santhosh-tekuri/jsonschema

Custom error message

deepak191093 opened this issue · 9 comments

deepak191093 commented

I want to return custom error message not predefined as it is not understandable to common people.

santhosh-tekuri commented

can you please elaborate what do you mean by that. may be giving an example would be better

santhosh-tekuri commented

Started working on this feature. Will post pull request tomarrow

deepak191093 commented

looking forward to it.

santhosh-tekuri commented

please check pull request #99
this pull request changes type of ValidationError.Message from string to struct implementing fmt.Stringer

go through the changes and let me know your opinion

santhosh-tekuri commented

closing. seems duplicate of #44

deepak191093 commented

i am using for json schema validation with 2020-12 draft. to send custom message which field should i mention in json schema file. Need a clarification on that.

santhosh-tekuri commented

@deepak191093 it is still work in progress. see issue #44 and PR #99

since this is a breaking change I have to bump the version. I am waiting for your opinion before I can release it

santhosh-tekuri commented

fix is available in v6.0.0-alpha.1

santhosh-tekuri commented

ValidationError.Message was string type. now it is changed to fmt.Stringer.
so you can create custom error message as follows:

import (
	"github.com/santhosh-tekuri/jsonschema/v5"
	"github.com/santhosh-tekuri/jsonschema/v5/msg"
)

func getCustomMessage(err *jsonschema.ValidationError) string {
	switch m := err.Message.(type) {
	case msg.Type:
		return fmt.Sprintf("i am expecting %s, but I got %s", m.Want, m.Got)
	default:
		return err.Message.String()
	}
}

the above code shows how to create custom error message for type mismatch. similarly you can add more cases in switch for customising different error messages. see msg subpackage for different error message structs.