Messagevisor

Internal concepts

Evaluation

Evaluation is the part of Messagevisor where authored definitions turn into actual runtime results. This includes translation lookup, raw-message formatting, segment matching, format resolution, and module execution.

Main evaluation modes

There are three practical evaluation surfaces:

  • message-key evaluation
  • raw-message evaluation
  • segment evaluation

Message-key evaluation

This uses a real message key from your project.

Examples:

  • SDK translate(messageKey, values, options)
  • CLI evaluate --message=...
  • message tests
  • target tests using message

This path depends on:

  • the built datafile
  • target inclusion/exclusion
  • locale inheritance
  • target context simplification
  • runtime context
  • modules

Raw-message evaluation

This evaluates a literal string through the runtime modules for a locale.

Examples:

  • SDK formatMessage(rawMessage, values, options)
  • CLI evaluate --rawMessage=...
  • locale tests using rawMessage
  • target tests using rawMessage
  • locale examples with rawMessage, which can be inspected with npx messagevisor examples --onlyLocales and in the generated Catalog

Use this when you want to inspect runtime formatting behavior without creating or referencing a real message key.

Segment evaluation

This answers one question: does this segment match the supplied context?

Examples:

  • CLI evaluate --segment=...
  • segment tests

This is the cleanest path when you are debugging conditional logic before layering message behavior on top.

Evaluation inputs

Depending on the surface, evaluation can use:

  • locale
  • target
  • context
  • values
  • currency
  • timeZone
  • formats
  • module options

Precedence and layering

Evaluation behavior usually follows this shape:

  1. authored definitions
  2. built target+locale datafile
  3. SDK instance state
  4. per-call evaluation overrides
  5. module execution

This is why it is so useful to keep examples, tests, and SDK usage aligned: they all help you inspect the same layered behavior.

Runtime context vs target context

This distinction matters a lot:

  • target context shapes the built artifact ahead of runtime
  • runtime context is supplied when evaluation happens

If something seems to disappear before runtime, target context is often the reason.

Missing translations

When a known message key is absent from a built target datafile, Messagevisor follows the normal SDK missing-translation behavior instead of inventing a special target-only evaluation model.

That keeps:

aligned with one another.

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