Auto merge of #25499 - NeverHappened:implement-form-dirname, r=jdm

Implement dirname support for form element

Added support for dirname in input on form submit
Added Dir getter / setter for HTMLElement
NOT YET Added get directionality according to https://html.spec.whatwg.org/multipage/dom.html#the-directionality

- [X] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #25379 (GitHub issue number if applicable)

9 files changed, 148 insertions, 7 deletions

diff --git a/components/script/Cargo.toml b/components/script/Cargo.toml
index 93813953aac..03eac6cae65 100644
--- a/components/script/Cargo.toml
+++ b/components/script/Cargo.toml
@@ -110,6 +110,7 @@ style_traits = {path = "../style_traits"}
 swapper = "0.1"
 tendril = {version = "0.4.1", features = ["encoding_rs"]}
 time = "0.1.12"
+unicode-bidi = "0.3.4"
 unicode-segmentation = "1.1.0"
 url = "2.0"
 utf-8 = "0.7"
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index eecff289cdb..268b263fc41 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -540,6 +540,16 @@ impl Element {
         }
         true // whatwg/html#5239
     }
+
+    // https://html.spec.whatwg.org/multipage/#the-directionality
+    pub fn directionality(&self) -> String {
+        self.downcast::<HTMLElement>()
+            .and_then(|html_element| html_element.directionality())
+            .unwrap_or_else(|| {
+                let node = self.upcast::<Node>();
+                node.parent_directionality()
+            })
+    }
 }
 
 #[allow(unsafe_code)]
diff --git a/components/script/dom/htmlelement.rs b/components/script/dom/htmlelement.rs
index ac0f99416c2..00d7a64ed32 100644
--- a/components/script/dom/htmlelement.rs
+++ b/components/script/dom/htmlelement.rs
@@ -27,6 +27,7 @@ use crate::dom::htmlframesetelement::HTMLFrameSetElement;
 use crate::dom::htmlhtmlelement::HTMLHtmlElement;
 use crate::dom::htmlinputelement::{HTMLInputElement, InputType};
 use crate::dom::htmllabelelement::HTMLLabelElement;
+use crate::dom::htmltextareaelement::HTMLTextAreaElement;
 use crate::dom::node::{document_from_node, window_from_node};
 use crate::dom::node::{BindContext, Node, NodeFlags, ShadowIncluding};
 use crate::dom::text::Text;
@@ -170,6 +171,11 @@ impl HTMLElementMethods for HTMLElement {
     // https://html.spec.whatwg.org/multipage/#dom-hidden
     make_bool_setter!(SetHidden, "hidden");
 
+    // https://html.spec.whatwg.org/multipage/#the-dir-attribute
+    make_getter!(Dir, "dir");
+    // https://html.spec.whatwg.org/multipage/#the-dir-attribute
+    make_setter!(SetDir, "dir");
+
     // https://html.spec.whatwg.org/multipage/#globaleventhandlers
     global_event_handlers!(NoOnload);
 
@@ -767,6 +773,48 @@ impl HTMLElement {
             })
             .count() as u32
     }
+
+    // https://html.spec.whatwg.org/multipage/#the-directionality.
+    // returns Some if can infer direction by itself or from child nodes
+    // returns None if requires to go up to parent
+    pub fn directionality(&self) -> Option<String> {
+        let element_direction: &str = &self.Dir();
+
+        if element_direction == "ltr" {
+            return Some("ltr".to_owned());
+        }
+
+        if element_direction == "rtl" {
+            return Some("rtl".to_owned());
+        }
+
+        if let Some(input) = self.downcast::<HTMLInputElement>() {
+            if input.input_type() == InputType::Tel {
+                return Some("ltr".to_owned());
+            }
+        }
+
+        if element_direction == "auto" {
+            if let Some(directionality) = self
+                .downcast::<HTMLInputElement>()
+                .and_then(|input| input.auto_directionality())
+            {
+                return Some(directionality);
+            }
+
+            if let Some(area) = self.downcast::<HTMLTextAreaElement>() {
+                return Some(area.auto_directionality());
+            }
+        }
+
+        // TODO(NeverHappened): Implement condition
+        // If the element's dir attribute is in the auto state OR
+        // If the element is a bdi element and the dir attribute is not in a defined state
+        // (i.e. it is not present or has an invalid value)
+        // Requires bdi element implementation (https://html.spec.whatwg.org/multipage/#the-bdi-element)
+
+        None
+    }
 }
 
 impl VirtualMethods for HTMLElement {
diff --git a/components/script/dom/htmlformelement.rs b/components/script/dom/htmlformelement.rs
index adbb790a181..30d1857de9d 100644
--- a/components/script/dom/htmlformelement.rs
+++ b/components/script/dom/htmlformelement.rs
@@ -950,7 +950,6 @@ impl HTMLFormElement {
                 match element {
                     HTMLElementTypeId::HTMLInputElement => {
                         let input = child.downcast::<HTMLInputElement>().unwrap();
-
                         data_set.append(&mut input.form_datums(submitter, encoding));
                     },
                     HTMLElementTypeId::HTMLButtonElement => {
@@ -981,10 +980,30 @@ impl HTMLFormElement {
                     _ => (),
                 }
             }
+
+            // Step: 5.13. Add an entry if element has dirname attribute
+            // An element can only have a dirname attribute if it is a textarea element
+            // or an input element whose type attribute is in either the Text state or the Search state
+            let child_element = child.downcast::<Element>().unwrap();
+            let input_matches =
+                child_element
+                    .downcast::<HTMLInputElement>()
+                    .map_or(false, |input| {
+                        input.input_type() == InputType::Text ||
+                            input.input_type() == InputType::Search
+                    });
+            let textarea_matches = child_element.is::<HTMLTextAreaElement>();
+            let dirname = child_element.get_string_attribute(&local_name!("dirname"));
+            if (input_matches || textarea_matches) && !dirname.is_empty() {
+                let dir = DOMString::from(child_element.directionality());
+                data_set.push(FormDatum {
+                    ty: DOMString::from("string"),
+                    name: dirname,
+                    value: FormDatumValue::String(dir),
+                });
+            }
         }
         data_set
-        // TODO: Handle `dirnames` (needs directionality support)
-        //       https://html.spec.whatwg.org/multipage/#the-directionality
     }
 
     /// <https://html.spec.whatwg.org/multipage/#constructing-the-form-data-set>
diff --git a/components/script/dom/htmlinputelement.rs b/components/script/dom/htmlinputelement.rs
index 441206c9dad..a5fefa095ae 100755
--- a/components/script/dom/htmlinputelement.rs
+++ b/components/script/dom/htmlinputelement.rs
@@ -75,6 +75,7 @@ use std::ptr::NonNull;
 use style::attr::AttrValue;
 use style::element_state::ElementState;
 use style::str::{split_commas, str_join};
+use unicode_bidi::{bidi_class, BidiClass};
 
 const DEFAULT_SUBMIT_VALUE: &'static str = "Submit";
 const DEFAULT_RESET_VALUE: &'static str = "Reset";
@@ -327,6 +328,36 @@ impl HTMLInputElement {
         )
     }
 
+    pub fn auto_directionality(&self) -> Option<String> {
+        match self.input_type() {
+            InputType::Text | InputType::Search | InputType::Url | InputType::Email => {
+                let value: String = self.Value().to_string();
+                Some(HTMLInputElement::directionality_from_value(&value))
+            },
+            _ => None,
+        }
+    }
+
+    pub fn directionality_from_value(value: &str) -> String {
+        if HTMLInputElement::is_first_strong_character_rtl(value) {
+            "rtl".to_owned()
+        } else {
+            "ltr".to_owned()
+        }
+    }
+
+    fn is_first_strong_character_rtl(value: &str) -> bool {
+        for ch in value.chars() {
+            return match bidi_class(ch) {
+                BidiClass::L => false,
+                BidiClass::AL => true,
+                BidiClass::R => true,
+                _ => continue,
+            };
+        }
+        false
+    }
+
     // https://html.spec.whatwg.org/multipage/#dom-input-value
     // https://html.spec.whatwg.org/multipage/#concept-input-apply
     fn value_mode(&self) -> ValueMode {
diff --git a/components/script/dom/htmltextareaelement.rs b/components/script/dom/htmltextareaelement.rs
index 9fd316e3a18..d077d9eec8f 100755
--- a/components/script/dom/htmltextareaelement.rs
+++ b/components/script/dom/htmltextareaelement.rs
@@ -22,6 +22,7 @@ use crate::dom::globalscope::GlobalScope;
 use crate::dom::htmlelement::HTMLElement;
 use crate::dom::htmlfieldsetelement::HTMLFieldSetElement;
 use crate::dom::htmlformelement::{FormControl, HTMLFormElement};
+use crate::dom::htmlinputelement::HTMLInputElement;
 use crate::dom::keyboardevent::KeyboardEvent;
 use crate::dom::node::{document_from_node, window_from_node};
 use crate::dom::node::{
@@ -173,6 +174,11 @@ impl HTMLTextAreaElement {
         )
     }
 
+    pub fn auto_directionality(&self) -> String {
+        let value: String = self.Value().to_string();
+        return HTMLInputElement::directionality_from_value(&value);
+    }
+
     fn update_placeholder_shown_state(&self) {
         let has_placeholder = !self.placeholder.borrow().is_empty();
         let has_value = !self.textinput.borrow().is_empty();
@@ -205,6 +211,12 @@ impl HTMLTextAreaElementMethods for HTMLTextAreaElement {
     // https://html.spec.whatwg.org/multipage/#dom-textarea-cols
     make_limited_uint_setter!(SetCols, "cols", DEFAULT_COLS);
 
+    // https://html.spec.whatwg.org/multipage/#dom-input-dirName
+    make_getter!(DirName, "dirname");
+
+    // https://html.spec.whatwg.org/multipage/#dom-input-dirName
+    make_setter!(SetDirName, "dirname");
+
     // https://html.spec.whatwg.org/multipage/#dom-fe-disabled
     make_bool_getter!(Disabled, "disabled");
 
diff --git a/components/script/dom/node.rs b/components/script/dom/node.rs
index c1da57eae88..05b81a84d5d 100644
--- a/components/script/dom/node.rs
+++ b/components/script/dom/node.rs
@@ -440,6 +440,26 @@ impl Node {
             .upcast::<Event>()
             .dispatch(self.upcast::<EventTarget>(), false);
     }
+
+    pub fn parent_directionality(&self) -> String {
+        let mut current = self.GetParentNode();
+
+        loop {
+            match current {
+                Some(node) => {
+                    if let Some(directionality) = node
+                        .downcast::<HTMLElement>()
+                        .and_then(|html_element| html_element.directionality())
+                    {
+                        return directionality;
+                    } else {
+                        current = node.GetParentNode();
+                    }
+                },
+                None => return "ltr".to_owned(),
+            }
+        }
+    }
 }
 
 pub struct QuerySelectorIterator {
diff --git a/components/script/dom/webidls/HTMLElement.webidl b/components/script/dom/webidls/HTMLElement.webidl
index ef529dc80af..c743c0a7129 100644
--- a/components/script/dom/webidls/HTMLElement.webidl
+++ b/components/script/dom/webidls/HTMLElement.webidl
@@ -14,8 +14,8 @@ interface HTMLElement : Element {
            attribute DOMString lang;
   [CEReactions]
            attribute boolean translate;
-  // [CEReactions]
-  //         attribute DOMString dir;
+  [CEReactions]
+           attribute DOMString dir;
   readonly attribute DOMStringMap dataset;
 
   // microdata
diff --git a/components/script/dom/webidls/HTMLTextAreaElement.webidl b/components/script/dom/webidls/HTMLTextAreaElement.webidl
index 99cf18e0c10..b09200f1dc5 100644
--- a/components/script/dom/webidls/HTMLTextAreaElement.webidl
+++ b/components/script/dom/webidls/HTMLTextAreaElement.webidl
@@ -13,8 +13,8 @@ interface HTMLTextAreaElement : HTMLElement {
   //          attribute boolean autofocus;
   [CEReactions, SetterThrows]
            attribute unsigned long cols;
-  // [CEReactions]
-  //          attribute DOMString dirName;
+  [CEReactions]
+           attribute DOMString dirName;
   [CEReactions]
            attribute boolean disabled;
   readonly attribute HTMLFormElement? form;