1 files changed, 110 insertions, 4 deletions
diff --git a/components/script/dom/validation.rs b/components/script/dom/validation.rs
index 7ba915092a2..e6b36ec809d 100755
--- a/components/script/dom/validation.rs
+++ b/components/script/dom/validation.rs
@@ -1,9 +1,115 @@
 /* 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 dom::validitystate::ValidationFlags;
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+use crate::dom::bindings::codegen::Bindings::EventBinding::EventBinding::EventMethods;
+use crate::dom::bindings::codegen::Bindings::HTMLElementBinding::HTMLElementMethods;
+use crate::dom::bindings::inheritance::Castable;
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::bindings::str::DOMString;
+use crate::dom::element::Element;
+use crate::dom::eventtarget::EventTarget;
+use crate::dom::htmldatalistelement::HTMLDataListElement;
+use crate::dom::htmlelement::HTMLElement;
+use crate::dom::node::Node;
+use crate::dom::validitystate::{ValidationFlags, ValidityState};
 
+/// Trait for elements with constraint validation support
 pub trait Validatable {
-    fn is_instance_validatable(&self) -> bool { true }
-    fn validate(&self, _validate_flags: ValidationFlags) -> bool { true }
+    fn as_element(&self) -> &Element;
+
+    // https://html.spec.whatwg.org/multipage/#dom-cva-validity
+    fn validity_state(&self) -> DomRoot<ValidityState>;
+
+    // https://html.spec.whatwg.org/multipage/#candidate-for-constraint-validation
+    fn is_instance_validatable(&self) -> bool;
+
+    // Check if element satisfies its constraints, excluding custom errors
+    fn perform_validation(&self, _validate_flags: ValidationFlags) -> ValidationFlags {
+        ValidationFlags::empty()
+    }
+
+    // https://html.spec.whatwg.org/multipage/#concept-fv-valid
+    fn validate(&self, validate_flags: ValidationFlags) -> ValidationFlags {
+        let mut failed_flags = self.perform_validation(validate_flags);
+
+        // https://html.spec.whatwg.org/multipage/#suffering-from-a-custom-error
+        if validate_flags.contains(ValidationFlags::CUSTOM_ERROR) {
+            if !self.validity_state().custom_error_message().is_empty() {
+                failed_flags.insert(ValidationFlags::CUSTOM_ERROR);
+            }
+        }
+
+        failed_flags
+    }
+
+    // https://html.spec.whatwg.org/multipage/#check-validity-steps
+    fn check_validity(&self) -> bool {
+        if self.is_instance_validatable() && !self.validate(ValidationFlags::all()).is_empty() {
+            self.as_element()
+                .upcast::<EventTarget>()
+                .fire_cancelable_event(atom!("invalid"));
+            false
+        } else {
+            true
+        }
+    }
+
+    // https://html.spec.whatwg.org/multipage/#report-validity-steps
+    fn report_validity(&self) -> bool {
+        // Step 1.
+        if !self.is_instance_validatable() {
+            return true;
+        }
+
+        let flags = self.validate(ValidationFlags::all());
+        if flags.is_empty() {
+            return true;
+        }
+
+        // Step 1.1.
+        let event = self
+            .as_element()
+            .upcast::<EventTarget>()
+            .fire_cancelable_event(atom!("invalid"));
+
+        // Step 1.2.
+        if !event.DefaultPrevented() {
+            println!(
+                "Validation error: {}",
+                validation_message_for_flags(&self.validity_state(), flags)
+            );
+            if let Some(html_elem) = self.as_element().downcast::<HTMLElement>() {
+                html_elem.Focus();
+            }
+        }
+
+        // Step 1.3.
+        false
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-cva-validationmessage
+    fn validation_message(&self) -> DOMString {
+        if self.is_instance_validatable() {
+            let flags = self.validate(ValidationFlags::all());
+            validation_message_for_flags(&self.validity_state(), flags)
+        } else {
+            DOMString::new()
+        }
+    }
+}
+
+// https://html.spec.whatwg.org/multipage/#the-datalist-element%3Abarred-from-constraint-validation
+pub fn is_barred_by_datalist_ancestor(elem: &Node) -> bool {
+    elem.upcast::<Node>()
+        .ancestors()
+        .any(|node| node.is::<HTMLDataListElement>())
+}
+
+// Get message for given validation flags or custom error message
+fn validation_message_for_flags(state: &ValidityState, failed_flags: ValidationFlags) -> DOMString {
+    if failed_flags.contains(ValidationFlags::CUSTOM_ERROR) {
+        state.custom_error_message().clone()
+    } else {
+        DOMString::from(failed_flags.to_string())
+    }
 }