How to display image in grails GSP?

Question

I'm still learning Grails and seem to have hit a stumbling block.

Here are the 2 domain classes:

class Photo {
    byte[] file 

    static belongsTo = Profile
}


class Profile {
    String fullName
    Set photos

    static hasMany = [photos:Photo]     
}

The relevant controller snippet:

class PhotoController {

    def viewImage = {

      def photo = Photo.get( params.id )
      byte[] image = photo.file 
      response.outputStream << image

    } 
} 

Finally the GSP snippet:

<img class="Photo" src="${createLink(controller:'photo', action:'viewImage', id:'profileInstance.photos.get(1).id')}" />

Now how do I access the photo so that it will be shown on the GSP? I'm pretty sure that profileInstance.photos.get(1).id is not correct.

Answer 1

If you have a url for the image, you just have to make sure you return the appropriate anser in the controller:

  def viewImage= {
    //retrieve photo code here
    response.setHeader("Content-disposition", "attachment; filename=${photo.name}")
    response.contentType = photo.fileType //'image/jpeg' will do too
    response.outputStream << photo.file //'myphoto.jpg' will do too
    response.outputStream.flush()
    return;
  }

Answer 2

As it is a Set, if you want the first element, you will have to go:

profileInstance.photos.toArray()[0].id

or

profileInstance.photos.iterator().next()

Answer 3

now, i actually think storing the photo as a binary blob in the database isnt the best solution - though you might have reasons why it needs to be done that way.

how about storing the name of the photo (and/or the path) instead? If name clashing issues are probable, use the md5 checksum of the photo as the name. Then the photo becomes a static resource, a simple file, instead of a more complicated and slower MVC request.