context.md

Context

Context helps developers take control over the actions of Restify endpoints by providing mechanisms to enforce conditions and override data before it is submitted to the database.

Forced Conditions

Conditions allow you to append custom conditions to select, update, and delete queries, forcing specific criteria to be met.

Override

The Override function lets you modify data before it is submitted to the database, ensuring that certain fields or values are set according to your application's logic.

Error Handling

The Error function lets you throw an error as endpoint response.

Example

Here’s an example of how to use RestPermission to manage permissions, conditions, and overrides:

func (article *Article) RestPermission(permissions restify.Permissions, context *restify.Context) bool {

    var user, err = GetUser(context.Request) // retrieve user from basic auth

    // Don't let user do anything if the user is not logged in
    if err != nil {
        context.Error(err, http.StatusUnauthorized)
        return false
    }

    // Enable delete only for admin users
    if !user.IsAdmin && permissions.Has("DELETE") {
        return false
    }

    // Automatically set user_id in context for VIEW, UPDATE, DELETE, BATCH operations to the current user
    if permissions.Has("VIEW", "UPDATE", "DELETE", "BATCH") {
        context.SetCondition("user_id", "=", user.UserID)
    }

    // Override user_id in context for CREATE, UPDATE, DELETE, SET operations to the current user only
    if permissions.Has("CREATE", "UPDATE", "DELETE", "SET") {
        context.Override(Article{
            UserID: user.UserID,
        })
    }

    return true
}

Custom Validation Errors

The AddValidationErrors function lets you throw validation errors as endpoint response.

func (app App) Register() error {
    //global hooks
    restify.OnBeforeSave(func(obj any, c *restify.Context) error {
        if user, ok := obj.(*User); ok {
			if user.Username == "unallowed" {
                c.AddValidationErrors(fmt.Errorf("this username is not allowed"))
                return fmt.Errorf("validation error")
            }
        }
		
        return nil
    })
	
    return nil
}