Rule engine
Stateless rule engine to assert statements given a context., (*1)
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:, (*2)
interpret
Returns the interpreted rules.
Using the example above the output would be: ['80 > 90 || 10 < 20'], (*3)
assert
Returns a boolean indicating the output.
Using the example above the output would be: true, (*4)
execute
Fires the success or fail callback if defined.
Using the example above the output would be: 'Hell yeah, I should listen it!', (*5)
Error handling
Different types of exceptions are thrown when something goes wrong:, (*6)
InvalidContextException
When the provided context isn't valid (accepts: ['string-key-1' => value-1, ..., 'string-key-x' => value-x])., (*7)
InvalidRuleException
When the provided rules aren't valid (accepts: 'string' or ['string-1', ..., 'string-x']), (*8)
InvalidCallbackException
When the provided success/fail callback isn't callable (accepts: function(){return 'Hey Ho! Let\'s go!';}), (*9)
Supported Operators
| Type |
Operator |
Representation |
| Comparison |
is greater than |
> |
| Comparison |
is greater or equal to |
>= |
| Comparison |
is less than |
< |
| Comparison |
is less or equal to |
<= |
| Comparison |
is equal to (alias: is) |
== |
| Comparison |
is not equal to (aliases: is not, isn't) |
!= |
| Comparison |
same as |
=== |
| Comparison |
not same as |
!== |
| Logical |
and |
&& |
| Logical |
or |
|\ |
| Containment |
contained in (alias: in) |
in |
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, (*10)
Wallogit.com
