What is it?

Isa is an odd little extension for Zend_Db_Table that offers named scopes.

How do I use it?

Toss vendor/Isa in your vendor folder and have your table classes extend from Isa_TableAbstract. Isa expects a PSR-0 style autoloader (PEAR, Zend, etc).

Define a scope

Scopes are just defined as methods within your table class. There are two rules:

1. Follow the naming convention "_is".
2. Within your scope, use the scope() method instead of Zend_Db_Table's select()

A simple example:

class Table_Person extends Isa_TableAbstract {
    protected function _isLeader() {
        $this->scope()->where('leader = ?', 1);    
    }
    
    protected function _isFemale() {
        $this->scope()->where('gender = ?', 'f');
    }
}

Use a scope

The easiest way to fetch records is Isa's overloading of __call.

$tablePerson = new Table_Person();
$tablePerson->isLeader(); //returns a rowset with all leaders

You can also use the is() function, like so:

$tablePerson->is('leader');

Chain scopes

The is() function can also merge scopes together:

$tablePerson->is('leader', 'female'); //returns all female leaders

Scopes with params

Scope functions can also have parameters:

//In your table class:
protected function _isOfGender($gender) {
    $this->scope()->where('gender = ?', $gender);
}

//When you use it singly:
$tablePerson->isOfGender('f');

The syntax changes a bit when using the is() function:

//The scope name is the first element of the array
$tablePerson->is(array('isOfGender', 'm'));

This isn't so useful when using one scope, but it's more for composing several:

//Fetches all female zombie leaders
$tablePerson->is('leader', 'zombie', array('ofGender', 'f'));

Default scope

If you define a scope called "_isDefaultScope", it will be automatically applied to every scope query you make. The main use cases are invariants like soft deletes, for instance.

Todo

• Accept scopes in a single array (applying scopes as filters in a search)
• Optionally return the select object instead of fetching
• Formalize composite scopes
• ?Cross table support for relations
• ?Move the scoping into an extended select object

About

Thanks to Michiel van Leening and Jan Wolters.