The Select Widget works a lot like the
radio button and check box widgets in that it allows a user to
choose one item from a group. However, the look and feel of a
SELECT widget is quite a bit different, as is the code that
manages it.
The Select Widget creates a pop-up list
as shown below:
The previous select widget was created using
the code shown below:
<FORM>
<SELECT NAME = "fruit">
<OPTION VALUE = "Apples">Apples
<OPTION VALUE = "Oranges">Oranges
<OPTION VALUE = "Pears">Pears
</SELECT>
</FORM>
Notice that the <SELECT> tag takes
a NAME attribute and includes several OPTIONS that define the
VALUES to be applied to that NAME.
Note that the VALUE attribute of the <OPTION>
tag is optional. If you do not include it, the value will be taken
from the text that follows the tag.
Thus, if you selected "Oranges" from the
select box shown above, the web browser would add the following
to the url encoded string it prepares for the server
fruit=Oranges
The <SELECT> tag also has several
attributes that affect how it works. The table below outlines
those attributes.
Attribute
Description
NAME
Specifies what name the browser should use for the name/value
pair sent in the HTTP body
SIZE
Specifies the number of choices that should be visible to the
user
SELECTED
Specifies the choice that is selected by default
MULTIPLE
Specifies that the user should be able to select multiple items in
the list
VALUE
Specifies the valueof a choice
Let's take a closer look at each of these
attributes.
The SIZE Attribute
The SIZE attribute specifies how many
choices in a select box should be made visible to the user at
one time. This is best seen by example, so let's look at one in
which SIZE is set to three (notice that there are four items so
the select widget will dynamically create a scroll bar).
That select widget was created using the
following code:
<FORM>
<SELECT NAME = "fruit" SIZE = "3">
<OPTION VALUE = "Apples">Apples
<OPTION VALUE = "Oranges">Oranges
<OPTION VALUE = "Pears">Pears
<OPTION VALUE = "Banana">Banana
</SELECT>
</FORM>
The SELECTED Attribute
The SELECTED attribute specifies which
choice will be selected by default. This is best shown by
example, so consider the following example in which we select
"Pears" by default.
That select widget was created using the
following code:
<FORM>
<SELECT NAME = "fruit" SIZE = "3">
<OPTION VALUE = "Apples">Apples
<OPTION VALUE = "Oranges">Oranges
<OPTION VALUE = "Pears" SELECTED>Pears
<OPTION VALUE = "Banana">Banana
</SELECT>
</FORM>
The MULTIPLE Attribute
The MULTIPLE attribute specifies that
the user should be able to select multiple choices at one time.
Typically, they will use the CONTROL key and a mouse click to
select or deselect choices individually or the SHIFT key plus a
mouse click to select groups of choices at once. This is best
seen by example, so try out the following select widget:
That select widget was created using the
following code:
<FORM>
<SELECT NAME = "fruit"
SIZE = "4" MULTIPLE>
<OPTION VALUE = "Apples">Apples
<OPTION VALUE = "Oranges">Oranges
<OPTION VALUE = "Pears">Pears
<OPTION VALUE = "Banana">Banana
</SELECT>
</FORM>