gitbook_download.js

/************************************************

gitbook  下载

使用方式：
1. 使用Chrome登陆gitbook
2. 进入你购买的专栏详情页面，点击阅读，进入阅读页面。
3. 在此页面打开控制台，贴入脚本回车运行
4. 可能会提示是否下载多个文件，选择是

*************************************************/

(function main() {

    var $ = function (selector) {
        return document.querySelector(selector)
    };

    var $$ = function (selector) {
        return document.querySelectorAll(selector)
    };

    /**
    *  格式化数字
    *  @param digitCount 位数
    */
    function formatNumber(number, digitCount) {

        var str = number + ''
        for (var i = 0; i < digitCount - str.length; i++) {
            str = "0" + str
        }
        return str
    }

    function postData(url, data) {
        // Default options are marked with *
        return fetch(url, {
            body: JSON.stringify(data), // must match 'Content-Type' header
            cache: 'no-cache', // *default, no-cache, reload, force-cache, only-if-cached
            credentials: 'same-origin', // include, same-origin, *omit
            headers: {
                'user-agent': 'Mozilla/4.0 MDN Example',
                'content-type': 'application/json'
            },
            method: 'POST', // *GET, POST, PUT, DELETE, etc.
            mode: 'cors', // no-cors, cors, *same-origin
            redirect: 'follow', // manual, *follow, error
            referrer: 'no-referrer', // *client, no-referrer
        })
            .then(response => response.json()) // parses response to JSON
    }


    function waitFor(judge, onfinish, onerror, maxRetry) {
        if (judge()) {
            onfinish()
            return true
        }
        var retryCount = 0
        var handler = setInterval(function () {
            if (judge()) {
                onfinish()
                clearInterval(handler)
                return
            }
            retryCount++
            if (maxRetry != 0 && retryCount >= maxRetry) {
                console.warn("重试达到最大次数")
                clearInterval(handler)
                onerror()
            }
        }, 500)
    }


    function doSave(value, type, name) {
        var blob;
        if (typeof window.Blob == "function") {
            blob = new Blob([value], { type: type });
        } else {
            var BlobBuilder = window.BlobBuilder || window.MozBlobBuilder || window.WebKitBlobBuilder || window.MSBlobBuilder;
            var bb = new BlobBuilder();
            bb.append(value);
            blob = bb.getBlob(type);
        }
        var URL = window.URL || window.webkitURL;
        var bloburl = URL.createObjectURL(blob);
        var anchor = document.createElement("a");
        if ('download' in anchor) {
            anchor.style.visibility = "hidden";
            anchor.href = bloburl;
            anchor.download = name;
            document.body.appendChild(anchor);
            var evt = document.createEvent("MouseEvents");
            evt.initEvent("click", true, true);
            anchor.dispatchEvent(evt);
            document.body.removeChild(anchor);
        } else if (navigator.msSaveBlob) {
            navigator.msSaveBlob(blob, name);
        } else {
            location.href = bloburl;
        }
    }


    function isArticleLoadSuccess(title) {
        console.log("waiting...")
        return $("#iframe").$(".topic_title") && $("#iframe").$(".topic_title").innerText == title
    }

    function downloadArticle(index, title) {

        var iframe = $("#iframe")

        var headerLinks = iframe.$$("link")
        for (var i = 0; i < headerLinks.length; i++) {
            if (headerLinks[i].tagName == "LINK") {
                var href = headerLinks[i].href
                headerLinks[i].href = href
            }
        }

        var headerLinks = iframe.$$("script")
        for (var i = 0; i < headerLinks.length; i++) {
            if (headerLinks[i].tagName == "SCRIPT") {
                var src = headerLinks[i].src
                headerLinks[i].src = src
            }
        }


        if (iframe.$(".audioWrapper")) {
            iframe.$("#audio").controls = "controls"
            iframe.$("#audio").style = ""
            iframe.$(".audioWrapper").append(iframe.$("#audio"))
        }

        var next_icon = iframe.$(".next_icon")
        if (next_icon) {
            iframe.$(".column_topic_view").removeChild(next_icon.parentNode)
        }
        var pre_icon = iframe.$(".pre_icon")
        if (pre_icon) {
            iframe.$(".column_topic_view").removeChild(pre_icon.parentNode)
        }

        // var header = "<head>" + $("#iframe").$("head").innerHTML + "</head>"
        
        var content = "<html>" + $("#iframe").$("html").innerHTML +
            "</html>";
        
        var fileName = formatNumber(index, 2) + "-" + title + ".html"
        doSave(content, "text/html", fileName)
        console.log("正在下载 " + fileName)
    }

    function viewArticle(start, end) {
        if (start > end) {
            console.log("END...")
            return;
        }
       	setTimeout(function() {
			 console.log("休息3秒...");
			  waitFor(
					() => iframe.contentWindow.clickOnTopic != null,

					() => {
						var selections = $("#iframe").$$(".catelog_item");
						var selection = selections[start]
                        selection.click()
                        // console.log(selection.getElementsByClassName(".catelog_ready_title>h2"))
						var title = selection.querySelector(".catelog_ready_title>h2").innerText;
                            
						console.log("正在加载 " + title)
						
						waitFor(
							() => isArticleLoadSuccess(title),
							() => {
								downloadArticle(start, title)
								viewArticle(start + 1, end)
							},
							() => {
								downloadArticle(start, title)
								viewArticle(start + 1, end)
							},
							10
						)
					},
					() => { },
					0
				)
			 
		}, 3 * 1000);

    }


    if (!$(".catalog_infos h2")) {
        console.error("页面没有加载完毕，请加载完后重试")
        return
    }
    console.log("正在下载：" + $(".catalog_infos h2").innerText)


    var iframe = document.createElement("iframe")
    iframe.setAttribute("src", location.href)
    iframe.setAttribute("width", "100%")
    iframe.setAttribute("height", "500px")
    iframe.id = "iframe"
    document.getElementsByTagName("body")[0].appendChild(iframe)
    iframe.$ = function (selector) {
        return this.contentDocument.querySelector(selector)
    };

    iframe.$$ = function (selector) {
        return this.contentDocument.querySelectorAll(selector)
    };


    iframe.onload = function () {
        var selections = this.$$(".catelog_item");
        var start = 0
        var end = selections.length - 1
        // var end = 1
        viewArticle(start, end)
        iframe.onload = null
    }

})()