#javascript_lib

sortChildren.js

/**
 * Copyright (c) 2017~2999 - cologler <skyoflw@gmail.com>
 * @param {any} root 
 * @param {any} options 
* */
function sortChildren(root, options) {
    options = Object.assign({
        filter: () => true,
        selector: z => z,
        comparer: (x, y) => x - y
    }, options || {});
    let items = [];
    for (var i = 0; i < root.childNodes.length; i++) {
        var item = root.childNodes[i];
        if (options.filter(item)) {
            items.push({
                nodeIndex: i,
                node: item
            });
        }
    }
    items = items.map((z, i) => {
        return {
            itemIndex: i,
            nodeIndex: z.nodeIndex,
            node: z.node
        };
    });
    if (items.length > 0) {
        const sortedItems = items.slice();
        sortedItems.sort((x, y) => {
            return options.comparer(
                options.selector(x.node),
                options.selector(y.node)
            );
        });
        sortedItems.reverse();
        sortedItems.forEach((z, i) => {
            const newItemIndex = sortedItems.length - i - 1;
            const olditemIndex = z.itemIndex;
            if (olditemIndex !== newItemIndex) {
                const newNodeIndex = items[newItemIndex].nodeIndex;
                const before = root.childNodes[newNodeIndex];
                console.assert(before !== undefined);
                root.insertBefore(z.node, before);
            }
        });
    }
}