didacte/ember-meta-meta

import Ember from 'ember';
const {Service} = Ember;

export default Service.extend({
  /**
   Store the default document title

   @method storeDefaultTitle
   */
  storeDefaultTitle() {
    this.set('defaultTitle', window.document.title);
  },

  /**
   Set metas to be injected

   For exemple :

   ```js
   this.get('meta').update({
        title: 'This Is News Title',
        description: 'This Is News Description',
        'og:image': 'https://exemple.net/latest-news.png'
      });
   ```

   @method update
   @param {Object} attributes
   */
  update(attributes) {
    this.set('attributes', attributes);
  },

  /**
   Inject given metas in document after completed didTransition

   @method insert
   */
  insert() {
    const attributes = this.get('attributes') || {title: this.get('defaultTitle')};
    const metas = document.querySelectorAll('meta[data-meta-meta="true"]');

    // Remove previously set metas
    for (let i = 0; i < metas.length; i++) {
      metas[i].removeAttribute('content');
    }

    // Set new metas
    Object.keys(attributes).forEach((key) => {
      this.setMeta(key, attributes[key]);
    });

    // Reset for next transition
    this.set('attributes', null);
  },

  /**
   Returns the title, exists solely to be reopen for your needs

   @method title
   */
  title(value) {
    return value;
  },

  /**
   Inject given meta in document.

   Exemple :

   ```js
   self.router.setMeta('title', 'Homepage of the Crew');
   ```

   @method setMetas
   @param {Object} attributes
   */
  setMeta(name, value) {
    let meta, key;

    if (name === 'title') {
      window.document.title = this.title(value);
    } else {
      key = (name.indexOf('og:') === -1) ? 'name' : 'property';
      meta = document.querySelector('meta[' + key + '="' + name + '"]');

      // Create meta tag if does not exist
      if (!meta) {
        meta = document.createElement('meta');
        meta.setAttribute(key, name);
        document.getElementsByTagName('head')[0].appendChild(meta);
      }

      meta.setAttribute('data-meta-meta', 'true');
      meta.setAttribute('content', value);
    }
  }
});