validating optional field is between certain range

[thegalang]

Package version eg. v9, v10: v10

Issue, Question or Enhancement:

Is there a way to validate optional fields? let's say I want to validate if field str has either length 0 (not included) or length greater than 5.

Code sample, to showcase or reproduce:

Currently, I made a custom validator and tag like so:

type TestStruct {
TestStr string `validate:"optional_gte=5"`
}

So these strings will pass: "" "galang". These will fail: "ka".

Is there any way to do this built-in? if not, I can submit a PR with my custom tags if it's beneficial.

[BrianLeishman]

You can use "omitempty," at the beginning of your validation.

type TestStruct {
TestStr string `validate:"omitempty,gte=5"`
}

[mattwelke]

I ran into this use case today. I had a string property that was optional but if provided, must be a string with length greater than or equal to 1.

I used a string pointer for its type and validate:"omitempty,min=1" and it worked for me. 👍