• Support for LiveView forms has been added thanks to the quality contribution of Mathias!

• Support for primary keys has been added

The latter may introduce breaking changes, therefore Polymoprhic Embed version has been bumped to 2.0.0

Migration from 1.x to 2.x is easy:

• Make sure that every existing polymorphic embedded_schema contains the setting @primary_key false

I imagine this is a pretty common need, and that many codebases would either have a schema with sets of null values, or end up having their own custom Ecto type implementations.

This library indeed provides a custom Ecto Type that determines the right embed schema to use, based on params to cast. Nice thing is, you can tell PolymorphicEmbed that the presence of specific params identifies a certain schema – no need for a “type” field in the params:)

In addition to the advantages that a library offers (get rid of boilerplate code in the app, reusable code across projects, bugfixes, …), it comes with some nice features:

• As mentioned, detect which types to use for the data being cast-ed, based on fields present in the data (no need for a type field in the data)
• Run changeset validations when a changeset/2 function is present (when absent, the library will introspect the fields to cast)
• Support for nested polymorphic embeds
• Support for nested embeds_one/embeds_many embeds
• Display form inputs for polymorphic embeds in Phoenix templates

Added those features in the Readme file.

Version 3.0.0 has been released!

We now encourage the use of polymorphic_embeds_one/2 and polymorphic_embeds_many/2 macros to define your polymorphic embeds.

If you’re curious as to why: a field containing a polymorphic list of embeds defaulted to nil before version 3. To follow embeds_many/3 we should default to []. This can only be done by forcing the :default option of the field/3 to [] (ie we can’t configure this in the Type). I added the new macros in order to set these kind of defaults setting up the field for the polymorphic embeds.

Thanks to Alexandre @Matsa59 for his contribution which led to this update!

Awesome, I’ve been working exactly with this problem this past week, my solution was built with an Ecto custom type, it works perfectly, but there’s a lot of boilerplate…

From the docs it seems like it will be almost a plug and play with just some minor adjustments, will open a branch and try it

Edit: Yeah, looking at the source of the lib it does what I was doing manually with a custom type, it took zero modifications in the code aside of changing the field type in the schema and configuring the lib, so far all the tests passed.

Support for ecto_sqlite3 has been added in version 1.7.0!

Other features added:

• :with option allowing to specify a custom changeset;
• :required option to specify whether the embed is required or not;
• traverse_errors/2 function to include polymorphic embeds’ errors.