Module must be found in the code path and export Function with an arity of three. An erlScriptAlias must also be set up in the configuration file for the web server.
If the HTTP request is a post request and a body is sent, content_length is the length of the posted data. If get is used, query_string is the data after ? in the URL.
ParsedHeader is the HTTP request as a key-value tuple list. The keys in ParsedHeader are in lower case.
SessionID is an identifier the server uses when deliver/2 is called. Do not assume anything about the datatype.
Use this callback function to generate dynamic web content dynamically. When a part of the page is generated, send the data back to the client through deliver/2. Notice that the first chunk of data sent to the client must at least contain all HTTP header fields that the response will generate. If the first chunk does not contain the end of HTTP header, that is, "\r\n\r\n", the server assumes that no HTTP header fields will be generated.