MD History: Implement search functionality.

chrome/browser/resources/md_history/history_item.js

Index: chrome/browser/resources/md_history/history_item.js
diff --git a/chrome/browser/resources/md_history/history_item.js b/chrome/browser/resources/md_history/history_item.js
index 242660db8aaf7a02a7c50c78b4db2e6fa31360de..a12844bbb8c0dab280e3c6094ea1c4ca7eb88fcc 100644
--- a/chrome/browser/resources/md_history/history_item.js
+++ b/chrome/browser/resources/md_history/history_item.js
@@ -13,7 +13,8 @@ Polymer({
 
     websiteTitle_: {
       type: String,
-      value: ''
+      value: '',
+      observer: 'setSearchedTextToBold_'
     },
 
     // Domain is the website text shown on the history-item next to the title.
@@ -47,6 +48,13 @@ Polymer({
       value: 0
     },
 
+    // Search term used in the chrome.send to obtain this history-item.
+    searchTerm: {
+      type: String,
+      value: '',
+      observer: 'setSearchedTextToBold_'
+    },
+
     selected: {
       type: Boolean,
       value: false,
@@ -90,5 +98,45 @@ Polymer({
 
     // Stops the 'tap' event from closing the menu when it opens.
     e.stopPropagation();
+  },
+
+  /**
+   * If the results shown are search results set the search term to be bold
+   * where it is displayed in the history-item title.
+   * @private
+   */
+  setSearchedTextToBold_: function() {
+    var i = 0;

[calamity, 2016/02/05 02:30:10]

Pull this.$.title into a local var here.

[tsergeant, 2016/02/08 22:59:01]

Bump on the comments in this file.

[hsampson, 2016/02/09 02:17:51]

Done.

+    if ((this.searchTerm != '') && (this.searchTerm != null)) {

[calamity, 2016/02/05 02:30:10]

nit: less parens.

[hsampson, 2016/02/09 02:17:51]

Done.

+      var searchText = new RegExp(this.quoteString_(this.searchTerm), 'gim');

[calamity, 2016/02/05 02:30:10]

nit: TBH, I kinda like just calling this re. searchText can mean too many
things.

[hsampson, 2016/02/09 02:17:51]

Done.

+      var match;
+      this.$.title.textContent = '';
+      while (match = searchText.exec(this.websiteTitle_)) {
+        if (match.index > i)

[calamity, 2016/02/05 02:30:10]

nit: This one needs braces since the content is 2 lines long.

[hsampson, 2016/02/09 02:17:51]

NA now.

+          this.$.title.appendChild(document.createTextNode(
+                this.websiteTitle_.slice(i, match.index)));
+        i = searchText.lastIndex;
+        // Mark the highlighted text in bold.
+        var b = document.createElement('b');
+        b.textContent = this.websiteTitle_.substring(match.index, i);
+        this.$.title.appendChild(b);
+      }
+      if (i < this.websiteTitle_.length)
+        this.$.title.appendChild(document.createTextNode(
+                this.websiteTitle_.slice(i)));
+    } else {
+      this.$.title.textContent = this.websiteTitle_;

[calamity, 2016/02/05 02:30:10]

Invert the condition above and early return in this case. Do you remember
DeMoivre's theorem? =P

[hsampson, 2016/02/09 02:17:51]

No idea what that is :P but done I think.

+    }
+  },
+
+  /**
+   * Quote a string so it can be used in a regular expression.
+   * @param {string} searchTerm The source string.
+   * @return {string} The escaped string.
+   * @private
+   */
+  quoteString_: function(searchTerm) {
+    return searchTerm.replace(/([\\\.\+\*\?\[\^\]\$\(\)\{\}\=\!\<\>\|\:])/g,
+        '\\$1');
   }
 });