domain: client
language: javascript
class Item class
Sends all updated, inserted, and deleted records from the item dataset to the application server for writing to the database.
The apply method can have the following parameters:
callback: if the parameter is not present and async parameter is false
or undefined, the request to the server is
sent synchronously, otherwise, the request is executed asynchronously and
after the response is received, the callback is executed
params - an object specifying user defined params, that can be used
on the server in the
on_apply
event handler for some additional processing
async: if its value is true, and callback parameter is missing, the request
is executed asynchronously
The order of parameters doesn’t matter.
The apply method
checks whether the item is a detail, and if it is, returns (the master saves the details changes)
checks whether the item is in edit or insert state , and if so, posts the record
checks if the change log has changes, and if not, executes callback if it is passed and then returns
triggers the on_before_apply event handler if one is defined for the item
sends changes to the server
server on receiving the request checks whether on_apply event handler is defined for the item, and if it is, executes it, otherwise generates and executes SQL query to write changes to the database, see also on_apply events topic
when generating an SQL query, checks whether a user, that send the request, has rights to make these changes, if not raises an exception
writes changes to the database
after writing changes to the database, server sends to the client results of the execution
if exception was raised during the operation on the server the client throws an exception, before throwing exception, if the callback parameter is passed, it is called and the error is passed as the callback function parameter
the client, based on the results, updates the change log
triggers the on_after_apply event handler if one is defined for the item
if the callback parameter is passed, it is called.
Note
The server, before writing new records to the database table, generates values for the primary fields. The client updates these fields, based on information received from the server. If you change values of some other fields in the on_apply event handler, these changes will not be reflected on the client. You can update them yourself using, for example, refresh_record method
var self = this;
this.apply(function(err) {
if (err) {
self.alert_error(err);
}
else {
//some code to execute after appling changes
}
});