initial commit

.gitignore

@@ -13,3 +13,4 @@
 
 # Dependency directories (remove the comment below to include it)
 # vendor/
+.idea/

README.md

@@ -1,2 +1,110 @@
 # go-form
-Render forms in go based on struct layout
+
+Render forms in go based on struct layout, and tags. 
+
+Please note that this package is a pre-alfa release and mainly only a visualization of my initial thought. 
+I am also trying to keep the footprint as low as possible without using third party packages.
+
+it can convert to following data: 
+```go		
+data := struct {
+    Form   ExampleForm
+    Errors []error
+}{
+    Form: ExampleForm{
+        Name:  "John Wick",
+        Email: "john.wick@gmail.com",
+        Address: &AddressBlock{
+            Street1: "121 Mill Neck",
+            City:    "Long Island",
+            State:   "NY",
+            Zip:     "11765",
+        },
+        CheckBox:  true,
+        CheckBox2: false,
+    },
+    Errors: []error{
+        fieldError{
+            Field: "Email",
+            Issue: "is already taken",
+        },
+        fieldError{
+            Field: "Address.Street1",
+            Issue: "is required",
+        },
+    },
+}
+```
+
+into : 
+![](example/example-go-form.png)
+
+Call `form_render` inside the template and pass it the `form struct` and the `errors` : 
+```html
+<form class="space-y-6" action="#" method="POST">
+    {{ form_render .Form .Errors }}
+    <div class="flex items-center justify-between">
+        <button type="submit" class="flex w-full justify-center rounded-md border border-transparent bg-indigo-600 py-2 px-4 text-sm font-medium text-white shadow-sm hover:bg-indigo-700 focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:ring-offset-2">Signup</button>
+    </div>
+</form>
+```
+
+There is currently only one template file for all the currently supported templates. I'm thinking of making a mini template for each type. 
+```html
+<div>
+    <label {{with .Id}}for="{{.}}"{{end}} class="block text-sm font-medium text-gray-700">{{.Label}}{{ if eq .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">
+            {{ range $k, $option := .Values }}
+            <option value="{{$option.Id}}">{{$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 }}
+        <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">
+        {{ end }}
+
+        {{range errors}}
+        <span class="text-sm text-red-600">{{.}}</span>
+        {{end}}
+    </div>
+</div>
+```
+
+Groups (nested structs) have their own template 
+```html
+<div class="mb-4 bg-gray-50 p-2 rounded-md">
+  <label class="block text-grey-darker text-sm font-bold mb-2">{{.Name }}</label>
+  {{ fields }}
+</div>
+```
+
+please note that the errors need to implement with the `FieldError` interface. otherwise they will be silently skipped. You can achieve that doing so : 
+
+```go
+type fieldError struct {
+    Field string
+    Issue string
+}
+
+func (fe fieldError) Error() string {
+    return fmt.Sprintf("%s:%s", fe.Field, fe.Issue)
+}
+
+func (fe fieldError) FieldError() (field, err string) {
+    return fe.Field, fe.Issue
+}
+```
+
+supported tags
+- label
+- placeholder
+- name
+- required
+
+
+## TODO 
+- better tag handling. maybe group all possible options into one tag or keep it as is. 
+- add validation to process the form once posted.

example/main.go

@@ -0,0 +1,138 @@
+package main
+
+import (
+	"fmt"
+	"github.com/donseba/go-form"
+	"html/template"
+	"net/http"
+)
+
+var inputTpl = `<div>
+  <label {{with .Id}}for="{{.}}"{{end}} class="block text-sm font-medium text-gray-700">{{.Label}}{{ if eq .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">
+	  {{ range $k, $option := .Values }}
+		<option value="{{$option.Id}}">{{$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 }}
+	<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">
+    {{ end }}
+	{{range errors}}
+     <span class="text-sm text-red-600">{{.}}</span>
+	{{end}}
+</div>
+</div>`
+
+var groupTpl = `<div class="mb-4 bg-gray-50 p-2 rounded-md">
+  <label class="block text-grey-darker text-sm font-bold mb-2">
+	{{.Name }}
+  </label>
+  {{ fields }}
+</div>`
+
+func main() {
+	tpl := template.Must(template.New("").Funcs(template.FuncMap{
+		"errors": func() []form.FieldError { return nil },
+	}).Parse(inputTpl))
+	gtpl := template.Must(template.New("").Funcs(template.FuncMap{
+		"fields": func() template.HTML { return "" },
+	}).Parse(groupTpl))
+	fb := form.NewForm(*tpl, *gtpl)
+
+	pageTpl := template.Must(template.New("").Funcs(fb.FuncMap()).Parse(`
+<html>
+  <head>
+    <link href="https://cdn.jsdelivr.net/npm/tailwindcss/dist/tailwind.min.css" rel="stylesheet">
+  </head>
+  <body class="bg-grey-lighter">
+    <div class="mt-8 sm:mx-auto sm:w-full sm:max-w-md">
+      <div class="bg-white py-8 px-4 shadow sm:rounded-lg sm:px-10">
+        <form class="space-y-6" action="#" method="POST">
+  		{{ form_render .Form .Errors }}
+  		<div class="flex items-center justify-between">
+            <button type="submit" class="flex w-full justify-center rounded-md border border-transparent bg-indigo-600 py-2 px-4 text-sm font-medium text-white shadow-sm hover:bg-indigo-700 focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:ring-offset-2">Signup</button>
+          </div>
+        </form>
+  	</div>
+    </div>
+  </body>
+</html>
+	`))
+
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/html")
+
+		data := struct {
+			Form   ExampleForm
+			Errors []form.FieldError
+		}{
+			Form: ExampleForm{
+				Name:  "John Wick",
+				Email: "john.wick@gmail.com",
+				Address: &AddressBlock{
+					Street1: "121 Mill Neck",
+					City:    "Long Island",
+					State:   "NY",
+					Zip:     "11765",
+				},
+				CheckBox:  true,
+				CheckBox2: false,
+			},
+			Errors: []form.FieldError{
+				fieldError{
+					Field: "Email",
+					Issue: "is already taken",
+				},
+				fieldError{
+					Field: "Address.Street1",
+					Issue: "is required",
+				},
+			},
+		}
+
+		err := pageTpl.Execute(w, data)
+		if err != nil {
+			_, _ = fmt.Fprint(w, err)
+			return
+		}
+
+	})
+
+	err := http.ListenAndServe(":3000", nil)
+	if err != nil {
+		panic(err)
+	}
+}
+
+type ExampleForm struct {
+	Name       string
+	Email      string `required:"true"`
+	Address    *AddressBlock
+	InputTypes form.InputFieldType `label:"Enum Example"`
+	CheckBox   bool
+	CheckBox2  bool
+}
+
+type AddressBlock struct {
+	Street1 string
+	City    string
+	State   string
+	Zip     string `label:"Postal Code"`
+}
+
+type fieldError struct {
+	Field string
+	Issue string
+}
+
+func (fe fieldError) Error() string {
+	return fmt.Sprintf("%s:%s", fe.Field, fe.Issue)
+}
+
+func (fe fieldError) FieldError() (field, err string) {
+	return fe.Field, fe.Issue
+}

fields.go

@@ -0,0 +1,63 @@
+package form
+
+type FieldType string
+
+const (
+	FieldTypeGroup     FieldType = "group"
+	FieldTypeCheckbox  FieldType = "checkbox"
+	FieldTypeChecklist FieldType = "checklist"
+	FieldTypeInput     FieldType = "input"
+	FieldTypeLabel     FieldType = "label"
+	FieldTypeRadios    FieldType = "radios"
+	FieldTypeDropdown  FieldType = "dropdown"
+	FieldTypeSubmit    FieldType = "submit"
+	FieldTypeTextArea  FieldType = "textArea"
+)
+
+type InputFieldType string
+
+const (
+	InputFieldTypeText     InputFieldType = "text"
+	InputFieldTypePassword InputFieldType = "password"
+	InputFieldTypeEmail    InputFieldType = "email"
+	InputFieldTypeTel      InputFieldType = "tel"
+	InputFieldTypeNumber   InputFieldType = "number"
+	InputFieldTypeNone     InputFieldType = ""
+)
+
+func (i InputFieldType) String() string {
+	return string(i)
+}
+
+func (i InputFieldType) Enum() []any {
+	return []interface{}{
+		InputFieldTypeText,
+		InputFieldTypePassword,
+		InputFieldTypeEmail,
+		InputFieldTypeTel,
+		InputFieldTypeNumber,
+	}
+}
+
+type FieldValue struct {
+	Id       string `json:"id,omitempty"`
+	Name     string `json:"name,omitempty"`
+	Value    string `json:"value,omitempty"`
+	Disabled bool   `json:"disabled,omitempty"`
+	Group    string `json:"group,omitempty"`
+}
+
+type FormField struct {
+	Id          string         `json:"id,omitempty"`
+	Placeholder string         `json:"placeholder,omitempty"`
+	Name        string         `json:"name,omitempty"`
+	Value       interface{}    `json:"value,omitempty"`
+	Type        FieldType      `json:"type,omitempty"`
+	InputType   InputFieldType `json:"inputType,omitempty"`
+	Label       string         `json:"label,omitempty"`
+	Step        string         `json:"step,omitempty"`
+	Values      []FieldValue   `json:"values,omitempty"`
+	Required    bool           `json:"required"`
+	Fields      []FormField    `json:"fields,omitempty"`
+	Legend      string         `json:"legend,omitempty"`
+}