Mozilla Firefox扩展（Extensions）开发——XPCOM&XUL(一)

XPCOM和XUL是被官方遗弃的技术，他们推荐使用Add-on SDK(https://developer.mozilla.org/en-US/Add-ons/SDK)，但有些时候你仍然可以使用这些技术实现你的需求。

《Let‘s build a Firefox extension》：

https://developer.mozilla.org/en-US/Add-ons/Overlay_Extensions/Firefox_addons_developer_guide/Let's_build_a_Firefox_extension

1、配置开发环境

Create a development profile

firefox.exe -no-remote -P dev

Firefox浏览器输入about:plugins，修改或添加如下配置项

2、创建一个简单的扩展：Hello World

扩展的目录结构如下：

各个文件的说明

install.rdf

<?xml version="1.0"?>
<RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:em="http://www.mozilla.org/2004/em-rdf#">
  <Description about="urn:mozilla:install-manifest">
    <!-- Unique ID for extension. Can be in e-mail address format or GUID format -->
    <em:id>[email protected]</em:id>
    <!-- Indicates that this add-on is an extension -->
    <em:type>2</em:type>
    <!-- Extension name displayed in Add-on Manager -->
    <em:name>Hello, World!</em:name>
    <!-- Extension version number. There is a version numbering scheme you must follow -->
    <em:version>0.1</em:version>
    <!-- Brief description displayed in Add-on Manager -->
    <em:description>My first extension.</em:description>
    <!-- Name of extension's primary developer. Change to your name -->
    <em:creator>Gomita</em:creator>
    <!-- Web page address through which extension is distributed -->
    <em:homepageURL>http://www.xuldev.org/helloworld/</em:homepageURL>
    <!-- This section gives details of the target application for the extension (in this case: Firefox 2) -->
    <em:targetApplication>
      <Description>
        <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
        <em:minVersion>2.0</em:minVersion>
        <em:maxVersion>4.0.0.*</em:maxVersion>
      </Description>
    </em:targetApplication>
  </Description>
</RDF>

overlay.xul

<?xml version="1.0"?>
<overlay id="helloworldOverlay" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
  <menupopup id="menu_ToolsPopup">
    <menuitem id="helloworldMenuitem" label="Hello, World!" insertbefore="sanitizeSeparator"
     oncommand="window.openDialog('chrome://helloworld/content/clock.xul','Clock','chrome,centerscreen,modal');"/>
  </menupopup>
</overlay>

clock.xul

<?xml version="1.0"?>
<?xml-stylesheet href="chrome://global/skin/"?>
<dialog id="clockDialog" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
    title="Clock"
    buttons="accept"
    onload="initClock();">
  <script type="application/javascript" src="chrome://helloworld/content/clock.js"/>
  <hbox align="center">
    <label value="Current Time:" />
    <textbox id="currentTime" />
  </hbox>
</dialog>

clock.js

function initClock() {
  showCurrentTime();
  window.setInterval(showCurrentTime, 1000);
}

function showCurrentTime() {
  var textbox = document.getElementById("currentTime");
  textbox.value = new Date().toLocaleTimeString();
  textbox.select();
}

将整个目录压缩（注意不要包含helloworld目录）为zip，将后缀改为xpi，安装。安装成功后打开工具菜单栏即可看到Hello World菜单。点击效果如下：

哈哈，今天是圣诞节呢，连主页广告都这么美美哒，所以截了个大图~