Error executing GraphQL query displayPageTemplates

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: Master
• Fix Version/s: 7.1.10 DXP FP23, 7.1.10.6 SP6, 7.1.X, 7.2.10 DXP FP12, 7.2.X, 7.3.7 CE GA8, 7.3.10 DXP FP2, 7.3.X, 7.4.0 CE GA1, 7.4.13 DXP GA1, Master
• Component/s: Headless Admin Content API
• Labels:
  • backend_test
  • liferay-dxp-71-sp6
  • liferay-fixpack-dxp-12-7210
  • liferay-fixpack-dxp-2-7310
  • liferay-fixpack-dxp-23-7110
• Branch Version/s:
  7.3.x, 7.2.x, 7.1.x
• Backported to Branch:
  Committed
• Fix Priority: 3
• Git Pull Request: https://github.com/liferay-headless/liferay-portal/pull/636

Executing the query displayPageTemplates returns an error instead of a valid response.

query {
  admin {
   displayPageTemplates(siteKey: "20124") {
      items {
        title
      }
    } 
  }
}

The problem seems to be that the GraphQLServletExtender assumes that every ResourceImpl implements the EntityModelResource interface and DisplayPateTemplateResourceImpl doesn't, so the following code in the GraphQLServletExtender class breaks:

private EntityModel _getEntityModel(
      Object resource, Map<String, String[]> parameterMap)
   throws Exception {

   EntityModelResource entityModelResource = (EntityModelResource)resource;

   return entityModelResource.getEntityModel(
      ContextProviderUtil.getMultivaluedHashMap(parameterMap));
}