simpleorm.dataset

Class SFieldMeta

java.lang.Object

simpleorm.dataset.SFieldMeta

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

SFieldReference, SFieldScalar

public abstract class SFieldMeta
extends java.lang.Object
implements java.io.Serializable

Each instance defines the meta data for a field in an SRecordMeta. Subclasses are used for specific data types, with SFieldObject being the most generic. Like JDBC, type conversions are made automatically.

Internally, the types are stored accurately. Ie. the SRecordInstance.getObject objects are the exact types as declared (String, Integer, Employee etc.) However, generous automatic conversions are performed both when accessing these from the application and when getting and setting columns in the database.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
boolean	quoteName

Method Summary

Modifier and Type	Method and Description
<T extends SFieldMeta> T	addFlag(SFieldFlags flag) Add a FieldFlag as an afterthought.
<T extends SFieldMeta> T	addValidator(SValidatorI val) Add a custom FieldValidator.
protected abstract java.lang.Object	convertToDataSetFieldType(java.lang.Object raw) Converts the parameter from the raw type parameter to the correct internal Object type that is stored in the data set.
protected void	doValidate(SRecordInstance instance) Called when individual field changed, or when record updated.
boolean	equals(java.lang.Object that)
java.lang.String	getFieldName()
protected java.util.EnumSet<SFieldFlags>	getFlags()
SRecordMeta	getRecordMeta()
java.util.Map	getUserProperties()
<T> T	getUserProperty(java.lang.Object key)
java.util.List<SValidatorI>	getValidators() Get the list of validators that are bound to this field.
int	hashCode()
boolean	isDescriptive()
protected boolean	isForeignKey()
boolean	isMandatory()
boolean	isUnqueried()
long	nextGeneratedValue(long minimum) This is used to fudge generation of key values for in databases that do not properly suport them.
<T extends SFieldMeta> T	putUserProperty(java.lang.Object key, java.lang.Object value)
abstract java.lang.Object	queryFieldValue(java.sql.ResultSet rs, int sqlIndex) Issues a JDBC get*() on the result set for the field and converts the database type to the appropriate internal type, eg, Double for a double field.
protected java.lang.Object	readResolve() Reflected into during de-serialization to return any pre-existing SFieldMeta object
<T extends SFieldMeta> T	setQuoted(boolean quoted) Causes the generated sql to quote ("") the column name.
abstract java.lang.String	toLongerString() Lists all the details of the field.
java.lang.String	toString() Lists the record and column name only.
java.lang.Object	writeFieldValue(java.lang.Object value) Converts a single value from internal representation to database representation.
void	writeFieldValue(java.sql.PreparedStatement ps, int sqlIndex, java.lang.Object value) Places a value in a prepared statement in the database representation used during SRecordInstance.flush.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

quoteName

public boolean quoteName

Method Detail

getFlags

protected java.util.EnumSet<SFieldFlags> getFlags()

isUnqueried

public boolean isUnqueried()

isDescriptive

public boolean isDescriptive()

setQuoted

public <T extends SFieldMeta> T setQuoted(boolean quoted)

Causes the generated sql to quote ("") the column name. Makes it case sensitive, allows reserved words and odd characters. Beware that Postgresql (only) defaults to lower case, not upper case.

queryFieldValue

public abstract java.lang.Object queryFieldValue(java.sql.ResultSet rs,
                                                 int sqlIndex)
                                          throws java.lang.Exception

Issues a JDBC get*() on the result set for the field and converts the database type to the appropriate internal type, eg, Double for a double field. The first column has sqlIndex==1.

Throws:

java.lang.Exception

convertToDataSetFieldType

protected abstract java.lang.Object convertToDataSetFieldType(java.lang.Object raw)
                                                       throws java.lang.Exception

Converts the parameter from the raw type parameter to the correct internal Object type that is stored in the data set. Returns the object if no conversion necessary. Used by SRecordInstance.setObject etc., Not getObject.

Throws:

java.lang.Exception

writeFieldValue

public void writeFieldValue(java.sql.PreparedStatement ps,
                            int sqlIndex,
                            java.lang.Object value)

Places a value in a prepared statement in the database representation used during SRecordInstance.flush. Can convert between internal values and database values, eg. TRUE to "Y".

(This does NOT need to handle NULL values (those are handled seperately by SRecordInstance))

writeFieldValue

public java.lang.Object writeFieldValue(java.lang.Object value)

Converts a single value from internal representation to database representation. Used primarily by the writeFieldValue above, but also used for converting optimistic lock values in SRecordInstance.flush.

Overidden by SFieldBoolean. (not by SFieldString).

NOTE: This does NOT need to handle NULL values (those are handled seperately by SRecordInstance)

toString

public java.lang.String toString()

Lists the record and column name only. Useful in traces.

Overrides:

toString in class java.lang.Object

toLongerString

public abstract java.lang.String toLongerString()

Lists all the details of the field.

isForeignKey

protected boolean isForeignKey()

nextGeneratedValue

public long nextGeneratedValue(long minimum)

This is used to fudge generation of key values for in databases that do not properly suport them. It is rough and fails if there are multiple JVMs, or the user switches schemas in Oracle etc.

readResolve

protected java.lang.Object readResolve()
                                throws java.io.ObjectStreamException

Reflected into during de-serialization to return any pre-existing SFieldMeta object

Throws:

java.io.ObjectStreamException

getFieldName

public java.lang.String getFieldName()

equals

public boolean equals(java.lang.Object that)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

getRecordMeta

public SRecordMeta getRecordMeta()

Returns:

the sRecordMeta

isMandatory

public boolean isMandatory()

addValidator

public <T extends SFieldMeta> T addValidator(SValidatorI val)

Add a custom FieldValidator. Validator corresponding to data constaints (type, length, not null, ...) are added automatically.

addFlag

public <T extends SFieldMeta> T addFlag(SFieldFlags flag)

Add a FieldFlag as an afterthought. Allows conditional flags in a constructor.

getValidators

public java.util.List<SValidatorI> getValidators()

Get the list of validators that are bound to this field. Can be useful for UI to know allowed values, etc.

doValidate

protected void doValidate(SRecordInstance instance)

Called when individual field changed, or when record updated. (Default behaviour is to call all registered validators.)

See Also:

SRecordInstance.onValidateField(simpleorm.dataset.SFieldMeta, java.lang.Object)

putUserProperty

public <T extends SFieldMeta> T putUserProperty(java.lang.Object key,
                                                java.lang.Object value)

getUserProperty

public <T> T getUserProperty(java.lang.Object key)

getUserProperties

public java.util.Map getUserProperties()