Link Handlers

You can create a link handler to intercept what happens when links are clicked using the CoreContentLinksDelegate.

The Moodle app automatically creates two link handlers for module plugins, so you don't need to create them in your plugin's JavaScript code anymore:

A handler to treat links to mod/pluginname/view.php?id=X. When this link is clicked, it will open your module in the app.
A handler to treat links to mod/pluginname/index.php?id=X. When this link is clicked, it will open a page in the app listing all the modules of your type inside a certain course.

If these aren't sufficient, link handlers have some advanced features that allow you to change how links behave under different conditions.

In order to implement a custom link handler, you should register an object implementing the CoreContentLinksHandler interface in the delegate. You can also achieve this extending the CoreContentLinksHandlerBase class:

class AddonModFooLinkHandler extends this.CoreContentLinksHandlerBase {}

this.CoreContentLinksDelegate.registerHandler(new AddonModFooLinkHandler());

Using patterns

You'll most likely need to match only certain links. You can define a Regular Expression pattern to filter clicks:

class AddonModFooLinkHandler extends this.CoreContentLinksHandlerBase {

    constructor() {
        super();

        this.pattern = RegExp('\/mod\/foo\/specialpage.php');
    }

}

Setting a priority

Multiple link handlers may apply to a given link. You can define the order of precedence by setting the priority; the handler with the highest priority will be used.

Handlers have a priority default priority of 0, so 1 or higher will override the default:

class AddonModFooLinkHandler extends this.CoreContentLinksHandlerBase {

    constructor() {
        super();

        this.priority = 1;
    }

}

Performing multiple actions

Once a link has been matched, the handler's getActions() method determines what the link should do. This method has access to the URL and its parameters.

Different actions can be returned depending on different conditions:

class AddonModFooLinkHandler extends this.CoreContentLinksHandlerBase {

    getActions(siteIds, url, params) {
        return [
            {
                action: function(siteId, navCtrl) {
                    // The actual behaviour of the link goes here.
                },
                sites: [
                    // ...
                ],
            },
            {
                // ...
            },
        ];
    }

}

Once handlers have been matched for a link, the actions will be fetched for all them and sorted by priority. The first valid action will be used to open the link.

If your handler is matched with a link, but a condition assessed in the getActions() method determines that you want to skip it, you can invalidate it by setting its sites property to an empty array.

Complex example

This will match all URLs containing /mod/foo/, and force those with an id parameter that's not in the supportedModFoos array to open in the user's browser, rather than the app:

const that = this;
const supportedModFoos = [...];

class AddonModFooLinkHandler extends this.CoreContentLinksHandlerBase {

    constructor() {
        super();

        this.pattern = new RegExp('\/mod\/foo\/');
        this.name = 'AddonModFooLinkHandler';
        this.priority = 1;
    }

    getActions(siteIds, url, params) {
        const action = {
            action() {
                that.CoreUtilsProvider.openInBrowser(url);
            },
        };

        if (supportedModFoos.indexOf(parseInt(params.id)) !== -1) {
            action.sites = [];
        }

        return [action];
    }

}

this.CoreContentLinksDelegate.registerHandler(new AddonModFooLinkHandler());

Using patterns​

Setting a priority​

Performing multiple actions​

Complex example​

Using patterns

Setting a priority

Performing multiple actions

Complex example