Impact of Struct Default Values on the required Rule

The properties of a Struct have default values, which in some cases can cause the required rule to become ineffective. For example:

type User struct {
    Name string `v:"required"`
    Age  uint   `v:"required"`
}

In this structure validation, the required check for the Age property will fail because Age will have a default value of 0 even if no input is provided.

There are three solutions:

1. Change the attribute to a pointer type, such as *int, *float64, *g.Var, etc., taking advantage of the pointer type’s default value of nil to bypass this issue.
2. Use a combined validation rule to compensate for the impact of default values on the required rule. For example, modifying the validation rule of the Age attribute in the example above to required|min:1 will achieve the desired business validation effect.
3. Use the Assoc joint validation method in Struct validation to set joint validation parameters. When validating parameters of the Struct type, the parameter values will be validated according to the parameters given in the Assoc method. If using the framework’s Server, with structured API input/output (XxxReq/XxxRes), the Server will automatically call Assoc for validation, so developers need not worry about the impact of default values. Documentation link: Struct Validation - Assoc