Friday, March 17, 2017

Using SharePoint Picture Library thumbnail and web optimized images in other lists


The post previous to this showed how to expose the thumbnail and web optimized images hidden from most users in a SharePoint Picture Library.

You could then use these images however you wish, to provide thumbnail views, use those thumbnails on pages, use the web optimized images wherever you would have used the original larger image, etc...

What if we want to take this to the next level?  What if we want to include these images in other lists so that users can select them, and we automatically have the web optimized and thumbnail versions there as well? 

If you add an image field to a SharePoint list, end users are expected to know how to add an image to a separate list repository, copy the URL of that picture, and paste it into the correct fields:

This process is a bit tougher than simply changing text or selecting an image.  What if we could also simplify the way users update the image?

So our goals here are:

1. Simplify user image selection process.
2. Make available thumbnail and web versions.

An Example

If we have a list that is "company announcements", where, every week, an new announcement and image is added, and this information is displayed as web part on the front page of the site.  This is a very simple implementation of SharePoint functionality, but it does run into two main challenges:

1. End users find the copying and pasting of an image url into an image field a more complex and error prone task.
2. End users sometimes add huge images to SharePoint, not knowing how to optimize them.

Also, if you have a list with image fields, views on that list that expose the field can be awkward and difficult to manage.  Replacing the image fields with the thumbnail versions makes the views appear much more manageable:

If we can simplify the way users select existing images in a list, and expose web optimized and thumbnail versions of those images, we can improve the user experience and leverage the optimized images for our own purposes.


1. Create a picture library with the thumbnail and web optimized image paths exposed. This is described in the prior post.  For our purposes, the title field needs to be populated.  The simplest way to do this is make the title field mandatory, so that users adding the picture must add a title.  Or, you can create workflow that copies the picture name to the title whenever a new item is created.  Whichever works best for you.

2. Create a lookup field in your destination list to the picture library.  Include the thumbnail image URL and Web Image URL as returned fields as follows:

3. Create three new fields in your destination list.  They are Thumbnail (type picture), Web Optimized (type picture), and 'Prior Image Thumbnail Name' (type single line of text).

4. Open SharePoint designer and create a new workflow against your destination list. Set this workflow to run automatically whenever an item is created or changed.

5. Create two workflow variables, ThumbNailURL, and WebImageURL, both type string.

6. Create a condition on your workflow to only run if an image is added to the list:

7. Populate the local workflow variables with the lookup values extracted from the source list:

8.  Extract just the URL from the lookup values as they have additional text prepended to the front using the 'Extract Substring from Index of String' action:

9.  We only want to run this workflow if the picture has been updated.  So we test to see if the 'Prior Image Thumbnail Name' has been changed to detect this condition:

10.  Now we set both of the image type path values, and we set the thumbnail name for testing against as in step 9:

11.  The entire workflow should look like this:

Save and publish this workflow.  After ensuring the image exists in the picture library, add the picture using the title lookup on your destination list.  This workflow should autopopulate both the thumbnail and web optimized image fields for your usage.


You can now expose those images for your own usage from the list, such as thumbnails for views, or using in web parts on other pages.

In our company announcement example, we now have a simpler way for users to select an image once they have added it to the picture library (drop down instead of copying and pasting url), and we have the two additional image types generated.  The web optimized version would be used on the company announcement web part on the home page, rather than the image uploaded by the user.  This will not only make the page more efficient, but can take care of styling issues caused by importing huge images.

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