fb-graph-reactions.js

$(function(){
		$.ajaxSetup({ cache: true });
	  $.getScript('//connect.facebook.net/en_US/sdk.js', function(){
	    FB.init({
	      appId: '{APP_ID}', // CHANGE APP_ID
	      version: 'v2.3' // or v2.1, v2.2, v2.3, ...
	    });
	  });
	});


// Load the Facebook SDK only once so that each time you
// get reactions, you doesn't have to get the script every time.
// Or you can download the Facebook Javascript SDK and store on your server then load from your server.
// Howerver it's totally up to you.
// var post_id = '40796308305_10155559964843306';
  
/**
 * Get reactions for a public posts.
 * @param  {mixed} post_id   Facebook post ID for which reactions will be pull down
 * @param  {Array} reactions Array of reactions. Example.  ['like', 'love', 'wow', 'haha']
 * @return {Promise} A promise will be return for. Return data will always have a 'err' property,
 *                     if there is no error then 'err' would be null. For succcessfull operation respose will be in the 'data' property.
 */
function getReactions(post_id, reactions) {
  var token = "USER_TOKEN"; // UPDATE THE TOKEN HERE
  var query = '?fields=reactions.type(LIKE).limit(0).summary(1).as(like),reactions.type(LOVE).limit(0).summary(1).as(love),reactions.type(WOW).limit(0).summary(1).as(wow),reactions.type(HAHA).limit(0).summary(1).as(haha),reactions.type(SAD).limit(0).summary(1).as(sad),reactions.type(ANGRY).limit(0).summary(1).as(angry),reactions.type(THANKFUL).limit(0).summary(1).as(thankful)';
  var full_query = post_id + query;

  

  return new Promise(function(resolve, reject) {
    if( Object.prototype.toString.call( reactions ) !== '[object Array]' ) {
      reject({error: 'arguments reactions must be an array.'});
      return;
    }

    FB.api(full_query, function(response) {
      if(!response || response.error) {
        reject({error: response.error});
      }
      var returnValue = {};
      reactions.forEach(function(reaction) {
        if(response.hasOwnProperty(reaction)) {
          returnValue[reaction] = response[reaction]['summary']['total_count'];
        }
      })
      resolve({err: null, data: returnValue});
      return;
    }, {access_token: token})
  })
}

// this is how you would call the function.
getReactions(post_id, ['like', 'love', 'wow'])
  .then((data) => {
    console.log(data);
    // Use the data to display on the web page.
    // returned value sould be similar to this
    // {
    //   like: 64,
    //   love: 33,
    //   wow: 12
    // }
  })
  .catch(err => {
    // handle errors
    console.log(err);
  })