Chrome外掛開發,美化網頁上的檔案列表。chrome-extension,background
上一篇文章 通過“content-scripts”的方式向頁面注入js和css來美化頁面,但是有一個弊端:一旦配置好需要注入的頁面,如果這個頁面地址以後發生變化,或者要新加一些URL進來,那麼得修改manifest.json這個檔案。試想如果一個Chrome外掛已經打包好,再去改程式碼是不可能的。
現在通過另一種方式來實現相同的功能,同時做到頁面地址動態可配置。以下是本次要處理的頁面(https://jiacrontab.iwannay.cn/download/)
每一行都是一個檔案的基本資訊,包括檔名、日期和檔案大小,檔名格式都是:專案名-版本-作業系統-平臺。現在檔案還少,檢視不是很困難,如果以後檔案多了,那麼找一個檔案是比較困難的。
這裡又不太可能在服務端讀取download目錄下的檔案,然後分類、分頁展示,那隻能在客戶端瀏覽器上想辦法了,Chrome外掛完全可以實現這個功能。
一、小試牛刀
開發Chrome外掛第一步,新建一個manifest.json檔案,並按官方文件的要求配置一些必要引數
{ "name": "WebFileFilterPro", "version": "1.0.0", "description": "fast sort your webpage files", "icons": { "16": "images/16.png", "48": "images/48.png","128": "images/128.png" }, "browser_action": { "default_icon": "images/16.png", "default_title": "WebFileFilterPro" }, "manifest_version": 2 }
name:外掛名稱
version:版本號
description:外掛描述
icons:外掛的圖示,不同尺寸用於不同地方
browser_action:右上角外掛欄的圖示資訊,包括:圖示的圖片路徑、滑鼠劃上去提示的文字
manifest_version:固定為2
注:更多manifest.json的配置參考:
一個簡單的沒有任何功能的Chrome外掛就完成了,去Chrome瀏覽器裡安裝下試試:開啟Chrome瀏覽器 - 更多工具 - 擴充套件程式,開啟“開發者模式” - 載入已解壓的擴充套件程式 - 選擇src目錄 - 確定
由圖可見,manifest.json裡配置的外掛名稱、版本號、外掛描述等資訊都體現了
二、加大難度
這個外掛的目的就是向特定頁面注入一些js和css檔案,實現可以分類檢視並且檔案多了還可以翻頁。新建一個配置頁面
把需要美化的頁面地址通過配置頁面儲存到Local Storage瀏覽器快取裡面,這樣做的好處是:需要美化的地址隨時可變,同時發現需要美化的頁面直接加進去就可以了,不用修改程式碼。
這個時候大殺器“background”就要出場了,官方描述是這樣的
Extensions are event based programs used to modify or enhance the Chrome browsing experience. Events are browser triggers, such as navigating to a new page, removing a bookmark, or closing a tab. Extensions monitor these events in their background script, then react with specified instructions.
大致意思是,“background”是常駐Chrome瀏覽器外掛後臺執行的,可以捕獲到很多行為:頁面跳轉、移除書籤、關閉一個tab頁等等。這裡不需要那麼強大的功能,只需要獲取使用者開啟的頁面地址,是不是在配置頁面配置的地址即可。
現在改下“manifest.json”檔案,加入新的配置
{ "name": "WebFileFilterPro", "version": "1.0.0", "description": "fast sort your webpage files", "icons": { "16": "images/16.png", "48": "images/48.png", "128": "images/128.png" }, "browser_action": { "default_icon": "images/16.png", "default_title": "WebFileFilterPro" }, "options_page": "settings.html", "permissions": [ "tabs", "http://*/*", "https://*/*" ], "background": { "scripts": [ "js/background.js" ], "persistent": false }, "manifest_version": 2 }
options_page:配置頁面地址(右鍵右上角外掛圖示,可以通過“選項”進入配置頁面)
background:後臺配置,包括js檔名和永續性設定
permissions:申請許可權列表
1)tabs:獲取使用者訪問頁面得URL地址,必須得有這個tabs許可權
2)http/https:向目標頁面裡注入css和js檔案需要的許可權
注:完整許可權api請訪問:permissions官方文件
現在來看下官方說的可以常駐後臺執行的“background.js”到底可以獲取到什麼些東西
chrome.tabs.onUpdated.addListener(function (tabId, changeInfo, tab) { if (changeInfo.status == "complete") { var url = tab.url; console.log("使用者訪問:" + url); console.log("快取裡設定的頁面:" + localStorage.url); }; });
在頁面重新整理完成事件裡面獲取“使用者訪問的頁面地址”和“配置頁面裡面配置的地址”,看看控制檯輸出
兩個地址都正確的獲取到了,如果使用者訪問的地址和配置的地址吻合,那麼向這個頁面注入css和js檔案
chrome.tabs.onUpdated.addListener(function (tabId, changeInfo, tab) { if (changeInfo.status == "complete") { var url = tab.url; console.log(url); if (localStorage.url != undefined && localStorage.url != '') { var urlList = localStorage.url.split("\n"); if (urlList.indexOf(url) != -1) { chrome.tabs.insertCSS(tabId, { file: "css/bootstrap.min.css" }); chrome.tabs.executeScript(tabId, { file: "js/jquery.min.js" }); chrome.tabs.executeScript(tabId, { file: "js/bootstrap.min.js" }); chrome.tabs.executeScript(tabId, { file: "js/filelist.js" }); } } }; });
使用“chrome.tabs.insertCSS”和“chrome.tabs.executeScript”這兩個api完成css和js的注入。有了jQuery和Bootstrap的注入,頁面就可以隨意美化了。同時在"filelist.js"裡面獲取頁面原有的內容,然後繫結的Bootstrap外掛上
//console.log("filelist.js"); var fileList = []; var preList = document.getElementsByTagName("pre"); if (preList.length == 1) { var lineList = preList[0].innerHTML.split("\n"); //console.log(lineList); if (lineList.length > 0) { var splitLinetext = []; var splitFileName = []; var fileName = ''; $.each(lineList, function (i, v) { //console.log(v); if (i == 0) { return true;//continue; } if (v == undefined || v == "") { var line = parseInt(i); line += 1; console.log("line:" + line + " is empty"); return true; } splitLinetext = v.split(/\s+/); if (splitLinetext.length != 5) { console.log(splitLinetext); return true; } fileName = splitLinetext[1].match(/>(\S*)</)[1]; //console.log(fileName); if (fileName == null || fileName == '') { console.log("fileName is or empty"); return true; } splitFileName = fileName.split('-'); if (splitFileName.length < 3) { console.log(splitFileName); return true; } fileList.push({ PartA: splitFileName[0], PartB: splitFileName[1], FileTime: formatDate(splitLinetext[2] + ' ' + splitLinetext[3]), FileSize: splitLinetext[4], FileName: fileName }); }); //console.log(fileList); var nodeDoctype = document.implementation.createDocumentType('html', '', ''); if (document.doctype) { document.replaceChild(nodeDoctype, document.doctype); } else { document.insertBefore(nodeDoctype, document.childNodes[0]); } $("html").attr("lang", "en"); $("head").html('<head><meta charset="UTF-8"><link rel="shortcut icon" href="" /><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta http-equiv="X-UA-Compatible" content="ie=edge"><title>FileList</title></head>'); $("[rel='shortcut icon']").attr("href", chrome.extension.getURL("images/16.png")); $("body").removeAttr("bgcolor").html('<nav class="navbar navbar-default navbar-static-top"><div class="container"><div class="row"><div class="col-sm-2 col-md-2 col-lg-2"></div><div class="col-sm-10 col-md-10 col-lg-10"><div class="navbar-header"><button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar"><span class="sr-only">Toggle navigation</span><span class="icon-bar"></span><span class="icon-bar"></span><span class="icon-bar"></span></button></div><div id="navbar" class="collapse navbar-collapse"><ul class="nav navbar-nav"></ul></div></div></div></div></nav><div class="container"><div class="row"><div id="nav" class="col-sm-2 col-md-2 col-lg-2"><ul class="nav nav-pills nav-stacked"></ul></div><div class="col-sm-10 col-md-10 col-lg-10"><table id="table" class="table table-bordered"></table><ul class="pager"><span id="pageIndexSpan"></span> / <span id="pageSizeSpan"></span> / <span id="totalCountSpan"></span> <li id="previousPageLi"><a href="javascript:;">Prev</a></li> <li id="nextPageLi"><a href="javascript:;">Next</a></li></ul></div></div></div>'); var partAs = getDistinctPartA(); $.each(partAs, function (idx, val) { $("#navbar ul").append("<li data-value=\"" + val + "\"><a href='javascript:;'><strong>" + val + "</strong></a></li>"); }); if (partAs.length > 0) { if (localStorage.partA != undefined && $.inArray(localStorage.partA, partAs) != -1) navBarLiClick(localStorage.partA); else navBarLiClick(partAs[0]); } else { $("body").html('<div class="container"><div class="row"><div class="col-sm-12 col-md-12 col-lg-12"><h3>no data, pls wait and refresh this page :)</h3></div></div></div>'); } } else { console.log("can't find any line in <pre> tag"); } } else { console.log("page's <pre> tag count illegal:" + preList.length); } $("body").on("click", "#navbar ul li", function () { navBarLiClick($(this).attr("data-value")); }); $("body").on("click", "#nav ul li", function () { navLiClick($(this).attr("data-parta"), $(this).attr("data-partb")); }); $("body").on("click", "#table tbody tr", function () { $(this).css("background", "#DCDCDC").siblings().css("background", ""); }); $("body").on("click", "#previousPageLi", function () { if (localStorage.pageIndex != 1) { localStorage.pageIndex = parseInt(localStorage.pageIndex) - 1; initFileList(localStorage.partA, localStorage.partB); } }); $("body").on("click", "#nextPageLi", function () { var totalPageCount = localStorage.totalCount % localStorage.pageSize == 0 ? localStorage.totalCount / localStorage.pageSize : Math.ceil(localStorage.totalCount / localStorage.pageSize); if (localStorage.pageIndex != totalPageCount) { localStorage.pageIndex = parseInt(localStorage.pageIndex) + 1; initFileList(localStorage.partA, localStorage.partB); } }); function formatDate(dt) { var date = new Date(dt); var aaaa = date.getFullYear(); var gg = date.getDate(); var mm = (date.getMonth() + 1); if (gg < 10) gg = "0" + gg; if (mm < 10) mm = "0" + mm; var cur_day = aaaa + "-" + mm + "-" + gg; var hours = date.getHours() var minutes = date.getMinutes() //var seconds = date.getSeconds(); if (hours < 10) hours = "0" + hours; if (minutes < 10) minutes = "0" + minutes; //if (seconds < 10) seconds = "0" + seconds; //return cur_day + " " + hours + ":" + minutes + ":" + seconds; return cur_day + " " + hours + ":" + minutes; } function getDistinctPartA() { return JSLINQ(fileList).Distinct(function () { return this.PartA; }).items; } function getDistinctPartB(partA) { return JSLINQ(fileList).Where(function () { return this.PartA == partA; }).Distinct(function () { return this.PartB; }).items; } function getFileListPage(partA, partB) { var totalPageCount = localStorage.totalCount % localStorage.pageSize == 0 ? localStorage.totalCount / localStorage.pageSize : Math.ceil(localStorage.totalCount / localStorage.pageSize); if (localStorage.pageIndex == 1) { $("#previousPageLi").addClass("disabled"); } else { $("#previousPageLi").removeClass("disabled"); } if (localStorage.pageIndex == totalPageCount) { $("#nextPageLi").addClass("disabled"); } else { $("#nextPageLi").removeClass("disabled"); } $("#pageIndexSpan").text(localStorage.pageIndex); $("#pageSizeSpan").text(localStorage.pageSize); $("#totalCountSpan").text(localStorage.totalCount); if (partB == 'all') { return JSLINQ(fileList).Reverse().Where(function () { return this.PartA == partA; }).Skip(parseInt(localStorage.pageSize) * (parseInt(localStorage.pageIndex) - 1)).Take(parseInt(localStorage.pageSize)).Select("PartB,FileTime,FileSize,FileName").items; } else { return JSLINQ(fileList).Reverse().Where(function () { return this.PartA == partA && this.PartB == partB; }).Skip(parseInt(localStorage.pageSize) * (parseInt(localStorage.pageIndex) - 1)).Take(parseInt(localStorage.pageSize)).Select("PartB,FileTime,FileSize,FileName").items; } } function getFileListTotalCount(partA, partB) { if (partB == 'all') { return JSLINQ(fileList).Count(function () { return this.PartA == partA; }); } else { return JSLINQ(fileList).Count(function () { return this.PartA == partA && this.PartB == partB; }); } } function navBarLiClick(partA) { $("#navbar ul li[data-value=\"" + partA + "\"]").addClass("active").siblings().removeClass("active"); $("#nav ul").empty(); $("#nav ul").append("<li data-parta=\"" + partA + "\" data-partb=\"all\"><a href='javascript:;'>all</a></li>"); var partB = ''; var list = getDistinctPartB(partA); //list.sort(); list.reverse(); $.each(list, function (i, v) { if (localStorage.partB != undefined && localStorage.partA != undefined && localStorage.partA == partA && localStorage.partB == v) { partB = localStorage.partB; $("#nav ul").append("<li class='active' data-parta=\"" + partA + "\" data-partb=\"" + v + "\"><a href='javascript:;'>" + v + "</a></li>"); } else { $("#nav ul").append("<li data-parta=\"" + partA + "\" data-partb=\"" + v + "\"><a href='javascript:;'>" + v + "</a></li>"); } }); if (partB == '') { partB = 'all'; $("#nav ul li:first").addClass("active"); } initFileList(partA, partB); } function navLiClick(partA, partB) { $("#nav ul li[data-partb=\"" + partB + "\"]").addClass("active").siblings().removeClass("active"); initFileList(partA, partB); } function initFileList(partA, partB) { if (localStorage.partA != partA || localStorage.partB != partB) { localStorage.pageIndex = 1; localStorage.pageSize = 10; } if (localStorage.partA != partA) { localStorage.partA = partA; } if (localStorage.partB != partB) { localStorage.partB = partB; } var totalCount = getFileListTotalCount(partA, partB); if (localStorage.totalCount != totalCount) { localStorage.totalCount = totalCount; } var fileList = getFileListPage(partA, partB); $("#table").empty(); // $("#table").append("<thead><tr><th>FileName</th><th>Time</th><th>FileSize</th><th>Operate</th></tr></thead><tbody>"); if (fileList.length > 0) { $.each(fileList, function (i, v) { $("#table").append("<tr><td>" + v.FileName + "</td><td>" + v.FileTime + "</td><td>" + v.FileSize + "</td><td><a href='" + v.FileName + "' target='_blank'>Link</a></td></tr>"); }); } else { $("#table").append("<tr><td colspan='4'><center>no data</center></td></tr>"); } $("#table").append("</tbody>"); }View Code
獲取原頁面裡面的所有檔案資訊,專案名去重放在頂部,用Bootstrap的navBar外掛展示,版本號由上到下依次放在左側的nav外掛上,右側則用Bootstrap的table展示檔案詳細資訊。效果如下
至此,分類、翻頁展示功能完美實現,以後就算檔案再多也可以快速找到了。
三、總結
通過“background”的方式注入,優點是頁面隨時可以配置,很方便,缺點是使用者訪問的每個頁面都需要“在background.js”裡面挨個過濾,感覺效率不行。個人還是比較喜歡“content_scripts”這種防止注入。
四、其他
本文僅拋磚引玉,Chrome外掛可以做的事情還有很多,更多使用場景大家自己去發揮。原始碼地址 Chrome商店 開發文件