PHP

Installation

Install the tggl/client package:

composer require tggl/client

Quick start

Instantiate a client with your API key and call evalContext to evaluate a context. A single API call evaluating all flags is performed, making all subsequent flag checking methods extremely fast.

This means that you do not need to cache results of isActive and get since they do not trigger an API call, they simply look up the data in the already fetched response.

use Tggl\Client\TgglClient;
 
// Some class to represent your context
class Context {
  $userId;
  $email;
}
 
$client = new TgglClient('YOUR_API_KEY');
 
// An API call to Tggl is performed here
$flags = $client->evalContext(new Context());
 
if ($flags->isActive('my-feature')) {
  // ...
}
 
if ($flags->get('my-feature') === 'Variation A') {
  // ...
}

Evaluating contexts in batches

If you have multiple contexts to evaluate at once, you can batch your calls in a single HTTP request which is much more performant:

$result = await $client->evalContexts([
  new Context('foo')
  new Context('bar')
]);
 
// Responses are returned in the same order
$fooFlags = $result[0];
$barFlags = $result[1];

isActive vs get

By design, you have no way of telling apart an inactive flag, a non-existing flag, a deleted flag, or a network error. This design choice prevents anything from breaking your app by just deleting a flag, messing up the API key rotation, or any other unforeseen event, it will simply consider any flag to be inactive.

get gives you the value of an active flag, and this value may be "falsy" (null, false, 0, or empty string), leading to unexpected behaviors:

if ($flags.get('my-feature')) {
  // If 'my-feature' is active, but its value is falsy this block won't be executed
}
 
if ($flags.isActive('my-feature')) {
  // Even if 'my-feature' has a falsy value, this block will be executed
}

Evaluate flags locally

It is possible to evaluate flags locally on the server but not recommended unless you have performance issues evaluating flags at a high frequency. Evaluating flags locally forces you to maintain the copy of flags configuration up to date and might be a source of issues.

use Tggl\Client\TgglLocalClient;
 
$client = new TgglLocalClient('YOUR_SERVER_API_KEY');
 
// This method performs an API call and updates the flags configuration
$client->fetchConfig();
 
// Evaluation is performed locally
$client->isActive(new Context(), 'my-feature')
 
// You can also get the value of a flag, with and without default value
$client->get(new Context(), 'my-feature')
$client->get(new Context(), 'my-feature', 42)

When evaluating flags locally it is your responsibility to keep the configuration up to date by calling fetchConfig when needed. You can use webhooks to be notified when the configuration changes.

You can cache the configuration and instantiate the client with the cached version, so you don't need to call fetchConfig:

$cachedConfig = $client->fetchConfig();
 
// Create another client with the cached config
$client = new TgglLocalClient('YOUR_SERVER_API_KEY', [
  'config' => $cachedConfig
]);