The INPUT Tag

The INPUT tag is used to specify a simple input element inside a FORM. It is a standalone tag; it does not surround anything and there is no terminating tag -- i.e., it is used in much the same way as IMG.

In Mosaic for X, various types of INPUT tags are instantiated as Motif widgets (text entry fields, toggle buttons, pushbuttons, etc.).

The attributes to INPUT are as follows:

TYPE must be one of:
- "text" (text entry field; this is the default)
- "password" (text entry field; entered characters are represented as asterisks)
- "checkbox" (a single toggle button; on or off)
- "radio" (a single toggle button; on or off; other toggles with the same NAME are grouped into "one of many" behavior)
- "submit" (a pushbutton that causes the current form to be packaged up into a query URL and sent to a remote server)
- "reset" (a pushbutton that causes the various input elements in the form to be reset to their default values)
NAME is the symbolic name (not a displayed name -- normal HTML within the form is used for that) for this input field. This must be present for all types but "submit" and "reset", as it is used when putting together the query string that gets sent to the remote server when the filled-out form is submitted.
VALUE, for a text or password entry field, can be used to specify the default contents of the field. For a checkbox or a radio button, VALUE specifies the value of the button when it is checked (unchecked checkboxes are disregarded when submitting queries); the default value for a checkbox or radio button is "on". For types "submit" and "reset", VALUE can be used to specify the label for the pushbutton.
CHECKED (no value needed) specifies that this checkbox or radio button is checked by default; this is only appropriate for checkboxes and radio buttons.
SIZE is the physical size of the input field in characters; this is only appropriate for text entry fields and password entry fields. If this is not present, the default is 20. Multiline text entry fields can be specified as SIZE=width,height; e.g. SIZE=60,12. Note: the SIZE attribute should not be used to specify multiline text entry fields now that the TEXTAREA tag is available.
MAXLENGTH is the maximum number of characters that are accepted as input; this is only appropriate for text entry fields and password entry fields (and only for single-line text entry fields at that). If this is not present, the default will be unlimited. The text entry field is assumed to scroll appropriately if MAXLENGTH is greater than SIZE.