Calling Functions

After defining and registering a function with a Dispatch endpoint, the next step is to dispatch work to functions.

Dispatching a function call

Function calls are typically dispatched in response to a trigger or event, for example when an HTTP request is received, or for each message in a message queue.

A function call can be dispatched using the Dispatch method on Dispatch functions, which accepts an input argument.

For example, given the following function that converts an integer to a string:

stringify := dispatch.Func("stringify", func (ctx context.Context, input int) (string, error) {
    return strconv.Itoa(input), nil
})

a call to the function (stringify(11)) could be dispatched like so:

id, err := stringify.Dispatch(context.Background(), 11)

This submits a function call to the Dispatch cloud service, which coordinates the execution of the function. The function is executed asynchronously.

The Dispatch method returns a globally unique identifier for the function call for observability purposes. If the function call could not be dispatched, an error is returned instead.

Next steps

See how to compose functions into workflows, how to test functions or how to call remote functions.