Parsys.java

/*
 * #%L
 * wcm.io
 * %%
 * Copyright (C) 2014 wcm.io
 * %%
 * 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.
 * #L%
 */
package io.wcm.wcm.parsys.controller;

import static io.wcm.wcm.parsys.ParsysNameConstants.PN_PARSYS_GENERATE_DEAFULT_CSS;
import static io.wcm.wcm.parsys.ParsysNameConstants.PN_PARSYS_NEWAREA_CSS;
import static io.wcm.wcm.parsys.ParsysNameConstants.PN_PARSYS_PARAGRAPH_CSS;
import static io.wcm.wcm.parsys.ParsysNameConstants.PN_PARSYS_PARAGRAPH_ELEMENT;
import static io.wcm.wcm.parsys.ParsysNameConstants.PN_PARSYS_WRAPPER_CSS;
import static io.wcm.wcm.parsys.ParsysNameConstants.PN_PARSYS_WRAPPER_ELEMENT;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import javax.annotation.PostConstruct;

import org.apache.commons.lang3.StringUtils;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.api.resource.ResourceResolver;
import org.apache.sling.api.resource.ValueMap;
import org.apache.sling.models.annotations.Model;
import org.apache.sling.models.annotations.injectorspecific.RequestAttribute;
import org.apache.sling.models.annotations.injectorspecific.SlingObject;
import org.osgi.annotation.versioning.ProviderType;

import com.day.cq.wcm.api.NameConstants;
import com.day.cq.wcm.api.WCMMode;
import com.day.cq.wcm.api.components.Component;
import com.day.cq.wcm.api.components.ComponentContext;
import com.day.cq.wcm.api.components.ComponentManager;
import com.google.common.collect.ImmutableMap;

import io.wcm.sling.commons.adapter.AdaptTo;
import io.wcm.sling.models.annotations.AemObject;

/**
 * Controller for paragraph system.
 * Unlike the AEM-builtin paragraph systems this parsys does not support column controls or iparsys inheritance,
 * but is only a simple paragraph system which allows full control about the markup generated for the child resources
 * and the new area.
 */
@Model(adaptables = SlingHttpServletRequest.class)
@ProviderType
public final class Parsys {

  static final String RA_PARSYS_PARENT_RESOURCE = "parsysParentResource";
  static final String SECTION_DEFAULT_CLASS_NAME = "section";
  static final String NEWAREA_RESOURCE_PATH = "./*";
  static final String NEWAREA_STYLE = "clear:both";
  static final String NEWAREA_CSS_CLASS_NAME = "new";
  static final String NEWAREA_CHILD_NAME = "newpar";
  static final String FALLBACK_NEWAREA_RESOURCE_TYPE = "wcm-io/wcm/parsys/components/parsys/newpar";
  static final String DEFAULT_ELEMENT_NAME = "div";

  /**
   * Allows to override the resource which children are iterated to display the parsys.
   */
  @RequestAttribute(name = RA_PARSYS_PARENT_RESOURCE, optional = true)
  private Resource parsysParentResource;

  @SlingObject
  private Resource currentResource;
  @SlingObject
  private ResourceResolver resolver;
  @AemObject
  private WCMMode wcmMode;
  @AemObject
  private ComponentContext componentContext;
  private ComponentManager componentManager;

  private boolean generateDefaultCss;
  private String paragraphCss;
  private String newAreaCss;
  private String paragraphElementName;
  private String wrapperElementName;
  private String wrapperCss;

  private List<Item> items;

  @PostConstruct
  private void activate() {
    // read customize properties from parsys component
    final ValueMap props = componentContext.getComponent().getProperties();
    generateDefaultCss = props.get(PN_PARSYS_GENERATE_DEAFULT_CSS, true);
    paragraphCss = props.get(PN_PARSYS_PARAGRAPH_CSS, String.class);
    newAreaCss = props.get(PN_PARSYS_NEWAREA_CSS, String.class);
    paragraphElementName = props.get(PN_PARSYS_PARAGRAPH_ELEMENT, String.class);
    wrapperElementName = props.get(PN_PARSYS_WRAPPER_ELEMENT, String.class);
    wrapperCss = props.get(PN_PARSYS_WRAPPER_CSS, String.class);

    // prepare paragraph items
    items = new ArrayList<>();
    if (parsysParentResource == null) {
      parsysParentResource = currentResource;
    }
    for (Resource childResource : parsysParentResource.getChildren()) {
      items.add(createResourceItem(childResource));
    }
    if (wcmMode != WCMMode.DISABLED) {
      items.add(createNewAreaItem());
    }
  }

  private Item createResourceItem(Resource resource) {
    CssBuilder css = new CssBuilder();
    if (generateDefaultCss) {
      css.add(SECTION_DEFAULT_CLASS_NAME);
    }
    css.add(paragraphCss);

    Map<String,String> htmlTagAttrs = getComponentHtmlTagAttributes(resource.getResourceType());

    // apply html tag attributes from component definition
    String itemElementName = paragraphElementName;
    if (StringUtils.isEmpty(itemElementName)) {
      itemElementName = StringUtils.defaultString(htmlTagAttrs.get(NameConstants.PN_TAG_NAME), DEFAULT_ELEMENT_NAME);
    }
    if (StringUtils.isEmpty(paragraphCss)) {
      css.add(htmlTagAttrs.get("class"));
    }

    return new Item(resource.getPath(), null, itemElementName, null, css.build(), false);
  }

  /**
   * Get HTML tag attributes from component.
   * @param resourceType Component path
   * @return Map (never null)
   */
  private Map<String, String> getComponentHtmlTagAttributes(String resourceType) {
    if (StringUtils.isNotEmpty(resourceType)) {
      Component component = componentManager().getComponent(resourceType);
      if (component != null && component.getHtmlTagAttributes() != null) {
        return component.getHtmlTagAttributes();
      }
    }
    return ImmutableMap.of();
  }

  private ComponentManager componentManager() {
    if (componentManager == null) {
      componentManager = AdaptTo.notNull(this.resolver, ComponentManager.class);
    }
    return componentManager;
  }

  private Item createNewAreaItem() {
    String style = null;
    CssBuilder css = new CssBuilder();
    css.add(NEWAREA_CSS_CLASS_NAME);
    if (generateDefaultCss) {
      style = NEWAREA_STYLE;
      css.add(SECTION_DEFAULT_CLASS_NAME);
    }
    css.add(newAreaCss);
    String newAreaElementName = StringUtils.defaultString(paragraphElementName, DEFAULT_ELEMENT_NAME);
    String newAreaResourceType = getNewAreaResourceType(componentContext.getComponent().getPath());
    return new Item(NEWAREA_RESOURCE_PATH, newAreaResourceType, newAreaElementName, style, css.build(), true);
  }

  /**
   * Get resource type for new area - from current parsys component or from a supertype component.
   * @param componentPath Component path
   * @return Resource type (never null)
   */
  private String getNewAreaResourceType(String componentPath) {
    Resource componentResource = resolver.getResource(componentPath);
    if (componentResource != null) {
      if (componentResource.getChild(NEWAREA_CHILD_NAME) != null) {
        return componentPath + "/" + NEWAREA_CHILD_NAME;
      }
      String resourceSuperType = componentResource.getResourceSuperType();
      if (StringUtils.isNotEmpty(resourceSuperType)) {
        return getNewAreaResourceType(resourceSuperType);
      }
    }
    return FALLBACK_NEWAREA_RESOURCE_TYPE;
  }

  /**
   * @return Paragraph system items
   */
  public List<Item> getItems() {
    return items;
  }

  /**
   * @return Element name for wrapper element
   */
  public String getWrapperElementName() {
    return StringUtils.defaultString(wrapperElementName, DEFAULT_ELEMENT_NAME);
  }

  /**
   * @return Wrapper element CSS
   */
  public String getWrapperCss() {
    return this.wrapperCss;
  }

  /**
   * @return True if the wrapper element should be rendered
   */
  public boolean isWrapperElement() {
    return StringUtils.isNotBlank(wrapperElementName);
  }


  /**
   * Paragraph system item.
   */
  public static final class Item {

    private final String resourcePath;
    private final String resourceType;
    private final String elementName;
    private final String style;
    private final String cssClassName;
    private final boolean newArea;

    Item(String resourcePath, String resourceType, String elementName, String style, String cssClassName, boolean newArea) {
      this.resourcePath = resourcePath;
      this.resourceType = resourceType;
      this.elementName = elementName;
      this.style = style;
      this.cssClassName = cssClassName;
      this.newArea = newArea;
    }

    /**
     * @return Resource path
     */
    public String getResourcePath() {
      return resourcePath;
    }

    /**
     * @return Resource type
     */
    public String getResourceType() {
      return resourceType;
    }

    /**
     * @return Name for item element
     */
    public String getElementName() {
      return elementName;
    }

    /**
     * @return Style string
     */
    public String getStyle() {
      return style;
    }

    /**
     * @return CSS classes
     */
    public String getCssClassName() {
      return cssClassName;
    }

    /**
     * @return true if this is the new area
     */
    public boolean isNewArea() {
      return newArea;
    }

  }

}