Package ch.tocco.nice2.model.entity.api.relation

Class LinkGenerator

java.lang.Object
ch.tocco.nice2.model.entity.api.relation.LinkGenerator
public final class LinkGenerator extends Object
Generates the value for the <link/> tag of a relation.

For 1:n relations, the foreign key column name is generated according to the following scheme 

     fk_LC(NOREL(<relation_name>))
where LC converts everything to lowercase and NOREL strips any leading rel prefix from the relation name (turning relUser into user).

For n:m relations, the link is a triple of the form 

     link_table_name:fk_column1:fk_column2
The link_table_name is created according to this scheme: 
     "nice_" LC(NOREL(<relation_name>)) "_to_" LC(NOREL(<reverse_relation_name>))
FKs ordering: owning:reverse

The two foreign key columns are created the same way as the foreign key columns for 1:n relations.

If a column- or table name exceeds a length of 63 chars (which is the maximum length for postgresql objects), it is reduced to 63 chars. To retain readability the reduction is done like this: 

 1. Split the name by underscore into a list of segments
 2. remove the last character from segments until the name is of appropriate length.
    If a segments is of length 1 don't modify it.
If the length cannot be reduced (because there are too many segments), an IllegalStateException is thrown.

  • Method Details Link icon

    • generateLink Link icon

      public static String generateLink(RelationModel model)
      Creates the link element for the given RelationModel using the information supplied with getName() for the given model and its reverse model. For 1:n relations, the foreign key column is returned, for n:m relations the link triple tablename:fk1:fk2 is returned. Please see class documentation for more detail.