This page is as small and concise as I could manage while still showing an example or two of all the following:
html, head, body,
head elements (required)
head elements (optional)
body elements (all optional)
I have several examples of CSS rules in here, one to format
the DIV that wraps the whole page and one to format the
form.
This page also has a form. Forms are crucial in CS 304, because they allow us to collect information from the user, whether a FaceBook post, an item to offer on eBay, or a review of an Amazon purchase.
Forms have to have the following:
form element, which should have
an action attribute specifying the script that will
process the form data.
select and textarea, which are ways of getting input
without the input tag. The select tag is for menus,
and the textarea tag is for large blocks of text.
submit button (<input type="submit">)
Some controls can be marked required by adding that
attribute. Modern browsers will prevent the form from being
submitted if any required control has an empty value
(the empty string). For many elements, such
as input, that's all you need.
For select, you need to ensure that the default
menu choice (option) has a value
that is the empty string. For textarea, the
default value is the text between the beginning tag and the
ending tag, so you need to snug them up right next to each
other to make it the empty string (not even a single space is
allowed).
In this example form, every control is required, so you can see this in action. Try it!
When the form is submitted, the data goes to the server (Apache), which directs it to the script, and the script outputs a response, which the browser uses to replace the current page.
In this example form, the echo responses with the information sent by the form, the collection of control names and values. Try it!