ICU MessageFormat for Dynamic Component Strings

[leagrdv]

Context

Dynamic strings in components are currently handled inconsistently, making localization and translation more difficult—especially when dealing with pluralization, gender, or language-specific word order.

Decision

All component strings that require partial replacement must use the ICU MessageFormat (Unicode standard).

This applies to:

• Component properties (e.g. labels, aria texts, helper texts)
• Any user-facing string with interpolated variables

Consequences

• More consistent handling of dynamic text
• Better support for localization and translation workflows
• Requires familiarity with ICU MessageFormat syntax and potential refactoring of existing strings

Example

<post-stepper
  textCompletedStep="Completed step"
  textCurrentStep="Current step"
  textStepNumber="Step {number}:"
  [currentIndex]="1"
>
  <post-stepper-item>Step 1</post-stepper-item>
  <post-stepper-item>Step 2</post-stepper-item>
  <post-stepper-item>Step 3</post-stepper-item>
  <post-stepper-item>Step 4</post-stepper-item>
</post-stepper>

"Step {current} of {total}"