IE11: ¿existe un polyfill/script para las variables CSS?

polyfill js

Question

Estoy desarrollando una página web en un entorno de navegador web mixto (Chrome / IE11). IE11 no admite variables CSS, ¿existe un polyfill o script que me permita usar variables CSS en IE11?

Answer 1

+1 para el enlace del fragmento de código-lápiz en la sección de comentarios de preguntas anterior de [I kode]. Sin embargo, una cosa que encontré es que el fragmento debe modificarse ligeramente para tener las declaraciones de funciones definidas en el formato JSON para que IE11 no se queje. A continuación se muestra la versión ligeramente modificada del fragmento de código de la pluma:

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();

Answer 2

Este polyfill permite un soporte casi completo para las propiedades personalizadas en IE11:
github.com/nuxodin/ie11CustomProperties

Cómo funciona

El script hace uso del hecho de que IE tiene un soporte mínimo de propiedades personalizadas donde las propiedades se pueden definir y leer teniendo en cuenta la cascada.
.myEl {-ie-test:''aaa''} // only one dash allowed! "-"
luego léelo en javascript:
getComputedStyle( querySelector(''.myEl'') )[''-ie-test'']

Características del archivo README:

• maneja contenido html agregado dinámico
• maneja dinámico agregado, -elementos
• encadenamiento --bar:var(--foo)
• Fallback var(--color, blue)
• : focus,: target,: hover
• integración js:
  • style.setProperty(''--x'',''y'')
  • style.getPropertyValue(''--x'')
  • getComputedStyle(el).getPropertyValue(''--inherited'')
• Estilos en línea: <div ie-style="--color:blue"...
• trabajos en cascada
• herencia obras
• bajo 3k (min + gzip) y sin dependencia

Manifestación:

https://rawcdn.githack.com/nuxodin/ie11CustomProperties/b851ec2b6b8e336a78857b570d9c12a8526c9a91/test.html

Answer 3

Probé esta versión de Polyfill pero terminé con errores cuando una línea en CSS tenía múltiples variables (fuente FI y color). Un colega mío me ayudó. Ver línea 94.

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();

Answer 4

Sí, siempre que esté procesando propiedades personalizadas de nivel raíz (IE9 +).

• GitHub : https://github.com/jhildenbiddle/css-vars-ponyfill
• NPM : https://www.npmjs.com/package/css-vars-ponyfill
• Demostración : https://codepen.io/jhildenbiddle/pen/ZxYJrR

Desde el archivo Léame:

Caracteristicas

• Transformación del lado del cliente de propiedades personalizadas CSS a valores estáticos
• Actualizaciones en vivo de valores de tiempo de ejecución en navegadores modernos y antiguos
• Transforma <link> , <style> y @import CSS
• Transforma las rutas relativas url() a URL absolutas
• Admite funciones var() encadenadas y anidadas
• Admite valores de recuperación de la función var()
• Admite componentes web / shadow DOM CSS
• Ver actualizaciones automáticas del modo en los cambios <link> y <style>
• Módulo UMD y ES6 disponible
• Definiciones de TypeScript incluidas
• Ligero (6k min + gzip) y sin dependencia

Limitaciones

• El soporte de propiedad personalizada se limita a: declaraciones raíz
• El uso de var () está limitado a valores de propiedad (según la https://github.com/jhildenbiddle/css-vars-ponyfill )

Aquí hay algunos ejemplos de lo que la biblioteca puede manejar:

Propiedades personalizadas de nivel raíz

:root {
    --a: red;
}

p {
    color: var(--a);
}

Propiedades personalizadas encadenadas

:root {
    --a: var(--b);
    --b: var(--c);
    --c: red;
}

p {
    color: var(--a);
}

Propiedades personalizadas anidadas

:root {
    --a: 1em;
    --b: 2;
}

p {
    font-size: calc(var(--a) * var(--b));
}

Valores de reserva

p {
    font-size: var(--a, 1rem);
    color: var(--b, var(--c, var(--d, red))); 
}

Transforma <link> , <style> y @import CSS

<link rel="stylesheet" href="/absolute/path/to/style.css">
<link rel="stylesheet" href="../relative/path/to/style.css">

<style>
    @import "/absolute/path/to/style.css";
    @import "../relative/path/to/style.css";
</style>

Transforma componentes web / DOM sombra

<custom-element>
  #shadow-root
    <style>
      .my-custom-element {
        color: var(--test-color);
      }
    </style>
    <div class="my-custom-element">Hello.</div>
</custom-element>

En aras de la integridad: especificaciones w3c

Espero que esto ayude.

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