forked from ebhomengo/niki
49 lines
1.3 KiB
Go
49 lines
1.3 KiB
Go
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// Copyright 2016 Qiang Xue. All rights reserved.
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// Use of this source code is governed by a MIT-style
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// license that can be found in the LICENSE file.
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package validation
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import "errors"
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type stringValidator func(string) bool
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// StringRule is a rule that checks a string variable using a specified stringValidator.
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type StringRule struct {
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validate stringValidator
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message string
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}
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// NewStringRule creates a new validation rule using a function that takes a string value and returns a bool.
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// The rule returned will use the function to check if a given string or byte slice is valid or not.
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// An empty value is considered to be valid. Please use the Required rule to make sure a value is not empty.
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func NewStringRule(validator stringValidator, message string) *StringRule {
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return &StringRule{
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validate: validator,
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message: message,
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}
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}
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// Error sets the error message for the rule.
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func (v *StringRule) Error(message string) *StringRule {
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return NewStringRule(v.validate, message)
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}
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// Validate checks if the given value is valid or not.
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func (v *StringRule) Validate(value interface{}) error {
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value, isNil := Indirect(value)
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if isNil || IsEmpty(value) {
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return nil
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}
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str, err := EnsureString(value)
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if err != nil {
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return err
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}
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if v.validate(str) {
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return nil
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}
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return errors.New(v.message)
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}
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