README

Stateless rule engine to assert statements given a context.

Install

$ composer require "subzeta/ruling" : "^2.0"

Usage example

require '/path/to/vendor/autoload.php';

use subzeta\Ruling\Ruling;

$my = new \stdClass();
$my->sensitivity = 80;
$my->joyfulness = 10;

(new Ruling())
    ->given([
        'sensitivity' => $my->sensitivity,
        'joyfulness' => $my->joyfulness
    ])->when(
        ':sensitivity is greater than 90 or :joyfulness is less than 20'
    )->then(function() {
        echo 'Hell yeah, I should listen music right now!';
    })->otherwise(function() {
        echo 'I\'m happy enough, thanks.';
    })->execute();

// Outputs: Hell yeah, I should listen music right now!

Calls

There are three main entrances:

interpret

Returns the interpreted rules. Using the example above the output would be: ['80 > 90 || 10 < 20']

assert

Returns a boolean indicating the output. Using the example above the output would be: true

execute

Fires the success or fail callback if defined. Using the example above the output would be: 'Hell yeah, I should listen it!'

Error handling

Different types of exceptions are thrown when something goes wrong:

InvalidContextException

When the provided context isn't valid (accepts: ['string-key-1' => value-1, ..., 'string-key-x' => value-x]).

InvalidRuleException

When the provided rules aren't valid (accepts: 'string' or ['string-1', ..., 'string-x'])

InvalidCallbackException

When the provided success/fail callback isn't callable (accepts: function(){return 'Hey Ho! Let's go!';})

Supported Operators

Notes

It's not necessary to provide callbacks for execute method, it will return a boolean instead as assert does.
Rules respect the operator precedence and evaluate the parenthesis from right to left.

Testing

$ phpunit

Recursive to do list

Increase the number of unit tests to prevent bad contexts or bad formatted rules from being executed.

To do

Improve the interpreted method response.

Changelist

Allow aliases ("is equal to" can be written as "is" and "is not equal to" as "is not"/"isn't").
Context values may permit callable functions too.
Added the strict comparison operators (same as, not same as).
It can be interesting to implement a kind of dump method to show the interpreted rule.
Added the "in" operator.
Context accepts array values.

License

MIT

subzeta / ruling

Maintainers

Details