nsIProtocol 示例不清楚

Question

我在 MDN 上比较了这个例子： https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XPCOM/Reference/Interface/nsIProtocolHandler#Implementation

关于如何创建自定义协议的附加组件： https://addons.mozilla.org/en-US/firefox/files/browse/141969/file/components/AboutFosdem.js#top

有人可以详细说明它到底想做什么。 SMTP 的东西让我大吃一惊。

我无法理解 MDN 上的示例在做什么，它在没有 chrome.manifst 的情况下做任何事情。我知道插件正在创建“fosdem://blah”，其中 blah 是我想要的任何内容，基于 WhereToGo 中的定义，但它使用 chrome.manifest。

我认为 mdn 示例与插件做同样的事情，我会在复制粘贴该 mdn 代码后做这样的事情来设置我的自定义协议：

function myCustomBlah() {}

myCustomBlah.prototype =
  makeProtocolHandler("mycustomblah",
                      -1,
                      "b14c2b67-8680-4c11-8d63-9403c7d4f757"); //i can generate any id

var components = [myCustomBlah];
const NSGetFactory = XPCOMUtils.generateNSGetFactory(components);

Answer 1

好吧，让我们举一个更合理的自定义协议处理程序示例。

我决定实现一个ddg: 协议处理程序，一旦注册，就可以在地址栏中输入ddg:some search terms（除其他外），它会加载 DuckDuckGo 搜索页面以查找“一些搜索词”。

组件

需要实现nsIProtocolHandler接口。

这个示例组件所做的是将“重定向”到 DuckDuckGo（好吧，不是真正的重定向，但它返回了一个用于 duckduckgo.com 的频道）。见内联 cmets。

var {classes: Cc,
     interfaces: Ci,
     manager: Cm,
     results: Cr,
     Constructor: CC
    } = Components;
Cm.QueryInterface(Ci.nsIComponentRegistrar);

Components.utils.import("resource://gre/modules/Services.jsm");
Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");

const SCHEME = "ddg";
const DDG_URI = Services.io.newURI("https://duckduckgo.com/?q=%s", null, null);

const nsIURI = CC("@mozilla.org/network/simple-uri;1", "nsIURI");

function DuckDuckGoProtocolHandler() {}
DuckDuckGoProtocolHandler.prototype = Object.freeze({
  classDescription: "DuckDuckGo Protocol Handler",
  contractID: "@mozilla.org/network/protocol;1?name=" + SCHEME,
  classID: Components.ID('{858ea860-129a-11e4-9191-0800200c9a66}'),
  QueryInterface: XPCOMUtils.generateQI([Ci.nsIProtocolHandler]),

  // nsIProtocolHandler
  scheme: SCHEME,
  defaultPort: -1, // No default port.

  // nsIProtocolHandler
  allowPort: function(port, scheme) {
    // This protocol handler does not support ports.
    return false;
  },

  // nsIProtocolHandler
  // Our protocol handler does not support authentication,
  // but it is OK to be loaded from any web-page, not just privileged pages""
  protocolFlags: Ci.nsIProtocolHandler.URI_NOAUTH |
                 Ci.nsIProtocolHandler.URI_LOADABLE_BY_ANYONE,

  // nsIProtocolHandler
  newURI: function(aSpec, aOriginCharset, aBaseURI) {
    // Nothing special here, actually. We were asked to create a new URI.

    // If there is a base-URI, this means that the browser tries to resolve
    // a dependent resource (an image, script) or the user clicked on a relative link.
    // In this case we cannot really return another "ddg" URI, but need to return
    // the proper https URI.
    if (aBaseURI && aBaseURI.scheme == SCHEME) {
      return Services.io.newURI(aSpec, aOriginCharset, DDG_URI);
    }

    // We don't care about the charset, so just ignore that
    // (we support what nsIURI supports).
    let rv = new nsIURI();
    rv.spec = aSpec;
    return rv;
  },

  // nsIProtocolHandler
  newChannel: function(aURI) {
    // We were asked to open a new channel.
    // We could implement an entirely custom channel that supports
    // (most of) nsIChannel. But that is tremendous work and outside
    // of the scope of this basic example (which is about protocol handlers and
    // not channels).
    // Or we can just return any other channel we can create.
    // Since we're going to implement the "ddg:" protocol, lets just open a
    // regular https channel to duckduckgo.com, use the URI as the search term
    // and return that channel.
    let spec = DDG_URI.spec.replace("%s", aURI.path);
    let channel = Services.io.newChannel(spec, aURI.originCharset, null);

    // Setting .originalURI will not only let other code know where this
    // originally came from, but the UI will actually show that .originalURI.
    channel.originalURI = aURI;

    return channel;
  }
});

chrome.manifest 中的组件注册

如果我们的组件是 JavaScript 组件，我们需要实现 NSGetFactory 通过 chrome.manifest 注册。幸运的是，XPCOMUtils.jsm 有一个帮手。

var NSGetFactory =
  XPCOMUtils.generateNSGetFactory([DuckDuckGoProtocolHandler]);

在引导加载项（和 Scratchpad）中注册

在 bootstrapped/restartless 插件（包括 SDK 插件）和 Scratchpad 中，需要手动注册组件，因为 chrome.manifest 注册不可用。

可以注册NSGetFactory(classID)的结果，但这里有一些代码手动创建工厂并注册它。

function Factory(component) {
  this.createInstance = function(outer, iid) {
    if (outer) {
      throw Cr.NS_ERROR_NO_AGGREGATION;
    }
    return new component();
  };
  this.register = function() {
    Cm.registerFactory(component.prototype.classID,
                       component.prototype.classDescription,
                       component.prototype.contractID,
                       this);
  };
  this.unregister = function() {
    Cm.unregisterFactory(component.prototype.classID, this);
  }
    Object.freeze(this);
  this.register();
}
var factory = new Factory(DuckDuckGoProtocolHandler);

请注意，在无需重启的附加组件中，您还需要取消注册它 再次关机！

factory.unregister();

在 Scratchpad 中测试

将组件代码和手动注册代码复制到暂存器中，将Enviroment设置为Browser，然后运行。然后在标签中打开ddg:some search terms ;)

Answer 2

哎呀，你打败了我。

我完全理解从 MDN 中删除的情况。

我写了这个例子，它有一个问题，它改变了 URL。我会阅读您的解决方案并与我的比较。

顺便说一句，我从 about:addons-memory 插件中删除了这个。在此示例中，如果您输入 somecustomblah:noitidart。它将带您访问 twitter.com/noitidart。问题是，网址从somecustomblah:noitidart 更改为twitter.com/Noitidart/，我想尝试修复，我认为您的解决方案可能有答案@nmaier。这种方式不需要chrome.manifest，也可以用reigsterComponents注册，用unregisterComponents注销。

确保根据您的协议生成您自己的 UUID：http://www.famkruithof.net/uuid/uuidgen

aDefaultPort 的第三个参数允许您执行 moz Central 正在执行的 SMTP 操作。如果您不想在使用端口时执行 SMTP 操作，则可以省略它，或者将其设为 null 或 undefined。

var {classes: Cc, interfaces: Ci, utils: Cu, results: Cr, manager: Cm} = Components; //can make this const if not in scratchpad
Cm.QueryInterface(Ci.nsIComponentRegistrar);
Cu.import('resource://gre/modules/Services.jsm');
Cu.import('resource://gre/modules/XPCOMUtils.jsm');

var nsIProtocolHandler = Ci.nsIProtocolHandler; //const

var unloaders = [];

function makeProtocolHandler(aProtocol, aClassID, aDefaultPort) {
    var obj = {
        classID: Components.ID(aClassID),
        classDescription: 'blah blah blah',
        contractID: '@mozilla.org/network/protocol;1?name=' + aProtocol,
        QueryInterface: XPCOMUtils.generateQI([nsIProtocolHandler]),
        scheme: aProtocol,
        defaultPort: aDefaultPort,
        protocolFlags: nsIProtocolHandler.URI_NORELATIVE | nsIProtocolHandler.URI_NOAUTH | nsIProtocolHandler.URI_LOADABLE_BY_ANYONE, //You must specify either URI_LOADABLE_BY_ANYONE, URI_DANGEROUS_TO_LOAD, URI_IS_UI_RESOURCE, or URI_IS_LOCAL_FILE in order for your protocol to work.
        newURI: function(aSpec, aOriginCharset, aBaseURI) {
            var uri = Cc['@mozilla.org/network/simple-uri;1'].createInstance(Ci.nsIURI);
            uri.spec = aSpec;
            console.log('uri=', uri);
            return uri;
        },

        newChannel: function(aURI) {
            //throw Cr.NS_ERROR_NOT_IMPLEMENTED;
            /* Get twitterName from URL */
            var postProtocolPath = aURI.spec.split(":")[1];
            var uri = Services.io.newURI("http://twitter.com/" + postProtocolPath, null, null);
            var channel = Services.io.newChannelFromURI(uri); //, null).QueryInterface(Ci.nsIHttpChannel); //i dont think i need to QI nsIHttpChannel
            /* Determines whether the URL bar changes to the URL */
            //channel.setRequestHeader("X-Moz-Is-Feed", "1", false);
            channel.originalURI = aURI;
            return channel;
        },
        getURIFlags: function(aURI) 0 // i dont think i need this? do I?
    };

    if (aDefaultPort == undefined || aDefaultPort == null) {
        aDefaultPort = -1;
    } else {
        obj.allowPort = function(port, scheme) {
            return port == aDefaultPort;
        };
    }

    return obj;
}

var myComponents = [myCustomBlah];

function myCustomBlah() {}
myCustomBlah.prototype = makeProtocolHandler('mycustomblah', 'b14c2b67-8680-4c11-8d63-9403c7d4f757'); //this uuid (2nd argument) should be generated by you from here: http://www.famkruithof.net/uuid/uuidgen

//const NSGetFactory = XPCOMUtils.generateNSGetFactory(components);


function registerComponents() {
    for (let [y, cls] in Iterator(myComponents)) {
        console.info('y: ', y, 'cls: ', cls);
        try {
            var factory = {
                _cls: cls,
                createInstance: function(outer, iid) {
                    if (outer) {
                        throw Cr.NS_ERROR_NO_AGGREGATION;
                    }
                    return new cls();
                }
            };
            Cm.registerFactory(cls.prototype.classID, cls.prototype.classDescription, cls.prototype.contractID, factory);
            unloaders.push(function() {
                Cm.unregisterFactory(factory._cls.prototype.classID, factory);
            });
        } catch (ex) {
            console.warn('failed to register module: ', cls.name, 'exception thrown: ', ex);
        }
    }
}

function unregisterComponents() {
    for (var i = 0; i < unloaders.length; i++) {
        unloaders[i]();
    }
}

registerComponents(); //run this to make it work. once this is run follwoing examples above: typing "about:yabba" will take you to bings homepage
//unregisterComponents(); //do this to remove it //after running this typing about:yabba will take you to problem loading page