Featurevisor module

Featurevisor module connects Messagevisor feature and experiment conditions to an existing Featurevisor SDK instance.

Install#

$ npm install --save \
    @messagevisor/sdk \
    @messagevisor/module-featurevisor \
    @featurevisor/sdk

SDK setup#

Create your Featurevisor instance first, then pass it to the Messagevisor module:

import { createInstance } from "@featurevisor/sdk";
import { createMessagevisor } from "@messagevisor/sdk";
import { createFeaturevisorModule } from "@messagevisor/module-featurevisor";
const f = createInstance({
  datafile: featurevisorDatafile,
});
const m = createMessagevisor({
  datafile: messagevisorDatafile,
  modules: [
    createFeaturevisorModule({
      instance: f,
      // passContext: true, // `false` by default
    }),
  ],
});

The module registers resolvers on the Messagevisor SDK instance:

• feature conditions call f.isEnabled(featureKey)
• experiment conditions call f.getVariation(experimentKey)

By default, Messagevisor does not pass its own evaluation context to Featurevisor. Enable passContext when you want Messagevisor's SDK-level and per-call context to be forwarded to Featurevisor evaluations.

Feature conditions#

Use feature conditions when a translation override should follow a Featurevisor flag:

translations:
  en: Checkout
overrides:
  - key: new-checkout
    conditions:
      feature: new-checkout
      operator: isEnabled
    translations:
      en: Faster checkout

You can also match when the flag is disabled:

overrides:
  - key: classic-checkout
    conditions:
      feature: new-checkout
      operator: isDisabled
    translations:
      en: Classic checkout

Experiment conditions#

Use experiment conditions when copy should follow the active Featurevisor variation:

translations:
  en: Continue
overrides:
  - key: bold-copy
    conditions:
      experiment: checkout-copy
      operator: hasVariation
      value: bold
    translations:
      en: Try the faster checkout

The experiment key maps to the Featurevisor feature key passed to getVariation. If Featurevisor returns null, the condition does not match.

Context#

By default, the module relies on context already configured on the Featurevisor instance. Messagevisor context is not forwarded:

const m = createMessagevisor({
  datafile: messagevisorDatafile,
  context: {
    platform: "web",
  },
  modules: [createFeaturevisorModule({ instance: f })],
});

Set passContext: true when Featurevisor should receive Messagevisor's combined SDK-level and per-call context:

const m = createMessagevisor({
  datafile: messagevisorDatafile,
  context: {
    platform: "web",
  },
  modules: [createFeaturevisorModule({ instance: f, passContext: true })],
});
m.translate("checkout.title", {}, {
  context: {
    userId: "user-123",
  },
});

With passContext: true, Featurevisor receives { platform: "web", userId: "user-123" } for the flag or variation evaluation.

Edge cases and behavior notes#

Keys map directly#

Messagevisor passes the authored feature or experiment key directly to Featurevisor.

Module order usually does not matter#

This module registers condition resolvers during setup. It does not format or transform message output, so it can usually be placed before or after formatting modules.

No resolver means no match#

Without this module, or another resolver integration, Messagevisor feature and experiment conditions evaluate as non-matches.

Related#

• Modules
• Conditions
• Overrides
• SDKs