Clarify path param naming (#32969)

In history (from some legacy frameworks), both `:name` and `name` are
supported as path path name, `:name` is an alias to `name`.

To make code consistent, now we should only use `name` but not `:name`.

Also added panic check in related functions to make sure the name won't
be abused in case some downstreams still use them.

services/context/base_form.go

@@ -0,0 +1,72 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package context
+
+import (
+	"strconv"
+	"strings"
+
+	"code.gitea.io/gitea/modules/optional"
+)
+
+// FormString returns the first value matching the provided key in the form as a string
+func (b *Base) FormString(key string) string {
+	return b.Req.FormValue(key)
+}
+
+// FormStrings returns a string slice for the provided key from the form
+func (b *Base) FormStrings(key string) []string {
+	if b.Req.Form == nil {
+		if err := b.Req.ParseMultipartForm(32 << 20); err != nil {
+			return nil
+		}
+	}
+	if v, ok := b.Req.Form[key]; ok {
+		return v
+	}
+	return nil
+}
+
+// FormTrim returns the first value for the provided key in the form as a space trimmed string
+func (b *Base) FormTrim(key string) string {
+	return strings.TrimSpace(b.Req.FormValue(key))
+}
+
+// FormInt returns the first value for the provided key in the form as an int
+func (b *Base) FormInt(key string) int {
+	v, _ := strconv.Atoi(b.Req.FormValue(key))
+	return v
+}
+
+// FormInt64 returns the first value for the provided key in the form as an int64
+func (b *Base) FormInt64(key string) int64 {
+	v, _ := strconv.ParseInt(b.Req.FormValue(key), 10, 64)
+	return v
+}
+
+// FormBool returns true if the value for the provided key in the form is "1", "true" or "on"
+func (b *Base) FormBool(key string) bool {
+	s := b.Req.FormValue(key)
+	v, _ := strconv.ParseBool(s)
+	v = v || strings.EqualFold(s, "on")
+	return v
+}
+
+// FormOptionalBool returns an optional.Some(true) or optional.Some(false) if the value
+// for the provided key exists in the form else it returns optional.None[bool]()
+func (b *Base) FormOptionalBool(key string) optional.Option[bool] {
+	value := b.Req.FormValue(key)
+	if len(value) == 0 {
+		return optional.None[bool]()
+	}
+	s := b.Req.FormValue(key)
+	v, _ := strconv.ParseBool(s)
+	v = v || strings.EqualFold(s, "on")
+	return optional.Some(v)
+}
+
+func (b *Base) SetFormString(key, value string) {
+	_ = b.Req.FormValue(key) // force parse form
+	b.Req.Form.Set(key, value)
+}