HTML5 编辑 API 之 Range 对象（二）

1.Range.cloneContents()
The Range.cloneContents() returns a DocumentFragment copying the objects of type Node included in the Range.

Syntax
documentFragment = range.cloneContents();

Example
range = document.createRange();
range.selectNode(document.getElementsByTagName("div").item(0));
documentFragment = range.cloneContents();
document.body.appendChild(documentFragment);

2.Range.cloneRange()
The Range.cloneRange() method returns a Range object with boundary points identical to the cloned Range.

The returned clone is copied by value, not reference, so a change in either Range does not affect the other.

Syntax
clone = range.cloneRange();
Example
range = document.createRange();
range.selectNode(document.getElementsByTagName("div").item(0));
clone = range.cloneRange();

3.Range.extractContents()
The Range.extractContents() method moves contents of the Range from the document tree into a DocumentFragment.

Event Listeners added using DOM Events are not retained during extraction. HTML attribute events are retained or duplicated as they are for the Node.cloneNode() method. HTML id attributes are also cloned, which can lead to an invalid document if a partially-selected node is extracted and appended to the document.

Partially selected nodes are cloned to include the parent tags necessary to make the document fragment valid.

Syntax
documentFragment = range.extractContents();

Example
var range = document.createRange();
range.selectNode(document.getElementsByTagName("div").item(0));
var documentFragment = range.extractContents();
document.body.appendChild(documentFragment);

4.insertNode

The Range.insertNode() method inserts a node at the start of the Range

The new node is inserted at the start boundary point of the Range. If the new node is to be added to a text Node, that Node is split at the insertion point, and the insertion occurs between the two text nodes.

If the new node is a document fragment, the children of the document fragment are inserted instead.

Syntax
range.insertNode(newNode);
Parameters

newNode
The Node to insert at the start of the range.
Example
range = document.createRange();
newNode = document.createElement("p");
newNode.appendChild(document.createTextNode("New Node Inserted Here"));
range.selectNode(document.getElementsByTagName("div").item(0));
range.insertNode(newNode);

5.compareBoundaryPoints

The Range.compareBoundaryPoints() method compares the boundary points of the Range with another one.

Syntax
compare = range.compareBoundaryPoints(how, sourceRange);
Return value

compare
A number, -1, 0, or 1, indicating whether the corresponding boundary-point of the Range is respectively before, equal to, or after the corresponding boundary-point of sourceRange.
Parameters

how
A constant describing the comparison method:
Range.END_TO_END compares the end boundary-point of sourceRange to the end boundary-point of Range.
Range.END_TO_START compares the end boundary-point of sourceRange to the start boundary-point of Range.
Range.START_TO_END compares the start boundary-point of sourceRange to the end boundary-point of Range.
Range.START_TO_START compares the start boundary-point of sourceRange to the start boundary-point of Range.
If the value of the parameter is invalid, a DOMException with a NOT_SUPPORTED_ERR code is thrown.

sourceRange
A Range to compare boundary points with the range.
Example
var range, sourceRange, compare;
range = document.createRange();
range.selectNode(document.getElementsByTagName("div")[0]);
sourceRange = document.createRange();
sourceRange.selectNode(document.getElementsByTagName("div")[1]);
compare = range.compareBoundaryPoints(Range.START_TO_END, sourceRange);

6.collapse

The Range.collapse() method collapses the Range to one of its boundary points.

A collapsed Range is empty, containing no content, specifying a single-point in a DOM tree. To determine if a Range is already collapsed, see the Range.collapsed property.

Syntax
range.collapse(toStart);
Parameters

toStart Optional
A boolean value: true collapses the Range to its start, false to its end. If omitted, it defaults to false .
Example
var range = document.createRange();

referenceNode = document.getElementsByTagName("div").item(0);
range.selectNode(referenceNode);
range.collapse(true);

7.detach

The Range.detach() method releases a Range from use. This lets the browser choose to release resources associated with this Range. Subsequent attempts to use the detached range will result in a DOMException being thrown with an error code of INVALID_STATE_ERR.

Syntax
range.detach();
Example
var range = document.createRange();

range.selectNode(document.getElementsByTagName("div").item(0));
range.detach();