[FEATURE] Possibility of add "required" in a one to many relationship

[marcosmoreno]

Currently if I create a one to many relationship (Owner-Car), I can create records in the many part with the relationship field empty (i.e. Car without an owner).

I was told in the jhipster domain language issue tracker that if Jhipster implements this, JHipster UML and the JDL would incorporate that. Any chance it is considered?

JHipster Version(s) 3.0

[deepu105]

This is a bit trickier to do so unless someone is willing to volunteer I don't think any of @jhipster/developers will have time to do this. Any way ill leave it open if any body wants to do this

[adornala]

@jhipster/developers : I can volunteer to work on this. Shall I go ahead?

[deepu105]

Yes please On 20 Apr 2016 00:12, "Amarnath Reddy Dornala" notifications@github.com wrote:

@jhipster/developers : I can volunteer to work on this. Shall I go ahead?

— You are receiving this because you are on a team that was mentioned. Reply to this email directly or view it on GitHub https://github.com/jhipster/generator-jhipster/issues/3417#issuecomment-211997121

[adornala]

Front end validation solves this right or want to edit Entity as well? Just making sure. If no owner is selected we can't create a Car!

[marcosmoreno]

@dornala actually if I edit the entity manually (adding the notnull directive in the ManyToOne field) the Front end does the validation already: If no owner is selected we can't create a car. Please see the my last comment in the linked issue in the description. I guess it would need adjustments in the entity generator and in the JDL parser, as not all OneToMany might need this validation.

[adornala]

Ya @marcosmoreno by adding notnull to one to many field in entity, we can make sure JPA transaction fails. If there is no Owner selected error(Internal Server Error) will be thrown , So, we add front end validation to make sure - save button shows up only when we have a owner for car(Avoiding internal server error).

Now, Requirement: If we are using JDL or Entity Generator to create entity. we want entity to be created with not null @ entity level and with front end validation. Is it Right?

[marcosmoreno]

I did not add the NotNull to the OneToMany, as I want to be able of saving owners without a car. What I observed is that in the entity Car, there was a ManyToOne relationship (note I did not have a ManyToOne in my JDL, it was added by JDL), and there I put the @NotNull. I wanted to be able of having Owners without Car, but no Cars without Owner. After building, Jhipster already tells me "The field is required" when I try to save the Car Entity (I also would have expected an "internal server error", but this is not what seems to happen - I get a 404 bad request in the console, so probably it is taking the message from that error).

In JDL:

relationship OneToMany {
  Owner{car} to Car{owner(ownerName)}
}

My Owner Entity has the following: (I did not touch this Entity)

@OneToMany(mappedBy = "owner")
    @JsonIgnore
    private Set<Car> cars = new HashSet<>();

My entity in the .domain package has this in the Car Entity:

    @ManyToOne
    @NotNull  //This is the one that I added
    private Owner owner;

So the requirement would be: being able of writing "required" in the JDL, in order that the NotNull is added to the @ManyToOne relationship.

I would expect something like:

relationship OneToMany {
  Owner{car} to Car{owner(ownerName),required} //just an idea on where to put the required
}

Jhipster already tells me "Field owner cannot be empty" when I try to save the Car Entity after my change, so (I do not see the need of adjusting the front-end (but maybe I am missing something). in the front-end, we could add the "required" to the field, to avoid the call to the server that is happening now.

I could help gladly to code if I would now where to start (I did not have a look at the sources yet).

[adornala]

Got it. Typo I meant ManytoOne.

[adornala]

Hi @deepu105 I need small help testing. I made all necessary changes. It working fine when I change name to something other than generator-jhipster(In package.json and linking it to yeoman as npm link) Any idea why it's happening deepu? Sorry if it's an easy fix, please guide me. This is my first contribution.

[deepu105]

I dont understand your issue.

This is the way to run the generator from a local instance

1. Install npm i -g generator-jhipster
2. Fork the generator to a local folder named generator-jhipster
3. Go inside the folder and run npm link
4. Make a small change to any log statement and run yo jhipster in someother new folder to check if its running your change
5. If not try running npm link generator-jhipster from the folder where you are trying to run yo jhipster

[deepu105]

closed via https://github.com/jhipster/generator-jhipster/pull/3503