Delphi TIdHTTP.Get() API fails with 400 Bad Request when parameter value contains space

I'm sending a number of parameters to an API using the TIdHTTP.Get() method.

I pull values for the actual API parameters from string variables or component Text properties (like a ComboBox, for example). Everything is fine until any of those values contains a space.

For example, one of the parameters is a full name field (example: 'John Smith')

Since it contains a space between the first and last name, once I send it to the API using te TIdHTTP.Get() method, it throws a 400 Bad Request error and fails.

If I eliminate the space from the value for that/any particular parameter, it goes through fine.

Code I'm using to test:

httpObject := TIdHTTP.Create;
    
httpObject.HTTPOptions := [hoForceEncodeParams];
httpobject.MaxAuthRetries := 3;
httpObject.ProtocolVersion := pv1_1;
httpObject.Request.Accept := 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8';
httpObject.Request.UserAgent := 'Mozilla/3.0 (compatible;Indy Library)';
httpObject.Request.ContentType := 'application/x-www-form-urlencoded; charset=utf-8';
    
URL := 'url string containing the parameters'; //string variable
httpObject.Get(URL);

API documentation says:

How can I address this?

Using Delphi Community Edition (which is 10.3) and its accompanying Indy components.

You have stated that you are submitting the data as Content-Type: application/x-www-form-urlencoded

That format does not allow spaces. You need to properly encode what you are submitting.

Two ways you can do this:

With Indy:

Encoded := TIdURI.URLEncode(str);

With TNetEncoding

Encoded := TNetEncoding.URL.Encode(str);