v143 · menu elements
Commands, checkboxes and radios
Half of what a menu contains is not an action but a setting: a view that is on, a mode that is one of three. The proposal handles both with the same element, and the vocabulary it uses is reflected back through IDL — so you can ask this browser exactly which parts it has.
The command vocabulary, by reflection
An enumerated IDL attribute reads back the empty string for a keyword it does not recognise. That makes the reflection a support probe for each individual command, not just for the attribute as a whole.
| command | reads back as | recognised? | what it does |
|---|
A custom command must begin with two dashes. That is not decoration: it is the rule that lets the platform add built-in commands later without colliding with an application's own, and a name without the dashes is discarded rather than passed through.
Items that carry state
What is missing here
| piece | present? | consequence |
|---|