gin golang：什么是 gin.Context.Keys

Question

I was tring to use the method context.GetBool ( here ) from the go-gin framework with some query params. It doesn't work as excepted and I think the Context.Keys is not populated by query params.

So my question is: what is gin.Context.Keys , and how should it be populated when making a request?

PS: the question was already asked here , but left without a proper answer.

Answer 1

tl;dr The Keys field is what backs up Gin's Context implementation of context.Context interface as a request-scoped key/value carrier.

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I think the Context.Keys is not populated by query params.

Correct. Context.Keys is unrelated to query params. Query params are available withContext.Query .

About Keys instead, the document on the struct field reads:

Keys is a key/value pair exclusively for the context of each request .

And these key/value pairs are accessible with Get and Set . The docs of this latter one are:

Set is used to store a new key/value pair exclusively for this context. It also lazy initializes c.Keys if it was not used previously.

Hence the field is similar to context package's Context.WithValue and Context.Value , eg request-scoped parameters . Gin's Context Keys is the exported map that stores the raw key/value pairs. The methods such as GetBool are convenience, in that you don't have to type-assert the interface{} values yourself.

Unlike other web frameworks, Gin's Context does not wrap a context.Context value (except for c.Request.Context ), instead it directly implements the interface. This includes theValue method itself, which also accesses the underlying Keys field.