. The last module you load will take precedence.