Godantic v1.5.0 — Custom Tags, Plugins & Dynamic Fields

🚀 Godantic v1.5.0 — Custom Tags, Plugins & Dynamic Fields

We are proud to announce Godantic v1.5.0, a powerful and extensible validation engine for Go! This release marks a significant leap forward in flexibility, allowing developers to inject custom logic and support dynamic schemas like never before.

✨ Highlights

✅ Custom Validation Tags

You can now register your own validation rules with type-safe generic functions:

godantic.RegisterCustom[string]("starts_with_A", func(val string, path string) *godantic.Error {
	if !strings.HasPrefix(val, "A") {
		return &godantic.Error{ErrType: "STARTS_WITH_A_ERR", Path: path, Message: "Field must start with A"}
	}
	return nil
})

Apply it using:

type User struct {
	Name *string `json:"name" validate:"starts_with_A"`
}

Supports multiple tags per field!

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🔌 Plugin-Based Validation

Godantic now supports embedded logic with:

type ValidationPlugin interface {
	Validate() *godantic.Error
}

Any struct that implements Validate() will be automatically invoked during validation. Works for nested fields and lists!

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🔄 Dynamic Field Validation

Support for polymorphic or runtime-defined fields with:

type DynamicFieldsValidator interface {
	GetValue() any
	GetValueType() string
	GetAttribute() string
}

Let your structs declare how they should be validated at runtime — ideal for schema-driven forms, rules, or input engines.

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⚙️ Improvements

• Refactored validation flow for better performance and modularity.
• Supports pointers, nested fields, arrays, enums, regex, formats, and conditions (when:).
• Enhanced path resolution for more accurate error messages.

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📚 Documentation

All docs are now available in the new docs/ folder, ready for GitHub Pages or your static site generator.

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🏁 Getting Started

go get github.com/grahms/godantic

Then explore docs/getting-started.md or the README for full examples.