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// Copyright 2014-2017 The html5ever Project Developers. See the
// COPYRIGHT file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! This module contains functionality for managing the DOM, including adding/removing nodes.
//!
//! It can be used by a parser to create the DOM graph structure in memory.
use crate::interface::{Attribute, ExpandedName, QualName};
use crate::{LocalName, Namespace};
use std::borrow::Cow;
use std::fmt::Debug;
use tendril::StrTendril;
pub use self::NodeOrText::{AppendNode, AppendText};
pub use self::QuirksMode::{LimitedQuirks, NoQuirks, Quirks};
/// Something which can be inserted into the DOM.
///
/// Adjacent sibling text nodes are merged into a single node, so
/// the sink may not want to allocate a `Handle` for each.
pub enum NodeOrText<Handle> {
AppendNode(Handle),
AppendText(StrTendril),
}
/// A document's quirks mode, for compatibility with old browsers. See [quirks mode on wikipedia]
/// for more information.
///
/// [quirks mode on wikipedia]: https://en.wikipedia.org/wiki/Quirks_mode
#[derive(PartialEq, Eq, Copy, Clone, Hash, Debug)]
pub enum QuirksMode {
/// Full quirks mode
Quirks,
/// Almost standards mode
LimitedQuirks,
/// Standards mode
NoQuirks,
}
/// Whether to interrupt further parsing of the current input until
/// the next explicit resumption of the tokenizer, or continue without
/// any interruption.
#[derive(PartialEq, Eq, Copy, Clone, Hash, Debug)]
pub enum NextParserState {
/// Stop further parsing.
Suspend,
/// Continue without interruptions.
Continue,
}
/// Special properties of an element, useful for tagging elements with this information.
#[derive(Default)]
#[non_exhaustive]
pub struct ElementFlags {
/// A document fragment should be created, associated with the element,
/// and returned in TreeSink::get_template_contents.
///
/// See [template-contents in the whatwg spec][whatwg template-contents].
///
/// [whatwg template-contents]: https://html.spec.whatwg.org/multipage/#template-contents
pub template: bool,
/// This boolean should be recorded with the element and returned
/// in TreeSink::is_mathml_annotation_xml_integration_point
///
/// See [html-integration-point in the whatwg spec][whatwg integration-point].
///
/// [whatwg integration-point]: https://html.spec.whatwg.org/multipage/#html-integration-point
pub mathml_annotation_xml_integration_point: bool,
}
/// A constructor for an element.
///
/// # Examples
///
/// Create an element like `<div class="test-class-name"></div>`:
pub fn create_element<Sink>(sink: &Sink, name: QualName, attrs: Vec<Attribute>) -> Sink::Handle
where
Sink: TreeSink,
{
let mut flags = ElementFlags::default();
match name.expanded() {
expanded_name!(html "template") => flags.template = true,
expanded_name!(mathml "annotation-xml") => {
flags.mathml_annotation_xml_integration_point = attrs.iter().any(|attr| {
attr.name.expanded() == expanded_name!("", "encoding")
&& (attr.value.eq_ignore_ascii_case("text/html")
|| attr.value.eq_ignore_ascii_case("application/xhtml+xml"))
})
},
_ => {},
}
sink.create_element(name, attrs, flags)
}
/// An abstraction over any type that can represent an element's local name and namespace.
pub trait ElemName: Debug {
fn ns(&self) -> &Namespace;
fn local_name(&self) -> &LocalName;
#[inline(always)]
fn expanded(&self) -> ExpandedName {
ExpandedName {
ns: self.ns(),
local: self.local_name(),
}
}
}
/// Methods a parser can use to create the DOM. The DOM provider implements this trait.
///
/// Having this as a trait potentially allows multiple implementations of the DOM to be used with
/// the same parser.
pub trait TreeSink {
/// `Handle` is a reference to a DOM node. The tree builder requires
/// that a `Handle` implements `Clone` to get another reference to
/// the same node.
type Handle: Clone;
/// The overall result of parsing.
///
/// This should default to Self, but default associated types are not stable yet.
/// [rust-lang/rust#29661](https://github.com/rust-lang/rust/issues/29661)
type Output;
//
type ElemName<'a>: ElemName
where
Self: 'a;
/// Consume this sink and return the overall result of parsing.
///
/// TODO:This should default to `fn finish(self) -> Self::Output { self }`,
/// but default associated types are not stable yet.
/// [rust-lang/rust#29661](https://github.com/rust-lang/rust/issues/29661)
fn finish(self) -> Self::Output;
/// Signal a parse error.
fn parse_error(&self, msg: Cow<'static, str>);
/// Get a handle to the `Document` node.
fn get_document(&self) -> Self::Handle;
/// What is the name of this element?
///
/// Should never be called on a non-element node;
/// feel free to `panic!`.
fn elem_name<'a>(&'a self, target: &'a Self::Handle) -> Self::ElemName<'a>;
/// Create an element.
///
/// When creating a template element (`name.ns.expanded() == expanded_name!(html "template")`),
/// an associated document fragment called the "template contents" should
/// also be created. Later calls to self.get_template_contents() with that
/// given element return it.
/// See [the template element in the whatwg spec][whatwg template].
///
/// [whatwg template]: https://html.spec.whatwg.org/multipage/#the-template-element
fn create_element(
&self,
name: QualName,
attrs: Vec<Attribute>,
flags: ElementFlags,
) -> Self::Handle;
/// Create a comment node.
fn create_comment(&self, text: StrTendril) -> Self::Handle;
/// Create a Processing Instruction node.
fn create_pi(&self, target: StrTendril, data: StrTendril) -> Self::Handle;
/// Append a node as the last child of the given node. If this would
/// produce adjacent sibling text nodes, it should concatenate the text
/// instead.
///
/// The child node will not already have a parent.
fn append(&self, parent: &Self::Handle, child: NodeOrText<Self::Handle>);
/// When the insertion point is decided by the existence of a parent node of the
/// element, we consider both possibilities and send the element which will be used
/// if a parent node exists, along with the element to be used if there isn't one.
fn append_based_on_parent_node(
&self,
element: &Self::Handle,
prev_element: &Self::Handle,
child: NodeOrText<Self::Handle>,
);
/// Append a `DOCTYPE` element to the `Document` node.
fn append_doctype_to_document(
&self,
name: StrTendril,
public_id: StrTendril,
system_id: StrTendril,
);
/// Mark a HTML `<script>` as "already started".
fn mark_script_already_started(&self, _node: &Self::Handle) {}
/// Indicate that a node was popped off the stack of open elements.
fn pop(&self, _node: &Self::Handle) {}
/// Get a handle to a template's template contents. The tree builder
/// promises this will never be called with something else than
/// a template element.
fn get_template_contents(&self, target: &Self::Handle) -> Self::Handle;
/// Do two handles refer to the same node?
fn same_node(&self, x: &Self::Handle, y: &Self::Handle) -> bool;
/// Set the document's quirks mode.
fn set_quirks_mode(&self, mode: QuirksMode);
/// Append a node as the sibling immediately before the given node.
///
/// The tree builder promises that `sibling` is not a text node. However its
/// old previous sibling, which would become the new node's previous sibling,
/// could be a text node. If the new node is also a text node, the two should
/// be merged, as in the behavior of `append`.
///
/// NB: `new_node` may have an old parent, from which it should be removed.
fn append_before_sibling(&self, sibling: &Self::Handle, new_node: NodeOrText<Self::Handle>);
/// Add each attribute to the given element, if no attribute with that name
/// already exists. The tree builder promises this will never be called
/// with something else than an element.
fn add_attrs_if_missing(&self, target: &Self::Handle, attrs: Vec<Attribute>);
/// Associate the given form-associatable element with the form element
fn associate_with_form(
&self,
_target: &Self::Handle,
_form: &Self::Handle,
_nodes: (&Self::Handle, Option<&Self::Handle>),
) {
}
/// Detach the given node from its parent.
fn remove_from_parent(&self, target: &Self::Handle);
/// Remove all the children from node and append them to new_parent.
fn reparent_children(&self, node: &Self::Handle, new_parent: &Self::Handle);
/// Returns true if the adjusted current node is an HTML integration point
/// and the token is a start tag.
fn is_mathml_annotation_xml_integration_point(&self, _handle: &Self::Handle) -> bool {
false
}
/// Called whenever the line number changes.
fn set_current_line(&self, _line_number: u64) {}
/// Indicate that a `script` element is complete.
fn complete_script(&self, _node: &Self::Handle) -> NextParserState {
NextParserState::Continue
}
}
/// Trace hooks for a garbage-collected DOM.
pub trait Tracer {
type Handle;
/// Upon a call to `trace_handles`, the tree builder will call this method
/// for each handle in its internal state.
fn trace_handle(&self, node: &Self::Handle);
}