The User entity Permalink to " The User entity"

NOTE: this is not created for microservices using some kinds of security, as detailed here.

This entity is a special entity as JHipster creates and manages it internally.

It contains some basic information:

  • a first name and a last name,
  • a login,
  • an email address,
  • a password (not in clear text),
  • authorities,
  • etc.

Creating an application from scratch will generate you some default users like the admin or the guest users.

Possible relationships Permalink to "Possible relationships"

Here are the possible relationships from/to this entity:

  • many-to-one relationships to this entity (a Car can have a many-to-one relationship to a User). This will generate a specific query in your new entity repository, so you can filter your entity on the current security user, which is a common requirement. On the generated Angular/React client UI you will have a dropdown in Car to select a User.
  • many-to-many and one-to-one relationships to the User entity, but the other entity must be the owner of the relationship (a Team can have a many-to-many relationship to User, but only the team can add/remove users, and a user cannot add/remove a team). On the front-end client UI, you will also be able to select a User in a multi-select box.

Modifying the User entity Permalink to "Modifying the User entity"

If you encounter a problem where you need to alter the User entity, we recommend not doing that. Modifying this default entity might break your app depending on the nature of the changes.

Instead, there are other available solutions like:

  • creating an entity composed of the User entity,
  • extending the User entity

Using composition Permalink to "Using composition"

If you need to add a new field to the entity, or add relationships to it, all you need do is create another entity, for instance:

entity ApplicationUser {
  additionalField Integer min(42) max(42)

relationship OneToOne {
  ApplicationUser{internalUser(login)} to @OnDelete("CASCADE") @Id User with builtInEntity

Here’s what this snippet does:

  • create a new entity named ApplicationUser with a field,
  • create a relationship from this entity to the standard User entity:
    • we use a OneToOne relationship to link a JHipster-created entity to this new one,
    • we use a unidirectional relationship in order not to modify the internally-managed User entity.

This is the recommended solution as it’s doable using the JDL. This solution is great for adding new fields and relationships (amongst other things) to the User entity without actually modifying it.

Using inheritance Permalink to "Using inheritance"

This solution does the same thing as the previous one, but isn’t as straightforward as the first one because you need to:

  • create a new entity by hand,
  • adapt the code to make it use this new entity,
  • potentially manage yourself the database migration to persist this new entity (depending on the nature of the changes).

It possesses, however, the same advantage as the previous one: you needn’t change the User entity by hand.

Creating your own default User entity Permalink to "Creating your own default User entity"

This one isn’t actually recommended, but is possible through the use of the user management skipping option (skipUserManagement application option in the JDL).

JHipster uses this option internally in some cases (for some options), and using it will:

  • not generate any user management code (front-end & back-end),
  • allow you to update the User entity (add/delete any field to it),

Additionally, you’ll have to create the entity and handle user management yourself.

It’s better to keep it false as the first two solutions are quite easy to do.