Bug 1132203 - Load JSON viewer only for top level documents; r=bz

--HG--
extra : rebase_source : b58c0faf87ae906f592e068aa2f54cb2acc38152

devtools/client/jsonview/converter-child.js

@@ -28,15 +28,20 @@ const childProcessMessageManager =
 // Must be power of 2. Used to copy the data stream in onStopRequest.
 const SEGMENT_SIZE = Math.pow(2, 17);
 
+const JSON_VIEW_MIME_TYPE = "application/vnd.mozilla.json.view";
+const CONTRACT_ID = "@mozilla.org/streamconv;1?from=" + JSON_VIEW_MIME_TYPE + "&to=*/*";
+const CLASS_ID = "{d8c9acee-dec5-11e4-8c75-1681e6b88ec1}";
+
 // Localization
 var jsonViewStrings = Services.strings.createBundle(
   "chrome://browser/locale/devtools/jsonview.properties");
 
 /**
- * This object detects application/json content type and converts it
- * into a JSON Viewer application that allows simple JSON inspection.
+ * This object detects 'application/vnd.mozilla.json.view' content type
+ * and converts it into a JSON Viewer application that allows simple
+ * JSON inspection.
  *
- * Based on JSON View: https://github.com/bhollis/jsonview/
+ * Inspired by JSON View: https://github.com/bhollis/jsonview/
  */
 var Converter = Class({
   extends: Unknown,
@@ -274,9 +279,6 @@ var Converter = Class({
 });
 
 // Stream converter component definition
-const CONTRACT_ID = "@mozilla.org/streamconv;1?from=application/json&to=*/*";
-const CLASS_ID = "{d8c9acee-dec5-11e4-8c75-1681e6b88ec1}";
-
 var service = xpcom.Service({
   id: components.ID(CLASS_ID),
   contract: CONTRACT_ID,
@@ -290,7 +292,6 @@ function register() {
     xpcom.register(service);
     return true;
   }
-
   return false;
 }
 
@@ -299,7 +300,6 @@ function unregister() {
     xpcom.unregister(service);
     return true;
   }
-
   return false;
 }
 

devtools/client/jsonview/converter-observer.js

@@ -12,32 +12,31 @@ const Ci = Components.interfaces;
 
 const {XPCOMUtils} = Cu.import("resource://gre/modules/XPCOMUtils.jsm", {});
 const {Services} = Cu.import("resource://gre/modules/Services.jsm", {});
+const {devtools} = Cu.import("resource://gre/modules/devtools/shared/Loader.jsm", {});
 
-const categoryManager = Cc["@mozilla.org/categorymanager;1"].getService(Ci.nsICategoryManager);
-
-// Load JsonView service module (converter-child.js) as soon as required.
+// Load JsonView services lazily.
 XPCOMUtils.defineLazyGetter(this, "JsonViewService", function() {
-  const {devtools} = Cu.import("resource://gre/modules/devtools/shared/Loader.jsm", {});
   const {JsonViewService} = devtools.require("devtools/client/jsonview/converter-child");
   return JsonViewService;
 });
 
-const JSON_TYPE = "application/json";
-const GECKO_VIEWER = "Gecko-Content-Viewers";
+XPCOMUtils.defineLazyGetter(this, "JsonViewSniffer", function() {
+  const {JsonViewSniffer} = devtools.require("devtools/client/jsonview/converter-sniffer");
+  return JsonViewSniffer;
+});
+
+// Constants
 const JSON_VIEW_PREF = "devtools.jsonview.enabled";
-const GECKO_TYPE_MAPPING = "ext-to-type-mapping";
 
 /**
  * Listen for 'devtools.jsonview.enabled' preference changes and
- * register/unregister the JSON View XPCOM service as appropriate.
+ * register/unregister the JSON View XPCOM services as appropriate.
  */
 function ConverterObserver() {
 }
 
 ConverterObserver.prototype = {
   initialize: function() {
-    this.geckoViewer = categoryManager.getCategoryEntry(GECKO_VIEWER, JSON_TYPE);
-
     // Only the DevEdition has this feature available by default.
     // Users need to manually flip 'devtools.jsonview.enabled' preference
     // to have it available in other distributions.
@@ -74,29 +73,13 @@ ConverterObserver.prototype = {
   },
 
   register: function() {
-    if (JsonViewService.register()) {
-      // Delete default JSON viewer (text)
-      categoryManager.deleteCategoryEntry(GECKO_VIEWER, JSON_TYPE, false);
-
-      // Append new *.json -> application/json type mapping
-      this.geckoMapping = categoryManager.addCategoryEntry(GECKO_TYPE_MAPPING,
-        "json", JSON_TYPE, false, true);
-    }
+    JsonViewSniffer.register();
+    JsonViewService.register();
   },
 
   unregister: function() {
-    if (JsonViewService.unregister()) {
-      categoryManager.addCategoryEntry(GECKO_VIEWER, JSON_TYPE,
-        this.geckoViewer, false, false);
-
-      if (this.geckoMapping) {
-        categoryManager.addCategoryEntry(GECKO_TYPE_MAPPING, "json",
-          this.geckoMapping, false, true);
-      } else {
-        categoryManager.deleteCategoryEntry(GECKO_TYPE_MAPPING,
-          JSON_TYPE, false)
-      }
-    }
+    JsonViewSniffer.unregister();
+    JsonViewService.unregister();
   },
 
   isEnabled: function() {

devtools/client/jsonview/converter-sniffer.js

@@ -0,0 +1,102 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const {Cc, Ci, components} = require("chrome");
+const xpcom = require("sdk/platform/xpcom");
+const {Unknown} = require("sdk/platform/xpcom");
+const {Class} = require("sdk/core/heritage");
+
+const categoryManager = Cc["@mozilla.org/categorymanager;1"].getService(Ci.nsICategoryManager);
+
+loader.lazyRequireGetter(this, "NetworkHelper",
+                               "devtools/shared/webconsole/network-helper");
+
+// Constants
+const JSON_TYPE = "application/json";
+const CONTRACT_ID = "@mozilla.org/devtools/jsonview-sniffer;1";
+const CLASS_ID = "{4148c488-dca1-49fc-a621-2a0097a62422}";
+const JSON_VIEW_MIME_TYPE = "application/vnd.mozilla.json.view";
+const JSON_VIEW_TYPE = "JSON View";
+const CONTENT_SNIFFER_CATEGORY = "net-content-sniffers";
+
+/**
+ * This component represents a sniffer (implements nsIContentSniffer
+ * interface) responsible for changing top level 'application/json'
+ * document types to: 'application/vnd.mozilla.json.view'.
+ *
+ * This internal type is consequently rendered by JSON View component
+ * that represents the JSON through a viewer interface.
+ */
+var Sniffer = Class({
+  extends: Unknown,
+
+  interfaces: [
+    "nsIContentSniffer",
+  ],
+
+  get wrappedJSObject() this,
+
+  getMIMETypeFromContent: function(aRequest, aData, aLength) {
+    // JSON View is enabled only for top level loads only.
+    if (!NetworkHelper.isTopLevelLoad(aRequest)) {
+      return "";
+    }
+
+    if (aRequest instanceof Ci.nsIChannel) {
+      try {
+        if (aRequest.contentDisposition == Ci.nsIChannel.DISPOSITION_ATTACHMENT) {
+          return "";
+        }
+      } catch (e) {
+        // Channel doesn't support content dispositions
+      }
+
+      // Check the response content type and if it's application/json
+      // change it to new internal type consumed by JSON View.
+      if (aRequest.contentType == JSON_TYPE) {
+        return JSON_VIEW_MIME_TYPE;
+      }
+    }
+
+    return "";
+  }
+});
+
+var service = xpcom.Service({
+  id: components.ID(CLASS_ID),
+  contract: CONTRACT_ID,
+  Component: Sniffer,
+  register: false,
+  unregister: false
+});
+
+function register() {
+  if (!xpcom.isRegistered(service)) {
+    xpcom.register(service);
+    categoryManager.addCategoryEntry(CONTENT_SNIFFER_CATEGORY, JSON_VIEW_TYPE,
+      CONTRACT_ID, false, false);
+    return true;
+  }
+
+  return false;
+}
+
+function unregister() {
+  if (xpcom.isRegistered(service)) {
+    categoryManager.deleteCategoryEntry(CONTENT_SNIFFER_CATEGORY,
+      JSON_VIEW_TYPE, false)
+    xpcom.unregister(service);
+    return true;
+  }
+  return false;
+}
+
+exports.JsonViewSniffer = {
+  register: register,
+  unregister: unregister
+}

devtools/client/jsonview/moz.build

@@ -13,6 +13,7 @@ DIRS += [
 DevToolsModules(
     'converter-child.js',
     'converter-observer.js',
+    'converter-sniffer.js',
     'json-viewer.js',
     'main.js',
     'utils.js',

devtools/shared/webconsole/network-helper.js

@@ -264,6 +264,24 @@ var NetworkHelper = {
     return null;
   },
 
+  /**
+   * Determines whether the request has been made for the top level document.
+   *
+   * @param nsIHttpChannel aRequest
+   * @returns Boolean True if the request represents the top level document.
+   */
+  isTopLevelLoad: function(aRequest)
+  {
+    if (aRequest instanceof Ci.nsIChannel) {
+      let loadInfo = aRequest.loadInfo;
+      if (loadInfo && loadInfo.parentOuterWindowID == loadInfo.outerWindowID) {
+        return (aRequest.loadFlags & Ci.nsIChannel.LOAD_DOCUMENT_URI);
+      }
+    }
+
+    return false;
+  },
+
   /**
    * Loads the content of aUrl from the cache.
    *