FORMS (Chapter 10 and Chapter 12)
Forms & Form Processing.
Form - a tool for collecting and delivering data from the user.
Forms and form types are what we will cover. Form processing and CGI scripts we will not.
Tags
<form> </form>
Two NECESSARY attributes action & method
action="mailto:YourPittAccountName@pitt.edu"
- action points to the application that will process the data captured by the form.
method="post"
-can equal "get" or "post"
post: With the HTTP "post" method, the form data set is included in the body of the form and sent to the processing agent.
The "get" method should be used when the form causes no side-effects. Many database searches have no visible side-effects and make ideal applications for the "get" method.
If the service associated with the processing of a form causes side effects (for example, if the form modifies a database or subscription to a service), the "post" method should be used.
- method tells the browser how to send the data to the server.
- "mailto:" always requires "post"
input tag - creates an input element (control) within a form
<input />
important attributes: name, value, type
name - required by most input controls
type - defines which input control you will provide to the user.
value - assign a default value to the field.
control types -
button - control that has no predefined funtion
text - allows the user to submit typed text.
checkbox - allows for multiple selections in a series.
file - sending an entire file
radio - button that ensures only one selection is made
submit - activates the coding as submission process of the browser or invokes the associated a-mail application.
reset - clear selections
Drop Down list boxes
Select tag - creates a list box made up of enclosed elements.
Note: If you want to have multiple selections use the keywords "select multiple" such as in the following example:attributes: name, size, style, multiple
*must contain at least one <option> </option> tag (element).