automatically updating data using cloud code in Parse.com - parse-platform

Question

I'm looking a method to automatically updating data using cloud code.
Let say I have a class Table.
inside of it, I have three column : firstname, lastname, and fullname.
Currently, I only have firstname and lastname data only. Column fullname is still empty.
Is it possible to fill the fullname automatically, by just combining the value in firstname and lastname?
Thank you,

Answer 1

#RoyH is 100% right to maintain your computed column as new objects are created. To do an initial migration, try a cloud function, like:
var _ = require("underscore");
Parse.Cloud.define("addFullnames", function(request, response) {
// useMasterKey if the calling user doesn't have permissions read or write to Table
Parse.Cloud.useMasterKey();
var query = new Parse.Query("Table");
// we'll call tables > 1000 an 'advanced topic'
query.limit = 1000;
query.find().then(function(results) {
_.each(results, function(result) {
var firstname = result.get("firstname") || "";
var lastname = result.get("lastname") || "";
result.set("fullname", (firstname + " " + lastname).trim());
});
return Parse.Object.saveAll(results);
}).then(function(results) {
response.success(results);
}, function(error) {
response.error(error);
});
});
Call it like this:
curl -X POST \
-H "X-Parse-Application-Id: your_app_id_here" \
-H "X-Parse-REST-API-Key: your_rest_key_here" \
-H "Content-Type: application/json" \
https://api.parse.com/1/functions/addFullnames
You can factor out the code inside _.each() to make a function that's called here and by a beforeSave hook to maintain the data as it is added.

Answer 2

Yes, you can either just put a value for "fullname" when you are saving "firstname" and "lastname" (before cloudcode). Alternately, you can use the before save/ after save cloudcode functions to insert a value into that column:
Take a look at:
https://parse.com/docs/cloud_code_guide#webhooks-beforeSave
https://parse.com/docs/cloud_code_guide#webhooks-afterSave