org.zkoss.idom
Interface Item

All Known Subinterfaces:
Group
All Known Implementing Classes:
AbstractGroup, AbstractItem, AbstractTextual, Attribute, Binary, CData, Comment, DocType, Document, Element, EntityReference, ProcessingInstruction, Text

public interface Item

Represents an item (aka., node) of a iDOM tree. A iDOM tree is not necessary also a W3C/DOM tree. However, in iDOM's implement, it is because all Vertices also implement related interface, such as Node.

Some vertices, currently only Element, might support attributes by implementing Attributable.

Due to the implementation of both Item and W3C/DOM's interfaces, many methods seem redudant (e.g., parent vs. getParentNode, and children vs. getChildNodes). Caller could use them interchangeably . However, it is suggested to use Item's API instead of Node's, because, like JDOM, Item's API is based Java collection classes and more consistent (from my point of view). The W3C/DOM API is used to work with utilities that work only with W3C/DOM.

Be carefult that some methods look similar, but behave different. Refer to package.html.

Author:
tomyeh
See Also:
Attributable, Binable

Field Summary
static int FIND_BY_PREFIX
          Indicates the namespace argument is a prefix rather than URI.
static int FIND_BY_REGEX
          Indicates the searching is based on regular expression (upon the name argument).
static int FIND_BY_TAGNAME
          Indicates the name argument is a tag name rather than local name.
static int FIND_IGNORE_CASE
          Indicates the searching is case insensitive.
static int FIND_RECURSIVE
          Indicates the searching looks for all descendants.
 
Method Summary
 void clearModified(boolean includingDescendant)
          Clears the modification flag of this item and all its children if includingDescendant is true.
 Item clone(boolean preserveModified)
          Clones this item.
 Item detach()
          Detach this item from its parent.
 Document getDocument()
          Gets the document that owns this item.
 Locator getLocator()
          Gets the locator of this item.
 java.lang.String getName()
          Gets the name of the item.
 Group getParent()
          Gets the parent item.
 java.lang.String getText()
          Gets the text of this item, or null if it is neither Textual nor Element.
 boolean isModified()
          Tests whether this item (or any of its children) is modified, i.e., the modification flag is set.
 boolean isReadonly()
          Tests whether this item is read-only.
 void setLocator(Locator loc)
          Sets the locator of this item.
 void setModified()
          Sets the modification flag.
 void setName(java.lang.String name)
          Sets the name of the item.
 void setParent(Group parent)
          Sets the parent item.
 void setReadonly(boolean readonly)
          Sets the read-only flag of this item.
 void setText(java.lang.String obj)
          Sets the text of this item.
 

Field Detail

FIND_BY_REGEX

static final int FIND_BY_REGEX
Indicates the searching is based on regular expression (upon the name argument). If not specified, exact-match is required.

See Also:
Constant Field Values

FIND_IGNORE_CASE

static final int FIND_IGNORE_CASE
Indicates the searching is case insensitive. This flag is ignored if FIND_BY_REGEX is specified.

See Also:
Constant Field Values

FIND_BY_TAGNAME

static final int FIND_BY_TAGNAME
Indicates the name argument is a tag name rather than local name.

See Also:
Constant Field Values

FIND_BY_PREFIX

static final int FIND_BY_PREFIX
Indicates the namespace argument is a prefix rather than URI.

See Also:
Constant Field Values

FIND_RECURSIVE

static final int FIND_RECURSIVE
Indicates the searching looks for all descendants. If not specified, only the children (not children of children) is searched.

See Also:
Constant Field Values
Method Detail

isReadonly

boolean isReadonly()
Tests whether this item is read-only. Note: A item is read-only if the read-only flag is set (setReadonly(boolean)) or any of its ancestor is read-only (i.e., the read-only flag is set).


setReadonly

void setReadonly(boolean readonly)
Sets the read-only flag of this item. It causes this item and all its descendants read-only, see isReadonly().


getName

java.lang.String getName()
Gets the name of the item. For vertices that support namespace (implements Namespaceable), it is the same as getTagName.

See Also:
Namespaceable.getTagName()

setName

void setName(java.lang.String name)
Sets the name of the item. For vertices that support namespace (implements Namespaceable), it is the same as setTagName.

Throws:
DOMException - with NOT_SUPPORTED_ERR if this item doesn't allow to change the name, e.g., Document and DocType
See Also:
Namespaceable.setTagName(java.lang.String)

getText

java.lang.String getText()
Gets the text of this item, or null if it is neither Textual nor Element. For Element, the text is the catenation of all its textual children, including Text, CDATA, and Binary.

Besides String-type value, some item, e.g., Binary, allows any type of objects. Caller could test whether a item implements the Binable interface, and use Binable.getValue instead. For binable vertices, getText is actually getValue().toString().

The returned value is neither trimmed nor normalized.


setText

void setText(java.lang.String obj)
Sets the text of this item.

Throws:
DOMException - with NOT_SUPPORTED_ERR if this item doesn't allow to change the value, e.g., Document and Element

getDocument

Document getDocument()
Gets the document that owns this item. The owning document is the first document in its ancestor. For DOM, the document can only be the root, so the owning documents of vertices in a DOM tree are all the same.


detach

Item detach()
Detach this item from its parent.

Because each item can belong to at most one parent at a time, it is important to detach it first, before added to another tree -- even if it is the same tree/parent.

It has the similar effect as:
getParent().getChildren().remove(this).

Naming reason: we don't call this method as getChildren() to be compatible with the naming style of Attributable.attributes -- which is limited to org.w3c.dom.Attr.getAttributes. Also, it doesn't have the setter and it is "live", so it 'seem' better to call it getChildren().

Returns:
this item

getParent

Group getParent()
Gets the parent item.


getLocator

Locator getLocator()
Gets the locator of this item.

Returns:
the locator; null if not available (default)

setLocator

void setLocator(Locator loc)
Sets the locator of this item.

Unlike other methods, it won't change the modification flag.

Parameters:
loc - the locator; null if not available

clone

Item clone(boolean preserveModified)
Clones this item. Unlike other objects, it does a deep cloning. Also, the returned object is detached by default. The readonly flags are cleaned. If preserveModified is false, all modification flags of the returned object are cleaned, too.


isModified

boolean isModified()
Tests whether this item (or any of its children) is modified, i.e., the modification flag is set.

IDOM is smart enough to set the modification flag only if it is really modified -- i.e., assigning a different value (not just calling any setter).

When an object is serialized, the modification flag is reset. Also, an object generated by clone(boolean) with preservedModified==false has also no modification flag set.


clearModified

void clearModified(boolean includingDescendant)
Clears the modification flag of this item and all its children if includingDescendant is true.

Unlike other methods, it doesn't affected by the read-only flag.

Parameters:
includingDescendant - whether to clear the modified flags of descendants

setModified

void setModified()
Sets the modification flag. Unlike clearModified(boolean), it won't set children's modification flags, rather it sets its parent's modification flag.

The modifiaction flag is maintain automatically, so you rarely needs to call this method.

Unlike other methods, it doesn't affected by the read-only flag.


setParent

void setParent(Group parent)
Sets the parent item.

DO NOT call this method. It is used internally. Instead, use detach or thru getChildren().



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