egroupware_official/phpgwapi/js/jsapi/egw_data.js
Hadi Nategh a3d9df3d53 Backport commit r47984 committed by Nathan Gray.
- Use timestamp to give cached dataFetch data a lifetime, currently 29 seconds.
- Add another callback for cache registration, called whenever the cache is used.
2014-08-06 11:11:30 +00:00

847 lines
24 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) {
/**
* How many UIDs we'll tell the server we know about. No need to pass the whole list around.
*/
var KNOWN_UID_LIMIT = 200;
/**
* Cache lifetime
*
* If cached results are used, we check their timestamp. If the timestamp
* is older than this, we will also ask for fresh data. For cached data
* younger than this, we only return the cache
*
* 29 seconds, 1 less then the fastest nextmatch autorefresh option
*/
var CACHE_LIFETIME = 29; // seconds
var lastModification = null;
/**
* cacheCallback stores callbacks that determine if data is placed
* into cacheStorage, or simply kept temporarily. It is indexed
* by prefix.
*
* @type Array
*/
var cacheCallback = {};
/**
* The uid function generates a session-unique id for the current
* application by appending the application name to the given uid.
*
* @param {string} _uid
* @param {string} _prefix
*/
function UID(_uid, _prefix)
{
_prefix = _prefix ? _prefix : _app;
return _prefix + "::" + _uid;
}
/**
* Looks like too much data is cached. Forget some.
*
* Tries to free up localStorage by removing the oldest cached data for the
* given prefix, but if none is found it will look at all cached data.
*
* @param {string} _prefix UID / application prefix
* @returns {Number} Number of cached recordsets removed, normally 1.
*/
function _clearCache(_prefix)
{
// Find cached items for the prefix, we prefer to expire just within the app
var indexes = [];
for(var i = 0; i < window.localStorage.length; i++)
{
if(window.localStorage.key(i).indexOf('cache_'+_prefix) == 0)
{
var key = window.localStorage.key(i);
var cached = JSON.parse(window.localStorage.getItem(key));
if(cached.lastModification)
{
indexes.push({
key: key,
lastModification: cached.lastModification
});
}
else
{
// No way to know how old it is, just remove it
window.localStorage.removeItem(key);
}
}
}
// Nothing for that prefix? Clear all cached data.
if(_prefix && indexes.length == 0)
{
return _clearCache('');
}
// Found some cached for that prefix, only remove the oldest
else if (indexes.length > 0)
{
indexes.sort(function(a,b) {
if(a.lastModification < b.lastModification) return 1;
if(a.lastModification > b.lastModification) return -1;
return 0;
})
window.localStorage.removeItem(indexes.pop().key);
return 1;
}
return indexes.length;
}
function parseServerResponse(_result, _callback, _context)
{
// Check whether the result is valid
// This result is not for us, quietly return
if(_result && typeof _result.type != 'undefined') return;
// "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'");
}
if (_result.lastModification)
{
lastModification = _result.lastModification;
}
if (_result.order && _result.data)
{
// Assemble the correct order uids
if(!(_result.order.length && _result.order[0] && _result.order[0].indexOf && _result.order[0].indexOf(_context.prefix) == 0))
{
for (var i = 0; i < _result.order.length; i++)
{
_result.order[i] = UID(_result.order[i], _context.prefix);
}
}
// Load all data entries that have been sent or delete them
for (var key in _result.data)
{
var uid = UID(key, (typeof _context == "object" && _context != null) ?_context.prefix : "");
if (_result.data[key] === null &&
(
typeof _context.refresh == "undefined" || _context.refresh && !jQuery.inArray(key,_context.refresh)
))
{
egw.dataDeleteUID(uid);
}
else
{
egw.dataStoreUID(uid, _result.data[key]);
}
}
// Tried to refresh a specific row and got nothing, so set it to null
// (triggers update for listeners), then remove it
if(_result.data.length == 0 && typeof _context == "object" && _context.refresh)
{
for(var i = 0; i < _context.refresh.length; i++)
{
var uid = UID(_context.refresh[i], _context.prefix);
egw.dataStoreUID(uid, null);
egw.dataDeleteUID(uid);
}
}
// Check to see if we need long-term caching of the query and its results
if(window.localStorage && _context.prefix && cacheCallback[_context.prefix] && !_context.no_cache)
{
// Ask registered callbacks if we should cache this
for(var i = 0; i < cacheCallback[_context.prefix].length; i++)
{
var cc = cacheCallback[_context.prefix][i];
var cache_key = false
if(cache_key = cc.callback.call(cc.context, _context))
{
cache_key = 'cache_' + _context.prefix + '::' + cache_key;
try
{
window.localStorage.setItem(cache_key,JSON.stringify(_result));
}
catch (e)
{
// Maybe ran out of space? Free some up.
if(e.name == 'QuotaExceededError' // storage quota is exceeded, remove cached data
|| 'NS_ERROR_DOM_QUOTA_REACHED') // FF-name
{
var count = _clearCache(_context.prefix);
egw.debug('info', 'localStorage full, removed ' + count + ' stored datasets');
}
// No, something worse happened
else
{
egw.debug('warning', 'Tried to cache some data. It did not work.', cache_key, e);
}
}
}
}
}
// 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,
"total": parseInt(_result.total),
"readonlys": _result.readonlys,
"rows": _result.rows,
"lastModification": lastModification
});
}
}
}
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 _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.
* @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.
*/
dataFetch: function (_execId, _queriedRange, _filters, _widgetId,
_callback, _context, _knownUids)
{
var lm = lastModification;
if(typeof _context.lastModification != "undefined") lm = _context.lastModification;
if (_queriedRange["no_data"])
{
lm = 0xFFFFFFFFFFFF;
}
else if (_queriedRange["only_data"])
{
lm = 0;
}
// Store refresh in context to not delete the other entries when server only returns these
if (typeof _queriedRange.refresh != "undefined")
{
if(typeof _queriedRange.refresh == "string")
{
_context.refresh = [_queriedRange.refresh];
}
else
{
_context.refresh = _queriedRange.refresh;
}
}
// Limit the amount of UIDs we say we know about to a sensible number, in case user is enjoying auto-pagination
var knownUids = _knownUids ? _knownUids : egw.dataKnownUIDs(_context.prefix ? _context.prefix : _app);
if(knownUids > KNOWN_UID_LIMIT)
{
knownUids.slice(typeof _queriedRange.start != "undefined" ? _queriedRange.start:0,KNOWN_UID_LIMIT);
}
// Check to see if we have long-term caching of the query and its results
if(window.localStorage && _context.prefix && cacheCallback[_context.prefix])
{
// Ask registered callbacks if we should cache this
for(var i = 0; i < cacheCallback[_context.prefix].length; i++)
{
var cc = cacheCallback[_context.prefix][i];
var cache_key = false
if(cache_key = cc.callback.call(cc.context, _context))
{
cache_key = 'cache_' + _context.prefix + '::' + cache_key;
var cached = window.localStorage.getItem(cache_key);
if(cached)
{
cached = JSON.parse(cached);
var needs_update = true;
// Check timestamp
if(cached.lastModification && ((Date.now()/1000) - cached.lastModification) < CACHE_LIFETIME)
{
needs_update = false;
}
egw.debug('log', 'Data cached query from ' + new Date(cached.lastModification*1000)+': ' + cache_key + '('+
(needs_update ? 'will be' : 'will not be')+" updated)\nprocessing...");
// Call right away with cached data, but set no_cache flag
// to avoid re-caching this data with a new timestamp.
// We may still ask the server though.
var no_cache = _context.no_cache;
_context.no_cache = true;
parseServerResponse(cached, _callback, _context);
_context.no_cache = no_cache;
// If cache registrant wants notification of cache useage,
// let it know
if(cc.notification)
{
cc.notification.call(cc.context, needs_update);
}
if(!needs_update)
{
// Cached data is new enough, skip the server call
return;
}
}
}
}
}
var request = egw.json(
_app+".etemplate_widget_nextmatch.ajax_get_rows.etemplate",
[
_execId,
_queriedRange,
_filters,
_widgetId,
knownUids,
lm
],
function(result) {
parseServerResponse(result, _callback, _context);
},
this,
true
);
request.sendRequest();
},
/**
* Turn on long-term client side cache of a particular request
* (cache the nextmatch query results) for fast, immediate response
* with old data.
*
* The request is still sent to the server, and the cache is updated
* with fresh data, and any needed callbacks are called again with
* the fresh data.
*
* @param {string} prefix UID / Application prefix should match the
* individual record prefix
* @param {function} callback_function A function that will analize the provided fetch
* parameters and return a reproducable cache key, or false to not cache
* the request.
* @param {function} notice_function A function that will be called whenever
* cached data is used. It is passed one parameter, a boolean that indicates
* if the server is or will be queried to refresh the cache. Do not fetch additional data
* inside this callback, and return quickly.
* @param {object} context Context for callback function.
*/
dataCacheRegister: function(prefix, callback_function, notice_function, context)
{
if(typeof cacheCallback[prefix] == 'undefined')
{
cacheCallback[prefix] = [];
}
cacheCallback[prefix].push({
callback: callback_function,
notification: notice_function || false,
context: context || null
});
},
/**
* Unregister a previously registered cache callback
* @param {string} prefix UID / Application prefix should match the
* individual record prefix
* @param {function} [callback] Callback function to un-register. If
* omitted, all functions for the prefix will be removed.
*/
dataCacheUnregister: function(prefix, callback)
{
if(typeof callback != 'undefined')
{
for(var i = 0; i < cacheCallback[prefix].length; i++)
{
if(cacheCallback[prefix][i].callback == callback)
{
cacheCallback[prefix].splice(i,1);
return;
}
}
}
// Callback not provided or not found, reset by prefix
cacheCallback[prefix] = [];
}
};
});
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 = {};
/**
* Uids and timers used for querying data uids, hashed by the first few
* bytes of the _execId, stored as an object of the form
* {
* "timer": <QUEUE TIMER>,
* "uids": <ARRAY OF UIDS>
* }
*/
var queue = {};
/**
* Contains the queue timeout in milliseconds.
*/
var QUEUE_TIMEOUT = 10;
/**
* 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)
{
// Expire old data, if there are no callbacks
if (time - localStorage[uid].timestamp > MAX_AGE && typeof registeredCallbacks[uid] == "undefined")
{
// 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 the optional context in which the callback will be
* executed
* @param _execId is the exec id which will be used in case the data is
* not available
* @param _widgetId is the widget id which will be used in case the uid
* has to be fetched.
*/
dataRegisterUID: function (_uid, _callback, _context, _execId, _widgetId) {
// 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,
"execId": _execId,
"widgetId" : _widgetId
});
// 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);
}
else if (_execId && _widgetId)
{
// Get the first 50 bytes of the exex id
var hash = _execId.substring(0, 50);
// Create a new queue if it does not exist yet
if (typeof queue[hash] === "undefined")
{
var self = this;
queue[hash] = { "uids": [], "timer": null };
queue[hash].timer = window.setTimeout(function () {
// Fetch the data
self.dataFetch(_execId, {"start": 0, "num_rows": 0, "only_data": true, "refresh": queue[hash].uids},
[], _widgetId, null, _context, null);
// Delete the queue entry
delete queue[hash];
}, 100);
}
// Push the uid onto the queue, removing the prefix
var parts = _uid.split("::");
parts.shift();
queue[hash].uids.push(parts.join('::'));
}
else
{
this.debug("log", "Data for uid " + _uid + " not available.");
}
},
/**
* 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 data of a given uid.
*
* @param _uid is the uid for which should be checked whether it has some
* data.
*/
dataGetUIDdata: function (_uid) {
return localStorage[_uid];
},
/**
* Returns all uids that have the given prefix
*
* @param {string} _prefix
* @return {array}
* TODO: Improve this
*/
dataKnownUIDs: function (_prefix) {
var result = [];
for (var key in localStorage)
{
var parts = key.split("::");
if (parts.shift() === _prefix && localStorage[key].data)
{
result.push(parts.join('::'));
}
}
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);
}
},
/**
* Force a refreash of the given uid from the server if known, and
* calls all associated callbacks.
*
* If the UID does not have any registered callbacks, it cannot be refreshed because the required
* execID and context are missing.
*
* @param {string} _uid is the uid which should be refreshed.
* @return {boolean} True if the uid is known and can be refreshed, false if unknown and will not be refreshed
*/
dataRefreshUID: function (_uid) {
if (typeof localStorage[_uid] === "undefined") return false;
if(typeof registeredCallbacks[_uid] !== "undefined" && registeredCallbacks[_uid].length > 0)
{
var _execId = registeredCallbacks[_uid][0].execId;
// This widget ID MUST be a nextmatch, because the data call is to etemplate_widget_nexmatch
var nextmatchId = registeredCallbacks[_uid][0].widgetId;
var uid = _uid.split("::");
var context = {
"prefix":uid.shift()
};
uid = uid.join("::");
this.dataFetch(_execId, {'refresh':uid}, {}, nextmatchId,false, context, [uid]);
return true;
}
return false;
},
/**
* Search for exact UID string or regular expression and return widgets using it
*
* @param {string|RegExp) _uid is the uid which should be refreshed.
* @return {object} UID: array of (nextmatch-)wigetIds
*/
dataSearchUIDs: function(_uid)
{
var matches = {};
var f = function(_uid)
{
if (typeof matches[_uid] == "undefined")
{
matches[_uid] = [];
}
if (typeof registeredCallbacks[_uid] !== "undefined")
{
for(var n=0; n < registeredCallbacks[_uid].length; ++n)
{
var callback = registeredCallbacks[_uid][n];
if (typeof callback.context != "undefined" &&
typeof callback.context.self != "undefined" &&
typeof callback.context.self._widget != "undefined")
{
matches[_uid].push(callback.context.self._widget);
}
}
}
};
if (typeof _uid == "object" && _uid.constructor.name == "RegExp")
{
for(var uid in localStorage)
{
if (_uid.test(uid))
{
f(uid);
}
}
}
else if (typeof localStorage[_uid] != "undefined")
{
f(_uid);
}
return matches;
},
/**
* Search for exact UID string or regular expression and call registered (nextmatch-)widgets refresh function with given _type
*
* This method is preferable over dataRefreshUID for app code, as it takes care of things like counters too.
*
* It does not do anything for _type="add"!
*
* @param {string|RegExp) _uid is the uid which should be refreshed.
* @param {string} _type "delete", "edit", "update", not useful for "add"!
* @return {array} (nextmatch-)wigets refreshed
*/
dataRefreshUIDs: function(_uid, _type)
{
var uids = this.dataSearchUIDs(_uid);
var widgets = [];
var uids4widget = [];
for(var uid in uids)
{
for(var n=0; n < uids[uid].length; ++n)
{
var widget = uids[uid][n];
var idx = widgets.indexOf(widget);
if (idx == -1)
{
widgets.push(widget);
idx = widgets.length-1;
}
// uids for nextmatch.refesh do NOT contain the prefix
var nm_uid = uid.replace(RegExp('^'+widget.controller.dataStorePrefix+'::'), '');
if (typeof uids4widget[idx] == "undefined")
{
uids4widget[idx] = [nm_uid];
}
else
{
uids4widget[idx].push(nm_uid);
}
}
}
for(var w=0; w < widgets.length; ++w)
{
widgets[w].refresh(uids4widget[w], _type);
}
return widgets;
}
};
});