prajna.data.field

Class TokenFieldDesc

java.lang.Object

prajna.data.field.FieldDesc<java.lang.String>

prajna.data.field.TokenFieldDesc

All Implemented Interfaces:

java.io.Serializable, Xmlizable

public class TokenFieldDesc
extends FieldDesc<java.lang.String>

Field description for short, tokenizable strings. The TokenFieldDesc allows both patterned tokens (using Pattern syntax) and limited-length tokens. The default maximum length is 64, though this can be overridden. It is expected to conform to the RDF token.

Author:

Edward Swing

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
TokenFieldDesc() Default constructor with no arguments, useful for cases where the descriptor is configured from XML elements.
TokenFieldDesc(java.lang.String fieldName) Constructor taking a field name.

Method Summary

Methods

Modifier and Type	Method and Description
DataType	getFieldType() Get the field type for this field description
int	getMaxLength() Get the maximum string length allowed by this descriptor
java.util.regex.Pattern	getPattern() Get the pattern used by this token field
boolean	isValid(java.lang.String value) Return whether a field value is valid.
java.lang.String	parse(java.lang.String stringVal) Parse the value into the format for this field description.
java.lang.String	parseValueIntoRecord(DataRecord rec, java.lang.String value) Validate the string value, and store it in a string field in the specified data record.
void	setPattern(java.util.regex.Pattern newPattern) Set the pattern used by this token field
protected void	setValues(org.w3c.dom.NodeList valueList) Set the values for this String field description.
void	storeDefaultIntoRecord(DataRecord rec) Store the default value into the data record provided.
org.w3c.dom.Element	toXml(org.w3c.dom.Document doc) Convert this field description to an XML Element.

Methods inherited from class prajna.data.field.FieldDesc

addSourceField, applyTransform, getDefaultValue, getFieldName, getLookupIndexField, getLookupTable, getLookupValueField, getSourceFields, getTransform, isMultiValue, loadFromXml, setDefaultValue, setFieldName, setMultiValue

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TokenFieldDesc

public TokenFieldDesc()

Default constructor with no arguments, useful for cases where the descriptor is configured from XML elements.

TokenFieldDesc

public TokenFieldDesc(java.lang.String fieldName)

Constructor taking a field name.

Parameters:

fieldName - the field name for this descriptor

Method Detail

getFieldType

public DataType getFieldType()

Get the field type for this field description

Specified by:

getFieldType in class FieldDesc<java.lang.String>

Returns:

FieldType.TEXT

getMaxLength

public int getMaxLength()

Get the maximum string length allowed by this descriptor

Returns:

the maximum string length

getPattern

public java.util.regex.Pattern getPattern()

Get the pattern used by this token field

Returns:

the pattern for this token field

isValid

public boolean isValid(java.lang.String value)

Return whether a field value is valid. This method checks of the string length is less than the maximum string length.

Specified by:

isValid in class FieldDesc<java.lang.String>

Parameters:

value - the field value

Returns:

true if the field is valid for this field description, false otherwise

parse

public java.lang.String parse(java.lang.String stringVal)

Parse the value into the format for this field description. This method ensures that the token has no leading or trailing whitespaces, tabs, or line feeds.

Specified by:

parse in class FieldDesc<java.lang.String>

Parameters:

stringVal - the value to parse

Returns:

the parsed string, the stringVal argument.

parseValueIntoRecord

public java.lang.String parseValueIntoRecord(DataRecord rec,
                                    java.lang.String value)

Validate the string value, and store it in a string field in the specified data record. If the value is valid, the DataRecord.setTextField method will be invoked. This method calls parse() to enforce the maximum length or any other restrictions or formats.

Specified by:

parseValueIntoRecord in class FieldDesc<java.lang.String>

Parameters:

rec - the DataRecord to parse the value into

value - the String value to be parsed

Returns:

the string value added

Throws:

java.lang.IllegalArgumentException - if the value is not a valid value of this Text Value field

setPattern

public void setPattern(java.util.regex.Pattern newPattern)

Set the pattern used by this token field

Parameters:

newPattern - the pattern for this token field

setValues

protected void setValues(org.w3c.dom.NodeList valueList)

Set the values for this String field description. This method looks for any element with a tag name of maxLength to specify the maximum length allowed for strings in this field. If the maxLength value is not set, this class uses Integer.MAX_VALUE as its maximum length. It also looks for a pattern attribute. If if finds such an attribute, it compiles the value into a regular expression pattern.

Specified by:

setValues in class FieldDesc<java.lang.String>

Parameters:

valueList - list of value nodes. These are child nodes of the values element

storeDefaultIntoRecord

public void storeDefaultIntoRecord(DataRecord rec)

Store the default value into the data record provided. If the default value is null, no action is taken.

Specified by:

storeDefaultIntoRecord in class FieldDesc<java.lang.String>

Parameters:

rec - the DataRecord to store the value into

toXml

public org.w3c.dom.Element toXml(org.w3c.dom.Document doc)

Convert this field description to an XML Element. This method creates a fieldDef element, sets the fieldName and fieldType, and creates a values child element. The values element contains the optional maxLength text node. If the default value is set, this method adds it as well.

Specified by:

toXml in interface Xmlizable

Specified by:

toXml in class FieldDesc<java.lang.String>

Parameters:

doc - The document used to construct the element

Returns:

the element representing this field description