2 Replies Latest reply on Feb 10, 2014 4:42 AM by

    [forge-dev] angular scaffold: parent/child relationship issues

    Thomas Frühbeck Newbie

      Hi,

      I wanted to work with AngularJS scaffold in Forge and ask for your help.

       

      With Forge2, I did not find the way to install the angularjs-scaffold-x

      as addon/plugin.

      Is there some guidance available on how to use oldstyle plugins as addons?

       

      Stepping back to Forge 1.4 I successfully created a simple parent/child

      application.

      On deployment on Wildfly 8.0.0 CR1 I found following issues:

       

      Setup: I created a parent and then a child, the child referencing the

      parent.

       

      Issue 1:

        - w/o any modifications I got a StackOverflowError in

      org.codehaus.jackson.map.ser.BeanSerializer because infinite loop

      between parent/child

       

      My solution was to:

          - import org.codehaus.jackson/jackson-jaxrs maven dependency

      (because this is, what Wildfly seems to use per default)

          - add @JsonManagedReference/@JsonBackReference on the

      parent.children and child.parent properties resp.

       

      Is there some simpler/more obvious fix for the problem?

       

      In Fasterxml Jackson 2.x there is a @JsonIdentityInfo, could this be a

      way to solve the issue?

      I seem to be unable to activate Fasterxml.Jackson on Wildfly

       

      Issue 2:

        - by above @JsonBackReference the child.parent property was not

      serialized and so the reference did not show up as selected in the

      parents options

       

      My solution was to rewrite the EditChildController to check for

      parent.id from the parents side (because child.parent is empty):

       

                           for (var idx=0; idx < item.children.length; idx++) {

                               if (item.children[idx].id === $scope.child.id) {

                                   $scope.parentSelection = labelObject;

                                   $scope.child.parent = wrappedObject;

                               }

                           }

       

      Original code:

                           if($scope.child.parent && item.id ==

      $scope.child.parent.id) {

                               $scope.parentSelection = labelObject;

                               $scope.child.parent = wrappedObject;

                               self.original.parent = $scope.child.parent;

                           }

       

      Again I ask for your expertise, if this is a problem I introduced by

      misusing @JsonBackReference or if this needs a fix in the scaffold.

       

      Thank you for your great work on Forge and this incredible AngularJS

      plugin

       

      Thomas

      _______________________________________________

      forge-dev mailing list

      forge-dev@lists.jboss.org

      https://lists.jboss.org/mailman/listinfo/forge-dev

       

        • 1. Re: [forge-dev] angular scaffold: parent/child relationship issues
          Sebastien Blanc Newbie

          On 02/10/2014 01:28 AM, Thomas Frühbeck wrote:

          Hi,

          I wanted to work with AngularJS scaffold in Forge and ask for your help.

           

          With Forge2, I did not find the way to install the angularjs-scaffold-x

          as addon/plugin.

          Is there some guidance available on how to use oldstyle plugins as addons?

           

          Stepping back to Forge 1.4 I successfully created a simple parent/child

          application.

          On deployment on Wildfly 8.0.0 CR1 I found following issues:

           

          Setup: I created a parent and then a child, the child referencing the

          parent.

           

          Issue 1:

             - w/o any modifications I got a StackOverflowError in

          org.codehaus.jackson.map.ser.BeanSerializer because infinite loop

          between parent/child

          Hey ! Vineet will certainly give you the right answer but  which

          strategy option did you use to generate your REST endpoint ? You have to

          make sure to use "--strategy ROOT_AND_NESTED_DTO" this way your

          relations will be managed well.

          i.e : "

           

          |rest endpoint-from-entity --contentType application/json org.jboss.aerogear.judconcricket.model.* --strategy ROOT_AND_NESTED_DTO

           

          |

           

           

          My solution was to:

               - import org.codehaus.jackson/jackson-jaxrs maven dependency

          (because this is, what Wildfly seems to use per default)

               - add @JsonManagedReference/@JsonBackReference on the

          parent.children and child.parent properties resp.

           

          Is there some simpler/more obvious fix for the problem?

           

          In Fasterxml Jackson 2.x there is a @JsonIdentityInfo, could this be a

          way to solve the issue?

          I seem to be unable to activate Fasterxml.Jackson on Wildfly

           

          Issue 2:

             - by above @JsonBackReference the child.parent property was not

          serialized and so the reference did not show up as selected in the

          parents <select> options

           

          My solution was to rewrite the EditChildController to check for

          parent.id from the parents side (because child.parent is empty):

           

                                for (var idx=0; idx < item.children.length; idx++) {

                                    if (item.children[idx].id === $scope.child.id) {

                                        $scope.parentSelection = labelObject;

                                        $scope.child.parent = wrappedObject;

                                    }

                                }

           

          Original code:

                                if($scope.child.parent && item.id ==

          $scope.child.parent.id) {

                                    $scope.parentSelection = labelObject;

                                    $scope.child.parent = wrappedObject;

                                    self.original.parent = $scope.child.parent;

                                }

           

          Again I ask for your expertise, if this is a problem I introduced by

          misusing @JsonBackReference or if this needs a fix in the scaffold.

           

          Thank you for your great work on Forge and this incredible AngularJS

          plugin

           

          Thomas

          _______________________________________________

          forge-dev mailing list

          forge-dev@lists.jboss.org

          https://lists.jboss.org/mailman/listinfo/forge-dev

           

           

          • 2. Re: [forge-dev] angular scaffold: parent/child relationship issues

             

            Hi Thomas,

             

               I've just started working on the AngularJS scaffold. But before that, I'd have to complete a test harness that could be used in the addon tests.

             

               About the cyclic and bi-di issues, we've attempted to resolve that via a mapping layer, instead of relying on @JsonIdentityInfo, @JsonManagedReference, @JsonBackReference, @XMLID, @XMLIDREF or similar such annotations.

             

               I recommend the mapping layer, because you can flatten/de-normalize relationships at the mapping layer in a manner you desire. What I've found from using most of these annotations is that while they resolve the serialization problem, they're not very useful to clients. Some like @JSONIdentityInfo require more work to be done in the client-side because clients simply do not understand the 'non-standardized' object referencing scheme invented by Jackson.

             

               In Forge, to create a REST resource that employs a mapping layer, use the DTO based REST resource generator, like so (in Forge 2):

             

               $ rest-generate-endpoints-from-entities --generator ROOT_AND_NESTED_DTO ...

             

               The generated layer is a bit crude at the moment - in the future we hope to have the mapping layer depend on a separate persistence layer.

             

               This isn't to say that you must not use such annotations. It just so happens that if you want to expose JPA entities as REST resources, handling relationships and proxied attributes like collections is not easy. You could use the annotations to construct the REST resource, but there are chances that you might not obey certain rules in REST like allowing modifications to the REST resources using a single representation. You may have to construct multiple resource representations for the same JPA entity - one for GET (so clients can obtain the JPA entity) and another for PUT/PATCH (to modify the JPA entity and/or it's relationships). If it so happens that using annotations is more pragmatic, then by all means use it. But if your concerns include the need to have consistent resource representations for JPA entities that also allow modifications to the entities via the same representation, then a mapping layer is probably the best option.

             

               You can find notes on them, in the links listed below. Feel free to fire any more queries.

               1. https://gist.github.com/VineetReynolds/5108580

               2. https://gist.github.com/VineetReynolds/5524706

             

            Vineet

             

             

            -


            Original Message -


            From: "Thomas Frühbeck" <fruehbeck@aon.at>

            To: "forge-dev List" <forge-dev@lists.jboss.org>

            Sent: Monday, February 10, 2014 5:58:44 AM

            Subject: angular scaffold: parent/child relationship issues

             

            Hi,

            I wanted to work with AngularJS scaffold in Forge and ask for your help.

             

            With Forge2, I did not find the way to install the angularjs-scaffold-x

            as addon/plugin.

            Is there some guidance available on how to use oldstyle plugins as addons?

             

            Stepping back to Forge 1.4 I successfully created a simple parent/child

            application.

            On deployment on Wildfly 8.0.0 CR1 I found following issues:

             

            Setup: I created a parent and then a child, the child referencing the

            parent.

             

            Issue 1:

              - w/o any modifications I got a StackOverflowError in

            org.codehaus.jackson.map.ser.BeanSerializer because infinite loop

            between parent/child

             

            My solution was to:

                - import org.codehaus.jackson/jackson-jaxrs maven dependency

            (because this is, what Wildfly seems to use per default)

                - add @JsonManagedReference/@JsonBackReference on the

            parent.children and child.parent properties resp.

             

            Is there some simpler/more obvious fix for the problem?

             

            In Fasterxml Jackson 2.x there is a @JsonIdentityInfo, could this be a

            way to solve the issue?

            I seem to be unable to activate Fasterxml.Jackson on Wildfly

             

            Issue 2:

              - by above @JsonBackReference the child.parent property was not

            serialized and so the reference did not show up as selected in the

            parents <select> options

             

            My solution was to rewrite the EditChildController to check for

            parent.id from the parents side (because child.parent is empty):

             

                                 for (var idx=0; idx < item.children.length; idx++) {

                                     if (item.children[idx].id === $scope.child.id) {

                                         $scope.parentSelection = labelObject;

                                         $scope.child.parent = wrappedObject;

                                     }

                                 }

             

            Original code:

                                 if($scope.child.parent && item.id ==

            $scope.child.parent.id) {

                                     $scope.parentSelection = labelObject;

                                     $scope.child.parent = wrappedObject;

                                     self.original.parent = $scope.child.parent;

                                 }

             

            Again I ask for your expertise, if this is a problem I introduced by

            misusing @JsonBackReference or if this needs a fix in the scaffold.

             

            Thank you for your great work on Forge and this incredible AngularJS

            plugin

             

            Thomas

            _______________________________________________

            forge-dev mailing list

            forge-dev@lists.jboss.org

            https://lists.jboss.org/mailman/listinfo/forge-dev

             

             

            _______________________________________________

            forge-dev mailing list

            forge-dev@lists.jboss.org

            https://lists.jboss.org/mailman/listinfo/forge-dev