This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The allowsFeature()
method of the FeaturePolicy
interface enables introspection of individual directives of the Feature Policy it is run on. It returns a Boolean
that is true
if and only if the specified feature is allowed in the specified context (or the default context if no context is specified).
Syntax
const allowed = FeaturePolicy.allowsFeature(<feature>)
or
const allowed = FeaturePolicy.allowsFeature(<feature>, <origin>)
Parameters
Feature name
A specific feature name must be specified.
Origin name
Optional
An origin URL to check the feature on. If it is omitted the default origin is used.
Return value
A Boolean
that is true
if and only if the feature is allowed.
Example
The following example queries whether or not the document is allowed to use camera API by the Feature Policy. Please note that Camera API might be restricted by the Permissions API, if the user did not grant the corresponding permission yet.
// First, get the Feature Policy object const featurePolicy = document.featurePolicy // Then query feature for specific const allowed = featurePolicy.allowsFeature("camera") if (allowed){ console.log("FP allows camera.") } else { console.log("FP does not allows camera.") }
Specifications
Specification | Status | Comment |
---|---|---|
Feature Policy The definition of 'allowsFeature' in that specification. |
Editor's Draft | Initial definition. |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
allowsFeature | Chrome
Full support
74
| Edge Full support 79 | Firefox
Full support
65
| IE No support No | Opera
Full support
62
| Safari No support No | WebView Android Full support 74 | Chrome Android
Full support
74
| Firefox Android
Full support
65
| Opera Android
Full support
48
| Safari iOS No support No | Samsung Internet Android Full support 11.0 |
Legend
- Full support
- Full support
- No support
- No support
- Experimental. Expect behavior to change in the future.
- Experimental. Expect behavior to change in the future.
- User must explicitly enable this feature.
- User must explicitly enable this feature.