HTML Dom tutorial 16-html Dom area object
1: Area object
An area object represents an area mapped to an image (image ing refers to an image with a clickable area)
Each time a <area> tag appears in an HTML document, an area object is created.
2: attributes of the Area object
Attribute |
Description |
IE |
F |
O |
W3C |
Accesskey |
Set or return the shortcut key for accessing a region. |
5 |
1 |
No |
Yes |
ALT |
Set or return the replacement text when the browser cannot display a certain area. |
5 |
1 |
9 |
Yes |
Coords |
Sets or returns the coordinates of the clickable areas in the image ing. |
5 |
1 |
9 |
Yes |
Hash |
Sets or returns the anchor part of the URL in a region. |
4 |
1 |
No |
No |
Host |
Set or return the host name and port of the URL in a region. |
4 |
1 |
No |
No |
Href |
Sets or returns the URL of the link in the image ing. |
4 |
1 |
9 |
Yes |
ID |
Sets or returns the ID of a region. |
4 |
1 |
9 |
Yes |
Nohref |
Sets or returns whether a region is active or not. |
5 |
1 |
9 |
Yes |
Pathname |
Sets or returns the path name of a URL in a region. |
4 |
1 |
9 |
No |
Protocol |
Set or return the protocol of the URL in a region. |
4 |
1 |
9 |
No |
Search |
Sets or returns the query string of a URL in a region. |
4 |
1 |
9 |
No |
Shape |
Sets or returns the shape of an area in the image ing. |
5 |
1 |
9 |
Yes |
Tabindex |
Sets or returns the tab key control order for a region. |
5 |
1 |
9 |
Yes |
Target |
Set or return the link-URL in the open area. |
4 |
1 |
9 |
Yes |
3: Standard attributes
Attribute |
Description |
IE |
F |
O |
W3C |
Classname |
Sets or returns the class attribute of an element. |
5 |
1 |
9 |
Yes |
Dir |
Set or return the direction of the text. |
5 |
1 |
9 |
Yes |
Lang |
Set or return element LanguageCode. |
5 |
1 |
9 |
Yes |
Title |
Sets or returns the title of an element. |
5 |
1 |
9 |
Yes |
4: Dir attribute
Definition: sets the Dir attribute or returns the text direction of the element.
Usage: See the following example:
<HTML>
<Body id = "myid" dir = "RTL">
<SCRIPT type = "text/JavaScript">
X = Document. getelementsbytagname ('body') [0];
Document. Write ("text direction:" +X. dir
);
Document. Write ("<br/> ");
Document. Write ("an alternate way :");
Document. Write (Document. getelementbyid ('myid'). dir
);
</SCRIPT>
</Body>
</Html>
5. Hash attributes
Definition: the hash attribute can be set or the anchor part of the URL in a region is returned.
Usage: See the following example. In the following example, you can change the anchor part of the URL # top to # bottom:
<HTML>
<Head>
<SCRIPT type = "text/JavaScript">
Function changelink ()
{
Document. getelementbyid ('venus'). Hash = "bottom"
}
</SCRIPT>
</Head>
<Body>
<Map Name = "planetmap">
<Area ID = "Venus" shape = "circle" coords = "124,58, 8" alt = "Venus" href = "venus2.htm # Top"/>
</Map>
<Input type = "button" onclick = "changelink ()" value = "change link"/>
</Body>
</Html>
6: Host attributes
As shown in the following example, the host name and port in the "Venus" area are returned:
<HTML>
<Body>
<Map Name = "planetmap">
<Area ID = "Venus" shape = "circle" coords = "124,58, 8" alt = "Venus" href = "venus.htm"/>
</Map>
<P> the hostname and port for the "Venus" area are:
<SCRIPT type = "text/JavaScript">
X = Document. getelementbyid ('venus ');
Document. Write (X. HOST );
</SCRIPT>
</P>
</Body>
</Html>
7: Search attributes
<HTML>
<Body>
<Map Name = "planetmap">
<Area ID = "Venus" shape = "circle" coords = "124,58, 8" alt = "Venus" href = "venus.htm? Id = Venus "/>
</Map>
<P> the hostname and port for the "Venus" area are:
<SCRIPT type = "text/JavaScript">
X = Document. getelementbyid ('venus ');
Document. Write (
X. Search
);
</SCRIPT>
</P>
</Body>
</Html>