CODEWITHSUNDEEP
firebasegoogle-cloud-firestorefirebase-security
Ankit Patel
Ankit Patel

Reputation: 67

Firestore Security Rule - Validate incoming data length is greater than 2 but field is not required

I know how to check if a field of an incoming data set is a string or not, but how do I do a conditional check if the field exists, then check if its a string:

For example, "last name" is not a required field, but if it's supplied, then check if its length is greater than 2. I get an error if I just check the length rule generally -> is there a way to check the length only if last_name exists?

Firestore Rule: request.resource.data.last_name.length() > 0

Upvotes: 2

Views: 1379

Answers (2)

Be Kind
Be Kind

Reputation: 5182

Function for validating that field would be like this:

function isLastNameValid() {
  return request.resource.data.last_name == null || request.resource.data.last_name.size() > 2;
}

Upvotes: 4

Doug Stevenson
Doug Stevenson

Reputation: 317948

Checking if a value is a string is effectively the same as checking for existence. So if you do this:

request.resource.data.last_name is string

It will also return false if it doesn't exist.

But if you don't care what the type is, and you just want to check if it exists at all (as a string, number, whatever):

"last_name" in request.resource.data

request.resource.data is a Map, so check it's documentation at those links.

Upvotes: 2

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