README

Simple feature flag checking for PHP >=5.5.

Installation

Install this package in your application using composer.

In the require section, add the following dependency:

"fraserreed/feature-flag": "~0.2"

Usage

Any of these approaches can be extended and put in a view helper in most frameworks.

Static Configuration

For static, array based feature flags, ideally used in multi-environment deploys.

First create the static filter:

$config = [
    'feature-one'   => true,
    'feature-two'   => false,
    'feature-three' => true,
    'feature-four'  => true
];

$featureFlagFilter = new \FeatureFlag\Filter\Simple( $config );

Then assert that a feature is enabled or not:

$featureFlag = new \FeatureFlag\FeatureFlag( $featureFlagFilter );

echo (int) $featureFlag->isEnabled( 'feature-one' ) . " should be true\n";
echo (int) $featureFlag->isEnabled( 'feature-two' ) . " should be false\n";
echo (int) $featureFlag->isEnabled( 'feature-three' ) . " should be true\n";
echo (int) $featureFlag->isEnabled( 'feature-four' ) . " should be true\n";
echo (int) $featureFlag->isEnabled( 'feature-five' ) . " should be false (doesn't exist)\n";

Distributed IP Address Weighting

For an expected distribution across the IPv4 spectrum, a weighted configuration can be used. A crc32 hash checksum is computed for the IP, modulo 100.

First create the filter with the expected distribution factor.

//feature flag will be enabled 75% of the time
$featureFlagFilter = new \FeatureFlag\Filter\DistributedIp( 75 );

Then assert that a feature is enabled or not:

$featureFlag = new \FeatureFlag\FeatureFlag( $featureFlagFilter );

echo (int) $featureFlag->isEnabled( 'feature-one', '192.168.0.161' ) . " should be false\n";
echo (int) $featureFlag->isEnabled( 'feature-one', '31.12.127.255' ) . " should be true\n";
echo (int) $featureFlag->isEnabled( 'feature-one', '46.248.224.183' ) . " should be true\n";
echo (int) $featureFlag->isEnabled( 'feature-one', '58.136.218.102' ) . " should be true\n";

Tests

To run the tests you'll need to have phpunit installed.

Running the tests:

$ phpunit

Contributing

For any issues, submit an issue via this repo. For contributing please fork and submit PRs.

License

MIT, see LICENSE.