Using External JavaScript Libraries

The framework’s content security policy mandates that external JavaScript libraries must be uploaded to Salesforce static resources. For more information on static resources, see “Static Resources” in the Salesforce online help.

You can’t use a <script> tag in a component. This restriction mitigates the risk of cross-site scripting attacks. You can add a <script> tag to an application’s template, which is a special type of component that extends aura:template.

resourceName is the Name of the static resource. In a managed packaged, the resource name must include the package namespace prefix, such as $Resource.yourNamespace__resourceName. For a stand-alone static resource, such as an individual graphic or script, that’s all you need. To reference an item within an archive static resource, add the rest of the path to the item using string concatenation.

The afterScriptsLoaded action in the client-side controller is called after the scripts are loaded and the component is rendered. Don’t use the init event to access scripts loaded by ltng:require. These scripts load asynchronously and are most likely not available when the init event handler is called.

Here are some considerations for loading scripts:

Loading Sets of Scripts

Specify a comma-separated list of resources in the scripts attribute to load a set of resources.

Due to a quirk in the way $Resource is parsed in expressions, use the join operator to include multiple $Resource references in a single attribute. For example, if you have more than one JavaScript library to include into a component the scripts attribute should be something like the following.

Note

Loading Order

The scripts are loaded in the order that they are listed.

One-Time Loading

Scripts load only once, even if they’re specified in multiple <ltng:require> tags in the same component or across different components.

Parallel Loading

Use separate <ltng:require> tags for parallel loading if you have multiple sets of scripts that are not dependent on each other.

Encapsulation

To ensure encapsulation and reusability, add the <ltng:require> tag to every .cmp or .app resource that uses the JavaScript library.

ltng:require also has a styles attribute to load a list of CSS resources. You can set the scripts and styles attributes in one <ltng:require> tag.