How to Achieve Dynamic Type Return in Go?

How to Handle Dynamic Type Return in Golang?

Scenario:

In Golang Revel development, repetitive code arises due to similar data return types involving type struct. Consider the following functions:

func (c Helper) Brands() []*models.Brand {

    // Query rethinkdb and populate the Brand model
    var brands []*models.Brand
    rows.All(&brands)

    return brands

}

func (c Helper) BlogPosts() []*models.Post {

    // Query rethinkdb and populate the Post model
    var posts []*models.Post
    rows.All(&posts)

    return posts

}

In both cases, the return type is the same (*[]struct). To avoid duplication, a dynamic return type approach is proposed:

func (c Helper) ReturnModels(modelName string) []*interface{} {

    // Query rethinkdb with modelName and return []*interface{}
}

Questions:

• Is dynamic type return possible?
• How to implement it?

Answer:

Yes, dynamic type return is achievable. The function should return interface{} rather than []*interface{}. Here's how it can be implemented:

func (c Helper) ReturnModels(modelName string) interface{} {

    // Query rethinkdb with modelName and return interface{}
}

To utilize the returned value, type switches or type assertions are employed to cast it back to its original type:

Example:

if brands, ok := ReturnModels("brands").([]Brand); ok {
    // ...
}

if posts, ok := ReturnModels("posts").([]Post); ok {
    // ...
}

By implementing this approach, code duplication can be significantly reduced by using a single helper function for data retrieval.

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