Maria-SubsetModel

A model class for use with Maria. The class has a SetModel interface. A SubsetModel object wraps a SetModel object and filters the contents to appear as a subset.

Examples

var myApp = {};

maria.Model.subclass(myApp, 'PersonModel', {
    properties: {
        _age: 0,
        getAge: function() {
            return this._age;
        },
        setAge: function(age) {
            age = +age;
            if (this._age !== age) {
                this._age = age;
                this.dispatchEvent({type: 'change'});
            }
        },
        isAdult: function() {
            return this._age >= 18;
        }
    }
});

maria.SubsetModel.subclass(myapp, 'AdultsModel', {
    properties: {
        predicate: function(personModel) {
            return personModel.isAdult();
        }
    }
});

var alpha = new myApp.PersonModel();
alpha.setAge(20);

var beta = new myApp.PersonModel();
beta.setAge(17);

var peopleModel = new maria.SetModel();

var adultsModel = new myapp.AdultsModel(peopleModel);

Adding and deleting people from the peopleModel automatically adds and removes them from the adultsModel as appropriate. Modifying people in the peopleModel also adds and removes them from the adultsModel as appropriate. All automatically.

peopleModel.add(alpha);
peopleModel.add(beta);
peopleModel.length;     // 2
adultsModel.length;     // 1
peopleModel.has(alpha); // true
peopleModel.has(beta);  // true
adultsModel.has(alpha); // true
adultsModel.has(beta);  // false
beta.setAge(18);
adultsModel.has(beta);  // true
adultsModel.length      // 2
beta.setAge(17);
adultsModel.has(beta);  // false

The adultsModel subset has the same interface as a set and can be used as the model object of a maria.SetView, for example.

Downloads

See http://peter.michaux.ca/downloads/maria-SubsetModel/

Status

Ready.

Browser Support

Tested working in IE6 and newer browsers by a variety of manufacturers.

Dependencies

Just Maria.

Source Code

GitHub: https://github.com/petermichaux/maria-SubsetModel

Build

To build the production ready files, you need JSMin or any other tool with the same command line interface. Then just type "make" at the command line and look in the build directory for the results.

For the record, this is how I installed JSMin. Note that I have /Users/peter/bin in my PATH.

$ cd ~/tmp
$ curl -O https://raw.github.com/douglascrockford/JSMin/master/jsmin.c
$ gcc -o jsmin jsmin.c
$ mv jsmin ~/bin
$ rm jsmin.c
$ which jsmin
/Users/peter/bin/jsmin

Tests

To run the automated tests, open tst/runner.html in a web browser.

Author

Peter Michaux
petermichaux@gmail.com
http://peter.michaux.ca/
@petermichaux

License

Simplified BSD License. See the included LICENSE file for details.

petermichaux / maria-SubsetModel