Dear member,

I would like to know how to add for a particular property a post condition or pre condition for a generat set method. For example I would like to generate an IllegalArgumentException in case the input argument of the set is negative. The generated code doesn't controll such situation.

I was trying to use:



I would like to get the generated set method:



but it doesn't work, such addional piece of code is not generated.

for the property settledPosition, but this meta attribute works only for adding methods to the class and not for adding peace of code for a methods generated.

Do you have to use a new template for such particular class?, can some one could give some hint about how to do it in this case.

Thanks,

David

P.S.: I can't use now inheritance for overriding this set method, because I have to propagate this change on all my classes (the application is big), I am thinking about using AOP for adding this behaviour, but I hope it could be solve easiers using hibernate tools generation.

change the templates to make them generate different code.

Max, I just want to change the behaviour for a particular property, no for all my generated get/set methods.

Changing the template will affect all properties.

Please, let me know any suggestion,

Thanks,

David

use an if statement that checks for a meta property or column name to do alternative generation.

Max, thanks again for your suggestion. I think for the moment as you said, there no other way to solve this problem, than modifying the template, that is way I have added an improvement on JIRA, in order to have in a future a better solution for this problem.

http://opensource.atlassian.com/projects/hibernate/browse/HBX-752

Thanks,

David Leal

Following the max comments about my issue on JIRA, the only solution will be to modify the template.

I guess the template to modify is:

http://anonhibernate.labs.jboss.com/tru ... essors.ftl:



but on the set definition, I don't see were is defined the body of the set operation.

Clease could you give me som hint about how to modify the corresponding template.

I would like to add a precondition, before a code assignation, for a particular property, for example: position.

Thanks in advance,

David

that one is for the interface, hence the interface part.

See http://anonhibernate.labs.jboss.com/tru ... essors.ftl for actuall propertyaccessors.

Looking int to this template, so the new template will be:

<#foreach property in pojo.getAllPropertiesIterator()>
<#if pojo.getMetaAttribAsBool(property, "gen-property", true)>
<#if pojo.hasFieldJavaDoc(property)>
/**
* ${pojo.getFieldJavaDoc(property, 4)}
*/
</#if>
<#include "Ejb3PropertyGetAnnotation.ftl"/>
${pojo.getPropertyGetModifiers(property)} ${pojo.getJavaTypeName(property, jdk5)} ${pojo.getGetterSignature(property)}() {
return this.${property.name};
}

${pojo.getPropertySetModifiers(property)} void set${pojo.getPropertyName(property)}(${pojo.getJavaTypeName(property, jdk5)} ${property.name}) {
<#if ${property.name} = "settledPosition">
throw new IllegalArgumentException(String.valueO(settledPosition));
</#if>
this.${property.name} = ${property.name};
}
</#if>
</#foreach>

but, what about if the property settledPosition, is used on other classes?, so I need to distinguish the situation, so the throw sentence will be generated ONLY for the property settledPosition belong to the class: com.schinvest.lra.domain.Position. Do you have any suggestion about how to control this situation.

I think that in order to use this new template, without modifying the original file on the jar, I have to put this template first on the classpath, isn't it?

Thanks in advance,

David Leal

probably better if you add a meta attribute to the properties you want specific behavior for and then check for that in the templates.

regarding templates you just need to set the templatepath to the root of your custom templates (putting them in front of the classpath might also work, but templatepath is the right way)

Max, following your recomendation, I am on the way, to the condition has to be improved. I have the following:



so, I want to check that settledPosition is present and true, then on the hbm file I have:



but I get System.out.println("hola"), on all my set methods for all generated classes.

Please could you give me any hint about this?,

Thanks again,

David

well that is because you are putting "true" in the last argument which is the default value if none is found ;)

Also note that another cause can be that you have put the meta element in the top of the file and all properties have inherited it - you avoid that with inherit="false"

On the original file you will see a similar use of getMetaAttribAsBool, at that place it uses the third argument too:



What I am duing is the same, if I don't put the true I get an Exception.

Conserning to the second suggestion, I am putting on the meta attribute on the property definition, not at the begining of the file, I have tried this posibility also, but I get the same result.

Your suggestion look good and with sense, but it doesn't work, probably because if you put a new meta attribute you have to tell hibernate it is a new meta attribute. As you can see I am using the same sintax as for property "gen-property", but hibernate expect such meta attribute.

It is a common problem (adding pre/post conditions), but it doesn't look so simple to really get the desire output. Have you tried such suggestion about meta attribute really? Where I can find the definition of the method invoked on the *.ftl files. I know it is Freemarker, but there are defined some method specifically for hibernate. For example like the method:



where is such getExtraClassCode defined?

On my opinions, it should be easier to define a method like getPreConditionMethodCode(), getPostConditionMethodCode(), that to get finally work modifying the template, :-)

Any why there is no so much documetation about how to add additional conditions to the generated methods, I would like it works but it doesn't.

Please let me know any other suggestion, and thanks again.

David

yes, because then it will return null and thus be undefined.
if not all elements has the meta attribute and no reasonable default is possible (you could maybe use an empty string?) then you should use the c2j.hasMetaAttribute(property, "blahblah") method (the ones on pojo is just shortcuts to this one.)

Then you can check if the property has the value or not.



yes - its still simple and it works just as described.



The templates are full of dependencies on metaattribute working so yes i have tried it.



On POJOClass.



see http://www.hibernate.org/hib_docs/tools ... e/#d0e1179 for how to expose your own java logic.



no one haven't sat down and written it yet. Want to contribute it ?

Your case would actually be a good way to demonstrate how to extend the templates.

Max and members,

Yust to send a final post to explain in detail how it works with the help of Max hints.

1. Copy the template PojoPropertyAccessors.ftl from hibernatetools.jar into a local directory. NOTE: In order hibernatetools can find it, you have to respect the same directory structure, for example:



Now add the location:



to the templatepath definition on hbm2java:



where lib.classpath includes the hibernatetools.jar and ${src.orm.hbm.dir} points to:



2. Define a meta-attribute pre-settled_position on the mapping file: Position.hbm.xml.



Note: You can add the meta-attribute settting it to true, for example:
<meta attribute="pre-settled_position">true</meta>

3. Finally on the template PojoPropertyAccessors.ftl, modify the generation of set method so if meta attribute pre-settled_position is pressent a pre-condition will be added:



4. Now after invoking: hbm2java target I get the following setSettledPosition method:



that's all folks,

Replying to Max:

1. Max let me know how to colaborate (on my Jira profile you can find me e-mail) on improving the documentation. I have only one problem: I am not english native, so probably I will need some help for correcting my english mistakes.

2. I think like you it is a good example for defining new templates, nevertheless if you open the door for adding extra code, it is a natural extension to meta attribute the class-code, to add a similar attributes for pre/post condition on methods. I am going to explain in more detail my reasons on the JIRA issue:

http://opensource.atlassian.com/projects/hibernate/browse/HBX-752

I think it is the right place for comment that,

Thanks,

David

your example is good, i would just put the code into the hbm.xml instead of just having true/false in the property.



i'm also not english native so don't worry ;)

improving documentation is best done by submitting a patch to the docs in the doc directory. It's just docbook so is pretty straightforward.



there is a big difference between static extra code and context sensitive code.