Creating image thumbnails through Grails ImageTools plugin

23 / Mar / 2010 by Abhishek Tejpaul 0 comments

In one of the projects recently, we had to generate the thumbnails dynamically from the client-provided images. We decided to use the Grails plugin named: ImageTools. This is a very basic plugin but provided very quick and stable solution to our use-case. You can read more about the plugin and how to install it here .

We decided to implement the solution in the form of a tag which gave us the ease to use it directly in a .gsp file. Here is how the code looked like in a taglib:

import org.grails.plugins.imagetools.ImageTool  // Import the ImageTool class in your taglib.

def thumbnail = { attrs ->;
def imgSrc = attrs['imgSrc']  // as the name suggests - the image source
def dimension = attrs['dimension'].toInteger()  //size of the image - giving 200 as a dimension gives you the thumbnail of around 200*200 in size.
def imageTool = new ImageTool()
imageTool.load(imgSrc)
imageTool.square()
imageTool.thumbnail(dimension)
imageTool.writeResult(thumbnailLocation,"JPEG")  //thumbnailLocation - provides the path to where you want to store the thumbnail image.
out << thumbnailLocation
}

This is all you need to create the thumbnail programatically through ImageTools plugin. The code above always creates the new thumbnail; we tried to improvise the above solution by saving the thumbnail in a folder and checking for the existence of the thumbnail before actually creating the thumbnail. This is how we achieved it:

def thumbnail = {attrs ->;
def imgSrc = attrs['imgSrc']
def dimension = attrs['dimension'].toInteger()
def thumbLocation = "/path/to/store/thumbnails"  + imgSrc
def file

// if thumbnail already exists, return the path to the image
if((file =  new File(thumbLocation)).exists()){
out << thumbLocation
}
else{
// the code to generate the thumbnail comes here.
}
}

Hope this helps.

— Abhishek

Intelligrape Software

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