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Validation

Lightning is a Go web framework that provides a lot of useful features, including validating user input. In this document, we will explore how to use the validating feature of the Lightning framework.

Validating User Input​

Validating user input is an essential part of any web application. It ensures that the data entered by the user is correct and meets the requirements of the application. Lightning provides a simple and easy-to-use way to validate user input.

Defining a Struct​

To validate user input, we first need to define a struct that represents the data we want to validate. In the example code provided, we have defined a User struct that contains fields for user data.

type User struct {
    Name     string `validate:"required" json:"name"`
    Password string `validate:"required,min=8,max=32" json:"password"`
    Email    string `validate:"required,email" json:"email"`
}

In this struct, each field has a validate tag that specifies the validation rules for that field. In this case, the Name field is required, the Password field is required and must be between 8 and 32 characters long, and the Email field is required and must be a valid email address.

You can find the detailed descriptions of the validations used in the fields contained on the structs below:

Binding and Validating User Input​

Once you have defined your validation struct, you can use it to validate incoming request data. In the following example, we use the JSONBody method to bind and validate the request body to the User struct:

app.Post("/validate", func(ctx *lightning.Context) {
    // Create a new User struct
    var user = &User{}

    // Bind and validate the request body to the User struct
    if err := ctx.JSONBody(user, true); err != nil {
        // If there is an error, return it as JSON
        ctx.Fail(-1, err.Error())
        return
    }

    // If there is no error, return the User struct as JSON
    ctx.Success(user)
})

In this route, we create a new User struct and bind the request body to it using the JSONBody method. This method automatically validates the input based on the validation tags defined in the struct.

If there is an error during validation, the JSONBody method returns an error, which we can handle by returning a JSON response with the error message.

If there is no error during validation, we can return the User struct as a JSON response.

Conclusion​

Validating user input is an essential part of any web application. Lightning provides a simple and easy-to-use way to validate user input using struct tags. By defining a struct with validation tags and using the JSONBody method, we can easily bind and validate user input in our routes.