ember-cli-meta-tags

An Ember CLI add-on to easily set tags (link, meta, script, noscript, etc.) in the document head.

Many social networks, sharing platforms, and search engines extract data from <meta> tags within a page's head tag. With this add-on, you can have those meta tags populated when entering individual Ember routes. This allows you to keep all logic within your client side application without needing a sophisticated web server to populate tags correctly.

This add-on is perfect for combining with a prerendering server side solution such as prerender.io or with Ember FastBoot (FastBoot compatibility requires ember-cli-meta-tags v2+ and Ember 2.7+).

Usage

Installation

In your Ember CLI project directory run:

ember install ember-cli-meta-tags

Upgrading to 5.x

Version 5.0 of this addon depends on ember-cli-head 0.4.0, which adds the requirement that the <HeadLayout /> is added once in an application-wide template (usually app/templates/application.hbs). For more info, see the ember-cli-head 0.4 upgrade note.

Using with Ember FastBoot

Version 4.0+ of this addon is designed to work with FastBoot >= 1.0.0-rc1. If you use an order version of fastboot stick with 3.X.

Version 2.0+ of this addon is built upon ember-cli-head and as a result it will work automatically out of the box with Ember FastBoot if you are running a version of Ember >= 2.7.

Using with other ember-cli-head addons

If you are using another addon that makes use of ember-cli-head (such as ember-page-title), or are directly using ember-cli-head in your app you will need to create a custom app/templates/head.hbs file and include ember-cli-meta-tag's component:

<HeadTags @headTags={{this.model.headTags}} />

Adding Tags Automatically On Transition

In order to dynamically add head tags from your routes all you need to do is provide a headTags property on the route. This property can either be an array of tags, or a function which when invoked with the route's context returns an array of tags. The head tags service will automatically collect all head tags from the currently active routes after transition.

Data structure

To define a head tag you will use the following structure:

  {
    // html element type (meta, link, etc.)
    type: 'meta',
    // unique id for nesting (see below)
    tagId: 'meta-description-tag',
    // key value attributes for the element
    attrs: {
      name: 'description',
      content: model.get('description')
    },
    // optional element content
    content: 'Element content here'
  }

Nesting

This library supports pulling tag definitions from nested routes without creating duplicate tags. Deeper nested routes will override parent route tags. In order to support this you need to provide a unique tagId property on your tag definition. Only one tag with a given tagId will ever be rendered in the head.

Head Tags object

You can also define the tags by providing an object as the value for the meta property on the route. This can either be in-lined in your route definition, or set as a property on the route prior to the didTransition event.

Example: static headTags property on the route

// app/routes/some-page.js
import Route from '@ember/routing/route';

export default Route.extend({
  headTags: [{
      type: 'meta',
      tagId: 'meta-og-name',
      attrs: {
        property: 'og:name',
        content: 'Ice-T'
      }
    },
    {
      type: 'link',
      tagId: 'canonical-link',
      attrs: {
        rel: 'canonical',
        content: 'http://mydomain.org/'
      }
    }]
});

Example: Setting the headTags property in afterModel

import Route from '@ember/routing/route';

export default Route.extend({
  afterModel(model) {
    this.setHeadTags(model);
  },

  setHeadTags(model) {
    let headTags = [{
      type: 'meta',
      tagId: 'meta-description-tag',
      attrs: {
        name: 'description',
        content: model.get('description')
      }
    }];

    this.set('headTags', headTags);
  }
});

headTags function

You can provide the headTags by implementing a headTags method on the route that returns the appropriate head tags.

Example:

// app/routes/some-page.js
import Route from '@ember/routing/route';

export default Route.extend({
  headTags() {
    // here we are pulling meta data from the model for this route
    let model = this.modelFor(this.routeName);
    return [{
      type: 'meta',
      tagId: 'meta-description-tag',
      attrs: {
        name: 'description',
        content: model.get('description')
      }
    }];
  }
});

When you visit '/some-page' the document head tag will be updated as follows:

<head>
  <!-- ... -->
  <meta name='description' content='Ice-T'>
  <!-- ... -->
</head>

These tags will automatically be cleared when transitioning away from this route.

Resetting Tags Outside of Transition

If you want to update the head tags for a route outside of a full transition (perhaps due to a controller query parameter change) you can directly call collectHeadTags on the head-tags service and all of the headTags in the current route hierarchy will be re-built.

Example

// app/routes/some-page.js
import Route from '@ember/routing/route';

export default Route.extend(RouteMetaMixin, {
  headTags() {
    let controller = this.controllerFor(this.routeName);
    // value of head tags updates with value of `era` on this
    // route's controller
    return [{
      type: 'meta',
      tagId: 'meta-title',
      attrs: {
        property: 'title',
        content: controller.get('era')
      }
    }]
  }
});


// app/controller/some-page.js
import Controller from '@ember/controller';

export default Controller.extend({
  headTagsService: Ember.inject.service('head-tags'),
  queryParameters: {
    era: 'e'
  },
  // this observer runs whenever the era query parameter updates
  // which by default does not trigger a full route transition
  // so we need to notify the service to rebuild tags
  eraObserver: Ember.observer('era', function() {
    this.get('headTagsService').collectHeadTags();
  }),
});

Route Meta Mixin

Including the RouteMetaMixin in your routes is no longer necessary if you provide the headTags property. However it's use is still supported and documented here.

Development

Instructions for developing on this add-on.

Installation

• git clone this repository
• npm install

Running

• ember serve
• Visit your app at http://localhost:4200.

Running Tests

• ember test
• ember test --serve

Building

• ember build

For more information on using ember-cli, visit http://www.ember-cli.com/.