Using Custom REST API inside UI designer

I presume this is evidently what you mean, I make a variable for a Javascript Expression and one by one assign data Values to the form fields to populate the information like so :

Created an API variable , name : peopleinformation

then i used in the form like so (in javascript expression variable):

`var fullname = peopleinformation[0].fullname;
var perdiem = peopleinformation[0].perdiem;
var supervisorname = peopleinformation[0].supervisorname;
var supervisoremail = peopleinformation[0].supervisoremail;

//populate the form with the information
$data.formInput.travelRequestInput.fullname = fullname;
$data.formInput.travelRequestInput.perdiem = perdiem;
$data.formInput.travelRequestInput.supervisorname = supervisorname;
$data.formInput.travelRequestInput.supervisoremail = supervisoremail;`

unfortunately , it still does not populate the information, here is my bos file uploaded on google Drive
https://drive.google.com/file/d/1iWpO3SI2ZGgh2yHYyVWPg9Fw6KUR22X6/view?u...

No help? Anyone? Lost with ideas here..

First of all, many thanks on your Reply

Now here is what i am trying to achieve, i want to use the REST api i have created (it uses postgreSQL as database to hold the data) to autocomplete the data on the form without them entering their name and perdiem and supervisor name and supervisor email so what they'd do, is to just select the number of days and it submits the data for Processing

So what the end game is is to get the data from the json REST api and then populate the form using the data it got from the REST in the ui designer. And yes i would still use the normal BDM for Bonitasoft to process the data, just using the REST to populate the UI designer form and thats all.

could this be because i am using a community version that its difficult to populate the form using some of these controls I see here?

I did it this way

i used the maven example you showed me to create a Webservice (REST API webservice) which uses PostgreSQL as backend to get the information from an external database now it gets the information in form of JSON like this

The REST api url is looking like this : http://localhost:8080/bonita/API/extension/sqlExample?queryId=getPersonalInformation&userId=101

Now displaying it on POSTMAN i get this JSON

[
    {
        "id": 1,
        "fullname": "Emeka Iwuagwu",
        "perdiem": 4500.00,
        "supervisorname": "James Hall",
        "supervisoremail": "jameshall@xxxxxxxxx.com",
        "userid": "101"
    }
]

Now i want to use that JSON it displayed on the REST api automatically to populate the UI designer form, How possible is this?

Thats the challenge now.

Like this?

var fullname = peopleinformation[0].fullname;
var perdiem = peopleinformation[0].perdiem;
var supervisorname = peopleinformation[0].supervisorname;
var supervisoremail = peopleinformation[0].supervisoremail;

//populate the form with the information
$data.formInput.travelRequestInput.fullname = fullname;
$data.formInput.travelRequestInput.perdiem = perdiem;
$data.formInput.travelRequestInput.supervisorname = supervisorname;
$data.formInput.travelRequestInput.supervisoremail = supervisoremail;

Thats what i currently have.

Oh wait , i just did that now .. still wont return the data. the name of the REST api variable is peopleinformation now when i do this
peopleinformation[0].fullname and set the value property, it wont show on the textbox.

My mistake i forgot to use the {{UserId.user_id}} variable to fetch the information now , it displays on the controls, my worry is how to make it save the Data to the DB at this point. as the value changed.

Please see information below sir @antoine.mottier

The final challenge i have is this , the widget controls I used to populate data from the REST API (Which was converted to JSON) now i want to save them inside the BDM (H2 Database) together with other information. it invariably returns different empty sets of information to the database. And wont let me spool my repots for the Approvals..

What can be done to handle this.

All seem to go fine now , just that it sends empty feilds for the fields which the values are set to use peopleinformation[0].*

which are these peopleinformation[0].fullname peopleinformation[0].supervisorname peopleinformation[0].supervisoremail peopleinformation[0].perdiem

Asides that, other things seem to work beautifully well

A screenshot of the information is given as below

If you request, i can send the BOS file for you to see.