HibTools - Custom Exporter newbie

dhartford · **Joined:** Fri Jul 30, 2004 4:02 pm **Posts:** 50

Hey all,
hibernate 3.2.4.ga, hibtools 3.2.0.ga.

I would like to create a custom exporter.

1) is there any good documentation/guideline/wiki/blog that will help someone get started on writing a custom exporter. Google and searching this forum didn't produce anything useful that I could find.

The intent of the custom exporter I'm trying to create is to generate a util class for all known stored procedures (haven't found a way to do this normally, so if there is please show me).

Ideally, I would like to create the exporter class, but have the exporter class not actually do anything, but be used simply as user-defined 'functions' for the template. Looking through the existing exporters, they all define .ftl's within the class itself which is why I'm asking if this is a reasonable expectation to have the exporter just be a util/function class to be used in a manually defined template or not.

Code:

<!-- template is required, exporterclass by itself for my custom exporter doesn't do anything -->
    <hbmtemplate
     template="sproc.ftl"  
          exporterclass="SprocExporter"
    >

sample sproc.ftl trying to get too:

Code:

<#foreach singlesproc in sproc.getProcedures()>
           System.out.println( ${sproc.getCatalog(singlesproc)} );
           System.out.println( ${sproc.getSchema(singlesproc)} );
           System.out.println( ${sproc.getProcedureName(singlesproc)} );
           System.out.println( ${sproc.getProcedureRemark(singlesproc)} );

<#foreach sproccolumn in sprocdetail.getProcedureColumns(singlesproc)>
           System.out.println( ${sprocdetail.getProcedureName(singlesproc)} );
           System.out.println( ${sprocdetail.getColumnName(singlesproc)} );
           System.out.println( ${sprocdetail.getColumnTypeName(singlesproc)} );
           System.out.println( ${sprocdetail.getColumnNullable(singlesproc)} );

           System.out.println( ${sprocdetail.getColumnRemark(singlesproc)} );
</#foreach>


</#foreach>

Now, for the real meat -- how to I pull this off? I'm guessing I need to identify the freemarker user-defined function with just the getTemplateHelper().putInContext(), and the getName() is not used?

Also assuming you want to extend AbstractExporter instead of GenericExporter, or should I be using GenericExporter?

Code:

public class SprocExporter extends AbstractExporter {

   @Override
   protected void doStart() {
      // TODO Auto-generated method stub
      
   }
   
   public String getName() {
      return "sproc"; //is this really needed?
   }   
   
   /**
    * Setup the context variables used by the exporter. Subclasses should call super.setupContext() to ensure all needed variables are in the context. 
    **/
   protected void setupContext() {
      super.setupContext();
      getTemplateHelper().putInContext("sproc", this);
      getTemplateHelper().putInContext("sprocdetail", this);
      if(!getProperties().containsKey("ejb3")) {
         getProperties().put("ejb3", "false");
      }
      if(!getProperties().containsKey("jdk5")) {
         getProperties().put("jdk5", "false");
      }   
   }
   

//how do I add this as a sub-method for freemarker template?
       private String[] getProcedures(){
               //impl
                return "to be implemented";
       }
   
//how do I add this as a sub-method for freemarker template, and 
//what should the parameter look like.
       private String getProcedureName(String procedure){
               //impl
                return "to be implemented";
       }

//should sprocdetail equivalent be it's own class?
     private String getSprocDetailColumnName(String procedure){
             //impl
             return "to be implemented";
     }


//use existing hibernate database connection...?


}

Sorry for the long post a lot of questions, I'm kinda jumping in both feet into the dark here.....

max · **Posted:** Sat Jul 12, 2008 8:01 am

The docs has an example of customizing code generation.

If you just want an instance of class which utility methods to call see http://docs.jboss.org/tools/2.1.0.Beta1 ... ml#d0e3308

dhartford · **Joined:** Fri Jul 30, 2004 4:02 pm **Posts:** 50

The utility method approach is perfect.

Now, for moving forward:

1) is 'hibernate.sometool.toolclass' always consistent, as in I shouldn't replace 'sometool' with a special value.

2) does there exist an example that actually does this approach (with specifying the hibernate.sometool.toolclass). The documentation show a template already in place instead of an external util class.

3) Is there direction as to how to write the util class -- should it be through AbstractExporter/GenericExporter (since I would like to re-use the database connection if possible), or should it be as a pure Freemarker and extend TemplateModelDirective for example.

Thanks for taking a look at my question,
-D

max · **Posted:** Tue Jul 15, 2008 8:11 am

dhartford wrote:

1) is 'hibernate.sometool.toolclass' always consistent, as in I shouldn't replace 'sometool' with a special value.

the "sometool" is whatever you want.

HTools looks after hibernate..*.toolclass and put whatever .* matches into the context.

Quote:

2) does there exist an example that actually does this approach (with specifying the hibernate.sometool.toolclass). The documentation show a template already in place instead of an external util class.

The example is <property key="hibernatetool.sometool.toolclass" value="x.y.z.NameOfToolClass"/>, you just insert the property line in your existing <configuration> tag and replace "sometool" with whatever name you want and the value with whatever classname you have.

Quote:

3) Is there direction as to how to write the util class -- should it be through AbstractExporter/GenericExporter (since I would like to re-use the database connection if possible), or should it be as a pure Freemarker and extend TemplateModelDirective for example.

It is just a java class, if you want to pass in specific things then you just pass it in.

dhartford · **Joined:** Fri Jul 30, 2004 4:02 pm **Posts:** 50

If there does not exist an example that is an external util class, I'll try to step through this.

I've implemented so far:

Code:

    
<!-- filepattern must have {class-name}, otherwise doesnt export (?) -->
<hbmtemplate
     filepattern="{package-name}/model/{class-name}Sproc.java"
     templatepath="./template"
     template="sproc.ftl"  
    >

<!-- hibernatetool.%value%.toolclass, the %value% is what is used in the ftl to call the class and it's methods -->
       <property key="hibernatetool.checksproc.toolclass" value="com.mydomain.CheckSproc"/>
       <property key="ejb3" value="true"/>
       <property key="jdk5" value="true"/>
       <property key="mycustomkey" value="mycustomvalue"/>
</hbmtemplate>   

CheckSproc:

Code:

public class CheckSprocs extends AbstractExporter{

   public CheckSprocs(){
        super();
        System.out.println("Constructor called");
      
      Session session = null;
      SessionFactory sessionFactory = null;
      try {       
         sessionFactory = getConfiguration().buildSessionFactory(); //nullpointerexception
         session = sessionFactory.openSession();      
         if (session == null){
            System.out.println("Session is null!");
         }
         
      }catch(Exception e){
         System.out.println(e);
      }
      
      Set<Object> keySet = getProperties().keySet();
      System.out.println("List of properties:");
      for (Iterator iterator = keySet.iterator(); iterator.hasNext();) {
         Object object = (Object) iterator.next();
         System.out.println(object);
      }      
      
   }


     public String hello(){
            return "hello, it is working!";
}

}

sample.ftl (checksproc.hello is working):

Code:

This is a test.

Should be saying hello: ${checksproc.hello()}

Now, specifically, how would this get access to

*Hibernate Session (the already setup database connection)
*the template Properties (mycustomkey/mycustomvalue)

The constructor does not seem to have access to anything, and according to the AbstractExporter, the toolclass is instantiated with no-param constructor.

max · **Posted:** Mon Jul 21, 2008 1:11 pm

dhartford wrote:

If there does not exist an example that is an external util class, I'll try to step through this.

a patch t the docs would be appreciated when you get it working ;)

Quote:

Code:

    
<!-- filepattern must have {class-name}, otherwise doesnt export (?) -->
<hbmtemplate
     filepattern="{package-name}/model/{class-name}Sproc.java"
     templatepath="./template"
     template="sproc.ftl"  
    >

<!-- hibernatetool.%value%.toolclass, the %value% is what is used in the ftl to call the class and it's methods -->
       <property key="hibernatetool.checksproc.toolclass" value="com.mydomain.CheckSproc"/>
       <property key="ejb3" value="true"/>
       <property key="jdk5" value="true"/>
       <property key="mycustomkey" value="mycustomvalue"/>
</hbmtemplate>   

filepattern looks for {class-name} to detect if it should iterate over classes or just the Configuration.

You can control that with the foreach attribute. foreach="entity, component" will do the same - but you would have to use *something* to distinguish the generated files and for that {class-name} is the best thing we got for now.

Quote:

CheckSproc:

Code:

public class CheckSprocs extends AbstractExporter{

   public CheckSprocs(){
        super();
        System.out.println("Constructor called");
      
      Session session = null;
      SessionFactory sessionFactory = null;
      try {       
         sessionFactory = getConfiguration().buildSessionFactory(); //nullpointerexception
         session = sessionFactory.openSession();      
         if (session == null){
            System.out.println("Session is null!");
         }
         
      }catch(Exception e){
         System.out.println(e);
      }
      
      Set<Object> keySet = getProperties().keySet();
      System.out.println("List of properties:");
      for (Iterator iterator = keySet.iterator(); iterator.hasNext();) {
         Object object = (Object) iterator.next();
         System.out.println(object);
      }      
      
   }


     public String hello(){
            return "hello, it is working!";
}

}

No need to extend AbstractExporter here; it is just a plain utility class.

Quote:

Now, specifically, how would this get access to

*Hibernate Session (the already setup database connection)

$cfg gives you access to the Configuration which you can use to get all the info you want...but noone asked for the db connection within the templates before - what is your usecase ?

ReverseEngineeringStrategy gets access to it because it more likely needs it - maybe that is what you need instead or ?

Quote:

*the template Properties (mycustomkey/mycustomvalue)

They are directly available as $mycustomkey.