to.etc.webapp.query

Class QField<R extends QField<R,?>,T>

java.lang.Object

to.etc.webapp.query.QField<R,T>

public class QField<R extends QField<R,?>,T>
extends Object

Class that provides means for making type safe queries. It always start at a certain root. Eg if you want to query Users mapped by User.class then look for the QUser.class. There is a static method get() that will return a QUserRoot object. The QUser.class or any other QField type cannot be instantiated otherwise. It makes sure you cannot query on wrong paths. When you want to restrict on a property of eg the User.class you can simply call the corresponding method and use that in queries, formbuilders and datatables. An annotation processor, TableAnnotationProcessor, has a hook in the compiler that will generate all fields for all classes that have the Entity annotation. Those Entity classes can be refactored at will, any paths that break will generate compiler warnings. Also provides a light wrapper interface around the QCriteria api to make queries look more natural. See also QFieldCompileTest and QFieldRunTest for how this works compared to the original api. There is no intention to replace anything, there is full compatibility and no obligation to use one or the other. The same query can be made by combining the two api's if necessary. The concept is that on every field restriction and operating methods can be called. Because eq is the default values can be added directly in the call to the property. If more values are supplied they ar or-ed. See also comment on eq,ne,or etc. The goal is the mirror the natural order of operators as much as possible with the possibility to brace parts of the query where desired without having to restructure the query.

Author:

Dennis Bekkering Created on Feb 3, 2013

Field Summary

Fields

Modifier and Type	Field and Description
protected QCriteria<T>	m_criteria
protected QBrace	m_qBrace
protected R	m_root

Constructor Summary

Constructors

Constructor and Description
QField(R root, QField<R,?> parent, String propertyNameInParent)

Method Summary

Modifier and Type	Method and Description
R	_$() Brace close, can be places anywhere natural.
R	$_() Brace open, can be places anywhere natural.
QCriteria<?>	criteria()
R	eq(T... t) equals
protected void	eqOrOr(IRestrictor<T> irestrictor, T... v) One value will have it's natural way.
R	gt(T... t) greater then
R	ne(T... t) not equals
R	or() or's the next restriction to this one as opposed to the original api where you call or before any thing that has to be or-ed.
List<T>	query(QDataContext dc) Call this on the root query, any other attempt will give a runtime exception.
T	queryOne(QDataContext dc) Call this on the root query, any other attempt will give a runtime exception.
String	toString()
protected void	validateGetCriteria()

Methods inherited from class java.lang.Object

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

Field Detail

m_root

@Nonnull
protected R extends QField<R,?> m_root

m_criteria

@Nullable
protected QCriteria<T> m_criteria

m_qBrace

protected QBrace m_qBrace

Constructor Detail

QField

public QField(@Nullable
              R root,
              @Nullable
              QField<R,?> parent,
              @Nullable
              String propertyNameInParent)

Method Detail

toString

public final String toString()

Overrides:

toString in class Object

gt

@Nonnull
public final R gt(@Nonnull
                           T... t)

greater then

Parameters:

t -

Returns:

eq

@Nonnull
public final R eq(@Nonnull
                           T... t)

equals

Parameters:

t -

Returns:

ne

@Nonnull
public final R ne(@Nonnull
                           T... t)

not equals

Parameters:

t -

Returns:

or

@Nonnull
public final R or()

or's the next restriction to this one as opposed to the original api where you call or before any thing that has to be or-ed. There is no and every restriction leads back to the root. Any next direct call to a retsriction will be and-ed.

Returns:

eqOrOr

protected final void eqOrOr(@Nonnull
                            IRestrictor<T> irestrictor,
                            @Nonnull
                            T... v)

One value will have it's natural way. More values will be or-ed together and added to the current level.

Parameters:

irestrictor -

v -

$_

@Nonnull
public final R $_()

Brace open, can be places anywhere natural. Can also be placed unnatural, that will give error's where possible or strange results. So use with care. Place them as if you are writing an sql statement or any other conditional structure.

Returns:

_$

@Nonnull
public final R _$()
                    throws Exception

Brace close, can be places anywhere natural. Can also be placed unnatural, that will give error's where possible or strange results. So use with care. Place them as if you are writing an sql statement or any other conditional structure.

Returns:

Throws:

Exception

query

@Nonnull
public final List<T> query(@Nonnull
                                    QDataContext dc)
                             throws Exception

Call this on the root query, any other attempt will give a runtime exception.

Parameters:

dc -

Returns:

Throws:

Exception

queryOne

@Nullable
public final T queryOne(@Nonnull
                                  QDataContext dc)
                           throws Exception

Call this on the root query, any other attempt will give a runtime exception.

Parameters:

dc -

Returns:

Throws:

Exception

validateGetCriteria

protected final void validateGetCriteria()
                                  throws Exception

Throws:

Exception

criteria

@Nonnull
public final QCriteria<?> criteria()