Dynamically Setting iframe's src Attribute in AngularJS

When working with iframes in AngularJS, it's often necessary to set the src attribute dynamically based on a variable. However, attempting to do so with standard assignment may result in an empty src attribute being rendered in the iframe.

Understanding the Issue and Solution

The issue arises when trying to set the src attribute with an un-trusted URL. AngularJS implements security measures to prevent potential XSS (cross-site scripting) attacks. To mitigate this, the $sce (Strict Contextual Escaping) service needs to be employed to "trust" the URL before assigning it.

The trustAsResourceUrl() method of the $sce service can be used to explicitly mark a URL as trusted, ensuring that it can be safely used in an AngularJS template.

Code Implementation

In the provided controllers/app.js file, inject the $sce service into the AppCtrl and modify the setProject() function as follows:

$scope.setProject = function (id) {
    $scope.currentProject = $scope.projects[id];
    $scope.currentProjectUrl = $sce.trustAsResourceUrl($scope.currentProject.url);
}

In the HTML template, update the iframe's src attribute to reference the currentProjectUrl variable:

Explanation

By calling trustAsResourceUrl(), the URL is marked as trusted and can be securely used in the AngularJS template. The ng-src directive will then set the iframe's src attribute with the trusted URL.

Additional Notes

• The trustAsResourceUrl() method should only be used when the URL is known to be safe and trusted.
• If the URL is not fully qualified (e.g., missing the scheme or hostname), AngularJS may throw a security warning.
• To address security concerns, it's always advisable to implement appropriate server-side validation and sanitization before accepting user-supplied URLs.