[SH iOS] Hooking browser into JS

This creates an end-to-end connection from the navigation stack into the
new third-party JS lib which will handle the highlighting/scrolling in
the page.

Change-Id: I95d2a0e89387708d573bfab4617fa5ff34f516c8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2354605
Commit-Queue: Tommy Martino <tmartino@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#798300}

ios/web/BUILD.gn

@@ -584,11 +584,13 @@ js_compile_bundle("main_frame_web_bundle") {
   closure_entry_point = "__crWeb.mainFrameWebBundle"
 
   sources = [
+    "//third_party/text-fragments-polyfill/src/src/text-fragment-utils.js",
     "web_state/js/resources/error.js",
     "web_state/js/resources/main_frame_context_menu.js",
     "web_state/js/resources/main_frame_web_bundle.js",
     "web_state/js/resources/navigation.js",
     "web_state/js/resources/scroll_workaround.js",
+    "web_state/js/resources/text_fragments.js",
   ]
 }
 

ios/web/navigation/crw_wk_navigation_handler.mm

@@ -24,6 +24,7 @@
 #import "ios/web/navigation/navigation_context_impl.h"
 #import "ios/web/navigation/navigation_manager_impl.h"
 #include "ios/web/navigation/navigation_manager_util.h"
+#import "ios/web/navigation/text_fragment_utils.h"
 #import "ios/web/navigation/web_kit_constants.h"
 #import "ios/web/navigation/wk_back_forward_list_item_holder.h"
 #import "ios/web/navigation/wk_navigation_action_policy_util.h"
@@ -1150,6 +1151,10 @@ void ReportOutOfSyncURLInDidStartProvisionalNavigation(
     }
   }
 
+  if (context && web::AreTextFragmentsAllowed(context)) {
+    web::HandleTextFragments(self.webStateImpl);
+  }
+
   [self.navigationStates setState:web::WKNavigationState::FINISHED
                     forNavigation:navigation];
 

ios/web/navigation/text_fragment_utils.h

@@ -12,6 +12,7 @@ class GURL;
 namespace web {
 
 class NavigationContext;
+class WebState;
 
 // This file contains helper functions relating to Text Fragments, which are
 // appended to the reference fragment in the URL and instruct the user agent
@@ -25,7 +26,7 @@ bool AreTextFragmentsAllowed(NavigationContext* context);
 
 // Checks the destination URL for Text Fragments. If found, searches the DOM for
 // matching text, highlights the text, and scrolls the first into view.
-void HandleTextFragments(NavigationContext* context);
+void HandleTextFragments(WebState* state);
 
 // Exposed for testing only.
 namespace internal {
@@ -33,7 +34,7 @@ namespace internal {
 // Checks the fragment portion of the URL for Text Fragments. Returns zero or
 // more dictionaries containing the parsed parameters used by the fragment-
 // finding algorithm, as defined in the spec.
-std::vector<base::Value> ParseTextFragments(const GURL& url);
+base::Value ParseTextFragments(const GURL& url);
 
 // Extracts the text fragments, if any, from a ref string.
 std::vector<std::string> ExtractTextFragments(std::string ref_string);

ios/web/navigation/text_fragment_utils.mm

@@ -6,7 +6,10 @@
 
 #include <cstring.h>
 
+#include "base/json/json_writer.h"
 #include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
+#include "base/strings/utf_string_conversions.h"
 #include "ios/web/common/features.h"
 #import "ios/web/public/navigation/navigation_context.h"
 #import "ios/web/public/web_state.h"
@@ -38,26 +41,35 @@ bool AreTextFragmentsAllowed(NavigationContext* context) {
   return context->HasUserGesture() && !context->IsSameDocument();
 }
 
-void HandleTextFragments(NavigationContext* context) {
-  // TODO(crbug.com/1099268): Parse URL fragment, execute JS using passed
-  // params.
+void HandleTextFragments(WebState* state) {
+  std::string fragment_param;
+  base::JSONWriter::Write(
+      internal::ParseTextFragments(state->GetLastCommittedURL()),
+      &fragment_param);
+
+  std::string script = base::ReplaceStringPlaceholders(
+      "__gCrWeb.textFragments.handleTextFragments($1, $2)",
+      {fragment_param, /* scroll = */ "true"},
+      /* offsets= */ nullptr);
+
+  state->ExecuteJavaScript(base::UTF8ToUTF16(script));
 }
 
 namespace internal {
 
-std::vector<base::Value> ParseTextFragments(const GURL& url) {
+base::Value ParseTextFragments(const GURL& url) {
   if (!url.has_ref())
     return {};
   std::vector<std::string> fragments = ExtractTextFragments(url.ref());
   if (fragments.empty())
     return {};
 
-  std::vector<base::Value> parsed;
+  base::Value parsed(base::Value::Type::LIST);
   for (const std::string& fragment : fragments) {
     base::Value parsed_fragment = TextFragmentToValue(fragment);
     if (parsed_fragment.type() == base::Value::Type::NONE)
       continue;
-    parsed.push_back(std::move(parsed_fragment));
+    parsed.Append(std::move(parsed_fragment));
   }
 
   return parsed;

ios/web/navigation/text_fragment_utils_unittest.mm

@@ -70,16 +70,16 @@ TEST_F(TextFragmentUtilsTest, AreTextFragmentsAllowed) {
 TEST_F(TextFragmentUtilsTest, ParseTextFragments) {
   GURL url_with_fragment(
       "https://www.example.com/#idFrag:~:text=text%201&text=text%202");
-  std::vector<base::Value> result =
-      internal::ParseTextFragments(url_with_fragment);
-  ASSERT_EQ(2u, result.size());
-  EXPECT_EQ("text%201", result[0].FindKey(kTextStartKey)->GetString());
-  EXPECT_EQ("text%202", result[1].FindKey(kTextStartKey)->GetString());
+  base::Value result = internal::ParseTextFragments(url_with_fragment);
+  ASSERT_EQ(2u, result.GetList().size());
+  EXPECT_EQ("text%201",
+            result.GetList()[0].FindKey(kTextStartKey)->GetString());
+  EXPECT_EQ("text%202",
+            result.GetList()[1].FindKey(kTextStartKey)->GetString());
 
   GURL url_no_fragment("www.example.com");
-  std::vector<base::Value> empty_result =
-      internal::ParseTextFragments(url_no_fragment);
-  EXPECT_TRUE(empty_result.empty());
+  base::Value empty_result = internal::ParseTextFragments(url_no_fragment);
+  EXPECT_TRUE(empty_result.is_none());
 }
 
 TEST_F(TextFragmentUtilsTest, ExtractTextFragments) {

ios/web/web_state/js/resources/main_frame_web_bundle.js

@@ -11,3 +11,4 @@ goog.require('__crWeb.error');
 goog.require('__crWeb.mainFrameContextMenu');
 goog.require('__crWeb.navigation');
 goog.require('__crWeb.scrollWorkaround');
+goog.require('__crWeb.textFragments');

ios/web/web_state/js/resources/text_fragments.js

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+goog.module('__crWeb.textFragments');
+goog.module.declareLegacyNamespace();
+
+const utils = goog.require(
+    'googleChromeLabs.textFragmentPolyfill.textFragmentUtils');
+
+/**
+ * @fileoverview Interface used for Chrome/WebView to call into the
+ * text-fragments-polyfill lib, which handles finding text fragments provided
+ * by the navigation layer, highlighting them, and scrolling them into view.
+ */
+
+(function() {
+
+  __gCrWeb['textFragments'] = {};
+
+  /**
+   * Attempts to identify and highlight the given text fragments and,
+   * optionally, scroll them into view.
+   */
+  __gCrWeb.textFragments.handleTextFragments = function(fragments, scroll) {
+    if (document.readyState === "complete" ||
+        document.readyState === "interactive") {
+      doHandleTextFragments(fragments, scroll);
+    } else {
+      document.addEventListener("DOMContentLoaded", () => {
+        doHandleTextFragments(fragments, scroll);
+      });
+    }
+  }
+
+  /**
+   * Does the actual work for handleTextFragments.
+   */
+  const doHandleTextFragments = function(fragments, scroll) {
+    let marks = [];
+
+    for (const fragment of fragments) {
+      let newMarks = utils.processTextFragmentDirective(fragment);
+      if (Array.isArray(newMarks))
+        marks.push(...newMarks);
+    }
+
+    if (scroll && marks.length > 0)
+      utils.scrollElementIntoView(marks[0]);
+
+    // TODO(crbug.com/1099268): Count successes/failures above and log metrics
+    // TODO(crbug.com/1099268): Make marks disappear on user interaction
+  }
+
+})();

ios/web/web_state/web_state_impl.mm

@@ -20,7 +20,6 @@
 #import "ios/web/navigation/navigation_context_impl.h"
 #import "ios/web/navigation/navigation_item_impl.h"
 #import "ios/web/navigation/session_storage_builder.h"
-#import "ios/web/navigation/text_fragment_utils.h"
 #import "ios/web/navigation/wk_based_navigation_manager_impl.h"
 #import "ios/web/navigation/wk_navigation_util.h"
 #include "ios/web/public/browser_state.h"
@@ -859,10 +858,6 @@ void WebStateImpl::OnNavigationFinished(web::NavigationContextImpl* context) {
       observer.FaviconUrlUpdated(this, cached_favicon_urls_);
     }
   }
-
-  if (AreTextFragmentsAllowed(context)) {
-    HandleTextFragments(context);
-  }
 }
 
 #pragma mark - NavigationManagerDelegate implementation