gulp-build-html/lib/lib.js

Used to process html files to automatically concat css and js files, and meanwhile update html references.

var Vinyl = require('vinyl'),
	GulpPluginError = require('gulp-util').PluginError,
	utils = require("wzh.node-utils"),
	fs = require("fs"),
	path = require("path"),
	Logger = require("xxlogger");

/** 插件名称 */
var PLUGIN_NAME = "gulp-build-html";

var logger = Logger.ofName(PLUGIN_NAME, PLUGIN_NAME + ".log");
logger.setLevel("warn");

/**
 * 引入文件时需要同步调整引用的HTML标签及属性
 * key：标签key，不区分大小写
 * value：属性key，不区分大小写
 * @type {{}}
 */
var htmlTagAndAttributeWhenRefactoringReference = {
	link: "href",
	script: "src",
	img: "src",
	audio: "src",
	video: "src",
	source: "src",
	"source-placeholder": "src"
};

/**
 * @constructor
 * @param {String} msg 错误消息
 */
var newGulpPluginError = function(msg){
	return new GulpPluginError(PLUGIN_NAME, msg);
};

/**
 * 调整给定字符串中的资源引用中的路径，使其成为相对于提供的基准路径的相对路径
 * @param {String} fileContent 声明资源引用的文件正文
 * @param {String} fileAbsolutePath 声明资源引用的文件的绝对路径
 * @param {String} baseAbsolutePath 调整资源引用的路径时，用于决定最终相对路径的基准路径的绝对路径。如：最终引用资源的html所在的目录
 * @return {String} 调整后的字符串
 */
var updateReferenceAsRelativeTo = function(fileContent, fileAbsolutePath, baseAbsolutePath){
	if(null == fileContent || "" === fileContent.trim())
		return fileContent;

	if(null == fileAbsolutePath || "" === fileAbsolutePath.trim())
		fileAbsolutePath = process.cwd();
	if(null == baseAbsolutePath || "" === baseAbsolutePath.trim())
		baseAbsolutePath = "/";

	var fileDirAbsolutePath = path.dirname(fileAbsolutePath);

	logger.info("Updating resource reference in {} as relative to {}", fileAbsolutePath, baseAbsolutePath);
	var newFileContent = fileContent;

	var regexpArr = [];
	for(var tagName in htmlTagAndAttributeWhenRefactoringReference)
		regexpArr.push({
			regexp: new RegExp("<\\s*" + tagName + "\\s+(.+?)\\s*\\/?\\s*>", "gim"),
			attr: htmlTagAndAttributeWhenRefactoringReference[tagName]
		});
	/* css 中通过 url 声明的资源引用 */
	regexpArr = regexpArr.concat({regexp: /\burl\b\s*\(\s*['"]?([^)'"]*)['"]?\s*\)/gim, attr: null});
	regexpArr.forEach(function(s){
		var linkRegExp = s.regexp;
		var tmp, beginIndex, endIndex;
		var dstString = "", attrStrIndex = 0, lastEndIndex = 0;
		while((tmp = linkRegExp.exec(newFileContent)) != null){
			logger.debug("Found reference: '{}' in '{}'", tmp[1], tmp[0]);

			var src, srcValue;
			if(null != s.attr && "" !== String(s.attr).trim()){
				src = utils.html.getAttribute(tmp[1], s.attr);

				var srcValue = !src? null: src.value.trim();
				if(null == srcValue || "" === srcValue)
					continue;
				if(utils.url.isAbsolute(srcValue)){
					logger.info("Skip {}", srcValue);
					continue;
				}

				attrStrIndex = tmp[0].indexOf(tmp[1]);
				beginIndex = tmp.index + attrStrIndex + src.valueIndex;
				endIndex = beginIndex + src.value.length;
			}else{
				src = tmp[1];
				srcValue = src.trim();

				if(null == srcValue || "" === srcValue)
					continue;
				if(utils.url.isAbsolute(srcValue)){
					logger.info("Skip {}", srcValue);
					continue;
				}

				attrStrIndex = tmp[0].indexOf(tmp[1]);
				beginIndex = tmp.index + attrStrIndex;
				endIndex = beginIndex + srcValue.length;
			}

			var referredFileAbsolutePath = path.resolve(fileDirAbsolutePath, srcValue);
			var replacement = path.relative(baseAbsolutePath, referredFileAbsolutePath).replace(/\\/gm, "/");
			logger.debug("Base file: {}", path.resolve(baseAbsolutePath));
			logger.debug("Referred file: {}", referredFileAbsolutePath);
			logger.debug("Replacement: {}", replacement);

			dstString += newFileContent.substring(lastEndIndex, beginIndex) + replacement;
			lastEndIndex = endIndex;
		}
		dstString += newFileContent.substring(lastEndIndex);

		newFileContent = dstString;
	});

	return newFileContent;
};

module.exports = {
	PLUGIN_NAME: PLUGIN_NAME,
	newGulpPluginError: newGulpPluginError,
	updateReferenceAsRelativeTo: updateReferenceAsRelativeTo,

	logger: logger
};