let cssVarPoly = {
init: function() {
// first lets see if the browser supports CSS variables
// No version of IE supports window.CSS.supports, so if that isn't supported in the first place we know CSS variables is not supported
// Edge supports supports, so check for actual variable support
if (window.CSS && window.CSS.supports && window.CSS.supports('(--foo: red)')) {
// this browser does support variables, abort
console.log('your browser supports CSS variables, aborting and letting the native support handle things.');
return;
} else {
// edge barfs on console statements if the console is not open... lame!
console.log('no support for you! polyfill all (some of) the things!!');
document.querySelector('body').classList.add('cssvars-polyfilled');
}
cssVarPoly.ratifiedVars = {};
cssVarPoly.varsByBlock = {};
cssVarPoly.oldCSS = {};
// start things off
cssVarPoly.findCSS();
cssVarPoly.updateCSS();
},
// find all the css blocks, save off the content, and look for variables
findCSS: function() {
let styleBlocks = document.querySelectorAll('style:not(.inserted),link[type="text/css"]');
// we need to track the order of the style/link elements when we save off the CSS, set a counter
let counter = 1;
// loop through all CSS blocks looking for CSS variables being set
[].forEach.call(styleBlocks, function (block) {
// console.log(block.nodeName);
let theCSS;
if (block.nodeName === 'STYLE') {
// console.log("style");
theCSS = block.innerHTML;
cssVarPoly.findSetters(theCSS, counter);
} else if (block.nodeName === 'LINK') {
// console.log("link");
cssVarPoly.getLink(block.getAttribute('href'), counter, function (counter, request) {
cssVarPoly.findSetters(request.responseText, counter);
cssVarPoly.oldCSS[counter] = request.responseText;
cssVarPoly.updateCSS();
});
theCSS = '';
}
// save off the CSS to parse through again later. the value may be empty for links that are waiting for their ajax return, but this will maintain the order
cssVarPoly.oldCSS[counter] = theCSS;
counter++;
});
},
// find all the "--variable: value" matches in a provided block of CSS and add them to the master list
findSetters: function(theCSS, counter) {
// console.log(theCSS);
cssVarPoly.varsByBlock[counter] = theCSS.match(/(--.+:.+;)/g) || [];
},
// run through all the CSS blocks to update the variables and then inject on the page
updateCSS: function() {
// first lets loop through all the variables to make sure later vars trump earlier vars
cssVarPoly.ratifySetters(cssVarPoly.varsByBlock);
// loop through the css blocks (styles and links)
for (let curCSSID in cssVarPoly.oldCSS) {
// console.log("curCSS:",oldCSS[curCSSID]);
let newCSS = cssVarPoly.replaceGetters(cssVarPoly.oldCSS[curCSSID], cssVarPoly.ratifiedVars);
// put it back into the page
// first check to see if this block exists already
if (document.querySelector('#inserted' + curCSSID)) {
// console.log("updating")
document.querySelector('#inserted' + curCSSID).innerHTML = newCSS;
} else {
// console.log("adding");
var style = document.createElement('style');
style.type = 'text/css';
style.innerHTML = newCSS;
style.classList.add('inserted');
style.id = 'inserted' + curCSSID;
document.getElementsByTagName('head')[0].appendChild(style);
}
};
},
// parse a provided block of CSS looking for a provided list of variables and replace the --var-name with the correct value
replaceGetters: function(curCSS, varList) {
// console.log(varList);
for (let theVar in varList) {
// console.log(theVar);
// match the variable with the actual variable name
let getterRegex = new RegExp('var\\(\\s*' + theVar + '\\s*\\)', 'g');
// console.log(getterRegex);
// console.log(curCSS);
curCSS = curCSS.replace(getterRegex, varList[theVar]);
// now check for any getters that are left that have fallbacks
let getterRegex2 = new RegExp('var\\(\\s*.+\\s*,\\s*(.+)\\)', 'g');
// console.log(getterRegex);
// console.log(curCSS);
let matches = curCSS.match(getterRegex2);
if (matches) {
// console.log("matches",matches);
matches.forEach(function (match) {
// console.log(match.match(/var\(.+,\s*(.+)\)/))
// find the fallback within the getter
curCSS = curCSS.replace(match, match.match(/var\(.+,\s*(.+)\)/)[1]);
});
}
// curCSS = curCSS.replace(getterRegex2,varList[theVar]);
};
// console.log(curCSS);
return curCSS;
},
// determine the css variable name value pair and track the latest
ratifySetters: function(varList) {
// console.log("varList:",varList);
// loop through each block in order, to maintain order specificity
for (let curBlock in varList) {
let curVars = varList[curBlock];
// console.log("curVars:",curVars);
// loop through each var in the block
curVars.forEach(function (theVar) {
// console.log(theVar);
// split on the name value pair separator
let matches = theVar.split(/:\s*/);
// console.log(matches);
// put it in an object based on the varName. Each time we do this it will override a previous use and so will always have the last set be the winner
// 0 = the name, 1 = the value, strip off the ; if it is there
cssVarPoly.ratifiedVars[matches[0]] = matches[1].replace(/;/, '');
});
};
// console.log(ratifiedVars);
},
// get the CSS file (same domain for now)
getLink: function(url, counter, success) {
var request = new XMLHttpRequest();
request.open('GET', url, true);
request.overrideMimeType('text/css;');
request.onload = function () {
if (request.status >= 200 && request.status < 400) {
// Success!
// console.log(request.responseText);
if (typeof success === 'function') {
success(counter, request);
}
} else {
// We reached our target server, but it returned an error
console.warn('an error was returned from:', url);
}
};
request.onerror = function () {
// There was a connection error of some sort
console.warn('we could not get anything from:', url);
};
request.send();
}
};
cssVarPoly.init();
let cssVarPoly = {
init: function() {
// first lets see if the browser supports CSS variables
// No version of IE supports window.CSS.supports, so if that isn't supported in the first place we know CSS variables is not supported
// Edge supports supports, so check for actual variable support
if (window.CSS && window.CSS.supports && window.CSS.supports('(--foo: red)')) {
// this browser does support variables, abort
// console.log('your browser supports CSS variables, aborting and letting the native support handle things.');
return;
} else {
// edge barfs on console statements if the console is not open... lame!
// console.log('no support for you! polyfill all (some of) the things!!');
document.querySelector('body').classList.add('cssvars-polyfilled');
}
cssVarPoly.ratifiedVars = {};
cssVarPoly.varsByBlock = {};
cssVarPoly.oldCSS = {};
// start things off
cssVarPoly.findCSS();
cssVarPoly.updateCSS();
},
// find all the css blocks, save off the content, and look for variables
findCSS: function() {
let styleBlocks = document.querySelectorAll('style:not(.inserted),link[type="text/css"]');
// we need to track the order of the style/link elements when we save off the CSS, set a counter
let counter = 1;
// loop through all CSS blocks looking for CSS variables being set
[].forEach.call(styleBlocks, function (block) {
// console.log(block.nodeName);
let theCSS;
if (block.nodeName === 'STYLE') {
// console.log("style");
theCSS = block.innerHTML;
cssVarPoly.findSetters(theCSS, counter);
} else if (block.nodeName === 'LINK') {
// console.log("link");
cssVarPoly.getLink(block.getAttribute('href'), counter, function (counter, request) {
cssVarPoly.findSetters(request.responseText, counter);
cssVarPoly.oldCSS[counter] = request.responseText;
cssVarPoly.updateCSS();
});
theCSS = '';
}
// save off the CSS to parse through again later. the value may be empty for links that are waiting for their ajax return, but this will maintain the order
cssVarPoly.oldCSS[counter] = theCSS;
counter++;
});
},
// find all the "--variable: value" matches in a provided block of CSS and add them to the master list
findSetters: function(theCSS, counter) {
// console.log(theCSS);
cssVarPoly.varsByBlock[counter] = theCSS.match(/(--.+:.+;)/g) || [];
},
// run through all the CSS blocks to update the variables and then inject on the page
updateCSS: function() {
// first lets loop through all the variables to make sure later vars trump earlier vars
cssVarPoly.ratifySetters(cssVarPoly.varsByBlock);
// loop through the css blocks (styles and links)
for (let curCSSID in cssVarPoly.oldCSS) {
// console.log("curCSS:",oldCSS[curCSSID]);
let newCSS = cssVarPoly.replaceGetters(cssVarPoly.oldCSS[curCSSID], cssVarPoly.ratifiedVars);
// put it back into the page
// first check to see if this block exists already
if (document.querySelector('#inserted' + curCSSID)) {
// console.log("updating")
document.querySelector('#inserted' + curCSSID).innerHTML = newCSS;
} else {
// console.log("adding");
var style = document.createElement('style');
style.type = 'text/css';
style.innerHTML = newCSS;
style.classList.add('inserted');
style.id = 'inserted' + curCSSID;
document.getElementsByTagName('head')[0].appendChild(style);
}
};
},
// parse a provided block of CSS looking for a provided list of variables and replace the --var-name with the correct value
replaceGetters: function(curCSS, varList) {
// console.log(varList);
for (let theVar in varList) {
// console.log(theVar);
// match the variable with the actual variable name
// console.log (theVar);
var res = theVar.match(/--[a-zA-Z0-9-]+/g);
// console.log (res[0]);
theVar = res[0];
let getterRegex = new RegExp('var\\(\\s*' + theVar + '\\s*\\)', 'g');
// console.log(getterRegex);
// console.log(curCSS);
curCSS = curCSS.replace(getterRegex, varList[theVar]);
// now check for any getters that are left that have fallbacks
let getterRegex2 = new RegExp('var\\(\\s*.+\\s*,\\s*(.+)\\)', 'g');
// console.log(getterRegex);
// console.log(curCSS);
let matches = curCSS.match(getterRegex2);
if (matches) {
// console.log("matches",matches);
matches.forEach(function (match) {
// console.log(match.match(/var\(.+,\s*(.+)\)/))
// find the fallback within the getter
curCSS = curCSS.replace(match, match.match(/var\(.+,\s*(.+)\)/)[1]);
});
}
// curCSS = curCSS.replace(getterRegex2,varList[theVar]);
};
// console.log(curCSS);
return curCSS;
},
// determine the css variable name value pair and track the latest
ratifySetters: function(varList) {
// console.log("varList:",varList);
// loop through each block in order, to maintain order specificity
for (let curBlock in varList) {
let curVars = varList[curBlock];
// console.log("curVars:",curVars);
// loop through each var in the block
curVars.forEach(function (theVar) {
// console.log(theVar);
// split on the name value pair separator
let matches = theVar.split(/:\s*/);
// console.log(matches);
// put it in an object based on the varName. Each time we do this it will override a previous use and so will always have the last set be the winner
// 0 = the name, 1 = the value, strip off the ; if it is there
cssVarPoly.ratifiedVars[matches[0]] = matches[1].replace(/;/, '');
});
};
// console.log(ratifiedVars);
},
// get the CSS file (same domain for now)
getLink: function(url, counter, success) {
var request = new XMLHttpRequest();
request.open('GET', url, true);
request.overrideMimeType('text/css;');
request.onload = function () {
if (request.status >= 200 && request.status < 400) {
// Success!
// console.log(request.responseText);
if (typeof success === 'function') {
success(counter, request);
}
} else {
// We reached our target server, but it returned an error
console.warn('an error was returned from:', url);
}
};
request.onerror = function () {
// There was a connection error of some sort
console.warn('we could not get anything from:', url);
};
request.send();
}
};
cssVarPoly.init();
5条答案
按热度按时间e7arh2l61#
是的,只要您正在处理根级别的自定义属性(IE9+)。
*GitHub:https://github.com/jhildenbiddle/css-vars-ponyfill
*国家预防机制:
*演示:https://codepen.io/jhildenbiddle/pen/ZxYJrR
来自自述文件:
特点
<link>
、<style>
和@import
CSSurl()
路径转换为绝对URLvar()
函数var()
函数回退值<link>
和<style>
更改时自动更新限制
:root
和:host
声明以下是库可以处理的一些示例:
根级别自定义属性
链接的自定义属性
嵌套的自定义属性
备用值
转换
<link>
、<style>
和@import
CSS转换Web组件/影子DOM
为完整起见:w3c specs
(无耻的自我推销:检查)
tnkciper2#
此polyfill几乎完全支持IE11中的自定义属性(不仅是根级别):
https://github.com/nuxodin/ie11CustomProperties
工作原理
该脚本利用了IE具有最小自定义属性支持的事实,其中可以在考虑级联的情况下定义和读取属性。
第一个月
然后用javascript来读:
getComputedStyle( querySelector('.myEl') )['-ie-test']
自述文件中的功能:
<style>
、<link>
元素--bar:var(--foo)
var(--color, blue)
style.setProperty('--x','y')
style.getPropertyValue('--x')
getComputedStyle(el).getPropertyValue('--inherited')
<div ie-style="--color:blue"...
演示:
https://rawcdn.githack.com/nuxodin/ie11CustomProperties/b851ec2b6b8e336a78857b570d9c12a8526c9a91/test.html
cyej8jka3#
+1的代码笔片段链接在上面的问题评论部分由[我有kode]。一件事,我发现,虽然是片段需要稍微修改,有函数声明定义在JSON格式的IE11没有抱怨。以下是代码笔片段的轻微修改版本:
63lcw9qa4#
我试过这个版本的Polyfill,但是当CSS中的一行有多个变量(FI字体和颜色)时,我的一个同事帮我解决了这个问题,见第94行。
rdrgkggo5#
要支持Internet Explorer,只需在index.html head标签中使用下面的脚本,它的工作就像一个魅力。