egroupware_official/phpgwapi/js/jsapi/egw_data.js

384 lines
11 KiB
JavaScript

/**
* eGroupWare eTemplate2
*
* @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
* @package etemplate
* @subpackage api
* @link http://www.egroupware.org
* @author Andreas Stöckel
* @copyright Stylite 2012
* @version $Id$
*/
/*egw:uses
egw_core;
egw_debug;
*/
"use strict";
egw.extend("data", egw.MODULE_APP_LOCAL, function (_app, _wnd) {
/**
* The uid function generates a session-unique id for the current
* application by appending the application name to the given uid.
*/
function UID(_uid)
{
return _app + "::" + _uid;
}
function parseServerResponse(_result, _callback, _context)
{
// Check whether the result is valid -- so "result" has to be an object
// consting of "order" and "data"
if (!(_result && typeof _result.order !== "undefined"
&& typeof _result.data !== "undefined"))
{
egw.debug("error", "Invalid result for 'dataFetch'");
}
// The "uidsMissing" contains a list of missing uids.
var uidsMissing = [];
if (_result.order && _result.data)
{
// Assemble the correct order uids
for (var i = 0; i < _result.order.length; i++)
{
_result.order[i] = UID(_result.order[i]);
}
// Load all data entries that have been sent or delete them
for (var key in _result.data)
{
var uid = UID(key);
if (_result.data[key] === null)
{
egw.dataDeleteUID(uid);
}
else
{
egw.dataStoreUID(uid, _result.data[key]);
}
}
// Call the callback function and pass the calculated "order" array
// as well as the "total" count and the "timestamp" to the listener.
if (_callback)
{
_callback.call(_context, {
"order": _result.order,
"lastModification": _result.lastModification,
"total": parseInt(_result.total),
"readonlys": _result.readonlys,
"rows": _result.rows
});
}
}
}
return {
/**
* The dataFetch function provides an abstraction layer for the
* corresponding "etemplate_widget_nextmatch::ajax_get_rows" function.
* The server returns the following structure:
* {
* order: [uid, ...],
* data:
* {
* uid0: data,
* ...
* uidN: data
* },
* total: <TOTAL COUNT>,
* lastModification: <LAST MODIFICATION TIMESTAMP>,
* readonlys: <READONLYS>
* }
* If a uid got deleted on the server above data is null.
* If a uid is omitted from data, is has not changed since lastModification.
*
* If order/data is null, this means that nothing has changed for the
* given range.
* The dataFetch function stores new data for the uid's inside the
* local data storage, the grid views are then capable of querying the
* data for those uids from the local storage using the
* "dataRegisterUID" function.
*
* @param execId is the execution context of the etemplate instance
* you're querying the data for.
* @param queriedRange is an object of the following form:
* {
* start: <START INDEX>,
* num_rows: <COUNT OF ENTRIES>
* }
* The range always corresponds to the given filter settings.
* @param filters contains the filter settings. The filter settings are
* those which are crucial for the mapping between index and uid.
* @param widgetId id with full namespace of widget
* @param knownUids is an array of uids already known to the client.
* This parameter may be null in order to indicate that the client
* currently has no data for the given filter settings.
* @param lastModification is the last timestamp that was returned from
* the server and for which the client has data. It may be null in
* order to indicate, that the client currently has no data or needs a
* complete refresh.
* @param callback is the function that should get called, once the data
* is available. The data passed to the callback function has the
* following form:
* {
* order: [uid, ...],
* total: <TOTAL COUNT>,
* lastModification: <LAST MODIFICATION TIMESTAMP>,
* readonlys: <READONLYS>
* }
* Please note that the "uids" comming from the server and the ones
* being parsed to the callback function differ. While the uids
* which are returned from the server are only unique inside the
* application, the uids which are used on the client are "globally"
* unique.
* @param context is the context in which the callback function will get
* called.
*/
dataFetch: function (_execId, _queriedRange, _filters, _widgetId,
_lastModification, _callback, _context)
{
var request = egw.json(
"etemplate_widget_nextmatch::ajax_get_rows::etemplate",
[
_execId,
_queriedRange,
_filters,
_widgetId,
egw.dataKnownUIDs(_app),
_lastModification
],
function(result) {
parseServerResponse(result, _callback, _context);
},
this,
true
);
request.sendRequest();
}
};
});
egw.extend("data_storage", egw.MODULE_GLOBAL, function (_app, _wnd) {
/**
* The localStorage object is used to store the data for certain uids. An
* entry inside the localStorage object looks like the following:
* {
* timestamp: <CREATION TIMESTAMP (local)>,
* data: <DATA>
* }
*/
var localStorage = {};
/**
* The registeredCallbacks map is used to store all callbacks registerd for
* a certain uid.
*/
var registeredCallbacks = {};
/**
* This constant specifies the maximum age of entries in the local storrage
* in milliseconds
*/
var MAX_AGE = 5 * 60 * 1000; // 5 mins
/**
* This constant specifies the interval in which the local storage gets
* cleaned up.
*/
var CLEANUP_INTERVAL = 30 * 1000; // 30 sec
/**
* Register a cleanup function, which throws away all data entries which are
* older than the given age.
*/
_wnd.setInterval(function() {
// Get the current timestamp
var time = (new Date).getTime();
// Iterate over the local storage
for (var uid in localStorage)
{
if (time - localStorage[uid].timestamp > MAX_AGE)
{
// Unregister all registered callbacks for that uid
egw.dataUnregisterUID(uid);
// Delete the data from the localStorage
delete localStorage[uid];
}
}
}, CLEANUP_INTERVAL);
return {
/**
* Registers the intrest in a certain uid for a callback function. If
* the data for that uid changes or gets loaded, the given callback
* function is called. If the data for the given uid is available at the
* time of registering the callback, the callback is called immediately.
*
* @param _uid is the uid for which the callback should be registered.
* @param _callback is the callback which should get called.
* @param _context is an optional parameter which can
*/
dataRegisterUID: function (_uid, _callback, _context) {
// Create the slot for the uid if it does not exist now
if (typeof registeredCallbacks[_uid] === "undefined")
{
registeredCallbacks[_uid] = [];
}
// Store the given callback
registeredCallbacks[_uid].push({
"callback": _callback,
"context": _context ? _context : null
});
// Check whether the data is available -- if yes, immediately call
// back the callback function
if (typeof localStorage[_uid] !== "undefined")
{
// Update the timestamp and call the given callback function
localStorage[_uid].timestamp = (new Date).getTime();
_callback.call(_context, localStorage[_uid].data);
}
},
/**
* Unregisters the intrest of updates for a certain data uid.
*
* @param _uid is the data uid for which the callbacks should be
* unregistered.
* @param _callback specifies the specific callback that should be
* unregistered. If it evaluates to false, all callbacks (or those
* matching the optionally given context) are removed.
* @param _context specifies the callback context that should be
* unregistered. If it evaluates to false, all callbacks (or those
* matching the optionally given callback function) are removed.
*/
dataUnregisterUID: function (_uid, _callback, _context) {
// Force the optional parameters to be exactly null
_callback = _callback ? _callback : null;
_context = _context ? _context : null;
if (typeof registeredCallbacks[_uid] !== "undefined")
{
// Iterate over the registered callbacks for that uid and delete
// all callbacks pointing to the given callback and context
for (var i = registeredCallbacks[_uid].length - 1; i >= 0; i--)
{
if ((!_callback || registeredCallbacks[_uid][i].callback === _callback)
&& (!_context || registeredCallbacks[_uid][i].context === _context))
{
registeredCallbacks[_uid].splice(i, 1);
}
}
// Delete the slot if no callback is left for the uid
if (registeredCallbacks[_uid].length === 0)
{
delete registeredCallbacks[_uid];
}
}
},
/**
* Returns whether data is available for the given uid.
*
* @param uid is the uid for which should be checked whether it has some
* data.
*/
dataHasUID: function (_uid) {
return typeof localStorage[_uid] !== "undefined";
},
/**
* Returns all uids that have the given prefix
* TODO: Improve this
*/
dataKnownUIDs: function (_prefix) {
var result = [];
for (var key in localStorage)
{
var parts = key.split("::");
if (parts[0] === _prefix)
{
result.push(parts[1]);
}
}
return result;
},
/**
* Stores data for the uid and calls all callback functions registered
* for that uid.
*
* @param _uid is the uid for which the data should be saved.
* @param _data is the data which should be saved.
*/
dataStoreUID: function (_uid, _data) {
// Get the current unix timestamp
var timestamp = (new Date).getTime();
// Store the data in the local storage
localStorage[_uid] = {
"timestamp": timestamp,
"data": _data
};
// Inform all registered callback functions and pass the data to
// those.
if (typeof registeredCallbacks[_uid] != "undefined")
{
for (var i = registeredCallbacks[_uid].length - 1; i >= 0; i--)
{
try {
registeredCallbacks[_uid][i].callback.call(
registeredCallbacks[_uid][i].context,
_data
);
} catch (e) {
// Remove this callback from the list
registeredCallbacks[_uid].splice(i, 1);
}
}
}
},
/**
* Deletes the data for a certain uid from the local storage and
* unregisters all callback functions associated to it.
*
* @param uid is the uid which should be deleted.
*/
dataDeleteUID: function (_uid) {
if (typeof localStorage[_uid] !== "undefined")
{
// Delete the element from the local storage
delete localStorage[_uid];
// Unregister all callbacks for that uid
this.dataUnregisterUID(_uid);
}
}
};
});