Java tutorial
/** * Copyright (C) 2010 Orbeon, Inc. * * This program is free software; you can redistribute it and/or modify it under the terms of the * GNU Lesser General Public License as published by the Free Software Foundation; either version * 2.1 of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU Lesser General Public License for more details. * * The full text of the license is available at http://www.gnu.org/copyleft/lesser.html */ package org.orbeon.oxf.xforms.xbl; import org.apache.commons.lang3.StringUtils; import org.dom4j.*; import org.orbeon.oxf.util.XPathCache; import org.orbeon.oxf.xforms.XFormsConstants; import org.orbeon.oxf.xforms.analysis.controls.LHHA; import org.orbeon.oxf.xforms.event.EventHandlerImpl; import org.orbeon.oxf.xml.NamespaceMapping; import org.orbeon.oxf.xml.dom4j.Dom4jUtils; import org.orbeon.saxon.dom4j.DocumentWrapper; import org.orbeon.saxon.om.NodeInfo; import org.orbeon.saxon.om.VirtualNode; import java.util.ArrayList; import java.util.Collections; import java.util.List; import java.util.StringTokenizer; public class XBLTransformer { public static final QName XBL_ATTR_QNAME = new QName("attr", XFormsConstants.XBL_NAMESPACE); public static final QName XBL_CONTENT_QNAME = new QName("content", XFormsConstants.XBL_NAMESPACE); public static final QName XXBL_ATTR_QNAME = new QName("attr", XFormsConstants.XXBL_NAMESPACE); /** * Apply an XBL transformation, i.e. apply xbl:content, xbl:attr, etc. * * NOTE: This mutates shadowTreeDocument. */ public static Document transform(final Document shadowTreeDocument, final Element boundElement, final boolean excludeNestedHandlers, final boolean excludeNestedLHHA) { final DocumentWrapper documentWrapper = new DocumentWrapper(boundElement.getDocument(), null, XPathCache.getGlobalConfiguration()); Dom4jUtils.visitSubtree(shadowTreeDocument.getRootElement(), new Dom4jUtils.VisitorListener() { boolean isNestedHandler(Element e) { return e.getParent() == boundElement && EventHandlerImpl.isEventHandler(e); } boolean isNestedLHHA(Element e) { return e.getParent() == boundElement && LHHA.isLHHA(e); } boolean mustFilterOut(Element e) { return excludeNestedHandlers && isNestedHandler(e) || excludeNestedLHHA && isNestedLHHA(e); } public void startElement(Element element) { // Handle xbl:content final boolean isXBLContent = element.getQName().equals(XBL_CONTENT_QNAME); final List<Node> resultingNodes; if (isXBLContent) { final String includesAttribute = element.attributeValue(XFormsConstants.INCLUDES_QNAME); final String scopeAttribute = element.attributeValue(XFormsConstants.XXBL_SCOPE_QNAME); final List<Node> contentToInsert; if (includesAttribute == null) { // All bound node content must be copied over (except nested handlers if requested) final List<Node> elementContent = Dom4jUtils.content(boundElement); final List<Node> clonedContent = new ArrayList<Node>(); for (final Node node : elementContent) { if (node instanceof Element) { final Element currentElement = (Element) node; if (!mustFilterOut(currentElement)) clonedContent.add(Dom4jUtils.copyElementCopyParentNamespaces(currentElement)); } else if (!(node instanceof Namespace)) { clonedContent.add(Dom4jUtils.createCopy(node)); } } contentToInsert = clonedContent; } else { // Apply CSS selector // Convert CSS to XPath final String xpathExpression = CSSParser.toXPath(includesAttribute); final NodeInfo boundElementInfo = documentWrapper.wrap(boundElement); // TODO: don't use getNamespaceContext() as this is already computed for the bound element final List<Object> elements = XPathCache.evaluate(boundElementInfo, xpathExpression, new NamespaceMapping(Dom4jUtils.getNamespaceContext(element)), null, null, null, null, null, null);// TODO: locationData if (elements.size() > 0) { // Clone all the resulting elements contentToInsert = new ArrayList<Node>(elements.size()); for (Object o : elements) { final NodeInfo currentNodeInfo = (NodeInfo) o; final Element currentElement = (Element) ((VirtualNode) currentNodeInfo) .getUnderlyingNode(); if (!mustFilterOut(currentElement)) contentToInsert.add(Dom4jUtils.copyElementCopyParentNamespaces(currentElement)); } } else { // Clone all the element's children if any // See: http://www.w3.org/TR/xbl/#the-content contentToInsert = new ArrayList<Node>(element.nodeCount()); for (Object o : element.elements()) { final Element currentElement = (Element) o; if (!mustFilterOut(currentElement)) contentToInsert.add(Dom4jUtils.copyElementCopyParentNamespaces(currentElement)); } } } // Insert content if any if (contentToInsert != null && contentToInsert.size() > 0) { final List<Node> parentContent = Dom4jUtils.content(element.getParent()); final int elementIndex = parentContent.indexOf(element); parentContent.addAll(elementIndex, contentToInsert); } // Remove <xbl:content> from shadow tree element.detach(); resultingNodes = contentToInsert; if (!StringUtils.isBlank(scopeAttribute)) { // If author specified scope attribute, use it setAttribute(resultingNodes, XFormsConstants.XXBL_SCOPE_QNAME, scopeAttribute, null); } else { // By default, set xxbl:scope="outer" on resulting elements setAttribute(resultingNodes, XFormsConstants.XXBL_SCOPE_QNAME, "outer", null); } } else { // Element is simply kept resultingNodes = Collections.singletonList((Node) element); } // Handle attribute forwarding final Attribute xblAttr = element.attribute(XBL_ATTR_QNAME); // standard xbl:attr (custom syntax) final Attribute xxblAttr = element.attribute(XXBL_ATTR_QNAME); // extension xxbl:attr (XPath expression) if (xblAttr != null) { // Detach attribute (not strictly necessary?) xblAttr.detach(); // Get attribute value final String xblAttrString = xblAttr.getValue(); final StringTokenizer st = new StringTokenizer(xblAttrString); while (st.hasMoreTokens()) { final String currentValue = st.nextToken(); final int equalIndex = currentValue.indexOf('='); if (equalIndex == -1) { // No a=b pair, just a single QName final QName valueQName = Dom4jUtils.extractTextValueQName(element, currentValue, true); if (!valueQName.getNamespaceURI().equals(XFormsConstants.XBL_NAMESPACE_URI)) { // This is not xbl:text, copy the attribute setAttribute(resultingNodes, valueQName, boundElement.attributeValue(valueQName), boundElement); } else { // This is xbl:text // "The xbl:text value cannot occur by itself in the list" } } else { // a=b pair final QName leftSideQName; { final String leftSide = currentValue.substring(0, equalIndex); leftSideQName = Dom4jUtils.extractTextValueQName(element, leftSide, true); } final QName rightSideQName; { final String rightSide = currentValue.substring(equalIndex + 1); rightSideQName = Dom4jUtils.extractTextValueQName(element, rightSide, true); } final boolean isLeftSideXBLText = leftSideQName.getNamespaceURI() .equals(XFormsConstants.XBL_NAMESPACE_URI); final boolean isRightSideXBLText = rightSideQName.getNamespaceURI() .equals(XFormsConstants.XBL_NAMESPACE_URI); final String rightSideValue; final Element namespaceElement; if (!isRightSideXBLText) { // Get attribute value rightSideValue = boundElement.attributeValue(rightSideQName); namespaceElement = boundElement; } else { // Get text value // "any text nodes (including CDATA nodes and whitespace text nodes) that are // explicit children of the bound element must have their data concatenated" rightSideValue = boundElement.getText();// must use getText() and not stringValue() namespaceElement = null; } if (rightSideValue != null) { // NOTE: XBL doesn't seem to says what should happen if the source attribute is not // found! We assume the rule is ignored in this case. if (!isLeftSideXBLText) { // Set attribute value setAttribute(resultingNodes, leftSideQName, rightSideValue, namespaceElement); } else { // Set text value // "value of the attribute on the right-hand side are to be represented as text // nodes underneath the shadow element" // TODO: "If the element has any child nodes in the DOM (any nodes, including // comment nodes, whitespace text nodes, or even empty CDATA nodes) then the pair // is in error and UAs must ignore it, meaning the attribute value is not forwarded" setText(resultingNodes, rightSideValue); } } } // TODO: handle xbl:lang? // TODO: handle type specifiers? } } else if (xxblAttr != null) { // Detach attribute (not strictly necessary?) xxblAttr.detach(); // Get attribute value final String xxblAttrString = xxblAttr.getValue(); final NodeInfo boundElementInfo = documentWrapper.wrap(boundElement); // TODO: don't use getNamespaceContext() as this is already computed for the bound element final List<Object> nodeInfos = XPathCache.evaluate(boundElementInfo, xxblAttrString, new NamespaceMapping(Dom4jUtils.getNamespaceContext(element)), null, null, null, null, null, null);// TODO: locationData if (nodeInfos.size() > 0) { for (Object nodeInfo : nodeInfos) { final NodeInfo currentNodeInfo = (NodeInfo) nodeInfo; if (currentNodeInfo.getNodeKind() == org.w3c.dom.Node.ATTRIBUTE_NODE) { // This is an attribute final Attribute currentAttribute = (Attribute) ((VirtualNode) currentNodeInfo) .getUnderlyingNode(); setAttribute(resultingNodes, currentAttribute.getQName(), currentAttribute.getValue(), currentAttribute.getParent()); } } } } // Prefix resulting xhtml:*/(@id |@for) // NOTE: We could also do the prefixing in the handlers, when the page is output. // // * Benefit of prefixing here: done statically // * Drawback of prefixing here: in the future if we try to reuse simple shadow trees this won't work // { // if (resultingNodes != null && resultingNodes.size() > 0) { // for (Iterator i = resultingNodes.iterator(); i.hasNext();) { // final Node node = (Node) i.next(); // if (node instanceof Element) { // Dom4jUtils.visitSubtree((Element) node, new Dom4jUtils.VisitorListener() { // public void startElement(Element element) { // if (XMLConstants.XHTML_NAMESPACE_URI.equals(element.getNamespaceURI())) { // // Found XHTML element // // // Update @id and @for if any // final Attribute idAttribute = element.attribute("id"); // if (idAttribute != null) { // idAttribute.setValue(prefix + idAttribute.getValue()); // } // final Attribute forAttribute = element.attribute("for"); // if (forAttribute != null) { // forAttribute.setValue(prefix + forAttribute.getValue()); // } // } // } // // public void endElement(Element element) { // } // // public void text(Text text) { // } // }); // } // } // } // } } private void setAttribute(List<Node> nodes, QName attributeQName, String attributeValue, Element namespaceElement) { if (nodes != null && nodes.size() > 0) { for (final Node node : nodes) { if (node instanceof Element) { final Element element = ((Element) node); // Copy missing namespaces, so that copying things like ref="foo:bar" work as expected Dom4jUtils.copyMissingNamespaces(namespaceElement, element); element.addAttribute(attributeQName, attributeValue); } } } } private void setText(List<Node> nodes, String value) { if (nodes != null && nodes.size() > 0) { for (final Node node : nodes) { if (node instanceof Element) { node.setText(value); } } } } public void endElement(Element element) { } public void text(Text text) { } }, true); return shadowTreeDocument; } }