domutils/lib/helpers.js

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.uniqueSort = exports.compareDocumentPosition = exports.removeSubsets = void 0;
var domhandler_1 = require("domhandler");
/**
 * Given an array of nodes, remove any member that is contained by another.
 *
 * @param nodes Nodes to filter.
 * @returns Remaining nodes that aren't subtrees of each other.
 */
function removeSubsets(nodes) {
    var idx = nodes.length;
    /*
     * Check if each node (or one of its ancestors) is already contained in the
     * array.
     */
    while (--idx >= 0) {
        var 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 (var ancestor = node.parent; ancestor; ancestor = ancestor.parent) {
            if (nodes.includes(ancestor)) {
                nodes.splice(idx, 1);
                break;
            }
        }
    }
    return nodes;
}
exports.removeSubsets = removeSubsets;
/**
 * Compare the position of one node against another node in any other document.
 * The return value is a bitmask with the following values:
 *
 * 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
 *
 * @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.
 */
function compareDocumentPosition(nodeA, nodeB) {
    var aParents = [];
    var bParents = [];
    if (nodeA === nodeB) {
        return 0;
    }
    var current = (0, domhandler_1.hasChildren)(nodeA) ? nodeA : nodeA.parent;
    while (current) {
        aParents.unshift(current);
        current = current.parent;
    }
    current = (0, domhandler_1.hasChildren)(nodeB) ? nodeB : nodeB.parent;
    while (current) {
        bParents.unshift(current);
        current = current.parent;
    }
    var maxIdx = Math.min(aParents.length, bParents.length);
    var idx = 0;
    while (idx < maxIdx && aParents[idx] === bParents[idx]) {
        idx++;
    }
    if (idx === 0) {
        return 1 /* DISCONNECTED */;
    }
    var sharedParent = aParents[idx - 1];
    var siblings = sharedParent.children;
    var aSibling = aParents[idx];
    var bSibling = bParents[idx];
    if (siblings.indexOf(aSibling) > siblings.indexOf(bSibling)) {
        if (sharedParent === nodeB) {
            return 4 /* FOLLOWING */ | 16 /* CONTAINED_BY */;
        }
        return 4 /* FOLLOWING */;
    }
    if (sharedParent === nodeA) {
        return 2 /* PRECEDING */ | 8 /* CONTAINS */;
    }
    return 2 /* PRECEDING */;
}
exports.compareDocumentPosition = compareDocumentPosition;
/**
 * Sort an array of nodes based on their relative position in the document and
 * remove any duplicate nodes. If the array contains nodes that do not belong
 * to the same document, sort order is unspecified.
 *
 * @param nodes Array of DOM nodes.
 * @returns Collection of unique nodes, sorted in document order.
 */
function uniqueSort(nodes) {
    nodes = nodes.filter(function (node, i, arr) { return !arr.includes(node, i + 1); });
    nodes.sort(function (a, b) {
        var relative = compareDocumentPosition(a, b);
        if (relative & 2 /* PRECEDING */) {
            return -1;
        }
        else if (relative & 4 /* FOLLOWING */) {
            return 1;
        }
        return 0;
    });
    return nodes;
}
exports.uniqueSort = uniqueSort;