Lazy load template and controller in angular UI-Router

Question

I am attempting to lazy load a controller and template in my UI-Router router.js file, but am having difficulty with the template.

The controller loads properly, but

Answer 1

Ok, thanks for the responses, but I have figured it out.

.state('log_in', {
url: '/log-in',
controller: 'controllerJsFile',
templateProvider: function() { return lazyDeferred.promise; },
resolve: {
    load: function($templateCache, $ocLazyLoad, $q, $http) {
        lazyDeferred = $q.defer();

        return $ocLazyLoad.load ({
          name: 'app.logIn',
          files: ['src/controllerJsFile.js']
        }).then(function() {
          return $http.get('src/htmlTemplateFile.tpl.html')
            .success(function(data, status, headers, config) {
              return lazyDeferred.resolve(data);
            }).
            error(function(data, status, headers, config) {
              return lazyDeferred.resolve(data);
            });
        });
    }
},
data: {
  public: true
}

})

So, after some more reading, I realized I had an issue with my promises. We create one called lazyDeferred which is the one to be returned to templateProvider and is declared as a global variable. templateProvider waits for the promise to be fulfilled.

After we load our controller, we create an XHR/ $http request to retrieve the template file. $http.get is a promise so we can return that, $ocLazyLoad.load also is a promise so we can return that as well. Finally, we just need to resolve the lazyDeferred one and that I think balloons through the promises and resolves all of them.

I apologize if this was not very clear, I'm not 100% sure of how this works.

Answer 2

In case you'd like to lazily load the controller, I would suggest follow these detailed answers:

• requirejs with angular - not resolving controller dependency with nested route
• angular-ui-router with requirejs, lazy loading of controller

In case we need to load dynamically the HTML template, it is much more easier. There is an example from this Q & A

• Trying to Dynamically set a templateUrl in controller based on constant

(the working plunker)

$stateProvider
  .state('home', {
    url: '/home',
    //templateUrl: 'index5templateA.html',   (THIS WORKS)
    templateProvider: function(CONFIG, $http, $templateCache) {
        console.log('in templateUrl ' + CONFIG.codeCampType);

        var templateName = 'index5templateB.html';

        if (CONFIG.codeCampType === "svcc") {
             templateName = 'index5templateA.html';
        } 
        var tpl = $templateCache.get(templateName);

        if(tpl){
          return tpl;
        }

        return $http
           .get(templateName)
           .then(function(response){
              tpl = response.data
              $templateCache.put(templateName, tpl);
              return tpl;
          });
    },

You can check these as well:

• Angular UI Router: decide child state template on the basis of parent resolved object
• Angular and UI-Router, how to set a dynamic templateUrl