ractive-ez-table/lib/groupBy.js

Ractive Ez UI Table

import utils from './utils.js';

const sortBy = (array, column) => {
	const compare 	= column.compare || utils.compare;
	const prop 		= utils.prop(column.path);
	const sorter	= column.sortDirection
		? (a, b) => compare(prop(a), prop(b))
		: (a, b) => compare(prop(b), prop(a));
		
	return array.slice().sort(sorter);
};

// not very "elegant"...
const rootGroupBy = (array, groups, sortColumn) => {
	
	const root = {
		subGroups: groupBy(array, groups, sortColumn),
		items: array
	};
	
	if (sortColumn && !root.groups && root.items) {
		root.items = sortBy(root.items, sortColumn);
	}
	
	return root;
	
};

const groupBy = (array, groups, sortColumn) => {

    if (array == null  || array.length == 0) return null;
    if (groups == null || groups.length == 0) return null;

    const group = groups[0];
    const remainingGroups = groups.slice(1);
	const prop = utils.prop(group.path);
    const sortedArray = sortBy(array, group);
    const groupings = [];

    const addGrouping = (grouping) => {

        if (remainingGroups.length) {
            grouping.subGroups = groupBy(grouping.items, remainingGroups, sortColumn);
        } else if (sortColumn != null) {
			grouping.items = sortBy(grouping.items, sortColumn);
		}

        groupings.push(grouping);
    }

    let currentGrouping = {
        column: group,
        value: prop(sortedArray[0]),
        items: [sortedArray[0]],
        subGroups: null
    };

    for (let i = 1; i < sortedArray.length; i++) {
        const record = sortedArray[i];

        if (prop(record) != currentGrouping.value) {
            addGrouping(currentGrouping);

            currentGrouping = {
                column: group,
                value: prop(record),
                items: [],
                subGroups: null
            }
        }

        currentGrouping.items.push(record);
    }

    addGrouping(currentGrouping);

    return groupings;
};

export default rootGroupBy;