@webcomponents/custom-elements
Version:
HTML Custom Elements Polyfill
101 lines (91 loc) • 4.4 kB
JavaScript
/*
* Distributed under both the W3C Test Suite License [1] and the W3C
* 3-clause BSD License [2]. To contribute to a W3C Test Suite, see the
* policies and contribution forms [3].
*
* [1] http://www.w3.org/Consortium/Legal/2008/04-testsuite-license
* [2] http://www.w3.org/Consortium/Legal/2008/03-bsd-license
* [3] http://www.w3.org/2004/10/27-testcases
* */
/* Source: https://github.com/w3c/web-platform-tests/blob/master/common/vendor-prefix.js
* The file has been modified to always be on (i.e. does not require usePrefixes=1 to
* start replacing prefixes). */
/* Use this script when you want to test APIs that use vendor prefixes
and define which objects need to be checked for prefixed versions, à la
<script src="vendor-prefix.js"
data-prefixed-objects='[{"ancestors":["navigator"], "name":"getUserMedia"}]'
data-prefixed-prototypes='[{"ancestors":["HTMLMediaElement"],"name":"srcObject"}]'></script>
data-prefixed-objects lets prefix objects in the global space
data-prefixed-prototypes adds prefixes to interfaces, for objects that
get created during the tests
NB: vendor prefixes are expected to go away in favor of putting
new features behind flag, so hopefully there will be only limited
need to use this
*/
(function () {
var aliases = {};
var documentingPrefixUsage = document.createElement('div');
var vendorPrefixes = ["moz", "ms", "o", "webkit", "Moz", "MS", "O", "WebKit", "op"];
function getParentObject(ancestors) {
var parent = window;
var currentName = "";
ancestors.forEach(function (p) {
currentName = currentName ? currentName + "." + p : p;
if (parent[p] === undefined) {
throw currentName + " is undefined, cannot set prefix alias on child object";
}
parent = parent[p];
});
return parent;
}
function prependPrefix(prefix, name) {
var newName = name[0].toUpperCase() + name.substr(1, name.length);
return prefix + newName;
}
function setPrototypeAlias(obj) {
var parent = getParentObject(obj.ancestors);
if (!parent.prototype.hasOwnProperty(obj.name)) {
vendorPrefixes.forEach(function (prefix) {
if (parent.prototype.hasOwnProperty(prependPrefix(prefix, obj.name))) {
Object.defineProperty(parent.prototype, obj.name,
{get: function() {return this[prependPrefix(prefix, obj.name)];},
set: function(v) {this[prependPrefix(prefix, obj.name)] = v;}
});
aliases[obj.ancestors.join(".") + ".prototype." + obj.name] = obj.ancestors.join(".") + ".prototype." + prependPrefix(prefix, obj.name);
return;
}
});
}
}
function setAlias(obj) {
var parent = getParentObject(obj.ancestors);
if (parent[obj.name] === undefined) {
vendorPrefixes.forEach(function (prefix) {
if (parent[prependPrefix(prefix, obj.name)] !== undefined) {
parent[obj.name] = parent[prependPrefix(prefix, obj.name)];
aliases[obj.ancestors.join(".") + "." + obj.name] = obj.ancestors.join(".") + "." + prependPrefix(prefix, obj.name);
return;
}
});
}
}
// For this version of vendor-prefixes.js, always replace the prefixes.
if (document.querySelector("script[data-prefixed-objects]")) {
var prefixObjectsData = document.querySelector("script[data-prefixed-objects]").dataset["prefixedObjects"];
try {
var prefixedObjects = JSON.parse(prefixObjectsData);
} catch (e) {
throw "couldn't parse data-prefixed-objects as JSON:" + e;
}
prefixedObjects.forEach(setAlias);
}
if (document.querySelector("script[data-prefixed-prototypes]")) {
var prefixProtoData = document.querySelector("script[data-prefixed-prototypes]").dataset["prefixedPrototypes"];
try {
var prefixedPrototypes = JSON.parse(prefixProtoData);
} catch (e) {
throw "couldn't parse data-prefixed-prototypes as JSON:" + e;
}
prefixedPrototypes.forEach(setPrototypeAlias);
}
})();