agsamantha/node_modules/domutils/lib/esm/helpers.js
2024-10-02 15:15:21 -05:00

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4.9 KiB
JavaScript

import { hasChildren } from "domhandler";
/**
* Given an array of nodes, remove any member that is contained by another
* member.
*
* @category Helpers
* @param nodes Nodes to filter.
* @returns Remaining nodes that aren't contained by other nodes.
*/
export function removeSubsets(nodes) {
let idx = nodes.length;
/*
* Check if each node (or one of its ancestors) is already contained in the
* array.
*/
while (--idx >= 0) {
const node = nodes[idx];
/*
* Remove the node if it is not unique.
* We are going through the array from the end, so we only
* have to check nodes that preceed the node under consideration in the array.
*/
if (idx > 0 && nodes.lastIndexOf(node, idx - 1) >= 0) {
nodes.splice(idx, 1);
continue;
}
for (let ancestor = node.parent; ancestor; ancestor = ancestor.parent) {
if (nodes.includes(ancestor)) {
nodes.splice(idx, 1);
break;
}
}
}
return nodes;
}
/**
* @category Helpers
* @see {@link http://dom.spec.whatwg.org/#dom-node-comparedocumentposition}
*/
export var DocumentPosition;
(function (DocumentPosition) {
DocumentPosition[DocumentPosition["DISCONNECTED"] = 1] = "DISCONNECTED";
DocumentPosition[DocumentPosition["PRECEDING"] = 2] = "PRECEDING";
DocumentPosition[DocumentPosition["FOLLOWING"] = 4] = "FOLLOWING";
DocumentPosition[DocumentPosition["CONTAINS"] = 8] = "CONTAINS";
DocumentPosition[DocumentPosition["CONTAINED_BY"] = 16] = "CONTAINED_BY";
})(DocumentPosition || (DocumentPosition = {}));
/**
* Compare the position of one node against another node in any other document,
* returning a bitmask with the values from {@link DocumentPosition}.
*
* Document order:
* > There is an ordering, document order, defined on all the nodes in the
* > document corresponding to the order in which the first character of the
* > XML representation of each node occurs in the XML representation of the
* > document after expansion of general entities. Thus, the document element
* > node will be the first node. Element nodes occur before their children.
* > Thus, document order orders element nodes in order of the occurrence of
* > their start-tag in the XML (after expansion of entities). The attribute
* > nodes of an element occur after the element and before its children. The
* > relative order of attribute nodes is implementation-dependent.
*
* Source:
* http://www.w3.org/TR/DOM-Level-3-Core/glossary.html#dt-document-order
*
* @category Helpers
* @param nodeA The first node to use in the comparison
* @param nodeB The second node to use in the comparison
* @returns A bitmask describing the input nodes' relative position.
*
* See http://dom.spec.whatwg.org/#dom-node-comparedocumentposition for
* a description of these values.
*/
export function compareDocumentPosition(nodeA, nodeB) {
const aParents = [];
const bParents = [];
if (nodeA === nodeB) {
return 0;
}
let current = hasChildren(nodeA) ? nodeA : nodeA.parent;
while (current) {
aParents.unshift(current);
current = current.parent;
}
current = hasChildren(nodeB) ? nodeB : nodeB.parent;
while (current) {
bParents.unshift(current);
current = current.parent;
}
const maxIdx = Math.min(aParents.length, bParents.length);
let idx = 0;
while (idx < maxIdx && aParents[idx] === bParents[idx]) {
idx++;
}
if (idx === 0) {
return DocumentPosition.DISCONNECTED;
}
const sharedParent = aParents[idx - 1];
const siblings = sharedParent.children;
const aSibling = aParents[idx];
const bSibling = bParents[idx];
if (siblings.indexOf(aSibling) > siblings.indexOf(bSibling)) {
if (sharedParent === nodeB) {
return DocumentPosition.FOLLOWING | DocumentPosition.CONTAINED_BY;
}
return DocumentPosition.FOLLOWING;
}
if (sharedParent === nodeA) {
return DocumentPosition.PRECEDING | DocumentPosition.CONTAINS;
}
return DocumentPosition.PRECEDING;
}
/**
* Sort an array of nodes based on their relative position in the document,
* removing any duplicate nodes. If the array contains nodes that do not belong
* to the same document, sort order is unspecified.
*
* @category Helpers
* @param nodes Array of DOM nodes.
* @returns Collection of unique nodes, sorted in document order.
*/
export function uniqueSort(nodes) {
nodes = nodes.filter((node, i, arr) => !arr.includes(node, i + 1));
nodes.sort((a, b) => {
const relative = compareDocumentPosition(a, b);
if (relative & DocumentPosition.PRECEDING) {
return -1;
}
else if (relative & DocumentPosition.FOLLOWING) {
return 1;
}
return 0;
});
return nodes;
}
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