8 Page: Short-hand for Common Patterns
The Web Server provides a simple utility library for building Web applications that consistent mostly of send/suspend/dispatch-created pages and request handling.
When used inside page
syntactically, a rename transformer for the procedure embedding function; otherwise, a syntax error.
A simple example:
Similarly, many Web applications make use almost exclusively of functions that are arguments to embed/url and immediately invoke send/suspend/dispatch.
automate this by expanding to functions that accept a request as the first argument (followed by any arguments specified in formals
) and immediately wrap their body in page
. This functions also cooperate with get-binding
by binding the request to the current-request
The binding interface of web-server/http is powerful, but subtle to use conveniently due to its protection against hostile clients.
(s) interface attempts to resolve this by providing a powerful interface with convenient defaults.
get-binding extracts the first binding of a form input from a request, while get-bindings extracts them all.
They accept a form identifier (id) as either a byte string, a string, or a symbol. In each case, the user input is compared in a case-sensitive way with the form input.
They accept an optional request argument (req) that defaults to the value of the current-request parameter used by lambda/page and define/page.
Finally, they accept an optional keyword argument (format) that specifies the desired return format. The default, 'string, produces a UTF-8 string (or #f if the byte string cannot be converted to UTF-8.) The 'bytes format always produces the raw byte string. The 'file format produces the file upload content (or #f if the form input was not an uploaded file.) The 'binding format produces the binding object.