Render image dynamically in CQ

[askdctm]

Hi All,

In post http://cq5cms.blogspot.in/2014/07/renders-image-dynamically-in-cq5.html, the below mentioned code is written.

Is it something like

- This code will automatically create renditions of images, when they are uploaded in DAM.

- Also, renditions can also be created by running custom workflows on DAM images? Any references to this would be helpful.

Any thoughts on this will be helpful.

import java.awt.Dimension;
import java.io.IOException;

import javax.jcr.Node;
import javax.jcr.PathNotFoundException;
import javax.jcr.Property;
import javax.jcr.RepositoryException;
import javax.jcr.Session;
import javax.servlet.ServletException;

import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Service;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.servlets.SlingSafeMethodsServlet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.day.cq.commons.ImageHelper;
import com.day.image.Layer;

/**
 * Renders the image dynamically
 * Usage: /content/geometrixx/en/products/circle.thumbnail.500.500.jpg
 */
@Component
@Service
@org.apache.felix.scr.annotations.Properties({
      @org.apache.felix.scr.annotations.Property(name="sling.servlet.resourceTypes", value="sling/servlet/default"),
      @org.apache.felix.scr.annotations.Property(name="sling.servlet.selectors", value={"resize","thumb","thumbnail"}),
      @org.apache.felix.scr.annotations.Property(name="sling.servlet.extensions", value={"jpg", "png", "gif"}),
      @org.apache.felix.scr.annotations.Property(name="sling.servlet.methods", value="GET")
})
public class CustomThumbnailServlet extends SlingSafeMethodsServlet {

 private static final long serialVersionUID = 1L;
 private final Logger log = LoggerFactory.getLogger(this.getClass());

 private final String ORIGINAL_PATH = "/jcr:content/renditions/original/jcr:content";
 private static final Dimension DEFAULT_DIMENSION = new Dimension(100, 100);
 
 @Override
 protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException{
try { 
  String[] selectors = request.getRequestPathInfo().getSelectors();
  String extension = request.getRequestPathInfo().getExtension();
  String imagePath = request.getRequestPathInfo().getResourcePath().substring(0, request.getRequestPathInfo().getResourcePath().indexOf("."));
  int maxHeight = selectors.length > 1 ? Integer.valueOf(selectors[1]).intValue() : (int)DEFAULT_DIMENSION.getHeight();
  int maxWidth = selectors.length > 2 ? Integer.valueOf(selectors[2]).intValue() : (int)DEFAULT_DIMENSION.getWidth();    
  boolean margin = (selectors.length > 3) && (selectors[3].equals("margin"));
 
  Session session = (Session)request.getResourceResolver().adaptTo(Session.class);
  Node imageNode = session.getNode(imagePath+"."+extension+ORIGINAL_PATH);
 
  Property data = imageNode.getProperty("jcr:data");
      Layer imageLayer = ImageHelper.createLayer(imageNode.getSession(), imageNode.getPath());
  imageLayer.resize(maxWidth, maxHeight);
 
  response.setContentLength((int)data.getLength());
  response.setContentType(imageLayer.getMimeType());
  imageLayer.write(imageLayer.getMimeType(), imageLayer.getMimeType().equals("image/gif") ? 255 : 1.0, response.getOutputStream());
 
} catch (PathNotFoundException e) {
e.printStackTrace();
} catch (RepositoryException e) {
e.printStackTrace();
}  
  }
}

[smacdonald2008]

All they are doing in this servlet is using the com.day.image.Layer API to manipulate images that are uploaded.

https://docs.adobe.com/docs/en/cq/5-6-1/javadoc/com/day/image/package-summary.html

WIth AEM - you have access to APIs that can dynamically re size and manipulate images, logos, etc, 

See this topic for more information about using these APIs:

http://docs.adobe.com/docs/en/aem/6-0/develop/the-basics/website.html#Creating the Logo Component

[Opkar_Gill · Accepted solution]

Details on running custom DAM workflows can be found here:https://docs.adobe.com/docs/en/aem/6-0/develop/extending/assets/media-handlers.html

For creating different renditions when uploading an asset, the following pages provide simple use cases:

http://www.albinsblog.com/2015/04/how-to-create-different-image-renditions-in-adobecq5.html#.VXCkZFx...

http://blogs.adobe.com/contentmanagement/tag/dam-update-asset/ 

[askdctm]

Hi All,

Thanks a lot for your reply.