Hello World

General
1

I have created a custom code event and I am able to call the event without any problems. However, I can’t for the life of me, figure out how to return a message “Hello World” to the REST API POST request.
What do I need to return inside my function:
Backendless.ServerCode.customEvent(‘Hello’, function(req) {
//i’ve tried returning some json, a console.log, an alert but can’t seem to generate a response
}
Any help would be appreciated.

2

Hey.

Here are few examples for you :

//returning a primitive value (will be wrapped into an object)
Backendless.ServerCode.customEvent('Hello', function(req) {
	return 'Hello World'; // an invoker will get { result: 'Hello World' }
}

//returning a complex object (no wrapping)
Backendless.ServerCode.customEvent('Hello', function(req) {
	return { foo: 'Bar' }; //an invoker will get { foo: 'Bar' }
}

//returning a Promise for async operations
Backendless.ServerCode.customEvent('Hello', function(req) {
	return new Promise((resolve, reject) => {
		//emulate async op
		setTimeout(() => {
                     resolve('Hello Async World') // an invoker will get { result: 'Hello Async World' }
                }, 100); 
	});
}

If it still doesn’t work for you, please give us an example of your code

3

Thank you very much for your response. The issue that I was having was actually not the code that I had written in the end, but my understanding of how Backendless works. For those that are having problems getting a simple custom event working, I will share my experience.

I create a file called Hello.js containing the following code:

Backendless.ServerCode.customEvent('Hello', function(req) {
return 'Hello World'; // an invoker will get { result: 'Hello World' }
}

I was running “npm run debug” in my terminal window and then trying to hit the end point: https://api.backendless.com/v1/servercode/events/Hello

After getting a 200 response I thought everything was working but I wasn’t getting any JSON returned.

This puzzled me so I decided to deploy my code anyway. As soon as the code was deployed and I hit the same end point everything worked and I received a JSON response:

{“result”: “Hello World”
}

So I guess, maybe the debug mode uses a local/internal end point, I am not sure, but either way, when the code is deployed it does work.

I would also just like to leave a comment… The Backendless product seems to be very complete and well designed. However, the documentation is incomplete and hard to follow. I am not a novice programmer, but have found it quite difficult getting up and running with Backendless. In particular, the custom events setup and workflow.

Keep up the good work guys.

4

Hi Garry,

If the debug mode is turned on, the code on your local machine will be executed in spite of another code is deployed in production mode.
Does it help you?

Artur.

5

Yes, makes perfect sense. Thank you Artur.

6

Apologies. I am also stuck on this task and the required steps are not clear to me. For example, I’ve already :

  • Installed npm i backendless
  • Got both Application ID and API Key
  • Got Hello.js file

But not sure where should I save it and how to proceed from this point onward.

your assistance is appreciated.

7

Hi @Amjad_Alsharif, could you please describe what you want to accomplish?

8

Thank you for the quick reply. I want to complete “Add Object With API” , specifically, steps 3-5 specified within the mission file.

9

Please open a new topic on the forum. This one is already marked as solved and is unrelated to what you’re trying to do.

Thanks,
Mark