# NAME GraphQL::Plugin::Convert::DBIC - convert DBIx::Class schema to GraphQL schema # PROJECT STATUS | OS | Build status | |:-------:|--------------:| | Linux | [![Build Status](https://travis-ci.org/graphql-perl/GraphQL-Plugin-Convert-DBIC.svg?branch=master)](https://travis-ci.org/graphql-perl/GraphQL-Plugin-Convert-DBIC) | [![CPAN version](https://badge.fury.io/pl/GraphQL-Plugin-Convert-DBIC.svg)](https://metacpan.org/pod/GraphQL::Plugin::Convert::DBIC) # SYNOPSIS use GraphQL::Plugin::Convert::DBIC; use My::Local::Schema; my $converted = GraphQL::Plugin::Convert::DBIC->to_graphql(My::Local::Schema->connect); print $converted->{schema}->to_doc; # DESCRIPTION This module implements the [GraphQL::Plugin::Convert](https://metacpan.org/pod/GraphQL%3A%3APlugin%3A%3AConvert) API to convert a [DBIx::Class::Schema](https://metacpan.org/pod/DBIx%3A%3AClass%3A%3ASchema) to [GraphQL::Schema](https://metacpan.org/pod/GraphQL%3A%3ASchema) etc. Its `Query` type represents a guess at what fields are suitable, based on providing a lookup for each type (a [DBIx::Class::ResultSource](https://metacpan.org/pod/DBIx%3A%3AClass%3A%3AResultSource)). ## Example Consider this minimal data model: blog: id # primary key articles # has_many title # non null language # nullable article: id # primary key blog # foreign key to Blog title # non null content # nullable ## Generated Output Types These [GraphQL::Type::Object](https://metacpan.org/pod/GraphQL%3A%3AType%3A%3AObject) types will be generated: type Blog { id: Int! articles: [Article] title: String! language: String } type Article { id: Int! blog: Blog title: String! content: String } type Query { blog(id: [Int!]!): [Blog] article(id: [Int!]!): [Blog] } Note that while the queries take a list, the return order is undefined. This also applies to the mutations. If this matters, request the primary key fields and use those to sort. ## Generated Input Types Different input types are needed for each of CRUD (Create, Read, Update, Delete). The create one needs to have non-null fields be non-null, for idiomatic GraphQL-level error-catching. The read one needs all fields nullable, since this will be how searches are implemented, allowing fields to be left un-searched-for. Both need to omit primary key fields. The read one also needs to omit foreign key fields, since the idiomatic GraphQL way for this is to request the other object, with this as a field on it, then request any required fields of this. Meanwhile, the update and delete ones need to include the primary key fields, to indicate what to mutate, and also all non-primary key fields as nullable, which for update will mean leaving them unchanged, and for delete is to be ignored. These input types are split into one input for the primary keys, which is a full input type to allow for multiple primary keys, then a wrapper input for updates, that takes one ID input, and a payload that due to the same requirements, is just the search input. Therefore, for the above, these input types (and an updated Query, and Mutation) are created: input BlogCreateInput { title: String! language: String } input BlogSearchInput { title: String language: String } input BlogIDInput { id: Int! } input BlogUpdateInput { id: BlogIDInput! payload: BlogSearchInput! } input ArticleCreateInput { blog_id: Int! title: String! content: String } input ArticleSearchInput { title: String content: String } input ArticleIDInput { id: Int! } input ArticleUpdateInput { id: ArticleIDInput! payload: ArticleSearchInput! } type Mutation { createBlog(input: [BlogCreateInput!]!): [Blog] createArticle(input: [ArticleCreateInput!]!): [Article] deleteBlog(input: [BlogIDInput!]!): [Boolean] deleteArticle(input: [ArticleIDInput!]!): [Boolean] updateBlog(input: [BlogUpdateInput!]!): [Blog] updateArticle(input: [ArticleUpdateInput!]!): [Article] } extends type Query { searchBlog(input: BlogSearchInput!): [Blog] searchArticle(input: ArticleSearchInput!): [Article] } # ARGUMENTS To the `to_graphql` method: a [DBIx::Class::Schema](https://metacpan.org/pod/DBIx%3A%3AClass%3A%3ASchema) object. # PACKAGE FUNCTIONS ## field\_resolver This is available as `\&GraphQL::Plugin::Convert::DBIC::field_resolver` in case it is wanted for use outside of the "bundle" of the `to_graphql` method. # DEBUGGING To debug, set environment variable `GRAPHQL_DEBUG` to a true value. # AUTHOR Ed J, `` # LICENSE Copyright (C) Ed J This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.