Move macaron to chi (#14293)

Use [chi](https://github.com/go-chi/chi) instead of the forked [macaron](https://gitea.com/macaron/macaron). Since macaron and chi have conflicts with session share, this big PR becomes a have-to thing. According my previous idea, we can replace macaron step by step but I'm wrong. :( Below is a list of big changes on this PR.

- [x] Define `context.ResponseWriter` interface with an implementation `context.Response`.
- [x] Use chi instead of macaron, and also a customize `Route` to wrap chi so that the router usage is similar as before.
- [x] Create different routers for `web`, `api`, `internal` and `install` so that the codes will be more clear and no magic .
- [x] Use https://github.com/unrolled/render instead of macaron's internal render
- [x] Use https://github.com/NYTimes/gziphandler instead of https://gitea.com/macaron/gzip
- [x] Use https://gitea.com/go-chi/session which is a modified version of https://gitea.com/macaron/session and removed `nodb` support since it will not be maintained. **BREAK**
- [x] Use https://gitea.com/go-chi/captcha which is a modified version of https://gitea.com/macaron/captcha
- [x] Use https://gitea.com/go-chi/cache which is a modified version of https://gitea.com/macaron/cache
- [x] Use https://gitea.com/go-chi/binding which is a modified version of https://gitea.com/macaron/binding
- [x] Use https://github.com/go-chi/cors instead of https://gitea.com/macaron/cors
- [x] Dropped https://gitea.com/macaron/i18n and make a new one in `code.gitea.io/gitea/modules/translation`
- [x] Move validation form structs from `code.gitea.io/gitea/modules/auth` to `code.gitea.io/gitea/modules/forms` to avoid dependency cycle.
- [x] Removed macaron log service because it's not need any more. **BREAK**
- [x] All form structs have to be get by `web.GetForm(ctx)` in the route function but not as a function parameter on routes definition.
- [x] Move Git HTTP protocol implementation to use routers directly.
- [x] Fix the problem that chi routes don't support trailing slash but macaron did.
- [x] `/api/v1/swagger` now will be redirect to `/api/swagger` but not render directly so that `APIContext` will not create a html render. 

Notices:
- Chi router don't support request with trailing slash
- Integration test `TestUserHeatmap` maybe mysql version related. It's failed on my macOS(mysql 5.7.29 installed via brew) but succeed on CI.

Co-authored-by: 6543 <6543@obermui.de>

1 files changed, 715 insertions, 0 deletions

diff --git a/vendor/gitea.com/go-chi/binding/binding.go b/vendor/gitea.com/go-chi/binding/binding.go
new file mode 100644
index 0000000000..acd2a7e171
--- /dev/null
+++ b/vendor/gitea.com/go-chi/binding/binding.go
@@ -0,0 +1,715 @@
+// Copyright 2014 Martini Authors
+// Copyright 2014 The Macaron Authors
+// Copyright 2020 The Gitea Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License"): you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+// Package binding is a middleware that provides request data binding and validation for Chi.
+package binding
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"mime/multipart"
+	"net/http"
+	"net/url"
+	"reflect"
+	"regexp"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/unknwon/com"
+)
+
+// Bind wraps up the functionality of the Form and Json middleware
+// according to the Content-Type and verb of the request.
+// A Content-Type is required for POST and PUT requests.
+// Bind invokes the ErrorHandler middleware to bail out if errors
+// occurred. If you want to perform your own error handling, use
+// Form or Json middleware directly. An interface pointer can
+// be added as a second argument in order to map the struct to
+// a specific interface.
+func Bind(req *http.Request, obj interface{}) Errors {
+	contentType := req.Header.Get("Content-Type")
+	if req.Method == "POST" || req.Method == "PUT" || len(contentType) > 0 {
+		switch {
+		case strings.Contains(contentType, "form-urlencoded"):
+			return Form(req, obj)
+		case strings.Contains(contentType, "multipart/form-data"):
+			return MultipartForm(req, obj)
+		case strings.Contains(contentType, "json"):
+			return JSON(req, obj)
+		default:
+			var errors Errors
+			if contentType == "" {
+				errors.Add([]string{}, ERR_CONTENT_TYPE, "Empty Content-Type")
+			} else {
+				errors.Add([]string{}, ERR_CONTENT_TYPE, "Unsupported Content-Type")
+			}
+			return errors
+		}
+	} else {
+		return Form(req, obj)
+	}
+}
+
+const (
+	_JSON_CONTENT_TYPE          = "application/json; charset=utf-8"
+	STATUS_UNPROCESSABLE_ENTITY = 422
+)
+
+// errorHandler simply counts the number of errors in the
+// context and, if more than 0, writes a response with an
+// error code and a JSON payload describing the errors.
+// The response will have a JSON content-type.
+// Middleware remaining on the stack will not even see the request
+// if, by this point, there are any errors.
+// This is a "default" handler, of sorts, and you are
+// welcome to use your own instead. The Bind middleware
+// invokes this automatically for convenience.
+func errorHandler(errs Errors, rw http.ResponseWriter) {
+	if len(errs) > 0 {
+		rw.Header().Set("Content-Type", _JSON_CONTENT_TYPE)
+		if errs.Has(ERR_DESERIALIZATION) {
+			rw.WriteHeader(http.StatusBadRequest)
+		} else if errs.Has(ERR_CONTENT_TYPE) {
+			rw.WriteHeader(http.StatusUnsupportedMediaType)
+		} else {
+			rw.WriteHeader(STATUS_UNPROCESSABLE_ENTITY)
+		}
+		errOutput, _ := json.Marshal(errs)
+		rw.Write(errOutput)
+		return
+	}
+}
+
+// Form is middleware to deserialize form-urlencoded data from the request.
+// It gets data from the form-urlencoded body, if present, or from the
+// query string. It uses the http.Request.ParseForm() method
+// to perform deserialization, then reflection is used to map each field
+// into the struct with the proper type. Structs with primitive slice types
+// (bool, float, int, string) can support deserialization of repeated form
+// keys, for example: key=val1&key=val2&key=val3
+// An interface pointer can be added as a second argument in order
+// to map the struct to a specific interface.
+func Form(req *http.Request, formStruct interface{}) Errors {
+	var errors Errors
+
+	ensurePointer(formStruct)
+	formStructV := reflect.ValueOf(formStruct)
+	parseErr := req.ParseForm()
+
+	// Format validation of the request body or the URL would add considerable overhead,
+	// and ParseForm does not complain when URL encoding is off.
+	// Because an empty request body or url can also mean absence of all needed values,
+	// it is not in all cases a bad request, so let's return 422.
+	if parseErr != nil {
+		errors.Add([]string{}, ERR_DESERIALIZATION, parseErr.Error())
+	}
+	errors = mapForm(formStructV, req.Form, nil, errors)
+	return append(errors, Validate(req, formStruct)...)
+}
+
+// MaxMemory represents maximum amount of memory to use when parsing a multipart form.
+// Set this to whatever value you prefer; default is 10 MB.
+var MaxMemory = int64(1024 * 1024 * 10)
+
+// MultipartForm works much like Form, except it can parse multipart forms
+// and handle file uploads. Like the other deserialization middleware handlers,
+// you can pass in an interface to make the interface available for injection
+// into other handlers later.
+func MultipartForm(req *http.Request, formStruct interface{}) Errors {
+	var errors Errors
+	ensurePointer(formStruct)
+	formStructV := reflect.ValueOf(formStruct)
+	// This if check is necessary due to https://github.com/martini-contrib/csrf/issues/6
+	if req.MultipartForm == nil {
+		// Workaround for multipart forms returning nil instead of an error
+		// when content is not multipart; see https://code.google.com/p/go/issues/detail?id=6334
+		if multipartReader, err := req.MultipartReader(); err != nil {
+			errors.Add([]string{}, ERR_DESERIALIZATION, err.Error())
+		} else {
+			form, parseErr := multipartReader.ReadForm(MaxMemory)
+			if parseErr != nil {
+				errors.Add([]string{}, ERR_DESERIALIZATION, parseErr.Error())
+			}
+
+			if req.Form == nil {
+				req.ParseForm()
+			}
+			for k, v := range form.Value {
+				req.Form[k] = append(req.Form[k], v...)
+			}
+
+			req.MultipartForm = form
+		}
+	}
+	errors = mapForm(formStructV, req.MultipartForm.Value, req.MultipartForm.File, errors)
+	return append(errors, Validate(req, formStruct)...)
+}
+
+// JSON is middleware to deserialize a JSON payload from the request
+// into the struct that is passed in. The resulting struct is then
+// validated, but no error handling is actually performed here.
+// An interface pointer can be added as a second argument in order
+// to map the struct to a specific interface.
+func JSON(req *http.Request, jsonStruct interface{}) Errors {
+	var errors Errors
+	ensurePointer(jsonStruct)
+
+	if req.Body != nil {
+		defer req.Body.Close()
+		err := json.NewDecoder(req.Body).Decode(jsonStruct)
+		if err != nil && err != io.EOF {
+			errors.Add([]string{}, ERR_DESERIALIZATION, err.Error())
+		}
+	}
+	return append(errors, Validate(req, jsonStruct)...)
+}
+
+// RawValidate is same as Validate but does not require a HTTP context,
+// and can be used independently just for validation.
+// This function does not support Validator interface.
+func RawValidate(obj interface{}) Errors {
+	var errs Errors
+	v := reflect.ValueOf(obj)
+	k := v.Kind()
+	if k == reflect.Interface || k == reflect.Ptr {
+		v = v.Elem()
+		k = v.Kind()
+	}
+	if k == reflect.Slice || k == reflect.Array {
+		for i := 0; i < v.Len(); i++ {
+			e := v.Index(i).Interface()
+			errs = validateStruct(errs, e)
+		}
+	} else {
+		errs = validateStruct(errs, obj)
+	}
+	return errs
+}
+
+// Validate is middleware to enforce required fields. If the struct
+// passed in implements Validator, then the user-defined Validate method
+// is executed, and its errors are mapped to the context. This middleware
+// performs no error handling: it merely detects errors and maps them.
+func Validate(req *http.Request, obj interface{}) Errors {
+	var errs Errors
+	v := reflect.ValueOf(obj)
+	k := v.Kind()
+	if k == reflect.Interface || k == reflect.Ptr {
+		v = v.Elem()
+		k = v.Kind()
+	}
+	if k == reflect.Slice || k == reflect.Array {
+		for i := 0; i < v.Len(); i++ {
+			e := v.Index(i).Interface()
+			errs = validateStruct(errs, e)
+			if validator, ok := e.(Validator); ok {
+				errs = validator.Validate(req, errs)
+			}
+		}
+	} else {
+		errs = validateStruct(errs, obj)
+		if validator, ok := obj.(Validator); ok {
+			errs = validator.Validate(req, errs)
+		}
+	}
+	return errs
+}
+
+var (
+	AlphaDashPattern    = regexp.MustCompile("[^\\d\\w-_]")
+	AlphaDashDotPattern = regexp.MustCompile("[^\\d\\w-_\\.]")
+	EmailPattern        = regexp.MustCompile("[\\w!#$%&'*+/=?^_`{|}~-]+(?:\\.[\\w!#$%&'*+/=?^_`{|}~-]+)*@(?:[\\w](?:[\\w-]*[\\w])?\\.)+[a-zA-Z0-9](?:[\\w-]*[\\w])?")
+)
+
+// Copied from github.com/asaskevich/govalidator.
+const _MAX_URL_RUNE_COUNT = 2083
+const _MIN_URL_RUNE_COUNT = 3
+
+var (
+	urlSchemaRx    = `((ftp|tcp|udp|wss?|https?):\/\/)`
+	urlUsernameRx  = `(\S+(:\S*)?@)`
+	urlIPRx        = `([1-9]\d?|1\d\d|2[01]\d|22[0-3])(\.(1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.([0-9]\d?|1\d\d|2[0-4]\d|25[0-4]))`
+	ipRx           = `(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))`
+	urlSubdomainRx = `((www\.)|([a-zA-Z0-9]([-\.][-\._a-zA-Z0-9]+)*))`
+	urlPortRx      = `(:(\d{1,5}))`
+	urlPathRx      = `((\/|\?|#)[^\s]*)`
+	URLPattern     = regexp.MustCompile(`^` + urlSchemaRx + `?` + urlUsernameRx + `?` + `((` + urlIPRx + `|(\[` + ipRx + `\])|(([a-zA-Z0-9]([a-zA-Z0-9-_]+)?[a-zA-Z0-9]([-\.][a-zA-Z0-9]+)*)|(` + urlSubdomainRx + `?))?(([a-zA-Z\x{00a1}-\x{ffff}0-9]+-?-?)*[a-zA-Z\x{00a1}-\x{ffff}0-9]+)(?:\.([a-zA-Z\x{00a1}-\x{ffff}]{1,}))?))\.?` + urlPortRx + `?` + urlPathRx + `?$`)
+)
+
+// IsURL check if the string is an URL.
+func isURL(str string) bool {
+	if str == "" || utf8.RuneCountInString(str) >= _MAX_URL_RUNE_COUNT || len(str) <= _MIN_URL_RUNE_COUNT || strings.HasPrefix(str, ".") {
+		return false
+	}
+	u, err := url.Parse(str)
+	if err != nil {
+		return false
+	}
+	if strings.HasPrefix(u.Host, ".") {
+		return false
+	}
+	if u.Host == "" && (u.Path != "" && !strings.Contains(u.Path, ".")) {
+		return false
+	}
+	return URLPattern.MatchString(str)
+
+}
+
+type (
+	// Rule represents a validation rule.
+	Rule struct {
+		// IsMatch checks if rule matches.
+		IsMatch func(string) bool
+		// IsValid applies validation rule to condition.
+		IsValid func(Errors, string, interface{}) (bool, Errors)
+	}
+
+	// ParamRule does same thing as Rule but passes rule itself to IsValid method.
+	ParamRule struct {
+		// IsMatch checks if rule matches.
+		IsMatch func(string) bool
+		// IsValid applies validation rule to condition.
+		IsValid func(Errors, string, string, interface{}) (bool, Errors)
+	}
+
+	// RuleMapper and ParamRuleMapper represent validation rule mappers,
+	// it allwos users to add custom validation rules.
+	RuleMapper      []*Rule
+	ParamRuleMapper []*ParamRule
+)
+
+var ruleMapper RuleMapper
+var paramRuleMapper ParamRuleMapper
+
+// AddRule adds new validation rule.
+func AddRule(r *Rule) {
+	ruleMapper = append(ruleMapper, r)
+}
+
+// AddParamRule adds new validation rule.
+func AddParamRule(r *ParamRule) {
+	paramRuleMapper = append(paramRuleMapper, r)
+}
+
+func in(fieldValue interface{}, arr string) bool {
+	val := fmt.Sprintf("%v", fieldValue)
+	vals := strings.Split(arr, ",")
+	isIn := false
+	for _, v := range vals {
+		if v == val {
+			isIn = true
+			break
+		}
+	}
+	return isIn
+}
+
+func parseFormName(raw, actual string) string {
+	if len(actual) > 0 {
+		return actual
+	}
+	return nameMapper(raw)
+}
+
+// Performs required field checking on a struct
+func validateStruct(errors Errors, obj interface{}) Errors {
+	typ := reflect.TypeOf(obj)
+	val := reflect.ValueOf(obj)
+
+	if typ.Kind() == reflect.Ptr {
+		typ = typ.Elem()
+		val = val.Elem()
+	}
+
+	for i := 0; i < typ.NumField(); i++ {
+		field := typ.Field(i)
+
+		// Allow ignored fields in the struct
+		if field.Tag.Get("form") == "-" || !val.Field(i).CanInterface() {
+			continue
+		}
+
+		fieldVal := val.Field(i)
+		fieldValue := fieldVal.Interface()
+		zero := reflect.Zero(field.Type).Interface()
+
+		// Validate nested and embedded structs (if pointer, only do so if not nil)
+		if field.Type.Kind() == reflect.Struct ||
+			(field.Type.Kind() == reflect.Ptr && !reflect.DeepEqual(zero, fieldValue) &&
+				field.Type.Elem().Kind() == reflect.Struct) {
+			errors = validateStruct(errors, fieldValue)
+		}
+		errors = validateField(errors, zero, field, fieldVal, fieldValue)
+	}
+	return errors
+}
+
+// Don't pass in pointers to bind to. Can lead to bugs.
+func ensureNotPointer(obj interface{}) {
+	if reflect.TypeOf(obj).Kind() == reflect.Ptr {
+		panic("Pointers are not accepted as binding models")
+	}
+}
+
+func validateField(errors Errors, zero interface{}, field reflect.StructField, fieldVal reflect.Value, fieldValue interface{}) Errors {
+	if fieldVal.Kind() == reflect.Slice {
+		for i := 0; i < fieldVal.Len(); i++ {
+			sliceVal := fieldVal.Index(i)
+			if sliceVal.Kind() == reflect.Ptr {
+				sliceVal = sliceVal.Elem()
+			}
+
+			sliceValue := sliceVal.Interface()
+			zero := reflect.Zero(sliceVal.Type()).Interface()
+			if sliceVal.Kind() == reflect.Struct ||
+				(sliceVal.Kind() == reflect.Ptr && !reflect.DeepEqual(zero, sliceValue) &&
+					sliceVal.Elem().Kind() == reflect.Struct) {
+				errors = validateStruct(errors, sliceValue)
+			}
+			/* Apply validation rules to each item in a slice. ISSUE #3
+			else {
+				errors = validateField(errors, zero, field, sliceVal, sliceValue)
+			}*/
+		}
+	}
+
+VALIDATE_RULES:
+	for _, rule := range strings.Split(field.Tag.Get("binding"), ";") {
+		if len(rule) == 0 {
+			continue
+		}
+
+		switch {
+		case rule == "OmitEmpty":
+			if reflect.DeepEqual(zero, fieldValue) {
+				break VALIDATE_RULES
+			}
+		case rule == "Required":
+			v := reflect.ValueOf(fieldValue)
+			if v.Kind() == reflect.Slice {
+				if v.Len() == 0 {
+					errors.Add([]string{field.Name}, ERR_REQUIRED, "Required")
+					break VALIDATE_RULES
+				}
+
+				continue
+			}
+
+			if reflect.DeepEqual(zero, fieldValue) {
+				errors.Add([]string{field.Name}, ERR_REQUIRED, "Required")
+				break VALIDATE_RULES
+			}
+		case rule == "AlphaDash":
+			if AlphaDashPattern.MatchString(fmt.Sprintf("%v", fieldValue)) {
+				errors.Add([]string{field.Name}, ERR_ALPHA_DASH, "AlphaDash")
+				break VALIDATE_RULES
+			}
+		case rule == "AlphaDashDot":
+			if AlphaDashDotPattern.MatchString(fmt.Sprintf("%v", fieldValue)) {
+				errors.Add([]string{field.Name}, ERR_ALPHA_DASH_DOT, "AlphaDashDot")
+				break VALIDATE_RULES
+			}
+		case strings.HasPrefix(rule, "Size("):
+			size, _ := strconv.Atoi(rule[5 : len(rule)-1])
+			if str, ok := fieldValue.(string); ok && utf8.RuneCountInString(str) != size {
+				errors.Add([]string{field.Name}, ERR_SIZE, "Size")
+				break VALIDATE_RULES
+			}
+			v := reflect.ValueOf(fieldValue)
+			if v.Kind() == reflect.Slice && v.Len() != size {
+				errors.Add([]string{field.Name}, ERR_SIZE, "Size")
+				break VALIDATE_RULES
+			}
+		case strings.HasPrefix(rule, "MinSize("):
+			min, _ := strconv.Atoi(rule[8 : len(rule)-1])
+			if str, ok := fieldValue.(string); ok && utf8.RuneCountInString(str) < min {
+				errors.Add([]string{field.Name}, ERR_MIN_SIZE, "MinSize")
+				break VALIDATE_RULES
+			}
+			v := reflect.ValueOf(fieldValue)
+			if v.Kind() == reflect.Slice && v.Len() < min {
+				errors.Add([]string{field.Name}, ERR_MIN_SIZE, "MinSize")
+				break VALIDATE_RULES
+			}
+		case strings.HasPrefix(rule, "MaxSize("):
+			max, _ := strconv.Atoi(rule[8 : len(rule)-1])
+			if str, ok := fieldValue.(string); ok && utf8.RuneCountInString(str) > max {
+				errors.Add([]string{field.Name}, ERR_MAX_SIZE, "MaxSize")
+				break VALIDATE_RULES
+			}
+			v := reflect.ValueOf(fieldValue)
+			if v.Kind() == reflect.Slice && v.Len() > max {
+				errors.Add([]string{field.Name}, ERR_MAX_SIZE, "MaxSize")
+				break VALIDATE_RULES
+			}
+		case strings.HasPrefix(rule, "Range("):
+			nums := strings.Split(rule[6:len(rule)-1], ",")
+			if len(nums) != 2 {
+				break VALIDATE_RULES
+			}
+			val := com.StrTo(fmt.Sprintf("%v", fieldValue)).MustInt()
+			if val < com.StrTo(nums[0]).MustInt() || val > com.StrTo(nums[1]).MustInt() {
+				errors.Add([]string{field.Name}, ERR_RANGE, "Range")
+				break VALIDATE_RULES
+			}
+		case rule == "Email":
+			if !EmailPattern.MatchString(fmt.Sprintf("%v", fieldValue)) {
+				errors.Add([]string{field.Name}, ERR_EMAIL, "Email")
+				break VALIDATE_RULES
+			}
+		case rule == "Url":
+			str := fmt.Sprintf("%v", fieldValue)
+			if len(str) == 0 {
+				continue
+			} else if !isURL(str) {
+				errors.Add([]string{field.Name}, ERR_URL, "Url")
+				break VALIDATE_RULES
+			}
+		case strings.HasPrefix(rule, "In("):
+			if !in(fieldValue, rule[3:len(rule)-1]) {
+				errors.Add([]string{field.Name}, ERR_IN, "In")
+				break VALIDATE_RULES
+			}
+		case strings.HasPrefix(rule, "NotIn("):
+			if in(fieldValue, rule[6:len(rule)-1]) {
+				errors.Add([]string{field.Name}, ERR_NOT_INT, "NotIn")
+				break VALIDATE_RULES
+			}
+		case strings.HasPrefix(rule, "Include("):
+			if !strings.Contains(fmt.Sprintf("%v", fieldValue), rule[8:len(rule)-1]) {
+				errors.Add([]string{field.Name}, ERR_INCLUDE, "Include")
+				break VALIDATE_RULES
+			}
+		case strings.HasPrefix(rule, "Exclude("):
+			if strings.Contains(fmt.Sprintf("%v", fieldValue), rule[8:len(rule)-1]) {
+				errors.Add([]string{field.Name}, ERR_EXCLUDE, "Exclude")
+				break VALIDATE_RULES
+			}
+		case strings.HasPrefix(rule, "Default("):
+			if reflect.DeepEqual(zero, fieldValue) {
+				if fieldVal.CanAddr() {
+					errors = setWithProperType(field.Type.Kind(), rule[8:len(rule)-1], fieldVal, field.Tag.Get("form"), errors)
+				} else {
+					errors.Add([]string{field.Name}, ERR_EXCLUDE, "Default")
+					break VALIDATE_RULES
+				}
+			}
+		default:
+			// Apply custom validation rules
+			var isValid bool
+			for i := range ruleMapper {
+				if ruleMapper[i].IsMatch(rule) {
+					isValid, errors = ruleMapper[i].IsValid(errors, field.Name, fieldValue)
+					if !isValid {
+						break VALIDATE_RULES
+					}
+				}
+			}
+			for i := range paramRuleMapper {
+				if paramRuleMapper[i].IsMatch(rule) {
+					isValid, errors = paramRuleMapper[i].IsValid(errors, rule, field.Name, fieldValue)
+					if !isValid {
+						break VALIDATE_RULES
+					}
+				}
+			}
+		}
+	}
+	return errors
+}
+
+// NameMapper represents a form tag name mapper.
+type NameMapper func(string) string
+
+var (
+	nameMapper = func(field string) string {
+		newstr := make([]rune, 0, len(field))
+		for i, chr := range field {
+			if isUpper := 'A' <= chr && chr <= 'Z'; isUpper {
+				if i > 0 {
+					newstr = append(newstr, '_')
+				}
+				chr -= ('A' - 'a')
+			}
+			newstr = append(newstr, chr)
+		}
+		return string(newstr)
+	}
+)
+
+// SetNameMapper sets name mapper.
+func SetNameMapper(nm NameMapper) {
+	nameMapper = nm
+}
+
+// Takes values from the form data and puts them into a struct
+func mapForm(formStruct reflect.Value, form map[string][]string,
+	formfile map[string][]*multipart.FileHeader, errors Errors) Errors {
+
+	if formStruct.Kind() == reflect.Ptr {
+		formStruct = formStruct.Elem()
+	}
+	typ := formStruct.Type()
+
+	for i := 0; i < typ.NumField(); i++ {
+		typeField := typ.Field(i)
+		structField := formStruct.Field(i)
+
+		if typeField.Type.Kind() == reflect.Ptr && typeField.Anonymous {
+			structField.Set(reflect.New(typeField.Type.Elem()))
+			errors = mapForm(structField.Elem(), form, formfile, errors)
+			if reflect.DeepEqual(structField.Elem().Interface(), reflect.Zero(structField.Elem().Type()).Interface()) {
+				structField.Set(reflect.Zero(structField.Type()))
+			}
+		} else if typeField.Type.Kind() == reflect.Struct {
+			errors = mapForm(structField, form, formfile, errors)
+		}
+
+		inputFieldName := parseFormName(typeField.Name, typeField.Tag.Get("form"))
+		if len(inputFieldName) == 0 || !structField.CanSet() {
+			continue
+		}
+
+		inputValue, exists := form[inputFieldName]
+		if exists {
+			numElems := len(inputValue)
+			if structField.Kind() == reflect.Slice && numElems > 0 {
+				sliceOf := structField.Type().Elem().Kind()
+				slice := reflect.MakeSlice(structField.Type(), numElems, numElems)
+				for i := 0; i < numElems; i++ {
+					errors = setWithProperType(sliceOf, inputValue[i], slice.Index(i), inputFieldName, errors)
+				}
+				formStruct.Field(i).Set(slice)
+			} else {
+				errors = setWithProperType(typeField.Type.Kind(), inputValue[0], structField, inputFieldName, errors)
+			}
+			continue
+		}
+
+		inputFile, exists := formfile[inputFieldName]
+		if !exists {
+			continue
+		}
+		fhType := reflect.TypeOf((*multipart.FileHeader)(nil))
+		numElems := len(inputFile)
+		if structField.Kind() == reflect.Slice && numElems > 0 && structField.Type().Elem() == fhType {
+			slice := reflect.MakeSlice(structField.Type(), numElems, numElems)
+			for i := 0; i < numElems; i++ {
+				slice.Index(i).Set(reflect.ValueOf(inputFile[i]))
+			}
+			structField.Set(slice)
+		} else if structField.Type() == fhType {
+			structField.Set(reflect.ValueOf(inputFile[0]))
+		}
+	}
+	return errors
+}
+
+// This sets the value in a struct of an indeterminate type to the
+// matching value from the request (via Form middleware) in the
+// same type, so that not all deserialized values have to be strings.
+// Supported types are string, int, float, and bool.
+func setWithProperType(valueKind reflect.Kind, val string, structField reflect.Value, nameInTag string, errors Errors) Errors {
+	switch valueKind {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		if val == "" {
+			val = "0"
+		}
+		intVal, err := strconv.ParseInt(val, 10, 64)
+		if err != nil {
+			errors.Add([]string{nameInTag}, ERR_INTERGER_TYPE, "Value could not be parsed as integer")
+		} else {
+			structField.SetInt(intVal)
+		}
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		if val == "" {
+			val = "0"
+		}
+		uintVal, err := strconv.ParseUint(val, 10, 64)
+		if err != nil {
+			errors.Add([]string{nameInTag}, ERR_INTERGER_TYPE, "Value could not be parsed as unsigned integer")
+		} else {
+			structField.SetUint(uintVal)
+		}
+	case reflect.Bool:
+		if val == "on" {
+			structField.SetBool(true)
+			break
+		}
+
+		if val == "" {
+			val = "false"
+		}
+		boolVal, err := strconv.ParseBool(val)
+		if err != nil {
+			errors.Add([]string{nameInTag}, ERR_BOOLEAN_TYPE, "Value could not be parsed as boolean")
+		} else if boolVal {
+			structField.SetBool(true)
+		}
+	case reflect.Float32:
+		if val == "" {
+			val = "0.0"
+		}
+		floatVal, err := strconv.ParseFloat(val, 32)
+		if err != nil {
+			errors.Add([]string{nameInTag}, ERR_FLOAT_TYPE, "Value could not be parsed as 32-bit float")
+		} else {
+			structField.SetFloat(floatVal)
+		}
+	case reflect.Float64:
+		if val == "" {
+			val = "0.0"
+		}
+		floatVal, err := strconv.ParseFloat(val, 64)
+		if err != nil {
+			errors.Add([]string{nameInTag}, ERR_FLOAT_TYPE, "Value could not be parsed as 64-bit float")
+		} else {
+			structField.SetFloat(floatVal)
+		}
+	case reflect.String:
+		structField.SetString(val)
+	}
+	return errors
+}
+
+// Pointers must be bind to.
+func ensurePointer(obj interface{}) {
+	if reflect.TypeOf(obj).Kind() != reflect.Ptr {
+		panic("Pointers are only accepted as binding models")
+	}
+}
+
+type (
+	// ErrorHandler is the interface that has custom error handling process.
+	ErrorHandler interface {
+		// Error handles validation errors with custom process.
+		Error(*http.Request, Errors)
+	}
+
+	// Validator is the interface that handles some rudimentary
+	// request validation logic so your application doesn't have to.
+	Validator interface {
+		// Validate validates that the request is OK. It is recommended
+		// that validation be limited to checking values for syntax and
+		// semantics, enough to know that you can make sense of the request
+		// in your application. For example, you might verify that a credit
+		// card number matches a valid pattern, but you probably wouldn't
+		// perform an actual credit card authorization here.
+		Validate(*http.Request, Errors) Errors
+	}
+)