json struct tag to omit zero value from objects

[bradfitz]

Feature request: a "jsonSkipZero" struct tag.

type Foo struct {
    A           int    `json:"a"`
    B           string `json:"a"`
    OptionalBar string `json:"optionalBar" jsonSkipZero:"true"`
    OptionalBaz int    `json:"optionalBaz" jsonSkipZero:"true"`
    OptionalQux *Qux   `json:"optionalQux" jsonSkipZero:"true"`
}

... so optionalStuff doesn't appear in the output object.

[gopherbot]

Comment 1 by robpike:

Not a vote up or down on the feature request, but if this goes in I'd be happier to see
the tag space not get another entry. The information relevant to package json should go
in the json tag.

[robpike]

Comment 2:

Status changed to Accepted.

[bradfitz]

Comment 3:

Russ, thoughts?

[rsc]

Comment 4:

i was going to say the same thing rob did.

[bradfitz]

Comment 5:

Preferred syntax, though?
OptionalBar string `json:"optionalBar +skipzero"`

[bradfitz]

Comment 6:

Per Russ:
`json:"optionalBar" json.omitzero:"true"`
... as there's a precedent in using a dot for flags (-test.v)

[gopherbot]

Comment 7 by crazy1be:

Any reason to not just have it as json.required and have it default to omitting if the
field is nil?
In any case, json.omitzero seems longer and more verbose than necessary. I would go for
something like json.optional, since it conveys what the tag actually means semantically.

[bradfitz]

Comment 8:

This issue was closed by revision 3f53475.

Status changed to Fixed.