feat: SEO field types and the complete SEO tab

classes/field_types.go

@@ -0,0 +1,139 @@
+package classes
+
+import (
+	"context"
+	"fmt"
+	"net/url"
+	"strings"
+
+	"git.golem15.com/golem15/summercms/modules/backpack"
+	"git.golem15.com/golem15/summercms/modules/pact"
+)
+
+// The elements of the SEO field types (assets/src/elements).
+const (
+	ElementText   = "golem15-seo-text"
+	ElementRobots = "golem15-seo-robots"
+	ElementSERP   = "golem15-seo-serp"
+	ElementImage  = "golem15-seo-image"
+)
+
+// The element bundle every SEO field type loads.
+var (
+	elementScripts = []string{"assets/dist/seo.js"}
+	elementStyles  = []string{"assets/dist/seo.css"}
+)
+
+// errRobotsInvalid is the refusal of a malformed robots value.
+const errRobotsInvalid = "golem15.seo::lang.robots.invalid"
+
+// FieldTypes returns the SEO admin field types:
+//   - seotext and mlseotext (E1): text with a live length counter; option
+//     measure: title (input) or description (textarea);
+//   - seorobots and mlseorobots (E2): the robots directives editor; option
+//     scope: record, rule or type; Decode refuses a malformed value;
+//   - seoimage (E7): an uploaded social image stored in the media bucket,
+//     its URL as the value (D-100); uploads need permission.
+//
+// app is asked for the booted application at request time.
+func FieldTypes(app func() *backpack.App, permission string) []pact.FormFieldType {
+	text := func(name string, translatable bool) pact.FormFieldType {
+		return pact.FormFieldType{
+			Name: name, Element: ElementText, Translatable: translatable,
+			Scripts: elementScripts, Styles: elementStyles,
+			Options: []string{"measure"}, CheckOptions: checkMeasure, Decode: decodeText,
+		}
+	}
+	robots := func(name string, translatable bool) pact.FormFieldType {
+		return pact.FormFieldType{
+			Name: name, Element: ElementRobots, Translatable: translatable,
+			Scripts: elementScripts, Styles: elementStyles,
+			Options: []string{"scope"}, CheckOptions: checkScope, Decode: decodeRobots,
+		}
+	}
+	return []pact.FormFieldType{
+		text("seotext", false),
+		text("mlseotext", true),
+		robots("seorobots", false),
+		robots("mlseorobots", true),
+		{
+			Name: "seoimage", Element: ElementImage,
+			Scripts: elementScripts, Styles: elementStyles,
+			Decode: decodeImage, Upload: UploadImage(app, permission),
+		},
+	}
+}
+
+func checkMeasure(options map[string]any) error {
+	if raw, ok := options["measure"]; ok {
+		if s, _ := raw.(string); s != "title" && s != "description" {
+			return fmt.Errorf("measure must be title or description, got %v", raw)
+		}
+	}
+	return nil
+}
+
+func checkScope(options map[string]any) error {
+	if raw, ok := options["scope"]; ok {
+		if s, _ := raw.(string); s != "record" && s != "rule" && s != "type" {
+			return fmt.Errorf("scope must be record, rule or type, got %v", raw)
+		}
+	}
+	return nil
+}
+
+// stringValue reads a submitted value as text; nil is "".
+func stringValue(v any) (string, bool) {
+	switch s := v.(type) {
+	case nil:
+		return "", true
+	case string:
+		return s, true
+	}
+	return "", false
+}
+
+func decodeText(_ context.Context, in pact.FormFieldValue) (pact.FormFieldDecoded, error) {
+	s, ok := stringValue(in.Value)
+	if !ok {
+		return pact.FormFieldDecoded{}, &pact.FormFieldError{Messages: []string{"The " + in.Field + " field must be text."}}
+	}
+	return pact.FormFieldDecoded{Value: strings.TrimSpace(s)}, nil
+}
+
+// decodeRobots stores a robots value in the fixed order; a malformed value
+// (reachable only through MCP or an import) is refused.
+func decodeRobots(_ context.Context, in pact.FormFieldValue) (pact.FormFieldDecoded, error) {
+	s, ok := stringValue(in.Value)
+	if !ok {
+		return pact.FormFieldDecoded{}, &pact.FormFieldError{Messages: []string{errRobotsInvalid}}
+	}
+	normal, err := NormalizeRobots(s)
+	if err != nil {
+		return pact.FormFieldDecoded{}, &pact.FormFieldError{Messages: []string{errRobotsInvalid}}
+	}
+	return pact.FormFieldDecoded{Value: normal}, nil
+}
+
+// decodeImage accepts an empty value, a path or an http(s) URL.
+func decodeImage(_ context.Context, in pact.FormFieldValue) (pact.FormFieldDecoded, error) {
+	s, ok := stringValue(in.Value)
+	s = strings.TrimSpace(s)
+	if !ok || !ValidImageURL(s) {
+		return pact.FormFieldDecoded{}, &pact.FormFieldError{Messages: []string{errImageURL}}
+	}
+	return pact.FormFieldDecoded{Value: s}, nil
+}
+
+// ValidURLRef reports whether v is a path ("/x", not "//x") or an absolute
+// http(s) URL with a host, without spaces or control characters.
+func ValidURLRef(v string) bool {
+	if v == "" || strings.ContainsFunc(v, func(r rune) bool { return r <= ' ' || r == 0x7f }) {
+		return false
+	}
+	if strings.HasPrefix(v, "/") {
+		return !strings.HasPrefix(v, "//")
+	}
+	u, err := url.Parse(v)
+	return err == nil && (u.Scheme == "http" || u.Scheme == "https") && u.Host != ""
+}