Working with Data

Loading Data

Chat is a backend-oriented component and expects remote data loaded by URL:

 view: "chat", url: "remote/data"

Data Services

Chat uses the following services to work with data:

1. Local Data

stores data on the client side in Data Collections
provides methods for getting and repainting the data
provides methods for getting chats, users and messages

const local = $$("chat").getService("local");
const chats = local.chats(); // returns chats collection

2. Operations

provides methods for adding/leaving/updating chats and messages

const ops = $$("chat").getService("operations");
ops.addMessage(cid, origin, text); // adds a new message

3. Backend

provides methods for issuing requests to the backend to fetch data and save the changes back

const back = $$("chat").getService("backend");
back.users().then((data) => console.log(data));

4. Upload

provides methods for uploading the avatars for chats

5. Helpers

provides methods for view templates, dateFormats, etc

const helpers = $$("chat").getService("helpers");
helpers.dateChatFormat(date); // sets new date format

Study the models folder in the source code for method signatures.

Data Operations

Getting chats

All loaded chats are stored in DataCollection. To access the collection call the .chats() method of the Local service:

const chat = $$("ch");
chat.getService("backend").ready().then(() => {
  const chats = chat.getService("local")
  .chats() // getting the collection
  .serialize(); // serializing the collection to access data elements
});

Each chat object has the following fields:

avatar (string) - the URL to load chat avatar from
date (object) - date object
direct_id (number) - the id of the user with whom a private chat is active
id (number) - the chat id
message (string) - the latest message in the chat
name (string) - the chat name
unread_count (number) - number of the unread messages in the chat (from the current user perspective)
users (array) - an array of users of the chat.

Chat object

{
  avatar: "remote/avatars/members.jpg",
  chat_id: 0,
  date: new Date(),
  direct_id: 0,
  id: 19,
  message: "Hi there",
  name: "Today's meeting",
  unread_count: 2,
  user_id: 2,
  users: [3, 4, 1]
}

Getting users

To get the users collection call the users() method of the Local service:

const chat = $$("ch");
chat.getService("backend").ready().then(() => {
  const users = chat.getService("local")
  .users() // getting the collection
  .serialize(); // serializing the collection to access data elements
});

A single user object has the following fields:

avatar (string) - URL to load user avatar from
email (string) - the user email
id (number) - the user id
name (string) - the user name
status (number) - the user status. Takes one of the following values:
- 1 - "none",
- 2 - "active",
- 3 - "busy",
- 4 - "away"

User object

  avatar: "remote/avatars/1.jpg"
  email: "alex@brown.com"
  id: 1
  name: "Alex Brown"
  status: 2

Getting messages

To access messages from a certain chat call the messages() method and pass the ID of the chat as a parameter:

const chat = $$("ch");
chat.getService("backend").ready().then(() => {
  chat.getService("local")
  .messages(6) // getting an array of messages from the chat with "id: 6"
  .then(messages => {
    console.log(messages); // messages array
  });
});

Related sample: Chat: Data Operations

The method returns a promise that resolves with an array of messages from the specified chat. Each message object has the following fields:

Message object

{
  chat_id: 6,
  date: new Date(),
  id: 19,
  text: "Who is on duty today?",
  user_id: 2,
  type: 901
}

chat_id (number) - the chat id
date (object) - date object
id (number) - the id of the message
text (string) - the text of the message (or time of the call)
user_id (number) - the id of the user the message was left by
type - included into the object in case of a call. The possible values are:
- 900 - call ended
- 901 - call was rejected
- 902 - call was missed.