trelloClient.js

/*
 * TODO: Better error management, we should be able to tell the client exactly what went wrong insteal of
 * vague messages such as "unauthorized access" or "strange error"
 */

function TrelloClient () {
  this.apiKey = null;
  this.apiSecret = null;
  this.clientToken = null;   // Required to see non public boards
  this.username = null;
  
  this.openBoards = [];
  this.currentLists = [];
  this.currentCards = [];
}

// If the user is logged into Trello, we can get his API key and secret for him
// The callback takes an err argument
TrelloClient.prototype.getApiCredentials = function (cb) {
  var self = this
    , callback = cb || function() {};

  $.ajax({ url: "https://trello.com/1/appKey/generate" }).done(function (data) {
    try {
      var html = $($.parseHTML(data))
        , apiKey = html.find("input#key").val()
        , apiSecret = html.find("input#secret").val()
        ;
      if (!apiKey || !apiSecret) {
        return callback("Couldn't get API key and secret from the returned HTML");
      } else {
        self.apiKey = apiKey;
        self.apiSecret = apiSecret;
        return callback(null);
      }
    } catch (e) {
      return callback(e);
    }
  }).fail(function () {
    return callback("Unauthorized access");
  });
};

// Simulates the user requesting then accepting a client token for this application
// The callback takes only one err argument
TrelloClient.prototype.getClientToken = function(cb) {
  var self = this
    , callback = cb || function() {};


  if (!this.apiKey) { return callback("Can't request token without an API key"); }

  // TODO: check the scope is right
  $.ajax({ url: "https://trello.com/1/authorize?key=" + self.apiKey + "&name=TrelloCapture&expiration=never&response_type=token&scope=read,write" }).done(function(data) {
    try {
      var html = $($.parseHTML(data))
        , approve = "Allow"
        , requestKey = html.find("input[name='requestKey']").val()
        , signature = html.find("input[name='signature']").val()
        ;
    } catch(e) { return callback(e); }
    
    $.ajax({ type: 'POST'
    , url: 'https://trello.com/1/token/approve'
    , data: { approve: approve, requestKey: requestKey, signature: signature }
    }).done(function(data) {
      try {
        var html = $($.parseHTML(data))
          , token = $(html[5]).html().replace(/ /g, '').replace(/\r\n/g, '').replace(/\n/g, '').replace(/\r/g, '')
          ;
      } catch (e) { return callback(e); }

      if (token && token.length === 64) {
        self.clientToken = token;
        return callback(null);
      } else {
        // Should probably loop on the html array to check whether its structure was changed
        return callback("Couldn't get valid token");
      }
    }).fail(function () {
      return callback("Trello refused to give a token");
    });
  }).fail(function () {
    return callback("Unauthorized access");
  });
};

// Simulates going to the frontpage and scrape the username
// If this.username is not populated, it means user is not logged in
// Callback takes one err argument
TrelloClient.prototype.getLoggedUsername = function (cb) {
  var self = this
    , callback = cb || function() {};
  
  $.ajax({ url: "https://trello.com/1/Members/me" }).done(function (data) {
    self.username = data.username;
    return callback(null);
  }).fail(function () {
    return callback("Unauthorized access");
  });
};


TrelloClient.prototype.getAllBoards = function (cb) {
  var self = this
    , callback = cb || function() {};  

  $.ajax({ url: "https://api.trello.com/1/members/" + this.username + "/boards?key=" + this.apiKey + "&token=" + this.clientToken }).done(function(data) {
    self.openBoards = _.filter(data, function(board) { return board.closed === false; });
    return callback(null);
  }).fail(function() {
    return callback("Unauthorized access");
  });
};


TrelloClient.prototype.getAllLabelsNames = function(boardId, cb) {
  var self = this
    , callback = cb || function() {};  

  $.ajax({ url: "https://api.trello.com/1/boards/" + boardId + "/labelNames?key=" + this.apiKey + "&token=" + this.clientToken }).done(function(data) {
    self.currentLabels = data;
    return callback(null);
  }).fail(function() {
    return callback("Unauthorized access");
  });
}


TrelloClient.prototype.getAllCurrentLists = function (boardId, cb) {
  var self = this
    , callback = cb || function() {};
    
  $.ajax({ url: "https://api.trello.com/1/boards/" + boardId + "/lists?key=" + this.apiKey + "&token=" + this.clientToken }).done(function(data) {
    self.currentLists = _.filter(data, function (list) { return list.closed === false; });
    return callback(null);
  }).fail(function() {
    return callback("Unauthorized access");
  });
};


TrelloClient.prototype.getAllCurrentCards = function (listId, cb) {
  var self = this
    , callback = cb || function() {};
    
  $.ajax({ url: "https://api.trello.com/1/lists/" + listId + "/cards?key=" + this.apiKey + "&token=" + this.clientToken }).done(function(data) {
    self.currentCards = _.filter(data, function (card) { return card.closed === false; });
    return callback(null);
  }).fail(function() {
    return callback("Unauthorized access");
  });
};


// Callback signature: err, createdCardId
TrelloClient.prototype.createCardAtBottomOfCurrentList = function (listId, cardName, cardDesc, _labels, cb) {
  var self = this
    , callback = cb || function() {}
    , labels = _labels.length > 0 ? '&labels=' + _labels.join(',') : ''
    ;
    
  $.ajax({ url: "https://api.trello.com/1/lists/" + listId + "/cards?key=" + this.apiKey + "&token=" + this.clientToken + labels
         , type: 'POST'
         , data: { name: cardName, desc: cardDesc, pos: 'top' }
         }).done(function(data) {
    return callback(null, data.id);
  }).fail(function() {
    return callback("Unauthorized access");
  });
};


// Callback signature: err, createdCardId
TrelloClient.prototype.putCardOnTopOfList = function (cardId, cb) {
  var self = this
    , callback = cb || function() {}
    ;
    
  $.ajax({ url: "https://api.trello.com/1/cards/" + cardId + "?key=" + this.apiKey + "&token=" + this.clientToken
         , type: 'PUT'
         , data: { pos: 'top' }
         }).done(function(data) {
    return callback(null, data.id);
  }).fail(function() {
    return callback("Unauthorized access");
  });
};


// TODO: a bit scrappy since it is dependent on the title Trello sends us. A better way would be to use the url or an API call
// Callback signature: err, boolean indicating whether login was successful or not
TrelloClient.prototype.logUserIn = function(email, password, cb) {
  var self = this
    , callback = cb || function() {};
    
  $.ajax({ url: "https://trello.com/authenticate"
         , type: 'POST'
         , data: { user: email, password: password, returnUrl: '/' }
         }).done(function(data, textStatus, jqXHR) {
           if (jqXHR.responseText.match(/<title>Log In[^<]*<\/title>/)) {   // Trello still wants us to login, so login was not successful
             return callback(null, false);
           } else {           
             return callback(null, true);
           }
         }).fail(function(jqXHR) {
           return callback("Strange error");
         });
};


// Take as input a base64-encoded image (for example given by the tabs API screenshot)
// And send attach it to a Trello card
TrelloClient.prototype.attachBase64ImageToCard = function(cardId, imageData, progressHandler, endHandler) {
  var imageDataElements = imageData.split(',')
    , mimeType = imageDataElements[0].split(':')[1].split(';')[0]
    , imageB64Data = imageDataElements[1]
    , byteString = atob(imageB64Data)
    , length = byteString.length
    , ab = new ArrayBuffer(length)
    , ua = new Uint8Array(ab)
    , blob, formData, request, i
    ;

  for (i = 0; i < length; i++) {
      ua[i] = byteString.charCodeAt(i);
  }
  
  blob = new Blob([ab], { type: mimeType });
  formData = new FormData();
  formData.append("key", this.apiKey);
  formData.append("token", this.clientToken);
  formData.append("file", blob, "trello-capture-screenshot.jpg");    // TODO slugify title or beginning of title
  
  request = new XMLHttpRequest();
  request.upload.addEventListener("progress", progressHandler || function () {});
  request.onload = endHandler || function () {};
  request.open("POST", "https://api.trello.com/1/cards/" + cardId + "/attachments");
  request.send(formData);
}