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//! patch module
//use crate::node::Text;
use crate::{Attribute, Node};
use std::fmt::Debug;
pub use tree_path::TreePath;
mod tree_path;
/// A Patch encodes an operation that modifies a real DOM element or native UI element
///
/// To update the real DOM that a user sees you'll want to first diff your
/// old virtual dom and new virtual dom.
///
/// This diff operation will generate `Vec<Patch>` with zero or more patches that, when
/// applied to your real DOM, will make your real DOM look like your new virtual dom.
///
/// Each of the Patch contains `TreePath` which contains an array of indexes for each node
/// that we need to traverse to get the target element.
///
/// Consider the following html:
///
/// ```html
/// <body>
/// <main>
/// <input type="text"/>
/// <img src="pic.jpg"/>
/// </main>
/// <footer>
/// <a>Link</a>
/// <nav/>
/// </footer>
/// </body>
/// ```
/// The corresponding DOM tree would be
/// ```bob
/// .─.
/// ( 0 ) <body>
/// `-'
/// / \
/// / \
/// / \
/// ▼ ▼
/// <main> .─. .─. <footer>
/// ( 0 ) ( 1 )
/// `-' `-'
/// / \ | \ '.
/// / \ | \ '.
/// ▼ ▼ | \ '.
/// .─. .─. ▼ ▼ ▼
/// ( 0 ) ( 1 ) .─. .─. .─.
/// `─' `─' ( 0 ) ( 1 ) ( 2 )
/// <input> <img> `─' `─' `─'
/// <a> <Text> <nav>
/// ```
/// To traverse to the `<nav>` element we follow the TreePath([0,1,2]).
/// 0 - is the root element which is always zero.
/// 1 - is the `footer` element since it is the 2nd element of the body.
/// 2 - is the `nav` element since it is the 3rd node in the `footer` element.
#[derive(Clone, Debug, PartialEq)]
pub struct Patch<'a, Ns, Tag, Leaf, Att, Val>
where
Ns: PartialEq + Clone + Debug,
Tag: PartialEq + Debug,
Leaf: PartialEq + Clone + Debug,
Att: PartialEq + Clone + Debug,
Val: PartialEq + Clone + Debug,
{
/// the tag of the node at patch_path
pub tag: Option<&'a Tag>,
/// the path to traverse to get to the target element
pub patch_path: TreePath,
/// the type of patch we are going to apply
pub patch_type: PatchType<'a, Ns, Tag, Leaf, Att, Val>,
}
/// the patch variant
#[derive(Clone, Debug, PartialEq)]
pub enum PatchType<'a, Ns, Tag, Leaf, Att, Val>
where
Ns: PartialEq + Clone + Debug,
Tag: PartialEq + Debug,
Leaf: PartialEq + Clone + Debug,
Att: PartialEq + Clone + Debug,
Val: PartialEq + Clone + Debug,
{
/// insert the nodes before the node at patch_path
InsertBeforeNode {
/// the nodes to be inserted before patch_path
nodes: Vec<&'a Node<Ns, Tag, Leaf, Att, Val>>,
},
/// insert the nodes after the node at patch_path
InsertAfterNode {
/// the nodes to be inserted after the patch_path
nodes: Vec<&'a Node<Ns, Tag, Leaf, Att, Val>>,
},
/// Append a vector of child nodes to a parent node id at patch_path
AppendChildren {
/// children nodes to be appended and their corresponding new_node_idx
children: Vec<&'a Node<Ns, Tag, Leaf, Att, Val>>,
},
/// remove the target node
RemoveNode,
/// ReplaceNode a node with another node. This typically happens when a node's tag changes.
/// ex: <div> becomes <span>
ReplaceNode {
/// the node that will replace the target node
replacement: Vec<&'a Node<Ns, Tag, Leaf, Att, Val>>,
},
/// Add attributes that the new node has that the old node does not
/// Note: the attributes is not a reference since attributes of same
/// name are merged to produce a new unify attribute
AddAttributes {
/// the attributes to be patched into the target node
attrs: Vec<&'a Attribute<Ns, Att, Val>>,
},
/// Remove attributes that the old node had that the new node doesn't
RemoveAttributes {
/// attributes that are to be removed from this target node
attrs: Vec<&'a Attribute<Ns, Att, Val>>,
},
}
impl<'a, Ns, Tag, Leaf, Att, Val> Patch<'a, Ns, Tag, Leaf, Att, Val>
where
Ns: PartialEq + Clone + Debug,
Tag: PartialEq + Debug,
Leaf: PartialEq + Clone + Debug,
Att: PartialEq + Clone + Debug,
Val: PartialEq + Clone + Debug,
{
/// return the path to traverse for this patch to get to the target Node
pub fn path(&self) -> &TreePath {
&self.patch_path
}
/// return the tag of this patch
pub fn tag(&self) -> Option<&Tag> {
self.tag
}
/// create an InsertBeforeNode patch
pub fn insert_before_node(
tag: Option<&'a Tag>,
patch_path: TreePath,
nodes: Vec<&'a Node<Ns, Tag, Leaf, Att, Val>>,
) -> Patch<'a, Ns, Tag, Leaf, Att, Val> {
Patch {
tag,
patch_path,
patch_type: PatchType::InsertBeforeNode { nodes },
}
}
/// create an InsertAfterNode patch
pub fn insert_after_node(
tag: Option<&'a Tag>,
patch_path: TreePath,
nodes: Vec<&'a Node<Ns, Tag, Leaf, Att, Val>>,
) -> Patch<'a, Ns, Tag, Leaf, Att, Val> {
Patch {
tag,
patch_path,
patch_type: PatchType::InsertAfterNode { nodes },
}
}
/// create a patch where we add children to the target node
pub fn append_children(
tag: &'a Tag,
patch_path: TreePath,
children: Vec<&'a Node<Ns, Tag, Leaf, Att, Val>>,
) -> Patch<'a, Ns, Tag, Leaf, Att, Val> {
Patch {
tag: Some(tag),
patch_path,
patch_type: PatchType::AppendChildren { children },
}
}
/// create a patch where the target element that can be traverse
/// using the patch path will be remove
pub fn remove_node(
tag: Option<&'a Tag>,
patch_path: TreePath,
) -> Patch<'a, Ns, Tag, Leaf, Att, Val> {
Patch {
tag,
patch_path,
patch_type: PatchType::RemoveNode,
}
}
/// create a patch where a node is replaced by the `replacement` node.
/// The target node to be replace is traverse using the `patch_path`
pub fn replace_node(
tag: Option<&'a Tag>,
patch_path: TreePath,
replacement: Vec<&'a Node<Ns, Tag, Leaf, Att, Val>>,
) -> Patch<'a, Ns, Tag, Leaf, Att, Val> {
Patch {
tag,
patch_path,
patch_type: PatchType::ReplaceNode { replacement },
}
}
/// create a patch where a new attribute is added to the target element
pub fn add_attributes(
tag: &'a Tag,
patch_path: TreePath,
attrs: Vec<&'a Attribute<Ns, Att, Val>>,
) -> Patch<'a, Ns, Tag, Leaf, Att, Val> {
Patch {
tag: Some(tag),
patch_path,
patch_type: PatchType::AddAttributes { attrs },
}
}
/// create patch where it remove attributes of the target element that can be traversed by the
/// patch_path.
pub fn remove_attributes(
tag: &'a Tag,
patch_path: TreePath,
attrs: Vec<&'a Attribute<Ns, Att, Val>>,
) -> Patch<'a, Ns, Tag, Leaf, Att, Val> {
Patch {
tag: Some(tag),
patch_path,
patch_type: PatchType::RemoveAttributes { attrs },
}
}
}