shyft/lib/engine/cursor.js

Model driven GraphQL API framework

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.processCursors = exports.processCursor = void 0;
var util_1 = require("./util");
var processCursor = function (entity, cursor, orderBy, reverse) {
    var _a, _b;
    var $LT = reverse ? '$gt' : '$lt';
    var $GT = reverse ? '$lt' : '$gt';
    var $LTE = reverse ? '$gte' : '$lte';
    var $GTE = reverse ? '$lte' : '$gte';
    var where = {};
    if (entity && cursor) {
        util_1.passOrThrow(util_1.isArray(cursor[entity.name]), function () { return 'Incompatible cursor for this entity'; });
        util_1.passOrThrow(util_1.isArray(orderBy), function () { return 'orderBy needs to be an array of order definitions'; });
        var orderList_1 = [];
        var orderMap_1 = {};
        orderBy.map(function (_a) {
            var attribute = _a.attribute, direction = _a.direction;
            util_1.passOrThrow(attribute && direction, function () {
                return 'orderBy needs to be an array of attributes and respective sort order';
            });
            orderMap_1[attribute] = direction;
        });
        var primaryAttribute_1 = entity.getPrimaryAttribute();
        var attributes_1 = entity.getAttributes();
        var foundUniqueAttribute_1 = false;
        cursor[entity.name].map(function (filter) {
            if (filter.length !== 2) {
                throw new Error('Cursor malformed');
            }
            var attributeName = filter[0];
            util_1.passOrThrow(attributes_1[attributeName], function () { return "Unknown attribute '" + attributeName + "' used in cursor"; });
            if (attributeName !== primaryAttribute_1.name) {
                util_1.passOrThrow(orderMap_1[attributeName], function () {
                    return "Cursor works only on sorted attributes (check: '" + attributeName + "')";
                });
            }
            var attribute = attributes_1[attributeName];
            // limit where clause to the first attribute which is defined as unique
            if (!foundUniqueAttribute_1) {
                orderList_1.push(attributeName);
            }
            if (attribute.unique || attributeName === primaryAttribute_1.name) {
                foundUniqueAttribute_1 = true;
            }
        });
        util_1.passOrThrow(foundUniqueAttribute_1, function () { return 'Cursor needs to have at least one attribute defined as unique'; });
        // if more than 2 attributes are used for the cursor take only the first and the last (primary key)
        if (orderList_1.length > 2) {
            orderList_1.splice(1, orderList_1.length - 2);
        }
        // simple filter for single attributes
        if (orderList_1.length === 1) {
            var attributeName = orderList_1[0];
            var value = cursor[entity.name][0][1];
            if (orderMap_1[attributeName] === 'DESC') {
                where[attributeName] = (_a = {},
                    _a[$LT] = value,
                    _a);
            }
            else {
                where[attributeName] = (_b = {},
                    _b[$GT] = value,
                    _b);
            }
        }
        else {
            where.$not = {};
            cursor[entity.name].map(function (filter) {
                var _a, _b, _c, _d;
                var attributeName = filter[0];
                var value = filter[1];
                // ignore attributes that obsolete due to prior unique attribute
                if (orderList_1.indexOf(attributeName) === -1) {
                    return;
                }
                var attribute = attributes_1[attributeName];
                if (attribute.unique) {
                    if (orderMap_1[attributeName] === 'DESC') {
                        where.$not[attributeName] = (_a = {},
                            _a[$GTE] = value,
                            _a);
                    }
                    else {
                        where.$not[attributeName] = (_b = {},
                            _b[$LTE] = value,
                            _b);
                    }
                }
                else {
                    where.$not[attributeName] = value;
                    if (orderMap_1[attributeName] === 'DESC') {
                        where[attributeName] = (_c = {},
                            _c[$LTE] = value,
                            _c);
                    }
                    else {
                        where[attributeName] = (_d = {},
                            _d[$GTE] = value,
                            _d);
                    }
                }
            });
        }
    }
    return where;
};
exports.processCursor = processCursor;
var processCursors = function (entity, args) {
    var after = args.after, before = args.before;
    var where = {
        $and: [
            exports.processCursor(entity, after, args.orderBy),
            exports.processCursor(entity, before, args.orderBy, true),
        ],
    };
    return where;
};
exports.processCursors = processCursors;