My Personal Best Practices For Using LaunchDarkly Feature Flags

snippet-1.cfm

<cfscript>

	public void function someControllerMethod( rc ) {

		if ( shouldUseProjectLoadTimeExperiment( rc.user.id ) ) {

			// .... experimental code.
			return;

		}

		// .... normal code.

	}

	// ---
	// PRIVATE METHODS.
	// ---

	private boolean function shouldUseProjectLoadTimeExperiment( userID ) {

		return( featureFlagService.getFeatureByUserID( userID, "performance-RAIN-1337-project-list-load-time" ) );

	}

</cfscript>

snippet-2.js

app.controller(
	"MyController",
	function( $scope, config ) {

		// ....
		$scope.shouldShowHotNewFeature = !! config.featureFlags[ "product-RAIN-007-hot-new-feature" ];
		// ....

	}
);

snippet-3.html

<ul class="nav">
	<li>
		<a href="#/home">Home</a>
	</li>
	<li>
		<a href="#/about">About</a>
	</li>
	<li>
		<a href="#/contact">Contact</a>
	</li>
	<li ng-if="shouldShowHotNewFeature">
		<a href="#/hawtness">Hawtness</a>
	</li>
</ul>

snippet-4.jsx

render() {

	return(
		<Badge>
			<Avatar
				imageUrl={ this.user.imageUrl }
				useLazyLoading={ this.featureFlags[ "performance-RAIN-123-lazy-loading-images" ] }
			/>
			{ this.user.name }
		</Badge>
	);

}

snippet-5.ts

class Avatar {

	private useLazyLoading: boolean;

	constructor( featureFlags: FeatureFlags ) {

		this.useLazyLoading = !! featureFlags[ "performance-RAIN-123-lazy-loading-images" ];

	}

	// ....

}

snippet-6.cfc

component {

	public struct function doSomething() {

		// ....

		if ( shouldUseSqlExperiment( userID ) ) {

			dataAccess.getDataWithOptimization( userID );

		} else {

			dataAccess.getData( userID );

		}

		// ....

	}

	// ---
	// PRIVATE METHODS.
	// ---

	private boolean function shouldUseSqlExperiment( userID ) {

		return( featureFlags.getFeatureByUserID( userID, "performance-RAIN-123-sql-optimization" ) );

	}
}

snippet-6.cfm

component {

	public struct function doSomething() {

		// ....

		if ( shouldUseSqlExperiment( userID ) ) {

			dataAccess.getDataWithOptimization( userID );

		} else {

			dataAccess.getData( userID );

		}

		// ....

	}

	// ---
	// PRIVATE METHODS.
	// ---

	private boolean function shouldUseSqlExperiment( userID ) {

		return( featureFlags.getFeatureByUserID( userID, "performance-RAIN-123-sql-optimization" ) );

	}
}

snippet-7.cfc

component {

	public struct function doSomething() {

		if ( shouldUseMoreRobustExperiment( userID ) ) {

			return( doSomethingWithOptimization() );

		}

		// ....

	}

	public struct function doSomethingWithOptimization() {

		// ....

	}

	// ---
	// PRIVATE METHODS.
	// ---

	private boolean function shouldUseMoreRobustExperiment( userID ) {

		return( featureFlags.getFeatureByUserID( userID, "performance-RAIN-123-more-robust-optimization" ) );

	}
}

snippet-7.cfm

component {

	public struct function doSomething() {

		if ( shouldUseMoreRobustExperiment( userID ) ) {

			return( doSomethingWithOptimization() );

		}

		// ....

	}

	public struct function doSomethingWithOptimization() {

		// ....

	}

	// ---
	// PRIVATE METHODS.
	// ---

	private boolean function shouldUseMoreRobustExperiment( userID ) {

		return( featureFlags.getFeatureByUserID( userID, "performance-RAIN-123-more-robust-optimization" ) );

	}
}

snippet-8.cfc

component {

	public void function api_end_point( requestContext ) {

		if ( shouldUseMoreRobustExperiment( userID ) ) {

			requestContext.data = optimizedService.doSomething();
			return;

		}

		requestContext.data = service.doSomething();

	}

	// ---
	// PRIVATE METHODS.
	// ---

	private boolean function shouldUseMoreRobustExperiment( userID ) {

		return( featureFlags.getFeatureByUserID( userID, "performance-RAIN-123-more-robust-optimization" ) );

	}
}

snippet-8.cfm

component {

	public void function api_end_point( requestContext ) {

		if ( shouldUseMoreRobustExperiment( userID ) ) {

			requestContext.data = optimizedService.doSomething();
			return;

		}

		requestContext.data = service.doSomething();

	}

	// ---
	// PRIVATE METHODS.
	// ---

	private boolean function shouldUseMoreRobustExperiment( userID ) {

		return( featureFlags.getFeatureByUserID( userID, "performance-RAIN-123-more-robust-optimization" ) );

	}
}