Merge pull request #8 from leapkit/refining-validations

feature: updating the validations API

docs/features/validations.md

@@ -0,0 +1,100 @@
+---
+title: Form Validation
+index: 3
+---
+
+Leapkit provides the `form/validate` package that offers a flexible and reusable way to validate form data by defining a set of validation rules that can be applied to form fields.
+
+### How to Use
+
+Validations are a set of rules stablished for different fields passed in the request. You can define these Validations to be used in your http handlers by and call the `form.Validate` function passing the `req` (*http.Request) and handling the `validate.Errors` returned. Example:
+
+```go
+
+passwordExp := regexp.MustCompile(`^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$)`)
+
+rules := validate.Fields(
+	validate.Field("email", validate.Required("email is required")),
+	validate.Field(
+		"password",
+		validate.Required("password is required"),
+		validate.MatchRegex(
+			passwordExp,
+			"Password must contain at least 8 characters, one uppercase letter, one lowercase letter, one number and one special character",
+		),
+)
+
+verrs := form.Validate(req, rules)
+if len(verrs) > 0 {
+	 // handle validation errors...
+}
+```
+
+### Built-in Rules
+
+You can build your set of rules for each validation by using the package's built-in functions.
+
+```go
+// General Rules:
+func Required(message ...string) Rule
+
+// String Rules:
+func Matches(field string, message ...string) Rule
+func MatchRegex(re *regexp.Regexp, message ...string) Rule
+func MinLength(min int, message ...string) Rule
+func MaxLength(max int, message ...string) Rule
+func WithinOptions(options []string, message ...string) Rule
+
+// Number Rules:
+func EqualTo(value float64, message ...string) Rule
+func LessThan(value float64, message ...string) Rule
+func LessThanOrEqualTo(value float64, message ...string) Rule
+func GreaterThan(value float64, message ...string) Rule
+func GreaterThanOrEqualTo(value float64, message ...string) Rule
+
+// UUID Rule:
+func ValidUUID(message ...string) Rule
+
+// Time Rules:
+func TimeEqualTo(u time.Time, message ...string) Rule
+func TimeBefore(u time.Time, message ...string) Rule
+func TimeBeforeOrEqualTo(u time.Time, message ...string) Rule
+func TimeAfter(u time.Time, message ...string) Rule
+func TimeAfterOrEqualTo(u time.Time, message ...string) Rule
+```
+
+### Custom validation Rules
+
+Alternatively, you can create your own validation rules. Example:
+
+```go
+func IsUnique(db *sqlx.DB ) func([]string) error {
+   	return func(emails []string) error {
+     		query := "SELECT EXISTS(SELECT 1 FROM users WHERE email = $1)"
+	  		stmt, err := db.Prepare(query)
+	  		if err != nil {
+	 				  return err
+	  		}
+
+	  		for _, email := range emails {
+			 			var exists bool
+			 			if err := stmt.QueryRow(email).Scan(&exists); err != nil {
+							  return err
+			 			}
+
+			 			if exists {
+							return fmt.Errorf("email '%s' already exists.", email)
+			 			}
+    		}
+
+    		return nil
+   	}
+}
+
+// ...
+rules := validation.Fields(
+	validation.Field("email", validate.Required(), IsUnique(db))
+  ...
+)
+...
+```

docs/index.md

@@ -1,9 +1,9 @@
 ---
-title: "LeapKit"
+title: "About LeapKit"
 index: 1
 ---
 
-LeapKit is a collection of tools to help you build your next application with Go. Its main purpose is to make web development as fast and simple as possible and is targeted at web developers trying to take the leap and launch their next project.
+LeapKit is a collection of packages to help you build your next application with Go. Its main purpose is to make web development as fast and simple as possible and is targeted at web developers trying to take the leap and launch their next project.
 
 There are two main components of LeapKit, the LeapKit Core and the LeapKit Template, these two make the use of LeapKit possible.
 
@@ -13,5 +13,4 @@ The LeapKit Core contains the Go libraries that facilitate the web development.
 
 
 ## LeapKit Template
-
 The LeapKit Template contains a starting point folder structure using the LeapKit core. It provides some CLI commands to facilitate the web development of your apps, the template can be copied and modified with the `gonew` command.

form/form.go → form/decode.go

@@ -1,6 +1,7 @@
 package form
 
 import (
+	"fmt"
 	"net/http"
 	"strings"
 
@@ -18,8 +19,8 @@ var (
 func init() {
 	// Register custom and common type decoder
 	// functions.
-	decoder.RegisterCustomTypeFunc(DecodeUUID, uuid.UUID{})
-	decoder.RegisterCustomTypeFunc(DecodeUUIDSlice, []uuid.UUID{})
+	decoder.RegisterCustomTypeFunc(decodeUUID, uuid.UUID{})
+	decoder.RegisterCustomTypeFunc(decodeUUIDSlice, []uuid.UUID{})
 }
 
 // RegisterCustomTypeFunc registers a custom type decoder func for a type.
@@ -54,3 +55,32 @@ func Decode(r *http.Request, dst interface{}) error {
 	err := decoder.Decode(dst, r.Form)
 	return err
 }
+
+// decodeUUID a single uuid from a string
+// and returns an error if there is a problem
+func decodeUUID(vals []string) (interface{}, error) {
+	uu, err := uuid.FromString(vals[0])
+	if err != nil {
+		err = fmt.Errorf("error parsing uuid: %w", err)
+	}
+
+	return uu, err
+}
+
+// decodeUUIDSlice decodes a slice of uuids from a string
+// and returns an error if there is a problem
+func decodeUUIDSlice(vals []string) (interface{}, error) {
+	var uus []uuid.UUID
+
+	for _, val := range vals {
+		uuid, err := uuid.FromString(val)
+		if err != nil {
+			err = fmt.Errorf("error parsing uuid: %w", err)
+			return nil, err
+		}
+
+		uus = append(uus, uuid)
+	}
+
+	return uus, nil
+}