This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The StylePropertyMapReadOnly
interface of the the CSS Typed Object Model API provides a read-only representation of a CSS declaration block that is an alternative to CSSStyleDeclaration
. Retrieve an instance of this interface using Element.computedStyleMap()
.
Properties
StylePropertyMapReadOnly.size
- Returns an unsinged long integer containing the size of the
StylePropertyMapReadOnly
object.
Methods
StylePropertyMapReadOnly.entries()
- Returns an array of a given object's own enumerable property
[key, value]
pairs, in the same order as that provided by afor...in
loop (the difference being that a for-in loop enumerates properties in the prototype chain as well). StylePropertyMapReadOnly.forEach()
- Executes a provided function once for each element of
StylePropertyMapReadOnly
. StylePropertyMapReadOnly.get()
- Returns the value of the specified property.
StylePropertyMapReadOnly.getAll()
- Returns an array of
CSSStyleValue
objects containing the values for the provided property. StylePropertyMapReadOnly.has()
- Indicates whether the specified property is in the
StylePropertyMapReadOnly
object. StylePropertyMapReadOnly.keys()
- Returns a new Array Iterator containing the keys for each item in
StylePropertyMapReadOnly
. StylePropertyMapReadOnly.values()
- Returns a new Array Iterator containing the values for each index in the
StylePropertyMapReadOnly
object.
Examples
We have to have an element to observe:
<p> This is a paragraph with some text. We can add some CSS, or not. The style map will include all the default and inherted CSS property values. </p> <dl id="output"></dl>
We add a touch of CSS with a custom property to better demonstrate the output:
p { --someVariable: 1.6em; --someOtherVariable: translateX(33vw); --anotherVariable: 42; line-height: var(--someVariable); }
We add JavaScript to grab our paragraph and return back a definition list of all the default CSS property values using computedStyleMap().
// get the element const myElement = document.querySelector('p'); // get the <dl> we'll be populating const stylesList = document.querySelector('#output'); // Retrieve all computed styles with computedStyleMap() const stylePropertyMap = myElement.computedStyleMap(); // iterate thru the map of all the properties and values, adding a <dt> and <dd> for each for (const [prop, val] of stylePropertyMap) { // properties const cssProperty = document.createElement('dt'); cssProperty.appendChild(document.createTextNode(prop)); stylesList.appendChild(cssProperty); // values const cssValue = document.createElement('dd'); cssValue.appendChild(document.createTextNode(val)); stylesList.appendChild(cssValue); }
Specifications
Specification | Status | Comment |
---|---|---|
CSS Typed OM Level 1 The definition of 'StylePropertyMapReadOnly' in that specification. |
Working Draft | Initial definition. |
Browser compatibility
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
StylePropertyMapReadOnly | Chrome Full support 66 | Edge Full support 79 | Firefox No support No | IE No support No | Opera Full support 53 | Safari No support No | WebView Android Full support 66 | Chrome Android Full support 66 | Firefox Android No support No | Opera Android Full support 47 | Safari iOS No support No | Samsung Internet Android Full support 9.0 |
entries | Chrome Full support 66 | Edge Full support 79 | Firefox No support No | IE No support No | Opera Full support 53 | Safari No support No | WebView Android Full support 66 | Chrome Android Full support 66 | Firefox Android No support No | Opera Android Full support 47 | Safari iOS No support No | Samsung Internet Android Full support 9.0 |
forEach | Chrome Full support 66 | Edge Full support 79 | Firefox No support No | IE No support No | Opera Full support 53 | Safari No support No | WebView Android Full support 66 | Chrome Android Full support 66 | Firefox Android No support No | Opera Android Full support 47 | Safari iOS No support No | Samsung Internet Android Full support 9.0 |
get | Chrome Full support 66 | Edge Full support 79 | Firefox No support No | IE No support No | Opera Full support 53 | Safari No support No | WebView Android Full support 66 | Chrome Android Full support 66 | Firefox Android No support No | Opera Android Full support 47 | Safari iOS No support No | Samsung Internet Android Full support 9.0 |
getAll | Chrome Full support 66 | Edge Full support 79 | Firefox No support No | IE No support No | Opera Full support 53 | Safari No support No | WebView Android Full support 66 | Chrome Android Full support 66 | Firefox Android No support No | Opera Android Full support 47 | Safari iOS No support No | Samsung Internet Android Full support 9.0 |
has | Chrome Full support 66 | Edge Full support 79 | Firefox No support No | IE No support No | Opera Full support 53 | Safari No support No | WebView Android Full support 66 | Chrome Android Full support 66 | Firefox Android No support No | Opera Android Full support 47 | Safari iOS No support No | Samsung Internet Android Full support 9.0 |
keys | Chrome Full support 66 | Edge Full support 79 | Firefox No support No | IE No support No | Opera Full support 53 | Safari No support No | WebView Android Full support 66 | Chrome Android Full support 66 | Firefox Android No support No | Opera Android Full support 47 | Safari iOS No support No | Samsung Internet Android Full support 9.0 |
size | Chrome Full support 66 | Edge Full support 79 | Firefox No support No | IE No support No | Opera Full support 53 | Safari No support No | WebView Android Full support 66 | Chrome Android Full support 66 | Firefox Android No support No | Opera Android Full support 47 | Safari iOS No support No | Samsung Internet Android Full support 9.0 |
values | Chrome Full support 66 | Edge Full support 79 | Firefox No support No | IE No support No | Opera Full support 53 | Safari No support No | WebView Android Full support 66 | Chrome Android Full support 66 | Firefox Android No support No | Opera Android Full support 47 | Safari iOS No support No | Samsung Internet Android Full support 9.0 |
@@iterator | Chrome Full support 66 | Edge Full support 79 | Firefox No support No | IE No support No | Opera Full support 53 | Safari No support No | WebView Android Full support 66 | Chrome Android Full support 66 | Firefox Android No support No | Opera Android Full support 47 | Safari iOS No support No | Samsung Internet Android Full support 9.0 |
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.