Implement minlength for <input> and <textarea>.

Source/core/html/HTMLTextAreaElement.cpp

Index: Source/core/html/HTMLTextAreaElement.cpp
diff --git a/Source/core/html/HTMLTextAreaElement.cpp b/Source/core/html/HTMLTextAreaElement.cpp
index 7ca0838c5313cde3fb9694071bf6070a5c014000..844aad59761c3ae4e4c9af9812dab9f6ce93f627 100644
--- a/Source/core/html/HTMLTextAreaElement.cpp
+++ b/Source/core/html/HTMLTextAreaElement.cpp
@@ -190,9 +190,11 @@ void HTMLTextAreaElement::parseAttribute(const QualifiedName& name, const Atomic
         }
     } else if (name == accesskeyAttr) {
         // ignore for the moment
-    } else if (name == maxlengthAttr)
+    } else if (name == maxlengthAttr) {
         setNeedsValidityCheck();
-    else
+    } else if (name == minlengthAttr) {
+        setNeedsValidityCheck();
+    } else
         HTMLTextFormControlElement::parseAttribute(name, value);
 }
 
@@ -447,14 +449,42 @@ int HTMLTextAreaElement::maxLength() const
     return ok && value >= 0 ? value : -1;
 }
 
+int HTMLTextAreaElement::minLength() const
+{
+    bool ok;
+    int value = getAttribute(minlengthAttr).string().toInt(&ok);
+    if (ok && value >= 0) {
+        int max = maxLength();

[keishi, 2014/08/01 03:14:54]

We don't need to clamp to maxLength

[Bartek Nowierski, 2014/10/03 12:52:00]

Done.

+        if (max >= 0 && value > max) {
+            value = max;
+        }
+        return value;
+    }
+    return -1;
+}
+
 void HTMLTextAreaElement::setMaxLength(int newValue, ExceptionState& exceptionState)
 {
+    int min = minLength();
     if (newValue < 0)
         exceptionState.throwDOMException(IndexSizeError, "The value provided (" + String::number(newValue) + ") is not positive or 0.");
+    else if (min >= 0 && newValue < min)
+        exceptionState.throwDOMException(IndexSizeError, "The value provided (" + String::number(newValue) + ") is less than minlength" + String::number(min) + ".");
     else
         setIntegralAttribute(maxlengthAttr, newValue);
 }
 
+void HTMLTextAreaElement::setMinLength(int newValue, ExceptionState& exceptionState)
+{
+    int max = maxLength();
+    if (newValue < 0)
+        exceptionState.throwDOMException(IndexSizeError, "The value provided (" + String::number(newValue) + ") is not positive or 0.");
+    else if (max >= 0 && newValue > max)
+        exceptionState.throwDOMException(IndexSizeError, "The value provided (" + String::number(newValue) + ") is more than maxlength" + String::number(max) + ".");
+    else
+        setIntegralAttribute(minlengthAttr, newValue);
+}
+
 String HTMLTextAreaElement::suggestedValue() const
 {
     return m_suggestedValue;
@@ -486,6 +516,8 @@ String HTMLTextAreaElement::validationMessage() const
     if (tooLong())
         return locale().validationMessageTooLongText(computeLengthForSubmission(value()), maxLength());
 
+    // TODO(bartekn): Add a message for tooShort().

[keishi, 2014/08/01 03:14:54]

I think you need to land the blink side change first (add to
WebLocalizedString.h)
And then land the chromium side chnges (blink_platform_impl.cc and
webkit_strings.grd)

[Bartek Nowierski, 2014/10/03 12:52:00]

I'll do it in the next patchset. Let's focus on getting this working first :)

+
     return String();
 }
 
@@ -499,6 +531,11 @@ bool HTMLTextAreaElement::tooLong() const
     return willValidate() && tooLong(value(), CheckDirtyFlag);
 }
 
+bool HTMLTextAreaElement::tooShort() const
+{
+    return willValidate() && tooShort(value(), CheckDirtyFlag);
+}
+
 bool HTMLTextAreaElement::tooLong(const String& value, NeedsToCheckDirtyFlag check) const
 {
     // Return false for the default value or value set by script even if it is
@@ -512,6 +549,21 @@ bool HTMLTextAreaElement::tooLong(const String& value, NeedsToCheckDirtyFlag che
     return computeLengthForSubmission(value) > static_cast<unsigned>(max);
 }
 
+bool HTMLTextAreaElement::tooShort(const String& value, NeedsToCheckDirtyFlag check) const
+{
+    // Return false for the default value or value set by script even if it is
+    // shorter than minLength.
+    if (check == CheckDirtyFlag && !lastChangeWasUserEdit())
+        return false;
+
+    int min = minLength();
+    if (min <= 0)
+        return false;
+    // An empty string is excluded from minlength check.
+    unsigned len = computeLengthForSubmission(value);
+    return len > 0 && len < static_cast<unsigned>(min);
+}
+
 bool HTMLTextAreaElement::isValidValue(const String& candidate) const
 {
     return !valueMissing(candidate) && !tooLong(candidate, IgnoreDirtyFlag);