Perl Device List
widgets list
All of the widgets use the NAME
attribute for the name of the field.
This is the name that is passed as the left side of the name=value
pair that is sent to the server.
The only widgets with a different behavior for the NAME attribute are RADIO and IMAGE, so there is a description of that unique behavior for those widgets. Otherwise, we will omit the description of the NAME attribute for each widget.
<INPUT TYPE=TEXT>
<INPUT TYPE=PASSWORD>
The TEXT
and PASSWORD
fields operate exactly the same, with the exception that the PASSWORD
field has its display obscured. The attributes supported are:
SIZE | The width of the field in characters |
MAXLENGTH | The maximum number of characters allowed in the field |
VALUE | A default value for the text field. This also works for PASSWORD , but it seems kind of silly. |
PASSWORD field
The
PASSWORD
field works exactly the same as the
TEXT
field. It sends its value to the server in the clear.
It should not be used for sending sensitive information (like passwords, for instance).
The
PASSWORD
field is fine for validating a user profile for a nonsensitive application like
Personalized Yahoo for example, but it is not secure enough for protecting important data.
<INPUT TYPE=CHECKBOX>
The CHECKBOX
widget is an on/off selector. It is usually rendered as a small box that can be checked or blank.
The name/value pair will be either name=on
or name=value
, if the VALUE
attribute is used.
These are the attributes for the CHECKBOX
widget:
VALUE | The value that will be sent if the box is checked. |
CHECKED | If present, this makes the default state checked. |
<INPUT TYPE=RADIO>
Radio widgets are like grouped check boxes. Each radio button can be either on or off, but only one radio button in a group can be on at a time.
A group of radio buttons are defined by giving them all the same NAME
.
Each radio button in a group should have a different VALUE
so that you can distinguish which one is checked.
NAME |
The name of the group this radio button belongs to |
VALUE |
The value that will be sent if the button is checked |
CHECKED |
If present, this is the default button. Only one button in a group should have this attribute. |
<INPUT TYPE=SUBMIT>
This widget is the submit button for the form. A form may have more than one submit button.
You will be able to determine which one was clicked by giving them different names.
VALUE | Used to set the text that is displayed in the button |
<INPUT TYPE=RESET>
The RESET
widget is a button that resets the form. It does not generate a name/value pair.
VALUE |
Used to set the text that is displayed in the button |
<INPUT TYPE=HIDDEN>
The HIDDEN
field is used for sending informational data to the server. It is not displayed, but its name/value pair gets sent
to the server along with the form. This is commonly used for maintaining context (we'll use this later in this module).
VALUE
|
The value sent with the name/value pair
|
<INPUT TYPE=IMAGE>
This is a graphical version of the SUBMIT
widget. It is commonly used for creating graphical buttons.
When you click the image, it submits the form along with the coordinates of where the image was clicked. This widget generates two name/value pairs like this:
name.x=35
name.y=42
NAME | The name for the name/value pairs. Note the description above for this widget's unique behavior. |
SRC | The URL of the image to display |
WIDTH | The width of the image |
HEIGHT | The height of the image |
BORDER | Defaults to having a border. Use BORDER=0 to turn it off. |
VALUE | There is no VALUE attribute for this widget! |
<SELECT>
</SELECT>
A widget that displays multiple choices, like a dropdown box or a selection box.
This element is an HTML container, so it requires an end tag. Within the container, each selection option is indicated with an
<OPTION>
tag. For example:
<SELECT NAME="parts" SIZE=4 MULTIPLE>
<OPTION> Strings
<OPTION SELECTED> Pickups
<OPTION> Bridge
<OPTION> Neck
<OPTION> Frets
<OPTION> Tuning machines
</SELECT>
Use the SELECTED
attribute in the OPTION
tag to indicate default selections.
SIZE |
The number of options displayed at once. Omit this for a drop-style box on some systems. |
MULTIPLE |
Include this attribute to allow multiple selections. |
<TEXTAREA>
</TEXTAREA>
A free-form text-entry area. Note that the WRAP
attribute is a common Netscape extension.
ROWS |
The height of the widget's display area in lines of text |
COLS |
The width of the widget's display area in columns of characters |
WRAP |
These are possible values:
HARD enables word wrap and passes the line breaks to the server.
SOFT enables word wrap and does not pass the line breaks to the server.
OFF disables word wrap.
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