io.github.mmm.property.builder.PropertyBuilder Maven / Gradle / Ivy
/* Copyright (c) The m-m-m Team, Licensed under the Apache License, Version 2.0
* http://www.apache.org/licenses/LICENSE-2.0 */
package io.github.mmm.property.builder;
import java.util.HashMap;
import java.util.Map;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
import io.github.mmm.base.metainfo.MetaInfo;
import io.github.mmm.property.AttributeReadOnly;
import io.github.mmm.property.Property;
import io.github.mmm.property.PropertyMetadata;
import io.github.mmm.property.builder.container.ListPropertyBuilder;
import io.github.mmm.property.builder.container.MapPropertyBuilder;
import io.github.mmm.property.builder.container.SetPropertyBuilder;
import io.github.mmm.property.object.SimpleProperty;
import io.github.mmm.validation.Validator;
import io.github.mmm.validation.main.ObjectValidatorBuilder;
/**
* Abstract base class for a {@link io.github.mmm.base.lang.Builder} to create instances of a particular type of
* {@link Property}.
* As a {@link Property} typically has only one single required parameter that is also the most specific parameter, it
* is provided to the {@link #build(String) build-method}. Therefore {@link ProcessBuilder} does not implement
* {@link io.github.mmm.base.lang.Builder} and does not follow the default builder-pattern providing a non-arg
* {@link io.github.mmm.base.lang.Builder#build() build()} method.
* For a specific {@link Property} type the builder should carry the same name with the suffix {@code Builder}. Example:
* {@link io.github.mmm.property.booleans.BooleanProperty} is build by
* {@link io.github.mmm.property.builder.lang.BooleanPropertyBuilder}.
*
* @param type of the {@link Property#get() property value}.
* @param type of the {@link Property} to build.
* @param type of the {@link ObjectValidatorBuilder validator builder} for {@link #withValidator()}.
* @param type of this {@link PropertyBuilder} itself.
*
* @since 1.0.0
*/
public abstract class PropertyBuilder, B extends ObjectValidatorBuilder, ?>, SELF extends PropertyBuilder> {
/** @see #getLock() */
protected final AttributeReadOnly lock;
private Consumer registry;
private Function factory;
private B validatorBuilder;
/** @see #valueExpression(Supplier) */
protected Supplier expression;
/** @see #value(Object) */
protected V value;
private Map metadataMap;
/**
* The constructor.
*
* @param lock the {@link #getLock() lock}.
*/
public PropertyBuilder(AttributeReadOnly lock) {
super();
this.lock = lock;
}
/**
* @return this object itself ({@code this}) for fluent API calls.
*/
@SuppressWarnings("unchecked")
protected SELF self() {
return (SELF) this;
}
/**
* @return the {@link PropertyMetadata#getLock() lock}.
*/
public AttributeReadOnly getLock() {
return this.lock;
}
/**
* @param consumer the {@link Consumer} {@link Consumer#accept(Object) receiving} the {@link Property} when
* {@link #build(String) build}.
* @return this builder itself ({@code this}) for fluent API calls.
*/
public SELF registry(Consumer consumer) {
if (this.registry != null) {
throw new IllegalStateException("Registry consumer already set!");
}
this.registry = consumer;
return self();
}
/**
* @param function the {@link Function} optionally {@link Function#apply(Object) providing} the {@link Property} to
* {@link #build(String) build}. If it returns a result other than {@code null} this will be used instead and
* the actual building is entirely replaced. This is a very specific feature provided for internal usage (to
* receive read-only view of already existing property).
* @return this builder itself ({@code this}) for fluent API calls.
*/
public SELF factory(Function function) {
if (this.factory != null) {
throw new IllegalStateException("Factory function already set!");
}
this.factory = function;
return self();
}
/**
* @param propertyValueExpression the {@link io.github.mmm.property.PropertyMetadata#getExpression() property value
* expression}.
* @return this builder itself ({@code this}) for fluent API calls.
*/
public SELF valueExpression(Supplier propertyValueExpression) {
this.expression = propertyValueExpression;
return self();
}
/**
* @param initialValue the {@link Property#get() initial value} of the {@link Property} to build.
* @return this builder itself ({@code this}) for fluent API calls.
*/
public SELF value(V initialValue) {
this.value = initialValue;
return self();
}
/**
* @param metaKey the {@link io.github.mmm.base.metainfo.MetaInfo#get(String) meta-info key}.
* @param metaValue the {@link io.github.mmm.base.metainfo.MetaInfo#get(String) meta-info value}.
* @return this builder itself ({@code this}) for fluent API calls.
*/
public SELF metaInfo(String metaKey, String metaValue) {
if (this.metadataMap == null) {
this.metadataMap = new HashMap<>();
}
this.metadataMap.put(metaKey, metaValue);
return self();
}
/**
* @return the {@link ObjectValidatorBuilder} corresponding to this type of builder.
*/
protected abstract B createValidatorBuilder();
/**
* @return a sub-builder for the {@link PropertyMetadata#getValidator() validator} of the {@link Property} to build.
* Use the {@link ObjectValidatorBuilder#and() and()} method to return from the sub-builder to this property
* builder when the validator is configured.
*/
public B withValidator() {
if (this.validatorBuilder == null) {
this.validatorBuilder = createValidatorBuilder();
}
return this.validatorBuilder;
}
/**
* @param name the {@link Property#getName() property name} of the {@link Property} to build.
* @return the {@link Property} to build.
*/
public final P build(String name) {
return build(name, false);
}
/**
* @param name the {@link Property#getName() property name} of the {@link Property} to build.
* @param ignoreExtensions - {@code true} to ignore a potential {@link #registry(Consumer)} and
* {@link #factory(Function)}, {@code false} otherwise.
* @return the {@link Property} to build.
*/
protected final P build(String name, boolean ignoreExtensions) {
P property = null;
if ((this.factory != null) && !ignoreExtensions) {
property = this.factory.apply(name);
}
if (property == null) {
property = build(name, newMetadata());
if (this.value != null) {
property.set(this.value);
}
}
if ((this.registry != null) && !ignoreExtensions) {
this.registry.accept(property);
}
return property;
}
private PropertyMetadata newMetadata() {
Validator validator = null;
if (this.validatorBuilder != null) {
validator = this.validatorBuilder.build();
}
return PropertyMetadata.of(this.lock, validator, null, MetaInfo.empty().with(this.metadataMap));
}
/**
* @param name the {@link Property#getName() property name} of the {@link Property} to build.
* @param newMetadata the {@link PropertyMetadata}.
* @return the {@link Property} to {@link #build(String) build}.
*/
protected abstract P build(String name, PropertyMetadata newMetadata);
/**
* @return a {@link ListPropertyBuilder} using {@link #build(String) this property configuration} for its elements.
*/
public ListPropertyBuilder asList() {
return builder(new ListPropertyBuilder<>(this.lock, build("ListItem", true)));
}
/**
* @return a {@link SetPropertyBuilder} using {@link #build(String) this property configuration} for its elements.
*/
public SetPropertyBuilder asSet() {
return builder(new SetPropertyBuilder<>(this.lock, build("SetItem", true)));
}
/**
* @return a {@link MapPropertyBuilder} using {@link #build(String) this property configuration} for its values and
* {@link String} as keys.
*/
public MapPropertyBuilder asMap() {
return builder(new MapPropertyBuilder<>(this.lock, build("MapItem", true)));
}
/**
* @param type of the {@link PropertyBuilder}.
* @param builder the {@link PropertyBuilder}.
* @return the configured {@code builder}.
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
protected > T builder(T builder) {
if (this.registry != null) {
builder.registry((Consumer) this.registry);
}
if (this.factory != null) {
builder.factory((Function) this.factory);
}
return builder;
}
/**
* @param type of the {@link Map#containsKey(Object) keys}.
* @param keyProperty the {@link io.github.mmm.property.container.map.MapProperty#getKeyProperty() key property}.
* @return a {@link MapPropertyBuilder} using {@link #build(String) this property configuration} for its values and
* {@link String} as keys.
*/
public MapPropertyBuilder asMap(SimpleProperty keyProperty) {
return new MapPropertyBuilder<>(this.lock, keyProperty, build("Value"));
}
}