Java tutorial
/** * 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 org.brixcms.markup.transform; import org.apache.wicket.Application; import org.apache.wicket.Component; import org.apache.wicket.markup.parser.filter.EnclosureHandler; import org.brixcms.markup.MarkupHelper; import org.brixcms.markup.MarkupSource; import org.brixcms.markup.tag.ComponentTag; import org.brixcms.markup.tag.Item; import org.brixcms.markup.tag.Tag; import org.brixcms.plugin.site.page.AbstractContainer; import org.brixcms.plugin.site.page.tile.TileTag; import java.util.ArrayList; import java.util.List; import java.util.Map; /** * Enables the use of wicket:enclosures with brix:tile tags. * <p/> * It will resolve the enclosure child elements based on either "brix:tile id" or wicket:id attributes. You can * reference wicket components within the tile using the 'child' attribute and a comma separated path. * <p/> * e.g. where the tile has the wicket component title as a child of wrapper <wicket:enclosure * child="mytile,wrapper,title"> <brix:tile id="mytile" /> </wicket:enclosure> * <p/> * TODO: - investigate if it is possible to have commas in brix:tile id or wicket:id as this would break id matching - * investigate if this works with wicket auto-tags * * @author James McIntosh */ public class EnclosureMarkupSourceTransformer extends MarkupSourceTransformer { public EnclosureMarkupSourceTransformer(MarkupSource delegate) { super(delegate); } private String getEnclosureTag() { return Application.get().getMapperContext().getNamespace() + ":enclosure"; } private String getIdAttribute() { return Application.get().getMapperContext().getNamespace() + ":id"; } @Override protected List<Item> transform(List<Item> items) { Tag enclosure = null; List<String> children = null; List<Tag> enclosureChildTags = null; for (Item i : items) { if (i instanceof Tag) { Tag tag = (Tag) i; if (isEnclosure(tag)) { if (tag.getType() == Tag.Type.OPEN) { // found opening enclosure enclosure = tag; children = getChildren(enclosure); enclosureChildTags = new ArrayList<Tag>(); } else if (tag.getType() == Tag.Type.CLOSE) { // tidy up on close tag updateEnclosureChildId(enclosure, children, enclosureChildTags); enclosure = null; children = null; enclosureChildTags = null; } } else if (enclosure != null && !children.isEmpty()) { // if we have open enclosure tag and children to find int index = checkIfTagIsChild(tag, children, enclosureChildTags); if (index != -1) { onChildFound(tag, children, enclosureChildTags, index); } } } } return items; } private boolean isEnclosure(Tag tag) { return getEnclosureTag().equals(tag.getName()); } /** * Gets the value of the "child" attribute and splits the path into a list * * @param enclosure * @return ids */ private List<String> getChildren(Tag enclosure) { Map<String, String> attributes = enclosure.getAttributeMap(); if (attributes != null) { if (attributes.containsKey(EnclosureHandler.CHILD_ATTRIBUTE)) { // split for nested components String[] children = attributes.get(EnclosureHandler.CHILD_ATTRIBUTE) .split("" + Component.PATH_SEPARATOR); ArrayList<String> list = new ArrayList<String>(); for (String child : children) { list.add(child); } return list; } } return null; } /** * Replaces the supplied enclosure child tag with the actual resolved comma separated component path * * @param enclosure * @param children * @param enclosureChildTags */ private void updateEnclosureChildId(Tag enclosure, List<String> children, List<Tag> enclosureChildTags) { Map<String, String> attributes = enclosure.getAttributeMap(); if (attributes != null) { String child = ""; for (int i = 0; i < children.size(); i++) { String childid = children.get(i); if (childid != null) { child += (child.length() > 0 ? Component.PATH_SEPARATOR : "") + childid; } else { Tag tag = enclosureChildTags.get(i); String id = getGeneratedTagId(tag); if (id != null) { // nested children are delimited by commas child += (child.length() > 0 ? Component.PATH_SEPARATOR : "") + id; } } } attributes.put(EnclosureHandler.CHILD_ATTRIBUTE, child); } } /** * Resolved the actual generated component wicket:id for the tag * * @param tag * @return */ private String getGeneratedTagId(Tag tag) { if (tag instanceof ComponentTag) { return MarkupHelper.getComponentID((ComponentTag) tag); } return null; } /** * Inspects the current tag and determine if it is one of the required child components for the enclosure * * @param tag * @param children * @param enclosureChildTags * @return */ private int checkIfTagIsChild(Tag tag, List<String> children, List<Tag> enclosureChildTags) { String id = getTagId(tag); if (id != null) { for (String child : children) { if (child == null) { continue; } if (child.equals(id)) { return children.indexOf(child); } } } return -1; } /** * Checks for an id attribute if a brix:tile then a wicket:id * * @param tag * @return */ private String getTagId(Tag tag) { Map<String, String> attributes = tag.getAttributeMap(); String id = null; if (attributes != null) { // look for brix:tile first "id" first then "wicket:id" if (tag instanceof TileTag) { id = attributes.get(AbstractContainer.MARKUP_TILE_ID); } if (id == null) { id = attributes.get(getWicketIdAttributeName(tag)); } return id; } return null; } private String getWicketIdAttributeName(Tag tag) { // TODO: this reference possibly could be smarter by somehow using // ComponentTag.getId() // ComponentTag comments indicate that wicket:id is the default and that // this could // potentially be different in cases such as auto-tags return getIdAttribute(); } /** * Updates the list of remaining child components to find and the list of already found tags which represent them * * @param tag * @param children * @param enclosureChildTags * @param index */ private void onChildFound(Tag tag, List<String> children, List<Tag> enclosureChildTags, int index) { if (index != -1) { children.remove(index); children.add(index, null); enclosureChildTags.add(index, tag); } } }