add string.create processor

internal/processing/string-create.go

@@ -0,0 +1,57 @@
+package processing
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"text/template"
+)
+
+type StringCreate struct {
+	config   ProcessorConfig
+	Template *template.Template
+}
+
+func (sc *StringCreate) Process(ctx context.Context, payload any) (any, error) {
+	var templateBuffer bytes.Buffer
+	err := sc.Template.Execute(&templateBuffer, payload)
+
+	if err != nil {
+		return nil, err
+	}
+
+	payloadString := templateBuffer.String()
+
+	return payloadString, nil
+}
+
+func (sc *StringCreate) Type() string {
+	return sc.config.Type
+}
+
+func init() {
+	RegisterProcessor(ProcessorRegistration{
+		Type: "string.create",
+		New: func(config ProcessorConfig) (Processor, error) {
+			params := config.Params
+			tmpl, ok := params["template"]
+
+			if !ok {
+				return nil, fmt.Errorf("string.create requires a template parameter")
+			}
+
+			templateString, ok := tmpl.(string)
+
+			if !ok {
+				return nil, fmt.Errorf("string.create template must be a string")
+			}
+
+			templateTemplate, err := template.New("template").Parse(templateString)
+
+			if err != nil {
+				return nil, err
+			}
+			return &StringCreate{config: config, Template: templateTemplate}, nil
+		},
+	})
+}