How to retrieve images associated with Asset Categories from custom code?

Issue

• When editing a category, it is possible to set images.
• However, when trying to get those images from my custom code, I am unable to do that. There are no related methods in AssetCategory objects.

Environment

• Liferay DXP 7.4

Resolution

• These images are handled by Liferay Commerce's modules instead of other modules related to the Asset Framework where Asset Categories belong to.
• That's why it is not as easy as access other categories' fields.
• In order to retrieve the images, you would have to use the Commerce API. For example, calling CPAttachmentFileEntryServiceUtil.getCPAttachmentFileEntries(). With this, you can call fetchFileEntry() on the CPAttachmentFileEntry objects to get the associated FileEntry.
• Find below a sample snippet (tested in 7.4 u 76):

  import com.liferay.account.constants.AccountConstants
  import com.liferay.asset.kernel.model.AssetCategory
  import com.liferay.commerce.media.CommerceMediaResolverUtil
  import com.liferay.commerce.product.model.CPAttachmentFileEntryConstants
  import com.liferay.commerce.product.service.CPAttachmentFileEntryServiceUtil
  import com.liferay.document.library.util.DLURLHelperUtil
  import com.liferay.portal.kernel.theme.ThemeDisplay
  import com.liferay.portal.kernel.util.PortalUtil
  import com.liferay.portal.kernel.workflow.WorkflowConstants
  
  def assetCategoryId = 000
  
  def themeDisplay = (ThemeDisplay)actionRequest.getAttribute(com.liferay.portal.kernel.util.WebKeys.THEME_DISPLAY)
  
  def cpAttachmentFileEntries = CPAttachmentFileEntryServiceUtil.getCPAttachmentFileEntries(
                                  PortalUtil.getClassNameId(AssetCategory.class), assetCategoryId, 
                                  CPAttachmentFileEntryConstants.TYPE_IMAGE, WorkflowConstants.STATUS_ANY, -1, -1)
  
  for (def cpAttachmentFileEntry in cpAttachmentFileEntries) {
    def fileEntry = cpAttachmentFileEntry.fetchFileEntry()
    out.println("fileEntry " + fileEntry.getFileName())
  
    def thumbnailSrc = DLURLHelperUtil.getThumbnailSrc(fileEntry, themeDisplay)
    out.println("thumbnailSrc " + thumbnailSrc)
  
    // You can also leverage CommerceMediaResolverUtil
    def url = CommerceMediaResolverUtil.getURL(AccountConstants.ACCOUNT_ENTRY_ID_ANY, 
                cpAttachmentFileEntry.getCPAttachmentFileEntryId())
    out.println("url " + url)
  
  }

Additional Information

• Some related feature requests:
  • LPD-924 Extend the taxonomy / categories to use the friendly URL and image across DXP (API Headless)
  • LPD-152 As a Site Administrator, I would like to have Categories' images without dependencies to Liferay Commerce modules