daybed.js

A library to use Daybed in your Javascript applications.

Usage

In the browser, just include the source file:

  <script src="//spiral-project.github.io/daybed.js/build/daybed.js"></script>

In node, just require the package:

  var Daybed = require('daybed.js');

Rationale

Note that Daybed is a REST backend, and does not require any particular library to be used in your applications.

daybed.js brings some helpers to ease the manipulation of sessions and asynchronous operations.

We heavily take advantage of Promises.

Example

Start a session

First, we start a new session on Daybed, and keep the token as if it was an admin password.

    var server = 'https://daybed.lolnet.org';

    var sessionPromise = Daybed.startSession(server)
      .then(function (session) {
        console.log("Keep this somewhere safe " + session.token);
        return session;
      });

Later, you will be able to re-use admin token you obtained :

    var sessionPromise = Daybed.startSession({ token: 'q89ryh..dcc' })
      .then(function (session) {
        console.log("Authenticated!");
        return session;
      })
      .catch(function (error) {
        console.log("Failed!");
      });

Note: The sessionPromise object is not a Session object.

You can build a Session object yourself:

    var sessionObject = new Daybed.Session(server, { token: 'q89ryh..dcc' });

Or get it out of the promise:

    var sessionObject;
    sessionPromise
      .then(function (session) {
          sessionObject = session;
      });

Setup

As the main developper of your app, it's common to start by defining a model on the Daybed server.

Let's say you want to build an app to list the books you would like to read.

    var books = {
      definition: {
        title: 'book',
        description: "The list of books to read",
        fields: [{
          name: "title",
          type: "string",
          label: "Title",
        },
        {
          name: "author",
          type: "string",
          label: "Author"
        },
        {
          name: "summary",
          type: "string",
          label: "Summary"
        }]
      }
    };

    var modelId = 'myapp:books';

    sessionPromise
      .then(function (session) {
        return session.saveModel(modelId, books);
      })
      .then(function (created) {
        console.log('Model created', created);
      })
      .catch(function (error) {
        console.error('An error occured', error);
      });

As a model owner, you can adjust the permissions. For example, you can decide that everyone can create, read, edit and delete their own records :

    sessionPromise
      .then(function (session) {
        return session.savePermissions(modelId, {
          'Everyone': ['create_record', 'read_own_records', 'delete_own_records',
                       'read_definition']
      })
      .then(function (permissions) {
        console.log('Permissions set', permissions)
      });

You're done !

You can now implement your application, and let your users manage their records !

In your application

Let's say, we want each user to store her session token in the local storage. The first time, a new token will be created :

    var token = localStorage.getItem('myapp:books:token');
    var sessionPromise = Daybed.startSession(server, { token: token })
      .then(function (session) {
        localStorage.setItem('myapp:books:token', session.token);
        return session;
      });

Fetch the list of records :

    var modelId = 'myapp:books';

    sessionPromise
      .then(function (session) {
        return session.getRecords(modelIds)
      })
      .then(function (records) {
        console.log(records.length + ' record(s).');
      });

Create new records :

    var book = {
      title: "Critique de la raison numérique",
      author: "Dominique Mazuet, Delga",
      summary: "http://www.librairie-quilombo.org/spip.php?article5532"
    };

    sessionPromise
      .then(function (session) {
        return session.saveRecord(modelId, book)
      })
      .catch(function (error) {
         console.error('An error occured', error);
      });

A word about tokens

Tokens are your authentication credentials, you can share yours, by using URL location hash for example (instead of localStorage) :

    var token = window.location.hash.slice(1);
    Daybed.startSession({ token: token })
      .then(function (session) {
        window.location.hash = session.token;
      });

This way, each user can share her identity on several devices, and even share her own privileges and collaborate with the entire world!

You can also create new ones and assign them to specific permissions:

    var sessionObject;
    sessionPromise
      .then(function (session) {
        sessionObject = session;
        return Daybed.getToken();
      })
      .then(function(infos) {
        console.log(infos.token + ' will be allowed to delete any record');

        var permissions = {};
        permissions[infos.credentials.id] = ['delete_all_records'];
        sessionObject.savePermissions(modelId, permissions);
      });

See also

Check out backbone-daybed, which brings Backbone.js helpers with jQuery instead of daybed.js.

References

• Promises error handling
• Optional authentication relies on Hawk
• Tokens are manipulated with SJCL