pixsy/node_modules/less/lib/less/functions/data-uri.js

86 lines
3.2 KiB
JavaScript

module.exports = function(environment) {
var Quoted = require("../tree/quoted"),
URL = require("../tree/url"),
functionRegistry = require("./function-registry"),
fallback = function(functionThis, node) {
return new URL(node, functionThis.index, functionThis.currentFileInfo).eval(functionThis.context);
},
logger = require('../logger');
functionRegistry.add("data-uri", function(mimetypeNode, filePathNode) {
if (!filePathNode) {
filePathNode = mimetypeNode;
mimetypeNode = null;
}
var mimetype = mimetypeNode && mimetypeNode.value;
var filePath = filePathNode.value;
var currentFileInfo = this.currentFileInfo;
var currentDirectory = currentFileInfo.relativeUrls ?
currentFileInfo.currentDirectory : currentFileInfo.entryPath;
var fragmentStart = filePath.indexOf('#');
var fragment = '';
if (fragmentStart !== -1) {
fragment = filePath.slice(fragmentStart);
filePath = filePath.slice(0, fragmentStart);
}
var fileManager = environment.getFileManager(filePath, currentDirectory, this.context, environment, true);
if (!fileManager) {
return fallback(this, filePathNode);
}
var useBase64 = false;
// detect the mimetype if not given
if (!mimetypeNode) {
mimetype = environment.mimeLookup(filePath);
if (mimetype === "image/svg+xml") {
useBase64 = false;
} else {
// use base 64 unless it's an ASCII or UTF-8 format
var charset = environment.charsetLookup(mimetype);
useBase64 = ['US-ASCII', 'UTF-8'].indexOf(charset) < 0;
}
if (useBase64) { mimetype += ';base64'; }
}
else {
useBase64 = /;base64$/.test(mimetype);
}
var fileSync = fileManager.loadFileSync(filePath, currentDirectory, this.context, environment);
if (!fileSync.contents) {
logger.warn("Skipped data-uri embedding of " + filePath + " because file not found");
return fallback(this, filePathNode || mimetypeNode);
}
var buf = fileSync.contents;
if (useBase64 && !environment.encodeBase64) {
return fallback(this, filePathNode);
}
buf = useBase64 ? environment.encodeBase64(buf) : encodeURIComponent(buf);
var uri = "data:" + mimetype + ',' + buf + fragment;
// IE8 cannot handle a data-uri larger than 32,768 characters. If this is exceeded
// and the --ieCompat flag is enabled, return a normal url() instead.
var DATA_URI_MAX = 32768;
if (uri.length >= DATA_URI_MAX) {
if (this.context.ieCompat !== false) {
logger.warn("Skipped data-uri embedding of " + filePath + " because its size (" + uri.length +
" characters) exceeds IE8-safe " + DATA_URI_MAX + " characters!");
return fallback(this, filePathNode || mimetypeNode);
}
}
return new URL(new Quoted('"' + uri + '"', uri, false, this.index, this.currentFileInfo), this.index, this.currentFileInfo);
});
};