Mapping Request Data

A dataModel is intended to help you manage data on an endpoint somewhere. To do this, Footwork needs to know where inside your dataModel the data actually is, and how that maps to the server side. This is needed so it can properly construct the data for outbound requests as well as map that back to your dataModel when it retrieves data.

Mapping Properties

To map properties in your dataModel you use the .map() method on an observable, passing it the 'path' and instance to map.

function Person (personData) {
  // you must boot the dataModel prior to mapping any properties
  var self = fw.dataModel.boot(this, {
    url: '/person'
  });

  self.name = fw.observable(personData.name).map('name', self);
  self.attr = {
    height: fw.observable(personData.height).map('attr.height', self),
    weight: fw.observable(personData.weight).map('attr.weight', self)
  };
}

var batman = new Person({
  name: 'Bruce Wayne',
  attr: {
    height: 6,
    weight: 220
  }
});

In the above example you see the name property as well as height and weight under attr. You will notice that height and weight are specified as properties of attr via the full path (attr.height/attr.weight). This dot-notation is used to describe or map the data on the backend.

Footwork will use these mappings to translate your dataModel to/from the form your backend uses. If fetching data from the server, the mappings will be used to determine what values from the response are written to what observables in your dataModel. Conversely, if you are performing an operation that requires the data be sent upstream then Footwork uses the mappings to convert your dataModel into its object literal form and then sending that over the wire.

Note

• Any observable property can be mapped. This includes observable, observableArray, computed, and collection properties.
• The path of a mapped variable does not necessarily have to match the actual path inside of your dataModel (although you generally want that to be the case, to avoid confusion/inconsistencies).

Unmapping Properties

If you need to unmap a property, that is done with dataModel.$removeMap():

function Person (personData) {
  // you must boot the dataModel prior to mapping any properties
  var self = fw.dataModel.boot(this, {
    url: '/person'
  });

  self.name = fw.observable(personData.name).map('name', self);
  self.attr = {
    height: fw.observable(personData.height).map('attr.height', self),
    weight: fw.observable(personData.weight).map('attr.weight', self)
  };

  self.noName = function () {
    self.$removeMap('name'); // removes the mapped observable for 'name'
  };
}