devextreme/dist/transpiled/data/remote_query.js

HTML5 JavaScript Component Suite for Responsive Web Development

"use strict";

var queryAdapters = require("./query_adapters"),
    errorsModule = require("./errors"),
    each = require("../core/utils/iterator").each,
    isFunction = require("../core/utils/type").isFunction,
    Deferred = require("../core/utils/deferred").Deferred,
    arrayQueryImpl = require("./array_query");

var remoteQueryImpl = function remoteQueryImpl(url, queryOptions, tasks) {
    tasks = tasks || [];
    queryOptions = queryOptions || {};

    var createTask = function createTask(name, args) {
        return { name: name, args: args };
    };

    var exec = function exec(executorTask) {
        var d = new Deferred(),
            _adapterFactory,
            _adapter,
            _taskQueue,
            _currentTask,
            _mergedSortArgs;

        var rejectWithNotify = function rejectWithNotify(error) {
            var handler = queryOptions.errorHandler;
            if (handler) {
                handler(error);
            }

            errorsModule._errorHandler(error);
            d.reject(error);
        };

        function mergeSortTask(task) {
            switch (task.name) {
                case "sortBy":
                    _mergedSortArgs = [task.args];
                    return true;

                case "thenBy":
                    if (!_mergedSortArgs) {
                        throw errorsModule.errors.Error("E4004");
                    }

                    _mergedSortArgs.push(task.args);
                    return true;
            }

            return false;
        }

        function unmergeSortTasks() {
            var head = _taskQueue[0],
                unmergedTasks = [];

            if (head && head.name === "multiSort") {
                _taskQueue.shift();
                each(head.args[0], function () {
                    unmergedTasks.push(createTask(unmergedTasks.length ? "thenBy" : "sortBy", this));
                });
            }

            _taskQueue = unmergedTasks.concat(_taskQueue);
        }

        try {
            _adapterFactory = queryOptions.adapter;
            if (!isFunction(_adapterFactory)) {
                _adapterFactory = queryAdapters[_adapterFactory];
            }

            _adapter = _adapterFactory(queryOptions);

            _taskQueue = [].concat(tasks).concat(executorTask);

            var optimize = _adapter.optimize;
            if (optimize) optimize(_taskQueue);

            while (_taskQueue.length) {
                _currentTask = _taskQueue[0];

                if (!mergeSortTask(_currentTask)) {
                    if (_mergedSortArgs) {
                        _taskQueue.unshift(createTask("multiSort", [_mergedSortArgs]));
                        _mergedSortArgs = null;
                        continue;
                    }

                    if (String(_currentTask.name) !== "enumerate") {
                        if (!_adapter[_currentTask.name] || _adapter[_currentTask.name].apply(_adapter, _currentTask.args) === false) {
                            break;
                        }
                    }
                }
                _taskQueue.shift();
            }

            unmergeSortTasks();

            _adapter.exec(url).done(function (result, extra) {
                if (!_taskQueue.length) {
                    d.resolve(result, extra);
                } else {
                    var clientChain = arrayQueryImpl(result, {
                        errorHandler: queryOptions.errorHandler
                    });
                    each(_taskQueue, function () {
                        clientChain = clientChain[this.name].apply(clientChain, this.args);
                    });
                    clientChain.done(d.resolve).fail(d.reject);
                }
            }).fail(rejectWithNotify);
        } catch (x) {
            rejectWithNotify(x);
        }

        return d.promise();
    };

    var query = {};

    each(["sortBy", "thenBy", "filter", "slice", "select", "groupBy"], function () {
        var name = String(this);
        query[name] = function () {
            return remoteQueryImpl(url, queryOptions, tasks.concat(createTask(name, arguments)));
        };
    });

    each(["count", "min", "max", "sum", "avg", "aggregate", "enumerate"], function () {
        var name = String(this);
        query[name] = function () {
            return exec.call(this, createTask(name, arguments));
        };
    });

    return query;
};

module.exports = remoteQueryImpl;