add option to pass dict style params down the line

example/main.go

@@ -8,19 +8,19 @@ import (
 )
 
 var inputTpl = `<div>
-  <label {{with .Id}}for="{{.}}"{{end}} class="block text-sm font-medium text-gray-700">{{.Label}}{{ if eq .Required true }}*{{end}}</label>
+  <label {{with .Field.Id}}for="{{.}}"{{end}} class="block text-sm font-medium text-gray-700">{{.Field.Label}}{{ if eq .Field.Required true }}*{{end}}</label>
   <div class="mt-1">
-	{{ if eq .Type "dropdown" }}
-	<select {{with .Id}}id="{{.}}"{{end}} name="{{.Name}}" class="bg-white block w-full rounded-md border border-gray-300 px-3 py-2 shadow-sm focus:border-indigo-500 focus:outline-none focus:ring-indigo-500 sm:text-sm">
-	  {{ $value := .Value }}
-	  {{ range $k, $option := .Values }}
+	{{ if eq .Field.Type "dropdown" }}
+	<select {{with .Field.Id}}id="{{.}}"{{end}} name="{{.Field.Name}}" class="bg-white block w-full rounded-md border border-gray-300 px-3 py-2 shadow-sm focus:border-indigo-500 focus:outline-none focus:ring-indigo-500 sm:text-sm">
+	  {{ $value := .Field.Value }}
+	  {{ range $k, $option := .Field.Values }}
 		<option value="{{$option.Value}}" {{ if eq $value $option.Value }}selected{{ end }} {{ if eq $option.Disabled true }}disabled{{ end }}>{{$option.Name}}</option>
 	  {{ end }}
     </select>
-	{{ else if eq .Type "checkbox" }}
-	<input {{with .Id}}id="{{.}}"{{end}} name="{{.Name}}" type="checkbox" {{ if eq .Required true }}required{{end}} {{ if eq .Value true }}checked{{end}} class="w-4 h-4 text-blue-600 bg-gray-100 border-gray-300 rounded focus:ring-blue-500 dark:focus:ring-blue-600 dark:ring-offset-gray-800 focus:ring-2 dark:bg-gray-700 dark:border-gray-600">
+	{{ else if eq .Field.Type "checkbox" }}
+	<input {{with .Field.Id}}id="{{.}}"{{end}} name="{{.Field.Name}}" type="checkbox" {{ if eq .Required true }}required{{end}} {{ if eq .Field.Value true }}checked{{end}} class="w-4 h-4 text-blue-600 bg-gray-100 border-gray-300 rounded focus:ring-blue-500 dark:focus:ring-blue-600 dark:ring-offset-gray-800 focus:ring-2 dark:bg-gray-700 dark:border-gray-600">
     {{ else }}
-	<input {{with .Id}}id="{{.}}"{{end}} name="{{.Name}}" placeholder="{{.Placeholder}}" {{with .Value}}value="{{.}}"{{end}} {{ if eq .Required true }}required{{end}} class="block w-full appearance-none rounded-md border border-gray-300 px-3 py-2 placeholder-gray-400 shadow-sm focus:border-indigo-500 focus:outline-none focus:ring-indigo-500 sm:text-sm">
+	<input {{with .Field.Id}}id="{{.}}"{{end}} name="{{.Field.Name}}" placeholder="{{.Field.Placeholder}}" {{with .Field.Value}}value="{{.}}"{{end}} {{ if eq .Required true }}required{{end}} class="block w-full appearance-none rounded-md border border-gray-300 px-3 py-2 placeholder-gray-400 shadow-sm focus:border-indigo-500 focus:outline-none focus:ring-indigo-500 sm:text-sm">
     {{ end }}
 	{{range errors}}
      <span class="text-sm text-red-600">{{.}}</span>

form.go

@@ -1,6 +1,7 @@
 package form
 
 import (
+	"errors"
 	"html/template"
 	"strings"
 )
@@ -23,14 +24,29 @@ func (f *Form) FuncMap() template.FuncMap {
 	}
 }
 
-func (f *Form) formRender(v interface{}, errs []FieldError) (template.HTML, error) {
+func (f *Form) formRender(v interface{}, errs []FieldError, kv ...any) (template.HTML, error) {
 	tr, err := NewTransformer(v)
 	if err != nil {
 		return "", err
 	}
 
 	fieldErrors := scanError(errs)
 
+	var data = make(map[string]any)
+	if len(kv) > 0 {
+		if len(kv)%2 != 0 {
+			return "", errors.New("invalid dict call")
+		}
+
+		for i := 0; i < len(kv); i += 2 {
+			key, ok := kv[i].(string)
+			if !ok {
+				return "", errors.New("dict keys must be strings")
+			}
+			data[key] = kv[i+1]
+		}
+	}
+
 	var html template.HTML
 	for _, field := range tr.Fields {
 		if field.Type == FieldTypeGroup {
@@ -45,7 +61,10 @@ func (f *Form) formRender(v interface{}, errs []FieldError) (template.HTML, erro
 					var subhtml template.HTML
 
 					for _, subField := range field.Fields {
-						fieldhtml, err := f.formFieldHTML(subField, fieldErrors)
+						fMap := copyMap(data)
+						fMap["Field"] = field
+
+						fieldhtml, err := f.formFieldHTML(subField, fieldErrors, fMap)
 						if err != nil {
 							continue
 						}
@@ -57,7 +76,10 @@ func (f *Form) formRender(v interface{}, errs []FieldError) (template.HTML, erro
 				},
 			})
 
-			err = gtpl.Execute(&sb, field)
+			fMap := copyMap(data)
+			fMap["Field"] = field
+
+			err = gtpl.Execute(&sb, fMap)
 			if err != nil {
 				return "", err
 			}
@@ -66,7 +88,7 @@ func (f *Form) formRender(v interface{}, errs []FieldError) (template.HTML, erro
 			continue
 		}
 
-		fieldHTML, err := f.formFieldHTML(field, fieldErrors)
+		fieldHTML, err := f.formFieldHTML(field, fieldErrors, data)
 		if err != nil {
 			return "", err
 		}
@@ -76,7 +98,7 @@ func (f *Form) formRender(v interface{}, errs []FieldError) (template.HTML, erro
 	return html, nil
 }
 
-func (f *Form) formFieldHTML(field FormField, errors map[string][]string) (template.HTML, error) {
+func (f *Form) formFieldHTML(field FormField, errors map[string][]string, data map[string]any) (template.HTML, error) {
 	tpl, err := f.template.Clone()
 	if err != nil {
 		return "", err
@@ -91,7 +113,11 @@ func (f *Form) formFieldHTML(field FormField, errors map[string][]string) (templ
 			return nil
 		},
 	})
-	err = tpl.Execute(&sb, field)
+
+	fMap := copyMap(data)
+	fMap["Field"] = field
+
+	err = tpl.Execute(&sb, fMap)
 	if err != nil {
 		return "", err
 	}
@@ -111,3 +137,11 @@ func scanError(errs []FieldError) map[string][]string {
 	}
 	return ret
 }
+
+func copyMap[K, V comparable](m map[K]V) map[K]V {
+	result := make(map[K]V)
+	for k, v := range m {
+		result[k] = v
+	}
+	return result
+}

go.mod

@@ -1,3 +1,3 @@
 module github.com/donseba/go-form
 
-go 1.19
+go 1.20