HTML DOM - Methods
In the DOM, HTML documents consist of a set of node objects. The nodes can be accessed with JavaScript or other programming languages. In this tutorial we will use JavaScript.
The programming interface of the DOM is defined by standard properties and methods.
Properties are often referred to as something that is (i.e. the name of a node).
Methods are often referred to as something that is done (i.e. remove a node).
HTML DOM Properties
Some DOM properties:
- x.innerHTML - the text value of x
- x.nodeName - the name of x
- x.nodeValue - the value of x
- x.parentNode - the parent node of x
- x.childNodes - the child nodes of x
- x.attributes - the attributes nodes of x
Note: In the list above, x is a node object (HTML element).
HTML DOM Methods
Some DOM methods:
- x.getElementById(id) - get the element with a specified id
- x.getElementsByTagName(name) - get all elements with a specified tag name
- x.appendChild(node) - insert a child node to x
- x.removeChild(node) - remove a child node from x
Note: In the list above, x is a node object (HTML element).
The easiest way to get or modify the content of an element is by using the innerHTML property.
innerHTML is not a part of the W3C DOM specification. However, it is supported by all major browsers.
The innerHTML property is useful for returning or replacing the content of HTML elements (including <html7gt; and <body>), it can also be used to view the source of a page that has been dynamically modified.
HTML DOM innerHTML Property
The following code gets the innerHTML (text) from the <p> element with id="intro":
HTML DOM innerHTML Property Example
<html>
<body>
<p id="intro">Hello World!</p>
<script type="text/javascript">
txt=document.getElementById("intro").innerHTML;
document.write("<p>The text from the intro paragraph: " + txt + "</p>");
</script>
</body>
</html>
In the example above, getElementById is a method, while innerHTML is a property.
We can also use the childNodes and nodeValue properties to get the content of an element.
The following code gets the value of the
element with id="intro":
HTML DOM childNodes and nodeValue Example
<html>
<body>
<p id="intro">Hello World!</p>
<script type="text/javascript">
txt=document.getElementById("intro").childNodes[0].nodeValue;
document.write("<p>The text from the intro paragraph: " + txt + "</p>");
</script>
</body>
</html>
In the example above, getElementById is a method, while childNodes and nodeValue are properties.
In this tutorial we will mostly use the innerHTML property. However, learning the method above is useful for understanding the tree structure of the DOM and dealing with XML files.
