be_endpoints.en.md

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Creating BackEnd Endpoints

We create backend endpoints by writing a regular function and add beEndpoint modifier to it. The function should receive a single argument, which is a Http.Connection pointer and it should use it to read the request data and send the response.

This modifier needs the following arguments:

method The HTTP method of the endpoint.

uri The route of the endpoint on the server.

Example

// a backend endpoint with the given route that accept GET method
// this endpoint used to retrieve the messages
@beEndpoint["GET", "/messages"]
func getMessages (conn: ptr[Http.Connection]) {
    // concatenate the messages with a line break between them.
    def response: String = String.merge(messages, "<br>");
    // add the required headers
    Http.print(conn, "HTTP/1.1 200 Ok\r\n");
    Http.print(conn, "Content-Type: text/plain\r\n");
    Http.print(conn, "Cache-Control: no-cache\r\n");
    Http.print(conn, "Content-Length: %d\r\n\r\n", response.getLength());
    // add the buffer content which contains the messages
    Http.print(conn, response.buf);
}

Note in our example how we defined a function that accept a connection and send the response by calling Http.print. First, we send the appropriate headers followed by the response body.

Also, we added the modifier to this function and set the accepted method to GET, and gave our endpoint the route /messages.