AutoFill <dl> label scraping and dynamic html in forms.

The mcphee.com site demonstrates two issues.  One is label scraping for forms that use <dl> <dt> and <dd> elements to partition labels and input elements.  The other is dynamic html where JavaScript is used to manipulate the form elements dynamically as the user proceeds through checkout.  These changes address both.  Label scraping is implemented for <dl> <dt> and <dd> elements.  Form filling, both at the FormManager and AutoFillManager levels are now more robust in the face of changing form structure between the time of page load and form fill.

This does not "fix" the mcphee page though, as we still do not fill the elements that are added to the page after the initial page load.

BUG=44323
TEST=AutoFillManagerTest.FormChangesRemoveField, AutoFillManagerTest.FormChangesAddField, FormManagerTest.LabelsInferredFromTableCellNested, FormManagerTest.LabelsInferredFromDefinitionList, FormManagerTest.FillFormChangedFormDataFields, manual tests using mphee.html and mcphee2.html sample files attached to bug report and original bug steps using live mcphee checkout.

Review URL: http://codereview.chromium.org/2240004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@48429 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 166 insertions, 120 deletions

diff --git a/chrome/renderer/form_manager.cc b/chrome/renderer/form_manager.cc
index 12b6353..83f6ed9 100644
--- a/chrome/renderer/form_manager.cc
+++ b/chrome/renderer/form_manager.cc
@@ -46,30 +46,28 @@ namespace {
 const size_t kRequiredAutoFillFields = 3;
 
 // This is a helper function for the FindChildText() function.
-// Returns the node value of the descendant or sibling of |node| that is a
-// non-empty text node.  This is a faster alternative to |innerText()| for
+// Returns the aggregated values of the descendants or siblings of |node| that
+// are non-empty text nodes.  This is a faster alternative to |innerText()| for
 // performance critical operations.  It does a full depth-first search so
-// can be used when the structure is not directly known.  It does not aggregate
-// the text of multiple nodes, it just returns the value of the first found.
-// "Non-empty" in this case means non-empty after the whitespace has been
-// stripped.
+// can be used when the structure is not directly known.  The text is
+// accumulated after the whitespace has been stripped.
 string16 FindChildTextInner(const WebNode& node) {
   string16 element_text;
   if (node.isNull())
     return element_text;
 
-  element_text = node.nodeValue();
-  TrimWhitespace(element_text, TRIM_ALL, &element_text);
-  if (!element_text.empty())
-    return element_text;
+  string16 node_text = node.nodeValue();
+  TrimWhitespace(node_text, TRIM_ALL, &node_text);
+  if (!node_text.empty())
+    element_text = node_text;
 
-  element_text = FindChildTextInner(node.firstChild());
-  if (!element_text.empty())
-    return element_text;
+  string16 child_text = FindChildTextInner(node.firstChild());
+  if (!child_text.empty())
+    element_text = element_text + child_text;
 
-  element_text = FindChildTextInner(node.nextSibling());
-  if (!element_text.empty())
-    return element_text;
+  string16 sibling_text = FindChildTextInner(node.nextSibling());
+  if (!sibling_text.empty())
+    element_text = element_text + sibling_text;
 
   return element_text;
 }
@@ -82,6 +80,132 @@ string16 FindChildText(const WebElement& element) {
   return FindChildTextInner(child);
 }
 
+// Helper for |InferLabelForElement()| that infers a label, if possible, from
+// a previous node of |element|.
+string16 InferLabelFromPrevious(
+    const WebFormControlElement& element) {
+  string16 inferred_label;
+  WebNode previous = element.previousSibling();
+  if (!previous.isNull()) {
+    // Eg. Some Text<input ...>
+    if (previous.isTextNode()) {
+      inferred_label = previous.nodeValue();
+      TrimWhitespace(inferred_label, TRIM_ALL, &inferred_label);
+    }
+
+    // If we didn't find text, check for previous paragraph.
+    // Eg. <p>Some Text</p><input ...>
+    // Note the lack of whitespace between <p> and <input> elements.
+    if (inferred_label.empty()) {
+      if (previous.isElementNode()) {
+        WebElement element = previous.to<WebElement>();
+        if (element.hasTagName("p")) {
+          inferred_label = FindChildText(element);
+        }
+      }
+    }
+
+    // If we didn't find paragraph, check for previous paragraph to this.
+    // Eg. <p>Some Text</p>   <input ...>
+    // Note the whitespace between <p> and <input> elements.
+    if (inferred_label.empty()) {
+      previous = previous.previousSibling();
+      if (!previous.isNull() && previous.isElementNode()) {
+        WebElement element = previous.to<WebElement>();
+        if (element.hasTagName("p")) {
+          inferred_label = FindChildText(element);
+        }
+      }
+    }
+
+    // Look for text node prior to <img> tag.
+    // Eg. Some Text<img/><input ...>
+    if (inferred_label.empty()) {
+      while (inferred_label.empty() && !previous.isNull()) {
+        if (previous.isTextNode()) {
+          inferred_label = previous.nodeValue();
+          TrimWhitespace(inferred_label, TRIM_ALL, &inferred_label);
+        } else if (previous.isElementNode()) {
+          WebElement element = previous.to<WebElement>();
+          if (!element.hasTagName("img"))
+            break;
+        } else {
+          break;
+        }
+        previous = previous.previousSibling();
+      }
+    }
+  }
+
+  return inferred_label;
+}
+
+// Helper for |InferLabelForElement()| that infers a label, if possible, from
+// surrounding table structure.
+// Eg. <tr><td>Some Text</td><td><input ...></td></tr>
+// Eg. <tr><td><b>Some Text</b></td><td><b><input ...></b></td></tr>
+string16 InferLabelFromTable(
+    const WebFormControlElement& element) {
+  string16 inferred_label;
+  WebNode parent = element.parentNode();
+  while (!parent.isNull() && parent.isElementNode() &&
+         !parent.to<WebElement>().hasTagName("td"))
+    parent = parent.parentNode();
+
+  if (!parent.isNull() && parent.isElementNode()) {
+    WebElement element = parent.to<WebElement>();
+    if (element.hasTagName("td")) {
+      WebNode previous = parent.previousSibling();
+
+      // Skip by any intervening text nodes.
+      while (!previous.isNull() && previous.isTextNode())
+        previous = previous.previousSibling();
+
+      if (!previous.isNull() && previous.isElementNode()) {
+        element = previous.to<WebElement>();
+        if (element.hasTagName("td")) {
+          inferred_label = FindChildText(element);
+        }
+      }
+    }
+  }
+
+  return inferred_label;
+}
+
+// Helper for |InferLabelForElement()| that infers a label, if possible, from
+// a surrounding definition list.
+// Eg. <dl><dt>Some Text</dt><dd><input ...></dd></dl>
+// Eg. <dl><dt><b>Some Text</b></dt><dd><b><input ...></b></dd></dl>
+string16 InferLabelFromDefinitionList(
+    const WebFormControlElement& element) {
+  string16 inferred_label;
+  WebNode parent = element.parentNode();
+  while (!parent.isNull() && parent.isElementNode() &&
+         !parent.to<WebElement>().hasTagName("dd"))
+    parent = parent.parentNode();
+
+  if (!parent.isNull() && parent.isElementNode()) {
+    WebElement element = parent.to<WebElement>();
+    if (element.hasTagName("dd")) {
+      WebNode previous = parent.previousSibling();
+
+      // Skip by any intervening text nodes.
+      while (!previous.isNull() && previous.isTextNode())
+        previous = previous.previousSibling();
+
+      if (!previous.isNull() && previous.isElementNode()) {
+        element = previous.to<WebElement>();
+        if (element.hasTagName("dt")) {
+          inferred_label = FindChildText(element);
+        }
+      }
+    }
+  }
+
+  return inferred_label;
+}
+
 }  // namespace
 
 FormManager::FormManager() {
@@ -427,62 +551,51 @@ bool FormManager::FillForm(const FormData& form) {
 
   for (size_t i = 0, j = 0;
        i < form_element->control_elements.size() && j < form.fields.size();
-       ++i, ++j) {
+       ++i) {
     // Once again, empty WebString != empty string16, so we have to explicitly
     // check for this case.
     if (form_element->control_elements[i].nameForAutofill().length() == 0 &&
         form.fields[j].name().empty())
       continue;
 
-    // We assume that the intersection of the fields in
-    // |form_element->control_elements| and |form.fields| is ordered, but it's
-    // possible that one or the other sets may have more fields than the other,
-    // so loop past non-matching fields in the set with more elements.
-    while (form_element->control_elements[i].nameForAutofill() !=
-           form.fields[j].name()) {
-      if (form_element->control_elements.size() > form.fields.size()) {
-        // We're at the end of the elements already.
-        if (i + 1 == form_element->control_elements.size())
-          break;
-        ++i;
-      } else if (form.fields.size() > form_element->control_elements.size()) {
-        // We're at the end of the elements already.
-        if (j + 1 == form.fields.size())
-          break;
-        ++j;
-      } else {
-        NOTREACHED();
-      }
-
-      continue;
+    size_t k = j;
+    while (k < form.fields.size() &&
+           form_element->control_elements[i].nameForAutofill() !=
+              form.fields[k].name()) {
+      k++;
     }
+    if (k >= form.fields.size())
+      continue;
 
     WebFormControlElement* element = &form_element->control_elements[i];
 
-    // It's possible that nameForAutofill() is empty if the form control element
-    // has no name or ID.  In that case, iter->nameForAutofill() must also be
-    // empty.
-    if (form.fields[j].name().empty())
+    // It's possible that nameForAutofill() is empty if the form control
+    // element has no name or ID.  In that case, iter->nameForAutofill() must
+    // also be empty.
+    if (form.fields[k].name().empty())
       DCHECK(element->nameForAutofill().isEmpty());
     else
-      DCHECK_EQ(form.fields[j].name(), element->nameForAutofill());
+      DCHECK_EQ(form.fields[k].name(), element->nameForAutofill());
 
-    if (!form.fields[j].value().empty() &&
+    if (!form.fields[k].value().empty() &&
         element->formControlType() != WebString::fromUTF8("submit")) {
       if (element->formControlType() == WebString::fromUTF8("text")) {
         WebInputElement input_element = element->to<WebInputElement>();
         // If the maxlength attribute contains a negative value, maxLength()
         // returns the default maxlength value.
         input_element.setValue(
-            form.fields[j].value().substr(0, input_element.maxLength()));
+            form.fields[k].value().substr(0, input_element.maxLength()));
         input_element.setAutofilled(true);
       } else if (element->formControlType() ==
                  WebString::fromUTF8("select-one")) {
         WebSelectElement select_element =
             element->to<WebSelectElement>();
-        select_element.setValue(form.fields[j].value());
+        select_element.setValue(form.fields[k].value());
       }
     }
+
+    // We found a matching form field so move on to the next.
+    ++j;
   }
 
   return true;
@@ -559,85 +672,18 @@ bool FormManager::FormElementToFormData(const WebFrame* frame,
 // static
 string16 FormManager::InferLabelForElement(
     const WebFormControlElement& element) {
-  string16 inferred_label;
-  WebNode previous = element.previousSibling();
-  if (!previous.isNull()) {
-    if (previous.isTextNode()) {
-      inferred_label = previous.nodeValue();
-      TrimWhitespace(inferred_label, TRIM_ALL, &inferred_label);
-    }
-
-    // If we didn't find text, check for previous paragraph.
-    // Eg. <p>Some Text</p><input ...>
-    // Note the lack of whitespace between <p> and <input> elements.
-    if (inferred_label.empty()) {
-      if (previous.isElementNode()) {
-        WebElement element = previous.to<WebElement>();
-        if (element.hasTagName("p")) {
-          inferred_label = FindChildText(element);
-        }
-      }
-    }
+  string16 inferred_label = InferLabelFromPrevious(element);
 
-    // If we didn't find paragraph, check for previous paragraph to this.
-    // Eg. <p>Some Text</p>   <input ...>
-    // Note the whitespace between <p> and <input> elements.
-    if (inferred_label.empty()) {
-      previous = previous.previousSibling();
-      if (!previous.isNull() && previous.isElementNode()) {
-        WebElement element = previous.to<WebElement>();
-        if (element.hasTagName("p")) {
-          inferred_label = FindChildText(element);
-        }
-      }
-    }
-
-    // Look for text node prior to <img> tag.
-    // Eg. Some Text<img/><input ...>
-    if (inferred_label.empty()) {
-      while (inferred_label.empty() && !previous.isNull()) {
-        if (previous.isTextNode()) {
-          inferred_label = previous.nodeValue();
-          TrimWhitespace(inferred_label, TRIM_ALL, &inferred_label);
-        } else if (previous.isElementNode()) {
-          WebElement element = previous.to<WebElement>();
-          if (!element.hasTagName("img"))
-            break;
-        } else {
-          break;
-        }
-        previous = previous.previousSibling();
-      }
-    }
+  // If we didn't find a label, check for table cell case.
+  if (inferred_label.empty()) {
+    inferred_label = InferLabelFromTable(element);
   }
 
-  // If we didn't find paragraph, check for table cell case.
-  // Eg. <tr><td>Some Text</td><td><input ...></td></tr>
-  // Eg. <tr><td><b>Some Text</b></td><td><b><input ...></b></td></tr>
+  // If we didn't find a label, check for definition list case.
   if (inferred_label.empty()) {
-    WebNode parent = element.parentNode();
-    while (!parent.isNull() && parent.isElementNode() &&
-           !parent.to<WebElement>().hasTagName("td"))
-      parent = parent.parentNode();
-
-    if (!parent.isNull() && parent.isElementNode()) {
-      WebElement element = parent.to<WebElement>();
-      if (element.hasTagName("td")) {
-        previous = parent.previousSibling();
-
-        // Skip by any intervening text nodes.
-        while (!previous.isNull() && previous.isTextNode())
-          previous = previous.previousSibling();
-
-        if (!previous.isNull() && previous.isElementNode()) {
-          element = previous.to<WebElement>();
-          if (element.hasTagName("td")) {
-            inferred_label = FindChildText(element);
-          }
-        }
-      }
-    }
+    inferred_label = InferLabelFromDefinitionList(element);
   }
 
   return inferred_label;
 }
+