Format #

JSON Schema object may contain a “format” field, that specifies the semantic of the data. Along with the “type” field, it defines the data type more precisely.

Example:

type: string
format: date-time

go-asyncapi supports several formats out of the box, see features page.

Adding a new format #

You can override any existing format the same way.

You can add an implementation for any new format or override the existing one. The templates you need are code/lang/typeFormat/<type>/<format>/usage and code/lang/typeFormat/<type>/<format>/definition, where <type> is the JSON Schema type (string, integer, number, boolean, array, object) and <format> is the format name. These templates must render the type definition and its usage.

For example, to add support for integer type with long format, create both templates with identical content:

{{ define "code/lang/typeFormat/integer/long/definition" }}
    int64
{{- end }}

{{ define "code/lang/typeFormat/integer/long/usage" }}
    int64
{{- end }}

Put them in a file with any name, say my_templates/jsonschema_formats.tmpl, and run the code generation:

go-asyncapi code --template-dir my_templates my_asyncapi.yml

As a result, all JSON Schema objects with type: integer and format: long will be rendered as int64 type in Go code.

In most cases, it’s sufficient to leave the “usage” and “definition” templates identical, but sometimes you may want to make them different. For example, if a format must be represented as a struct:

{{ define "code/lang/typeFormat/object/myStruct/definition" }}
    type {{goIDUpper .}} struct {
        Field1 string `json:"field1"`
        Field2 int    `json:"field2"`
    }
{{- end }}

{{ define "code/lang/typeFormat/object/myStruct/usage" }}
    {{ goPkg . }}{{ goIDUpper . }}
{{- end }}

See also templating guide for more details.