README

The Hoa project was archived, and no upgrades or patches are neither provided nor accepted by merge requests.

HOA Packages include some code that is Deprecated for PHP 8.0 and PHP 8.1, but we needed these packages to run on modern PHP versions.

What's changed in from?

The changes mainly affected the return data type hinting in methods declaration, access to uninitialized properties.

How to use

We've currently forked the following packages, primarily to make hoa/ruler work with PHP 8.1:

If you use someone's package, that requires hoa – simply add forks to your project root composer.json: we have marked forks as a replacement, so composer will install them instead of the original packages.

Versions

We've forked from the latest hoa package versions and bump own versions starting from 1.0.

Testing

Before running the test suites, the development dependencies must be installed:

$ composer install

Then, to run all the test suites:

$ vendor/bin/hoa test:run

For more information, please read the contributor guide.

Quick usage

As a quick overview, we propose to see a very simple example that manipulates a simple rule with a simple context. After, we will add a new operator in the rule. And finally, we will see how to save a rule in a database.

Three steps

So first, we create a context with two variables: group and points, and we then assert a rule. A context holds values to concretize a rule. A value can also be the result of a callable. Thus:

$ruler = new Hoa\Ruler\Ruler();

// 1. Write a rule.
$rule  = 'group in ["customer", "guest"] and points > 30';

// 2. Create a context.
$context           = new Hoa\Ruler\Context();
$context['group']  = 'customer';
$context['points'] = function () {
    return 42;
};

// 3. Assert!
var_dump(
    $ruler->assert($rule, $context)
);

/**
 * Will output:
 *     bool(true)
 */

In the next example, we have a User object and a context that is populated dynamically (when the user variable is concretized, two new variables, group and points are created). Moreover, we will create a new operator/function called logged. There is no difference between an operator and a function except that an operator has two operands (so arguments).

Adding operators and functions

For now, we have the following operators/functions by default: and, or, xor, not, = (is as an alias), !=, >, >=, <, <=, in and sum. We can add our own by different way. The simplest and volatile one is given in the following example. Thus:

// The User object.
class User
{
    const DISCONNECTED = 0;
    const CONNECTED    = 1;

    public $group      = 'customer';
    public $points     = 42;
    protected $_status = 1;

    public function getStatus()
    {
        return $this->_status;
    }
}

$ruler = new Hoa\Ruler\Ruler();

// New rule.
$rule  = 'logged(user) and group in ["customer", "guest"] and points > 30';

// New context.
$context         = new Hoa\Ruler\Context();
$context['user'] = function () use ($context) {
    $user              = new User();
    $context['group']  = $user->group;
    $context['points'] = $user->points;

    return $user;
};

// We add the logged() operator.
$ruler->getDefaultAsserter()->setOperator('logged', function (User $user) {
    return $user::CONNECTED === $user->getStatus();
});

// Finally, we assert the rule.
var_dump(
    $ruler->assert($rule, $context)
);

/**
 * Will output:
 *     bool(true)
 */

Also, if a variable in the context is an array, we can access to its values from a rule with the same syntax as PHP. For example, if the a variable is an array, we can write a[0] to access to the value associated to the 0 key. It works as an hashmap (PHP array implementation), so we can have strings & co. as keys. In the same way, if a variable is an object, we can call a method on it. For example, if the a variable is an array where the value associated to the first key is an object with a foo method, we can write: a[0].foo(b) where b is another variable in the context. Also, we can access to the public attributes of an object. Obviously, we can mixe array and object accesses. Please, take a look at the grammar (hoa://Library/Ruler/Grammar.pp) to see all the possible constructions.

Saving a rule

Now, we have two options to save the rule, for example, in a database. Either we save the rule as a string directly, or we will save the serialization of the rule which will avoid further interpretations. In the next example, we see how to serialize and unserialize a rule by using the Hoa\Ruler\Ruler::interpret static method:

$database->save(
    serialize(
        Hoa\Ruler\Ruler::interpret(
            'logged(user) and group in ["customer", "guest"] and points > 30'
        )
    )
);

And for next executions:

$rule = unserialize($database->read());
var_dump(
    $ruler->assert($rule, $context)
);

When a rule is interpreted, its object model is created. We serialize and unserialize this model. To see the PHP code needed to create such a model, we can print the model itself (as an example). Thus:

echo Hoa\Ruler\Ruler::interpret(
    'logged(user) and group in ["customer", "guest"] and points > 30'
);

/**
 * Will output:
 *     $model = new \Hoa\Ruler\Model();
 *     $model->expression =
 *         $model->and(
 *             $model->func(
 *                 'logged',
 *                 $model->variable('user')
 *             ),
 *             $model->and(
 *                 $model->in(
 *                     $model->variable('group'),
 *                     [
 *                         'customer',
 *                         'guest'
 *                     ]
 *                 ),
 *                 $model->{'>'}(
 *                     $model->variable('points'),
 *                     30
 *                 )
 *             )
 *         );
 */

Have fun!

Documentation

The hack book of Hoa\Ruler contains detailed information about how to use this library and how it works.

To generate the documentation locally, execute the following commands:

$ composer require --dev hoa/devtools
$ vendor/bin/hoa devtools:documentation --open

More documentation can be found on the project's website: hoa-project.net.

Getting help

There are mainly two ways to get help:

• On the #hoaproject IRC channel,
• On the forum at users.hoa-project.net.

Contribution

Do you want to contribute? Thanks! A detailed contributor guide explains everything you need to know.

License

Hoa is under the New BSD License (BSD-3-Clause). Please, see LICENSE for details.

Related projects

The following projects are using this library:

• RulerZ, Powerful implementation of the Specification pattern in PHP,
• ownCloud, A safe home for all your data,
• PhpMetrics, Static analysis tool for PHP,
• hiqdev/php-billing, a billing library in PHP
• atoum/ruler-extension, This extension allows to filter test results in atoum.