com.jcorporate.expresso.core.dataobjects
Interface DataField

All Known Implementing Classes:

DefaultDataField, JoinedDataField

public interface DataField

This class represents a single field of data that is stored within the data object. It will provide basic manipulations such as it's original value, and attribute holdings.

Since:

Expresso 5.0.1

Author:

Michael Rimov

Method Summary

BigDecimal	asBigDecimal() Retrieve the wrapped object as a BigDecimal object or zero if we're unable to convert it.
Boolean	asBoolean() Retrieve the boolean object value.
Date	asDate() Retrieve the wrapped object as a Date object or possibly null if we can't convert it or the object is null.
Double	asDouble() Retrieve the wrapped object as a Double object or zero if we can't convert i
Integer	asInteger() Retrieves the wrapped object as an Integer or zero if it's an invalid format.
InputStream	asStream() Allows for retrieval of BLOB database types.
String	asString() Retrieves the wrapped object as a String
void	cacheIsChangedComparison() call after add() or update().
void	checkValue() Make sure the value of the field is valid.
Map	getAllAttributes() Returns a Read Only Map of all attributes in name-value pairs.
Object	getAttribute(String attributeName) Retrieves any user defined attributes for this field.
DataFieldMetaData	getFieldMetaData() Returns a handle to the Field MetaData object.
Object	getOriginalValue() Deprecated. 8/04 v.5.5 do not expose this cache Retrieve the last original value if the data has changed. Will return null if isChanged() is false
DataObject	getOwner() Returns a handle to the DataObject that is the container for this Data Field
Object	getValue() Retrieves the wrapped object for the Data Field
boolean	isChanged() Used for change logging.
boolean	isNull() Returns true if the object is null.
boolean	isValueSet() Used for change logging.
void	resetChanged() Resets the changed flag and sets the original value field to null
void	setAttribute(String attributeName, Object value) Sets an attribute for this particular instance of the Data field
void	setFieldMetaData(DataFieldMetaData newMetadata) Sets the metadata object for this field.
void	setOwner(DataObject newOwner) Sets the owner of a given DataObject
void	setValue(Object newValue) Sets the wrapped object for the data field

Method Detail

getValue

public Object getValue()

Retrieves the wrapped object for the Data Field

Returns:

java.lang.Object or null

asString

public String asString()

Retrieves the wrapped object as a String

Returns:

java.lang.String

asBoolean

public Boolean asBoolean()

Retrieve the boolean object value.

Returns:

java.lang.Boolean

asInteger

public Integer asInteger()

Retrieves the wrapped object as an Integer or zero if it's an invalid format.

Returns:

a java.lang.Integer object, or null if the object is null.

asDate

public Date asDate()

Retrieve the wrapped object as a Date object or possibly null if we can't convert it or the object is null.

Returns:

a properly instantiated Date Object if we're able to convert it.

asBigDecimal

public BigDecimal asBigDecimal()

Retrieve the wrapped object as a BigDecimal object or zero if we're unable to convert it.

Returns:

a properly instantiated BigDecimal Object if we're able to convert it.

asDouble

public Double asDouble()

Retrieve the wrapped object as a Double object or zero if we can't convert i

Returns:

a properly instantiated Double Object if we're able to convert it.

getOriginalValue

public Object getOriginalValue()

Deprecated. 8/04 v.5.5 do not expose this cache Retrieve the last original value if the data has changed. Will return null if isChanged() is false

Returns:

the original object or null

asStream

public InputStream asStream()

Allows for retrieval of BLOB database types.

Returns:

java.io.InputStream

isChanged

public boolean isChanged()

Used for change logging.

Returns:

true if the field has changed since the last reset

isValueSet

public boolean isValueSet()

Used for change logging.

Returns:

true if the field has been set since the last reset

checkValue

public void checkValue()
                throws DataException

Make sure the value of the field is valid.

Throws:

DataException - if the field value is not valid

resetChanged

public void resetChanged()

Resets the changed flag and sets the original value field to null

setValue

public void setValue(Object newValue)

Sets the wrapped object for the data field

Parameters:

newValue - a new Object to set the value to

isNull

public boolean isNull()

Returns true if the object is null.

Returns:

true if the object is null

setAttribute

public void setAttribute(String attributeName,
                         Object value)

Sets an attribute for this particular instance of the Data field

Parameters:

attributeName - the name of the attribute to set

value - the value to set it to

getAttribute

public Object getAttribute(String attributeName)

Retrieves any user defined attributes for this field.

Parameters:

attributeName - the name of the attribute to retrieve

Returns:

an object or null if the attribute doesn't exist

getAllAttributes

public Map getAllAttributes()

Returns a Read Only Map of all attributes in name-value pairs. If there are no attributes then getAllAttributes will return a null map.

Returns:

java.util.map

getOwner

public DataObject getOwner()

Returns a handle to the DataObject that is the container for this Data Field

Returns:

DataObject the containing data object.

setOwner

public void setOwner(DataObject newOwner)

Sets the owner of a given DataObject

Parameters:

newOwner - The new parent object.

getFieldMetaData

public DataFieldMetaData getFieldMetaData()

Returns a handle to the Field MetaData object.

Returns:

DataFieldMetaData

setFieldMetaData

public void setFieldMetaData(DataFieldMetaData newMetadata)

Sets the metadata object for this field.

Parameters:

newMetadata - the new Field Meta data object... for example DBField

cacheIsChangedComparison

public void cacheIsChangedComparison()

call after add() or update(). The currentValue of data fields should be considered the baseline, the 'original value' for purposes of determining 'isChanged'