Write a row to DB on UI load?

Question

I would like to have an interface that, when it is accessed/loaded/refreshed by user, will write a row to a table in the database. 
 Is this possible? 
 
 Idea: Perhaps by using a!writeToDataStoreEntity, or a!startProcess? But it seems that these do not work outside of a "button click" by the user. Trying to add it outside of a button is giving me errors like this one: 
 Could not display interface. Please check definition and inputs. Interface Definition: Expression evaluation error : Cannot create context for UI expression. Reason: A value of type "Reaction Tree" was stored in the variable "write", but values of this type cannot be stored in SAIL context variables. Use a with() variable or change the type of this value. 
 Thank you in advance for any ideas or advice!

Shanmukha · Accepted Answer

Hi Agustin, 
 
Did you try this with Web API and configure it in integration and call it as a rule in the UI?

Shanmukha · Answer

Hi Agustin, 
 
Sorry for the delayed response. If it not working then we must use the tradition SOAP based web service calling from the UI. This should defiantly work. 
 
I hope it may help you.

Jim Schweitzer · Answer

You're not going to be able to call an a!httpWrite() or an integration rule that POSTs data from a load(), those have to be bound to buttons/links with bind() or called from a saveInto(). User action is required to trigger something like this.

agustinc477366 · Answer

Dear Jim and Raghavendra, Thank you very much for your inputs! Thanks to your input, I was able to accomplish this using a workaround making use of some of the suggestions mentioned. While, as Jim mentioned, it is not possible to use POST requests without user trigger/click, I was able to find a workaround by making a GET request to a custom Google Apps Script (external web service), then using that to add the row to a DB (it acts as a POST request). I ended up writing to an external DB instead (but if I needed to write to an internal DB, I would have called the Web API from Google Apps Script to write back to Appian, as Raghavendra suggested). The code in the UI looks like this: load( local!temp: a!httpQuery( url: urlwithparameters(" script.google.com/.../exec", {[parameter names here]}, {[parameter values here]}) ), {} ) 
 For anyone trying to accomplish this, the Google Apps Script code is quite simple; basically is using the doGet method detailed here: 
 developers.google.com/.../web 
 Thank you again, Jim and Raghavendra! Agustin