developing Core requirement

Input Constraints Used

Group: interactive-components • Guideline: control-information

Summary in Plain English

The constraints and conditions on a field - required format, length, allowed values - are made available to the user.

Why It Matters

Constraints discovered only by failing are a guessing game, which is costly for people with cognitive disabilities and for anyone whose input is slow or effortful.

Examples from the Draft

Worked examples the W3C editors wrote into the provision itself, not examples invented here.

required line length
date format
password format

Test Procedure from the W3C Draft

Quoted from the provision's informative document, informative/guidelines/interactive-components/control-information/input-constraints-used.md. It is the group's own procedure, not an editorial testing guide.

Procedure

For each input:

Confirm it has a visual information that describes the constraint.
Inspect the code and accessibility tree (when applicable) and confirm that the constraint is programmatically listed in the code and associated with the input.

Expected results

#1 and #2 are true.

Methods Suggested Upstream

Implementation methods listed in the informative document.

HTML: To programmatically indicate, use the pattern attribute or write the information in a label; to visually indicate, add the requirements to the page near the input.

Recommended Practices (Upstream)

The constraints remain persistent.

W3C Raw Source Text

Verbatim from guidelines/groups/interactive-components/control-information/input-constraints-used.md · informative document: informative/guidelines/interactive-components/control-information/input-constraints-used.md

Field constraints and conditions are available.

:::example
* required line length
* date format
* password format
:::