Updating a CSS style globally with variable in scope - css

Question

I'm currently building an app that has the option to change the theme. A theme in this instance, simply consists of changing the color of a few key elements in the app.
So currently, on all elements that require the theme color, I have given them the css class has-main-color.
In the controller, I get their desired color from the web service and set it to the scope as $scope.mainColor = color;.
All of this works fine, but the problem I'm getting is that I can't find a suitable method of applying this color to the has-main-color class.
Currently, I'm trying the following:
<style>
.has-main-color {
color: {{mainColor}}
}
</style>
As you could probably guess, this doesn't work so well.
So what would be the best approach to solve this problem using AngularJS?

Answer 1

Look at the documentation page for ngStyle. It has almost exactly what you want.
<input type="button" value="set" ng-click="myStyle={color:'red'}">
<input type="button" value="clear" ng-click="myStyle={}">
<br/>
<span ng-style="myStyle">Sample Text</span>
<pre>myStyle={{myStyle}}</pre>

Answer 2

I don't think you can use a class to do this, however try this
<div ng-app="test-app" ng-controller="MyController" theme-wrapper="{{mainColor}}">
<div class="has-main-color">Top1</div>
<div>Child 1</div>
<div class="has-main-color">Top1</div>
<div>Child 1</div>
<div class="has-main-color">Top1</div>
<div>Child 1</div>
<br />
<input type="button" value="Red" ng-click="color('red')" />
<input type="button" value="Green" ng-click="color('green')" />
<input type="button" value="Blue" ng-click="color('blue')" />
</div>
JS
var app = angular.module('test-app', []);
app.controller('MyController', function($scope, $rootScope, $timeout){
$scope.mainColor = 'grey';
$scope.color = function(color) {
$scope.mainColor = color;
}
});
app.directive('themeWrapper', function(){
var counter = 0, regex = /^theme-wrapper-\d+$/;
return {
restrict: 'A',
link: function(scope, elm, attrs){
attrs.$observe('themeWrapper', function(value){
var className = 'theme-wrapper-' + (counter++);
$('<style>.' + className + ' .has-main-color{color: ' + value + ';}</style>').appendTo('head');
var classes = elm.attr('class').split(' ');
angular.forEach(classes, function(v, i){
if(regex.test(v)) {
elm.removeClass(v);
}
});
elm.addClass(className);
});
}
}
});
Demo: Fiddle
Another easy fix
<div ng-app="test-app" ng-controller="MyController">
<div style="color: {{mainColor}}">Top1</div>
<div>Child 1</div>
<div style="color: {{mainColor}}">Top1</div>
<div>Child 1</div>
<div style="color: {{mainColor}}">Top1</div>
<div>Child 1</div>
<br />
<input type="button" value="Red" ng-click="color('red')" />
<input type="button" value="Green" ng-click="color('green')" />
<input type="button" value="Blue" ng-click="color('blue')" />
</div>
JS
var app = angular.module('test-app', []);
app.controller('MyController', function($scope, $rootScope, $timeout){
$scope.mainColor = 'grey';
$scope.color = function(color) {
$scope.mainColor = color;
}
})
Demo: Fiddle

Answer 3

If anyone would like to use your original approach, I came across the same problem today and threw together a (tiny!) directive for style which allows for angular expressions inside inline style sheets.
https://github.com/deanmcpherson/angular-inline-style
Allows for
body { background-color: {{bgColor}}; }
With bg color attached to the appropriate scope.