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/*
* Copyright 2000-2014 Vaadin Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.vaadin.ui.declarative;
import java.beans.IntrospectionException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.lang.annotation.Annotation;
import java.util.Collection;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Document.OutputSettings.Syntax;
import org.jsoup.nodes.DocumentType;
import org.jsoup.nodes.Element;
import org.jsoup.nodes.Node;
import org.jsoup.parser.Parser;
import org.jsoup.select.Elements;
import com.vaadin.annotations.DesignRoot;
import com.vaadin.ui.Component;
import com.vaadin.ui.declarative.DesignContext.ComponentCreatedEvent;
import com.vaadin.ui.declarative.DesignContext.ComponentCreationListener;
/**
* Design is used for reading a component hierarchy from an html string or input
* stream and, conversely, for writing an html representation corresponding to a
* given component hierarchy.
*
* <p>
* In html form a valid nonempty component hierarchy contains a single root
* element located under the <body> tag. A hierarchy of components is
* achieved by nesting other elements under the root element. An empty component
* hierarchy is represented as no elements under the <body> tag.
*
* <p>
* For writing a component hierarchy the root element is specified as a
* Component parameter or as a DesignContext object containing the root
* Component. An empty hierarchy can be written by giving a null root Component.
*
* @since 7.4
* @author Vaadin Ltd
*/
public class Design implements Serializable {
/**
* Callback for creating instances of a given component class when reading
* designs. The default implementation, {@link DefaultComponentFactory} will
* use <code>Class.forName(className).newInstance()</code>, which might not
* be suitable e.g. in an OSGi environment or if the Component instances
* should be created as managed CDI beans.
* <p>
* Use {@link Design#setComponentFactory(ComponentFactory)} to configure
* Vaadin to use a custom component factory.
*
*
* @since 7.4.1
*/
public interface ComponentFactory extends Serializable {
/**
* Creates a component based on the fully qualified name derived from
* the tag name in the design.
*
* @param fullyQualifiedClassName
* the fully qualified name of the component to create
* @param context
* the design context for which the component is created
*
* @return a newly created component
*/
public Component createComponent(String fullyQualifiedClassName,
DesignContext context);
}
/**
* Default implementation of {@link ComponentFactory}, using
* <code>Class.forName(className).newInstance()</code> for finding the
* component class and creating a component instance.
*
* @since 7.4.1
*/
public static class DefaultComponentFactory implements ComponentFactory {
@Override
public Component createComponent(String fullyQualifiedClassName,
DesignContext context) {
Class<? extends Component> componentClass = resolveComponentClass(
fullyQualifiedClassName, context);
assert Component.class.isAssignableFrom(componentClass) : "resolveComponentClass returned "
+ componentClass + " which is not a Vaadin Component class";
try {
return componentClass.newInstance();
} catch (Exception e) {
throw new DesignException("Could not create component "
+ fullyQualifiedClassName, e);
}
}
/**
* Resolves a component class based on the fully qualified name of the
* class.
*
* @param qualifiedClassName
* the fully qualified name of the resolved class
* @param context
* the design context for which the class is resolved
* @return a component class object representing the provided class name
*/
protected Class<? extends Component> resolveComponentClass(
String qualifiedClassName, DesignContext context) {
try {
Class<?> componentClass = Class.forName(qualifiedClassName);
return componentClass.asSubclass(Component.class);
} catch (ClassNotFoundException e) {
throw new DesignException(
"Unable to load component for design", e);
}
}
}
private static volatile ComponentFactory componentFactory = new DefaultComponentFactory();
/**
* Sets the component factory that is used for creating component instances
* based on fully qualified class names derived from a design file.
* <p>
* Please note that this setting is global, so care should be taken to avoid
* conflicting changes.
*
* @param componentFactory
* the component factory to set; not <code>null</code>
*
* @since 7.4.1
*/
public static void setComponentFactory(ComponentFactory componentFactory) {
if (componentFactory == null) {
throw new IllegalArgumentException(
"Cannot set null component factory");
}
Design.componentFactory = componentFactory;
}
/**
* Gets the currently used component factory.
*
* @see #setComponentFactory(ComponentFactory)
*
* @return the component factory
*
* @since 7.4.1
*/
public static ComponentFactory getComponentFactory() {
return componentFactory;
}
/**
* Parses the given input stream into a jsoup document
*
* @param html
* the stream containing the design
* @return the parsed jsoup document
* @throws IOException
*/
private static Document parse(InputStream html) {
try {
Document doc = Jsoup.parse(html, "UTF-8", "", Parser.htmlParser());
return doc;
} catch (IOException e) {
throw new DesignException("The html document cannot be parsed.");
}
}
/**
* Constructs a component hierarchy from the design specified as an html
* document. The hierarchy must contain at most one top-level component,
* which should be located under <body>. Also invalid html containing
* the hierarchy without <html>, <head> and <body> tags is
* accepted. You can optionally pass an instance for the root component with
* some uninitialized instance fields. The fields will be automatically
* populated when parsing the design based on the component ids, local ids,
* and captions of the components in the design.
*
* @param html
* the html document describing the component design
* @param rootInstance
* the root instance with fields to be mapped to components in
* the design
* @return the DesignContext created while traversing the tree. The
* top-level component of the created component hierarchy can be
* accessed using result.getRootComponent(), where result is the
* object returned by this method.
* @throws IOException
*/
private static DesignContext parse(InputStream html, Component rootInstance) {
Document doc = parse(html);
return designToComponentTree(doc, rootInstance);
}
/**
* Constructs a component hierarchy from the design specified as an html
* document given as a string. The hierarchy must contain at most one
* top-level component, which should be located under <body>. Also
* invalid html containing the hierarchy without <html>, <head>
* and <body> tags is accepted. You can optionally pass an instance
* for the root component with some uninitialized instance fields. The
* fields will be automatically populated when parsing the design based on
* the component ids, local ids, and captions of the components in the
* design.
*
* @param html
* the html document describing the component design
* @param rootInstance
* the root instance with fields to be mapped to components in
* the design
* @return the DesignContext created while traversing the tree. The
* top-level component of the created component hierarchy can be
* accessed using result.getRootComponent(), where result is the
* object returned by this method.
* @throws IOException
*/
private static DesignContext parse(String html, Component rootInstance) {
Document doc = Jsoup.parse(html);
return designToComponentTree(doc, rootInstance);
}
/**
* Constructs a component hierarchy from the design specified as an html
* tree.
*
* <p>
* If a component root is given, the component instances created during
* reading the design are assigned to its member fields based on their id,
* local id, and caption
*
* @param doc
* the html tree
* @param componentRoot
* optional component root instance. The type must match the type
* of the root element in the design. Any member fields whose
* type is assignable from {@link Component} are bound to fields
* in the design based on id/local id/caption
*/
private static DesignContext designToComponentTree(Document doc,
Component componentRoot) {
if (componentRoot == null) {
return designToComponentTree(doc, null, null);
} else {
return designToComponentTree(doc, componentRoot,
componentRoot.getClass());
}
}
/**
* Constructs a component hierarchy from the design specified as an html
* tree.
*
* <p>
* If a component root is given, the component instances created during
* reading the design are assigned to its member fields based on their id,
* local id, and caption
*
* @param doc
* the html tree
* @param componentRoot
* optional component root instance. The type must match the type
* of the root element in the design.
* @param classWithFields
* a class (componentRoot class or a super class) with some
* member fields. The member fields whose type is assignable from
* {@link Component} are bound to fields in the design based on
* id/local id/caption
*/
private static DesignContext designToComponentTree(Document doc,
Component componentRoot, Class<?> classWithFields) {
DesignContext designContext = new DesignContext(doc);
designContext.readPackageMappings(doc);
// No special handling for a document without a body element - should be
// taken care of by jsoup.
Element root = doc.body();
Elements children = root.children();
if (children.size() > 1) {
throw new DesignException(
"The first level of a component hierarchy should contain at most one root component, but found "
+ children.size() + ".");
}
Element element = children.size() == 0 ? null : children.first();
if (componentRoot != null) {
if (element == null) {
throw new DesignException(
"The root element cannot be null when the specified root Component is"
+ " not null.");
}
// user has specified root instance that may have member fields that
// should be bound
final FieldBinder binder;
try {
binder = new FieldBinder(componentRoot, classWithFields);
} catch (IntrospectionException e) {
throw new DesignException(
"Could not bind fields of the root component", e);
}
// create listener for component creations that binds the created
// components to the componentRoot instance fields
ComponentCreationListener creationListener = new ComponentCreationListener() {
@Override
public void componentCreated(ComponentCreatedEvent event) {
binder.bindField(event.getComponent(), event.getLocalId());
}
};
designContext.addComponentCreationListener(creationListener);
// create subtree
designContext.readDesign(element, componentRoot);
// make sure that all the member fields are bound
Collection<String> unboundFields = binder.getUnboundFields();
if (!unboundFields.isEmpty()) {
throw new DesignException(
"Found unbound fields from component root "
+ unboundFields);
}
// no need to listen anymore
designContext.removeComponentCreationListener(creationListener);
} else {
// createChild creates the entire component hierarchy
componentRoot = element == null ? null : designContext
.readDesign(element);
}
designContext.setRootComponent(componentRoot);
return designContext;
}
/**
* Generates an html tree representation of the component hierarchy having
* the root designContext.getRootComponent(). The hierarchy is stored under
* <body> in the tree. The generated tree represents a valid html
* document.
*
*
* @param designContext
* a DesignContext object specifying the root component
* (designContext.getRootComponent()) of the hierarchy
* @return an html tree representation of the component hierarchy
*/
private static Document createHtml(DesignContext designContext) {
// Create the html tree skeleton.
Document doc = new Document("");
DocumentType docType = new DocumentType("html", "", "", "");
doc.appendChild(docType);
Element html = doc.createElement("html");
doc.appendChild(html);
html.appendChild(doc.createElement("head"));
Element body = doc.createElement("body");
html.appendChild(body);
// Append the design under <body> in the html tree. createNode
// creates the entire component hierarchy rooted at the
// given root node.
Component root = designContext.getRootComponent();
if (root != null) {
Node rootNode = designContext.createElement(root);
body.appendChild(rootNode);
}
designContext.writePackageMappings(doc);
return doc;
}
/**
* Loads a design for the given root component.
* <p>
* This methods assumes that the component class (or a super class) has been
* marked with an {@link DesignRoot} annotation and will either use the
* value from the annotation to locate the design file, or will fall back to
* using a design with the same same as the annotated class file (with an
* .html extension)
* <p>
* Any {@link Component} type fields in the root component which are not
* assigned (i.e. are null) are mapped to corresponding components in the
* design. Matching is done based on field name in the component class and
* id/local id/caption in the design file.
* <p>
* The type of the root component must match the root element in the design
*
* @param rootComponent
* The root component of the layout
* @return The design context used in the load operation
* @throws DesignException
* If the design could not be loaded
*/
public static DesignContext read(Component rootComponent)
throws DesignException {
// Try to find an @DesignRoot annotation on the class or any parent
// class
Class<? extends Component> annotatedClass = findClassWithAnnotation(
rootComponent.getClass(), DesignRoot.class);
if (annotatedClass == null) {
throw new IllegalArgumentException(
"The class "
+ rootComponent.getClass().getName()
+ " or any of its superclasses do not have an @DesignRoot annotation");
}
DesignRoot designAnnotation = annotatedClass
.getAnnotation(DesignRoot.class);
String filename = designAnnotation.value();
if (filename.equals("")) {
// No value, assume the html file is named as the class
filename = annotatedClass.getSimpleName() + ".html";
}
InputStream stream = annotatedClass.getResourceAsStream(filename);
if (stream == null) {
throw new DesignException("Unable to find design file " + filename
+ " in " + annotatedClass.getPackage().getName());
}
Document doc = parse(stream);
DesignContext context = designToComponentTree(doc, rootComponent,
annotatedClass);
return context;
}
/**
* Find the first class with the given annotation, starting the search from
* the given class and moving upwards in the class hierarchy.
*
* @param componentClass
* the class to check
* @param annotationClass
* the annotation to look for
* @return the first class with the given annotation or null if no class
* with the annotation was found
*/
private static Class<? extends Component> findClassWithAnnotation(
Class<? extends Component> componentClass,
Class<? extends Annotation> annotationClass) {
if (componentClass == null) {
return null;
}
if (componentClass.isAnnotationPresent(annotationClass)) {
return componentClass;
}
Class<?> superClass = componentClass.getSuperclass();
if (!Component.class.isAssignableFrom(superClass)) {
return null;
}
return findClassWithAnnotation((Class<? extends Component>) superClass,
annotationClass);
}
/**
* Loads a design from the given file name using the given root component.
* <p>
* Any {@link Component} type fields in the root component which are not
* assigned (i.e. are null) are mapped to corresponding components in the
* design. Matching is done based on field name in the component class and
* id/local id/caption in the design file.
* <p>
* The type of the root component must match the root element in the design.
*
* @param filename
* The file name to load. Loaded from the same package as the
* root component
* @param rootComponent
* The root component of the layout
* @return The design context used in the load operation
* @throws DesignException
* If the design could not be loaded
*/
public static DesignContext read(String filename, Component rootComponent)
throws DesignException {
InputStream stream = rootComponent.getClass().getResourceAsStream(
filename);
if (stream == null) {
throw new DesignException("File " + filename
+ " was not found in the package "
+ rootComponent.getClass().getPackage().getName());
}
return read(stream, rootComponent);
}
/**
* Loads a design from the given stream using the given root component. If
* rootComponent is null, the type of the root node is read from the design.
* <p>
* Any {@link Component} type fields in the root component which are not
* assigned (i.e. are null) are mapped to corresponding components in the
* design. Matching is done based on field name in the component class and
* id/local id/caption in the design file.
* <p>
* If rootComponent is not null, its type must match the type of the root
* element in the design
*
* @param stream
* The stream to read the design from
* @param rootComponent
* The root component of the layout
* @return The design context used in the load operation
* @throws DesignException
* If the design could not be loaded
*/
public static DesignContext read(InputStream design, Component rootComponent) {
if (design == null) {
throw new DesignException("Stream cannot be null");
}
Document doc = parse(design);
DesignContext context = designToComponentTree(doc, rootComponent);
return context;
}
/**
* Loads a design from the given input stream
*
* @param design
* The stream to read the design from
* @return The root component of the design
*/
public static Component read(InputStream design) {
DesignContext context = read(design, null);
return context.getRootComponent();
}
/**
* Writes the given component tree in design format to the given output
* stream.
*
* @param component
* the root component of the component tree, null can be used for
* generating an empty design
* @param outputStream
* the output stream to write the design to. The design is always
* written as UTF-8
* @throws IOException
*/
public static void write(Component component, OutputStream outputStream)
throws IOException {
DesignContext dc = new DesignContext();
dc.setRootComponent(component);
write(dc, outputStream);
}
/**
* Writes the component, given in the design context, in design format to
* the given output stream. The design context is used for writing local ids
* and other information not available in the component tree.
*
* @param designContext
* The DesignContext object specifying the component hierarchy
* and the local id values of the objects. If
* designContext.getRootComponent() is null, an empty design will
* be generated.
* @param outputStream
* the output stream to write the design to. The design is always
* written as UTF-8
* @throws IOException
* if writing fails
*/
public static void write(DesignContext designContext,
OutputStream outputStream) throws IOException {
Document doc = createHtml(designContext);
write(doc, outputStream);
}
/**
* Writes the given jsoup document to the output stream (in UTF-8)
*
* @param doc
* the document to write
* @param outputStream
* the stream to write to
* @throws IOException
* if writing fails
*/
private static void write(Document doc, OutputStream outputStream)
throws IOException {
doc.outputSettings().indentAmount(4);
doc.outputSettings().syntax(Syntax.html);
doc.outputSettings().prettyPrint(true);
outputStream.write(doc.html().getBytes());
}
}
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