/** * eGroupWare eTemplate2 * * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License * @package etemplate * @subpackage dataview * @link http://www.egroupware.org * @author Andreas Stöckel * @copyright Stylite 2011-2012 * @version $Id$ */ /*egw:uses et2_core_common; et2_core_inheritance; et2_dataview_interfaces; et2_dataview_view_aoi; et2_dataview_view_row; egw_action.egw_action; */ /** * The fetch timeout specifies the time during which the controller tries to * consolidate requests for rows. */ var ET2_DATAVIEW_FETCH_TIMEOUT = 50; var ET2_DATAVIEW_STEPSIZE = 50; /** * The et2_dataview_controller class is the intermediate layer between a grid * instance and the corresponding data source. It manages updating the grid, * as well as inserting and deleting rows. */ var et2_dataview_controller = Class.extend({ /** * Constructor of the et2_dataview_controller, connects to the grid * callback. * * @param _grid is the grid the controller should controll. * @param _dataProvider is an object implementing the et2_IDataProvider * interface. * @param _rowCallback is the callback function that gets called when a row * is requested. * @param _linkCallback is the callback function that gets called for * requesting action links for a row. The row data, the index of the row and * the uid are passed as parameters to the function. * uid is passed to the function. * @param _context is the context in which the _rowCallback and the * _linkCallback are called. * @param _actionObjectManager is the object that manages the action * objects. */ init: function (_grid, _dataProvider, _rowCallback, _linkCallback, _context, _actionObjectManager) { // Copy the given arguments this._grid = _grid; this._dataProvider = _dataProvider; this._rowCallback = _rowCallback; this._linkCallback = _linkCallback; this._context = _context; this._actionObjectManager = _actionObjectManager; // Initialize the "index map" which contains all currently displayed // containers hashed by the "index" this._indexMap = {}; // Timer used for queing fetch requests this._queueTimer = null; // Array which contains all currently queued indices in the form of // an associative array this._queue = {}; // Register the dataFetch callback this._grid.setDataCallback(this._gridCallback, this); }, destroy: function () { this._clearTimer(); this._super(); }, /** * The update function queries the server for changes in the currently * managed index range -- those changes are then merged into the current * view without a complete rebuild of every row. */ update: function () { // Clear the fetch queue this._queue = {}; this._clearTimer(); // --------- // TODO: Actually stuff here should be done if the server responds that // there at all were some changes (needs implementation of "refresh") // Remove all rows which are outside the view range this._grid.cleanup(); // Remove all index entries which are currently not displayed for (var key in this._indexMap) { if (!this._indexMap[key].row) { delete this._indexMap[key]; } } // --------- // Get the currently visible range from the grid var range = this._grid.getIndexRange(); // Force range.top and range.bottom to contain an integer if (range.top === false) { range.top = range.bottom = 0; } // Require that range from the server this._queueFetch(et2_bounds(range.top, range.bottom + 1), true); }, /** * Rebuilds the complete grid. */ reset: function () { // Throw away all internal mappings and reset the timestamp this._indexMap = {}; // Clear the grid this._grid.clear(); // Update the data this.update(); }, /* -- PRIVATE FUNCTIONS -- */ _getIndexEntry: function (_idx) { // Create an entry in the index map if it does not exist yet if (typeof this._indexMap[_idx] === "undefined") { this._indexMap[_idx] = { "row": null, "uid": null, "ao": null }; } // Always update the index of the entries before returning them. This is // neccessary, as when we remove the uid from an entry without row, its // index does not get updated any further this._indexMap[_idx]["idx"] = _idx; return this._indexMap[_idx]; }, /** * Inserts a new data row into the grid. index and uid are derived from the * given management entry. If the data for the given uid does not exist yet, * a "loading" placeholder will be shown instead. The function will do * nothing if there already is a row associated to the entry. This function * will not re-insert a row if the entry already had a row. * * @param _entry is the management entry for the index the row will be * displayed at. * @param _update specifies whether the row should be updated if _entry.row * already exists. * @return true, if all data for the row has been available, false * otherwise. */ _insertDataRow: function (_entry, _update) { // Abort if the entry already has a row but the _insert flag is not set if (_entry.row && !_update) { return true; } // Context used for the callback functions var ctx = {"self": this, "entry": _entry}; // Create a new row instance, if it does not exist yet var createdRow = false; if (!_entry.row) { createdRow = true; _entry.row = new et2_dataview_row(this._grid); _entry.row.setDestroyCallback(this._destroyCallback, ctx); } // Load the row data if we have a uid for the entry this.hasData = false; // Gets updated by the _dataCallback if (_entry.uid) { // Register the callback / immediately load the data this._dataProvider.dataRegisterUID(_entry.uid, this._dataCallback, ctx); } // Display the loading "row prototype" if we don't have data for the row if (!this.hasData) { // Get the average height, the "-5" derives from the td padding var avg = Math.round(this._grid.getAverageHeight() - 5) + "px"; var prototype = this._grid.getRowProvider().getPrototype("loading"); $j("div", prototype).css("height", avg); var node = _entry.row.getJNode(); node.empty(); node.append(prototype.children()); } // Insert the row into the table -- the same row must never be inserted // twice into the grid, so this function only executes the following // code only if it is a newly created row. if (createdRow) { this._grid.insertRow(_entry.idx, _entry.row); } return this.hasData; }, /** * Function which gets called by the grid when data is requested. * * @param _idxStart is the index of the first row for which data is * requested. * @param _idxEnd is the index of the last requested row. */ _gridCallback: function (_idxStart, _idxEnd) { var needsData = false; // Iterate over all elements the dataview requested and create a row // which indicates that we are currently loading data for (var i = _idxStart; i <= _idxEnd; i++) { var entry = this._getIndexEntry(i); // Insert the row for the entry -- do not update rows which are // already existing, as we do not have new data for those. if (!this._insertDataRow(entry, false) && needsData === false) { needsData = i; } } // Queue fetching that data range if (needsData !== false) { this._queueFetch(et2_bounds(needsData, _idxEnd + 1), false); } }, /** * The _queueFetch function is used to queue a fetch request. * TODO: Refresh is currently not used */ _queueFetch: function (_range, _isUpdate) { // Force immediate to be false _isUpdate = _isUpdate ? _isUpdate : false; // Push the requests onto the request queue var start = Math.max(0, _range.top); var end = Math.min(this._grid.getTotalCount(), _range.bottom); for (var i = start; i < end; i++) { if (typeof this._queue[i] === "undefined") { this._queue[i] = 1; // Stage 1 -- queued } } // Start the queue timer, if this has not already been done if (this._queueTimer === null && !_isUpdate) { var self = this; this._queueTimer = window.setTimeout(function () { self._flushQueue(false); }, ET2_DATAVIEW_FETCH_TIMEOUT); } if (_isUpdate) { this._flushQueue(true); } }, /** * Flushes the queue. */ _flushQueue: function (_isUpdate) { // Clear any still existing timer this._clearTimer(); // Mark all elements in a radius of ET2_DATAVIEW_STEPSIZE var marked = {}; var r = _isUpdate ? 0 : Math.floor(ET2_DATAVIEW_STEPSIZE / 2); var total = this._grid.getTotalCount(); for (var key in this._queue) { if (this._queue[key] > 1) continue; key = parseInt(key); var b = Math.max(0, key - r); var t = Math.min(key + r, total - 1); var c = 0; for (var i = b; i <= t && c < ET2_DATAVIEW_STEPSIZE; i ++) { if (typeof this._queue[i] == "undefined" || this._queue[i] === 1) { this._queue[i] = 2; // Stage 2 -- pending or available marked[i] = true; c++; } } } // Create a list with start indices and counts var fetchList = []; var entry = null; var last = 0; // Get the int keys and sort the array numeric var arr = et2_arrayIntKeys(marked).sort( function(a,b){return a > b ? 1 : (a == b ? 0 : -1)}); for (var i = 0; i < arr.length; i++) { if (i == 0 || arr[i] - last > 1) { if (entry) { fetchList.push(entry); } entry = { "start": arr[i], "count": 1 }; } else { entry.count++; } last = arr[i]; } if (entry) { fetchList.push(entry); } // Special case: If there are no entries in the fetch list and this is // an update, create an dummy entry, so that we'll get the current count if (fetchList.length === 0 && _isUpdate) { fetchList.push({ "start": 0, "count": 0 }); } // Execute all queries for (var i = 0; i < fetchList.length; i++) { // Build the query var query = { "start": fetchList[i].start, "num_rows": fetchList[i].count, "refresh": false }; // Context used in the callback function var ctx = { "self": this, "start": query.start, "count": query.num_rows, }; // Call the callback this._dataProvider.dataFetch(query, this._fetchCallback, ctx); } }, _clearTimer: function () { // Reset the queue timer upon destruction if (this._queueTimer) { window.clearTimeout(this._queueTimer); this._queueTimer = null; } }, /** * */ _dataCallback: function (_data) { // Set the "hasData" flag this.self.hasData = true; // Call the row callback with the new data -- the row callback then // generates the row DOM nodes that will be inserted into the grid if (this.self._rowCallback) { // Remove everything from the current row this.entry.row.clear(); // Fill the row DOM Node with data var tr = this.entry.row.getDOMNode(); this.self._rowCallback.call( this.self._context, _data, tr, this.entry.idx, this.entry ); // If we have an object manager, create a new action object for this // row and a new row AOI if (this.self._linkCallback && this.self._actionObjectManager) { // Call the link callback var links = this.self._linkCallback.call( this.self._context, _data, this.entry.idx, this.entry.uid ); // Create the action object var aom = this.self._actionObjectManager; this.entry.ao = aom.addObject( this.entry.uid, new et2_dataview_rowAOI(tr) ); // Update the action links this.entry.ao.updateActionLinks(links); } // Invalidate the current row entry this.entry.row.invalidate(); } }, /** * */ _destroyCallback: function (_row) { // There is no further row connected to the entry this.entry.row = null; // Unregister the data callback this.self._dataProvider.dataUnregisterUID(this.entry.uid, this.self._dataCallback, null); }, /** * Returns an array containing "_count" index mapping entries starting from * the index given in "_start". */ _getIndexMapping: function (_start, _count) { var result = []; for (var i = _start; i < _start + _count; i++) { result.push(this._getIndexEntry(i)); } return result; }, /** * Updates the grid according to the new order. The function simply does the * following: It iterates along the new order (given in _order) and the old * order given in _idxMap. Iteration variables used are * a) i -- points to the current entry in _order * b) idx -- points to the current grid row that will be effected by * this operation. * c) mapIdx -- points to the current entry in _indexMap * The following cases may occur: * a) The current entry in the old order has no uid or no row -- in that * case the row at the current position is simply updated, * the old pointer will be incremented. * b) The two uids differ -- insert a new row with the new uid, do not * increment the old pointer. * c) The two uids are the same -- increment the old pointer. * In a last step all rows that are left in the old order are deleted. All * newly created index entries are returned. This function does not update * the internal mapping in _idxMap. */ _updateOrder: function (_start, _count, _idxMap, _order) { // The result contains the newly created index map entries which have to // be merged with the result var result = []; // Iterate over the new order var mapIdx = 0; var idx = _start; for (var i = 0; i < _order.length; i++, idx++) { var current = _idxMap[mapIdx]; if (!current.row || !current.uid) { // If there is no row yet at the current position or the uid // of that entry is unknown, simply update the entry. current.uid = _order[i]; current.idx = idx; // Only update the row, if it is displayed (e.g. has a "loading" // row displayed) -- this is needed for prefetching if (current.row) { this._insertDataRow(current, true); } mapIdx++; } else if (current.uid !== _order[i]) { // Insert a new row at the new position var entry = { "idx": idx, "uid": _order[i], "row": null }; this._insertDataRow(entry, true); // Remember the new entry result.push(entry); } else { // Do nothing, the uids do not differ, just update the index of // the element current.idx = idx; mapIdx++; } } // Delete as many rows as we have left, invalidate the corresponding // index entry for (var i = mapIdx; i < _idxMap.length; i++) { this._grid.deleteRow(idx); _idxMap[i].uid = null; } return result; }, _mergeResult: function (_newEntries, _invalidStartIdx, _diff, _total) { if (_newEntries.length > 0 || _diff > 0) { // Create a new index map var newMap = {}; // Insert all new entries into the new index map for (var i = 0; i < _newEntries.length; i++) { newMap[_newEntries[i].idx] = _newEntries[i]; } // Merge the old map with all old entries for (var key in this._indexMap) { // Get the corresponding index entry var entry = this._indexMap[key]; // Calculate the new index -- if rows were deleted, we'll // have to adjust the index var newIdx = entry.idx >= _invalidStartIdx ? entry.idx - _diff : entry.idx; if (newIdx >= 0 && newIdx < _total && typeof newMap[newIdx] === "undefined") { entry.idx = newIdx; newMap[newIdx] = entry; } } // Make the new index map the current index map this._indexMap = newMap; } }, _fetchCallback: function (_response) { // Do nothing if _response.order evaluates to false if (!_response.order) { return; } // Make sure _response.order.length is not longer than the requested // count var order = _response.order.splice(0, this.count); // Get the current index map for the updated region var idxMap = this.self._getIndexMapping(this.start, this.count); // Update the grid using the new order. The _updateOrder function does // not update the internal mapping while inserting and deleting rows, as // this would move us to another asymptotic runtime level. var res = this.self._updateOrder(this.start, this.count, idxMap, order); // Merge the new indices, update all indices with rows that were not // affected and invalidate all indices if there were changes this.self._mergeResult(res, this.start + order.length, idxMap.length - order.length, _response.total); // Update the total element count in the grid this.self._grid.setTotalCount(_response.total); } });