docs(examples): add a basic and a more complex example in examples dir

examples/complex/complex.go

@@ -0,0 +1,110 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/romdo/go-validate"
+)
+
+type Manifest struct {
+	Spec *Spec `json:"spec"`
+}
+
+func (s *Manifest) Validate() error {
+	return validate.RequireField("Spec", s.Spec)
+}
+
+type Spec struct {
+	Containers []*Container `json:"containers"`
+	Images     []*Image     `json:"images"`
+}
+
+func (s *Spec) Validate() error {
+	var errs error
+
+	if len(s.Containers) == 0 {
+		errs = validate.AppendFieldError(errs,
+			"Containers", "must contain at least one item",
+		)
+	} else {
+		imgs := map[string]bool{}
+		for _, img := range s.Images {
+			if img.Name != "" {
+				imgs[img.Name] = true
+			}
+		}
+		for i, c := range s.Containers {
+			if c.ImageRef != "" && !imgs[c.ImageRef] {
+				errs = validate.Append(errs, &validate.Error{
+					Field: fmt.Sprintf("containers.%d.imageRef", i),
+					Msg: fmt.Sprintf(
+						"image with name '%s' not found", c.ImageRef,
+					),
+				})
+			}
+		}
+	}
+
+	if len(s.Images) == 0 {
+		errs = validate.AppendFieldError(errs,
+			"Images", "must contain at least one item",
+		)
+	}
+
+	return errs
+}
+
+type Container struct {
+	Name     string `json:"name"`
+	ImageRef string `json:"imageRef"`
+}
+
+func (s *Container) Validate() error {
+	var errs error
+	errs = validate.Append(errs, validate.RequireField("Name", s.Name))
+	errs = validate.Append(errs, validate.RequireField("ImageRef", s.ImageRef))
+
+	return errs
+}
+
+type Image struct {
+	Name string `json:"name"`
+	URI  string `json:"uri"`
+	Tag  string `json:"tag"`
+}
+
+func (s *Image) Validate() error {
+	var errs error
+	errs = validate.Append(errs, validate.RequireField("Name", s.Name))
+	errs = validate.Append(errs, validate.RequireField("URI", s.URI))
+	errs = validate.Append(errs, validate.RequireField("Tag", s.Tag))
+
+	return errs
+}
+
+func main() {
+	manifest := &Manifest{
+		Spec: &Spec{
+			Containers: []*Container{
+				{
+					ImageRef: "server",
+				},
+				{
+					Name:     "worker",
+					ImageRef: "myServer",
+				},
+			},
+			Images: []*Image{
+				{
+					Name: "server",
+				},
+			},
+		},
+	}
+
+	errs := validate.Validate(manifest)
+
+	for _, err := range validate.Errors(errs) {
+		fmt.Println(err)
+	}
+}