style-loader
Version:
style loader module for webpack
84 lines (83 loc) • 2.48 kB
JavaScript
"use strict";
var stylesInDOM = [];
function getIndexByIdentifier(identifier) {
var result = -1;
for (var i = 0; i < stylesInDOM.length; i++) {
if (stylesInDOM[i].identifier === identifier) {
result = i;
break;
}
}
return result;
}
function modulesToDom(list, options) {
var idCountMap = {};
var identifiers = [];
for (var i = 0; i < list.length; i++) {
var item = list[i];
var id = options.base ? item[0] + options.base : item[0];
var count = idCountMap[id] || 0;
var identifier = "".concat(id, " ").concat(count);
idCountMap[id] = count + 1;
var indexByIdentifier = getIndexByIdentifier(identifier);
var obj = {
css: item[1],
media: item[2],
sourceMap: item[3],
supports: item[4],
layer: item[5]
};
if (indexByIdentifier !== -1) {
stylesInDOM[indexByIdentifier].references++;
stylesInDOM[indexByIdentifier].updater(obj);
} else {
var updater = addElementStyle(obj, options);
options.byIndex = i;
stylesInDOM.splice(i, 0, {
identifier: identifier,
updater: updater,
references: 1
});
}
identifiers.push(identifier);
}
return identifiers;
}
function addElementStyle(obj, options) {
var api = options.domAPI(options);
api.update(obj);
var updater = function updater(newObj) {
if (newObj) {
if (newObj.css === obj.css && newObj.media === obj.media && newObj.sourceMap === obj.sourceMap && newObj.supports === obj.supports && newObj.layer === obj.layer) {
return;
}
api.update(obj = newObj);
} else {
api.remove();
}
};
return updater;
}
module.exports = function (list, options) {
options = options || {};
list = list || [];
var lastIdentifiers = modulesToDom(list, options);
return function update(newList) {
newList = newList || [];
for (var i = 0; i < lastIdentifiers.length; i++) {
var identifier = lastIdentifiers[i];
var index = getIndexByIdentifier(identifier);
stylesInDOM[index].references--;
}
var newLastIdentifiers = modulesToDom(newList, options);
for (var _i = 0; _i < lastIdentifiers.length; _i++) {
var _identifier = lastIdentifiers[_i];
var _index = getIndexByIdentifier(_identifier);
if (stylesInDOM[_index].references === 0) {
stylesInDOM[_index].updater();
stylesInDOM.splice(_index, 1);
}
}
lastIdentifiers = newLastIdentifiers;
};
};