FieldValue (MMBase 1.9-SNAPSHOT

All Known Implementing Classes:

AbstractFieldValue, BasicFieldValue, BasicFunctionValue, RemoteFieldValue_Proxy
```
public interface FieldValue
```
This interface represents a value stored in a node.

Since:

MMBase 1.6

Version:

$Id$

Author:

Pierre van Rooden

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`boolean`	`canModify()` Returns whether this value can be changed.
`Object`	`get()` Returns the value as an Object.
`Field`	`getField()` Returns the Field object belonging to this value.
`Node`	`getNode()` Returns the Node to which this value belongs.
`boolean`	`isNull()`
`void`	`set(Object value)` Sets the value, passing any Object The object type may vary and is generally stored in memory as-is, which means that, generally, the get() method returns the same object.
`void`	`setBoolean(boolean value)` Sets the value, passing a boolean value.
`void`	`setByte(byte[] value)` Sets the value, passing a byte array.
`void`	`setDate(Date value)` Sets the value, passing a java.util.Date object.
`void`	`setDouble(double value)` Sets the value, passing a double value.
`void`	`setFLoat(float value)` Sets the value, passing a float value.
`void`	`setInt(int value)` Sets the value, passing a int value.
`void`	`setLong(long value)` Sets the value, passing a long value.
`void`	`setNode(Node value)` Sets the value, passing a Node.
`void`	`setObject(Object value)`
`void`	`setString(String value)` Sets the value, passing a String.
`void`	`setXML(Document value)` Sets the value, passing a org.w3c.dom.Document object.
`boolean`	`toBoolean()` Returns the value as an boolean (`true` or `false`).
`byte[]`	`toByte()` Returns the value as a byte array.
`Date`	`toDate()` Returns the value as a `java.util.Date` If the value cannot be converted, this method returns `null`
`double`	`toDouble()` Returns the value as a double.
`float`	`toFloat()` Returns the value as a float.
`int`	`toInt()` Returns the value as an int.
`long`	`toLong()` Returns the value as a long.
`Node`	`toNode()` Returns the value as a Node.
`String`	`toString()` Returns the value as a String.
`Document`	`toXML()` Returns the value as a `org.w3c.dom.Document` If the node value is not itself a Document, the method attempts to attempts to convert the String value into an XML.
`Element`	`toXML(Document tree)` Returns the value as a `org.w3c.dom.Element` If the node value is not itself a Document, the method attempts to attempts to convert the String value into an XML.

- Method Detail
  - canModify
```
boolean canModify()
```
    Returns whether this value can be changed. Some field values (such as the values of the number, owner, and otype fields) cannot be changed through this interface (but some may be changed through other means).
    
    Returns:
    
    true if the value can be changed
  - isNull
```
boolean isNull()
```
  - get
```
Object get()
```
    Returns the value as an Object. The object type may vary and is dependent on how data was stored in a field. I.e. It may be possible for an Integer field to return it's value as a String if it was stored that way in the first place.
    
    Returns:
    
    the field value as an object
  - getField
```
Field getField()
```
    Returns the Field object belonging to this value.
    
    Returns:
    
    the field object. Why not return Field?
  - getNode
```
Node getNode()
```
    Returns the Node to which this value belongs.
    
    Returns:
    
    the Node object
  - toBoolean
```
boolean toBoolean()
```
    Returns the value as an boolean (true or false). If the actual value is a Boolean object, this call returns it's (primitive) boolean value. If the actual value is a Number object, this call returns true if the value is a positive, non-zero, value. In other words, values '0' and '-1' are concidered false. If the value is a string, this call returns true if the value is "true" or "yes" (case-insensitive). In all other cases (including calling byte fields), false is returned.
    
    Returns:
    
    the field value as a boolean
  - toByte
```
byte[] toByte()
```
    Returns the value as a byte array. This function returns either the value of a byte field, or the byte value of a string (converted using the default encoding, i.e. UTF8) Other types of values return an empty byte-array.
    
    Returns:
    
    the field value as a byte array
  - toFloat
```
float toFloat()
```
    Returns the value as a float. This function attempts to convert the value to a float. Numeric fields are simply converted. Boolean fields return 0.0 if false, and 1.0 if true. String fields are parsed. If a parsed string contains an error, ot the field value is not of a type that can be converted (i.e. a byte array), this function returns -1.0.
    
    Returns:
    
    the field value as a float
  - toDouble
```
double toDouble()
```
    Returns the value as a double. This function attempts to convert the value to a double. Numeric fields are simply converted. Double may be truncated. Boolean fields return 0.0 if false, and 1.0 if true. String fields are parsed. If a parsed string contains an error, ot the field value is not of a type that can be converted (i.e. a byte array), this function returns -1.0.
    
    Returns:
    
    the field value as a double
  - toLong
```
long toLong()
```
    Returns the value as a long. This function attempts to convert the value to a long. Numeric fields are simply converted. Double and float values may be truncated. Boolean fields return 0 if false, and 1 if true. String fields are parsed. If a parsed string contains an error, ot the field value is not of a type that can be converted (i.e. a byte array), this function returns -1
    
    Returns:
    
    the field value as a long.
  - toInt
```
int toInt()
```
    Returns the value as an int. This function attempts to convert the value to an int. Numeric fields are simply converted. Double and float values may be truncated. For Node values, the numeric key is returned. Long values return -1 of the value is too large. Boolean fields return 0 if false, and 1 if true. String fields are parsed. If a parsed string contains an error, ot the field value is not of a type that can be converted (i.e. a byte array), this function returns -1
    
    Returns:
    
    the field value as an int.
  - toNode
```
Node toNode()
```
    Returns the value as a Node. This function attempts to retrieve the node represented by the value. For numeric fields the node is retrieved using the numeric values as the node key. String fields are used as Node aliases, withw hich to retrieve the Node. If the node does not exist, or the value is of anotehr type, the function returns null.
    
    Returns:
    
    the field value as a Node
  - toString
```
String toString()
```
    Returns the value as a String. Byte arrays are converted to string using the default encoding (UTF8). Node values return a string representation of their numeric key. DOM Documents are serialized to a proper strign represnattion fo the xml. For other values the result is calling the toString() method on the actual object.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    the field value as a String
  - toXML
```
Document toXML()
        throws IllegalArgumentException
```
    Returns the value as a org.w3c.dom.Document If the node value is not itself a Document, the method attempts to attempts to convert the String value into an XML. If the value cannot be converted, this method returns null
    
    Returns:
    
    the field value as a Document
    
    Throws:
    
    IllegalArgumentException - if the Field is not of type TYPE_XML.
  - toDate
```
Date toDate()
```
    Returns the value as a java.util.Date If the value cannot be converted, this method returns null
    
    Returns:
    
    the field value as Date
    
    Since:
    
    MMBase-1.8
  - toXML
```
Element toXML(Document tree)
       throws IllegalArgumentException
```
    Returns the value as a org.w3c.dom.Element If the node value is not itself a Document, the method attempts to attempts to convert the String value into an XML. This method fails (throws a IllegalArgumentException) if the Field is not of type TYPE_XML. If the value cannot be converted, this method returns null
    
    Parameters:
    
    tree - the DOM Document to which the Element is added (as the document root element)
    
    Returns:
    
    the field value as an Element
    
    Throws:
    
    IllegalArgumentException - if the Field is not of type TYPE_XML.
  - set
```
void set(Object value)
```
    Sets the value, passing any Object The object type may vary and is generally stored in memory as-is, which means that, generally, the get() method returns the same object. Note that for an XML field String values are converted to a XML document, and individual builders may make their own changes. The object is converted to the actual type (using the getXXX() methods detailed above) once the node is stored, though that does not affect the data in-memory until the Node is read anew from the storage. Note that this behavior may change in the future and therefor code should not be dependent on this. By preference, use the more specific methods for setting data (i.e. setString()).
    
    Parameters:
    
    value - the field value as an Object
    
    See Also:
    
    get()
  - setObject
```
void setObject(Object value)
```
  - setBoolean
```
void setBoolean(boolean value)
```
    Sets the value, passing a boolean value. This value is converted to a Boolean object.
    
    Parameters:
    
    value - the field value as a boolean
    
    See Also:
    
    toBoolean()
  - setFLoat
```
void setFLoat(float value)
```
    Sets the value, passing a float value. This value is converted to a Float object.
    
    Parameters:
    
    value - the field value as a float
    
    See Also:
    
    toFloat()
  - setDouble
```
void setDouble(double value)
```
    Sets the value, passing a double value. This value is converted to a Double object.
    
    Parameters:
    
    value - the field value as a double
    
    See Also:
    
    toDouble()
  - setLong
```
void setLong(long value)
```
    Sets the value, passing a long value. This value is converted to a Long object.
    
    Parameters:
    
    value - the field value as a long
    
    See Also:
    
    toLong()
  - setInt
```
void setInt(int value)
```
    Sets the value, passing a int value. This value is converted to a Integer object.
    
    Parameters:
    
    value - the field value as a int
    
    See Also:
    
    toInt()
  - setByte
```
void setByte(byte[] value)
```
    Sets the value, passing a byte array.
    
    Parameters:
    
    value - the field value as a byte array
    
    See Also:
    
    toByte()
  - setString
```
void setString(String value)
```
    Sets the value, passing a String.
    
    Parameters:
    
    value - the field value as a String
    
    See Also:
    
    toString()
  - setNode
```
void setNode(Node value)
```
    Sets the value, passing a Node.
    
    Parameters:
    
    value - the field value as a Node
    
    See Also:
    
    toNode()
  - setXML
```
void setXML(Document value)
```
    Sets the value, passing a org.w3c.dom.Document object.
    
    Parameters:
    
    value - the field value as a XML Document
    
    See Also:
    
    toXML(org.w3c.dom.Document)
  - setDate
```
void setDate(Date value)
```
    Sets the value, passing a java.util.Date object.
    
    Parameters:
    
    value - the field value as a java.util.Date Document
    
    Since:
    
    MMBase-1.8
    
    See Also:
    
    toDate()

Interface FieldValue

Method Summary

Method Detail

canModify

isNull

get

getField

getNode

toBoolean

toByte

toFloat

toDouble

toLong

toInt

toNode

toString

toXML

toDate

toXML

set

setObject

setBoolean

setFLoat

setDouble

setLong

setInt

setByte

setString

setNode

setXML

setDate