[sethbattin]

This change checks window.location for query parameters to override LD service data.

Usage

Enabling Boolean Feature Flags

You can enable a set of boolean feature flags with a comma-delimited list in the features query parameter:

POST /users?features=send-onboarding-email
# Overrides the `send-onboarding-email` boolean feature flag, setting it to `true`
GET /users/101?features=show-user-email,user-nicknames,hide-inactive-users
# Enables the `show-user-email`, `user-nicknames`, and `hide-inactive-users` feature flags

Advanced Feature Flag Overriding

If you need to temporarily set a boolean feature flag to false or override the variation reported by a multivariate feature flag, you can use features.{feature_flag} query parameters:

POST /users?features.verify-email=false&features.email-frequency=weekly
# Disables the `verify-email` feature flag and sets the `email-frequency` variation to "weekly"

The values "true" and "false" are converted into true and false boolean values. If the query parameter value is omitted, then the feature flag will be reported as enabled:

GET /users/101?features.show-user-email
# Enables the `show-user-email` feature flag

Missing features

• Changes are not "sticky"; query param overrides must be included in every request.
• Edits to this component do not propagate through hot module reloading; gluestick restart is required
• Query parameters are not passed to backend calls [followup issue here]
• New code test coverage

Example

This is how I tested the feature:

// /src/components/Home.js
/* @flow */
import React, { Component } from "react";
import { FeatureFlag } from "react-launch-darkly";

export default class Home extends Component {
  render () {
    return (
      <div>
        <div>Home</div>
        <FeatureFlag
          flagKey="test-key"
          renderFeatureCallback={this._renderFeature}
          renderDefaultCallback={this._renderDefault}
        />
      </div>
    );
  }
  _renderFeature () {
    return (
      <div>I'm a new feature1111</div>
    );
  }
  _renderDefault() {
    return (
      <div>I'm NOT a new feature223</div>
    )
  }
}

// /src/components/MasterLayout.js
/* @flow */
import React, { Component, PropTypes } from "react";
import Helmet from "react-helmet";
import config from "../config/application";
import { LaunchDarkly } from "react-launch-darkly";


export default class MasterLayout extends Component {
  static propTypes = {
    children: PropTypes.any
  };

  render () {
    return (
      <div>
        <Helmet {...config.head}/>
        <LaunchDarkly {...config.launchDarkly} >
          {this.props.children}
        </LaunchDarkly>
      </div>
    );
  }
}

// /src/config/application.js
// ...
const config = {
  development: {
// ....
    launchDarkly: {
      clientId: "local",
      user: {
        key: "myuserkey"
      }
    }
  },
//....

[jacobmoretti]

Looks good so far! Just a few comments. I think its missing a piece of functionality. Also, whats the current state of the tests? I saw comments left in so wasn't sure.

[jacobmoretti]

This link should be removed and include general guidance on how the query params should be formatted. Since its a link to our enterprise github, its not available for the public and doesn't provide any value for anyone but us.

[jacobmoretti]

This works for supporting the advanced overriding, e.g., ?features.flagA=true but I'm not seeing support for the basic list of boolean flags, e.g., ?features=flagA,flagB,flagC.

[sethbattin]

You are right and I will fix that.

[sethbattin]

@jacobmoretti I added the basic override cases, and I inlined the spec

[jacobmoretti]

Minor nitpick but instead of escaping the double quotes here, lets just use single quotes or backticks.

[jacobmoretti]

@sethbattin Ok, ignore my previous comment. I just added travis-ci. So far changes look good to me, there are just lint issues right now: yarn lint.

[sethbattin]

@jacobmoretti looks like I don't have write access, so I can't merge. If you're still good with it, would you check it off for me?

[jacobmoretti]

@sethbattin Thanks, merged!