Backbone.Flexisync

v0.1.0

Maintained by Nico Burns @nicoburns.

Overrides Backbone.Sync with support for fetching and combining data from multiple sources (multiple api endpoints, localstorage and or an in-memory cache) in a single fetch() call.

Depends on Underscore, Backbone, and jQuery. You can swap out the dependencies with a custom configuration. AMD compatible.

Documentation

http://github.com/nicoburns/backbone.flexisync/wiki

Changelog

0.1.0

• Initial release

Usage

Include Backbone.Flexisync and config options after having included Backbone.js, and then call activate to replace the default sync implementation:

<script type="text/javascript" src="backbone.js"></script>
<script type="text/javascript" src="backbone.flexisync.js"></script>
<script type="text/javascript">
	// Which datastores to fetch from (in order of preference)
    Backbone.Flexisync.options.fetchFrom = ["memory", "localstorage", "remote"];

    // If cacheTo is specified then the return data of remote requests is cached to the specified
    // data stores and can be fetched from there the next time that data is requested.
    Backbone.Flexisync.options.cacheTo = ["memory", "localstorage"];

    // Enables the plugin
    Backbone.Flexisync.activate();
</script>;

Create and add remote 'datasources'. This tells the synclayer where it can get certain data from.

var usersSource = {
    url: "http://mysites.com/api/users",
    returnData: ["users"],
    parse: function (rawApiResponse) {
    	// This function is useful if the API sends back data in different format to the one that
    	// you want. However, in this case we just pass through the raw response

    	// This value is sent to any RequestMatcher that requires 'users' data
        return {
        	"users": rawApiResponse
        }
    }
};
Backbone.Flexisync.datastores.remote.addSource(usersSource);

var usergroupsSource = {
    url: "http://mysites.com/api/usergroups",
    returnData: ["usergroups"],
    parse: function (rawApiResponse) {
    	// This value is sent to any RequestMatcher that requires 'usergroups' data
        return {
        	"usergroups": rawApiResponse
        }
    }
};
Backbone.Flexisync.datastores.remote.addSource(usergroupsSource);

Create and register a 'Request Matcher'. This matches against the url you pass to your model, and tells the synclayer that it should intercept a fetch request.

var parseGroupData = function (data, id) {
	var users, usergroup;
	// This function takes the usergroups stored user id's and fetches the user data
	// for each id, returning an object with full user data (rather than merely id's)
	// The id comes from the brackets in the regex above

	users = [],
	usergroup = data.usergroups[id];
    _.each(usergroup.users, function (id) {
        if (data.users[id]) users.push(data.users[id]);
    });
    usergroup.users = users;

    // This value is sent to the model
    return usergroup;
}

var usergroupsMatcher = {
    pattern: /^usergroups\/([0-9]+)$/, // Matches flexisync://usergroups/123
    requiredData: ["users", "usergroups"], // These are the same as the datasource's returnData
    parse: parseGroupData
};
Backbone.Flexisync.RequestMatcher.register(usergroupsMatcher);

Create your Models and Collections as normal, specifying a special url, and optionally overiding the datastores to fetch from on a per model or per fetch basis

var usergroupsModel = Backbone.Model.extend({
  url: function () {
  	return "flexisync://usergroups" + this.get("id"); // Url is 'flexisync://' + the RequestMatcher's pattern
  }
  // ... everything else is normal.
});
usergroupsModel.fetch();

// For this fetch, only allow the remote datastore fetch from the server)
usergroupsModel.fetch({from: "remote"});

RequireJS

Backbone.Flexisync is fully AMD compatible, so simply require it as a dependency.

Have fun!

License

Licensed under MIT license

Copyright (c) 2013 Nico Burns

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.