The mobile service solution manages the synchronization of the offline data.
Requirements:
By default Servoy will load the first 200 pks when a form is used. This is not needed in the service solution and can be prevented by calling databaseManager.setCreateEmptyFormFoundsets() in the solution onopen global method:
function onSolutionOpen() { // prevent prefilling of form foundsets with default query databaseManager.setCreateEmptyFormFoundsets() }
The ws_read(version,name) on the offline_data form has to return an OfflineDataDescription (=JSON) object filled with foundset data the developer wants the mobile client to retrieve.
An OfflineDataDescription instance is created with:
var retval = plugins.mobileservice.createOfflineDataDescription('data_');
Note: the argument is optional and is used to call rest endpoints for row data at forms starting with this prefix
Then we need to provide a list of relation names which should be used in traversal to find all data, like:
var traverse = new Array(); traverse.push('accountmanager_to_companies'); traverse.push('companies_to_contacts');
Lastly we have instruct the OfflineDataDescription to collect the data, starting with root foundset (containing records) and return.
retval.addFoundSet(fs_contact, traverse); return retval;
Basically addFoundSet in the service solution exposes an unrelated foundset to the mobile client, which can be used in an unrelated way like in a (first) form or databaseManager.getFoundset(...)
For each record in the provided (unrelated) foundset the specified relations are traversed and all data taken.
In order to provide a mobile client with user specific data the ws_authenticate(useruid,password) method should be added:
function ws_authenticate(useruid,password) { //TODO find user and check password against pwhash column if (password == 'demo')//static demo check { var retval = new Object(); retval.username = useruid; return retval; } return false; }
In the ws_read method we can utilize the authenticate username variable via
var authenticate_info = questionParams.ws_authenticate[0]; globals.username = authenticate_info.username;
Here the authenticate username is put into a global variable which in turn can be used like:
//prepare personal data var fs_contact = globals.contact_data$username;//global related foundset using username global var, containing the account manager contact
Full ws_read method for personalized data.
function ws_read(version,name) { var questionParams = arguments[arguments.length-1]; //create return value var retval = plugins.mobileservice.createOfflineDataDescription('data_'); //setting the key for user_select relation var authenticate_info = questionParams.ws_authenticate[0]; globals.username = authenticate_info.username; //prepare personal data var fs_contact = globals.contact_data$username;//global related foundset using username global var, containing the account manager contact /** * @type {Array<String>} */ var traverse = new Array(); traverse.push('accountmanager_to_companies'); traverse.push('companies_to_contacts'); retval.addFoundSet(fs_contact, traverse); return retval; }
Row/record data is retrieved in separate calls for each entity, for example for "orders" row data results in a call to "orders" form is made on ws_read method.
Note: If a prefix is provided in the offlinedata the call will end up at prefix+entityname, example for prefix "data_" the call happens on form "data_orders"
ws_read is with a list of pks it wants as row data for, example code:
function ws_read(version,method) { var questionParams = arguments[arguments.length-1]; if (method == 'list') { /** * @type {String} */ var ids = questionParams.ids[0]; if (ids != null && ids != '') { var idsa = ids.split(',', -1); if (idsa.length > 0) { var json = plugins.mobileservice.getRowDescriptions(foundset.getDataSource(), idsa) return json; } } } throw 404; }
TIP: since ws_read for entities is likely the same, it might be beneficial to create a base form containing this logic and extend from this form
ws_update is called for changes made by mobile client, example code:
function ws_update(data,version,pk) { if (foundset.find()) { foundset.contact_id = pk; var count = foundset.search(); if (count > 0) { var rec = foundset.getRecord(1); databaseManager.copyMatchingFields(data,rec,true); databaseManager.saveData(rec); } } }
ws_create is called for new records on the mobile client, example code:
function ws_create(data,version,pk) { var rec = foundset.getRecord(foundset.newRecord()); databaseManager.copyMatchingFields(data,rec,true); databaseManager.saveData(rec); }
Note: the retrieved PK (and derived FK's) is always UUID's if the underlaying datamodel is not UUID based, keep and apply a mapping!
ws_delete is called for deleted record in the mobile client, example code:
function ws_delete(version,pk) { if (foundset.find()) { var table = databaseManager.getTable(controller.getDataSource()); var pkname = table.getRowIdentifierColumnNames()[0] foundset[pkname] = pk; var count = foundset.search(); if (count > 0) { var rec = foundset.getRecord(1); foundset.deleteRecord(rec); } } }
By default the mobile client will do a rest call per changed row, these are separated calls so every call will be on a fresh new client on the serverside.
Because of this a transaction can't be used for all the changes of 1 mobile client and then fail a sync when something goes wrong. If the sync should be in 1 call, so that a transaction can be used over all the calls to the above ws_update/ws_create/ws_delete methods, a ws_update method must be created on the offline_data form.
This ws_update method then gets a full data package of all the changes that a mobile client has, this will then be dispatched over all the methods that are described above.
An example of a ws_update method on the offline_data form:
function ws_update(data,version,authenticateResult) { try { databaseManager.startTransaction(); plugins.mobileservice.performSync(data,version,authenticateResult); databaseManager.commitTransaction(); } catch (e) { databaseManager.rollbackTransaction(); // log the error and return false to that the mobile client will know the sync did fail. application.output(e,LOGGINGLEVEL.ERROR); return false; } }
This code above starts a transaction then calls the performSync method of the mobile service plugin. This plugin will dispatch all the changes to the various ws_update/create/delete methods of the entity forms. If something goes wrong then an exception will be thrown and the transaction will rollback.