Writing Attributes as fixed length strings

[BrianJHenry]

Hi, it's very possible I'm just missing something completely and this is very simple.

I'm struggling to figure out how to write out string type Attributes as fixed length strings instead of variable length strings.

Say I have:

H5File file = new()
        {
            ["group-name"] = new H5Group()
            {
                Attributes = new()
                {
                    ["first-attribute-name"] = "SecondAttribute", // I would like this to be written as a fixed length string where the length is equal to the length of the string "SecondAttribute"
                    ["second-attribute-name"] = "FirstAttribute"  // I would like this to be written as a fixed length string where the length is equal to the length of the string "FirstAttribute"
                }
            }
        };
        file.Write("path/to/file", new H5WriteOptions(
            DefaultStringLength: 10, // The attributes are written out as fixed strings instead of variable strings, but it's always fixed length of 10.
            FieldStringLengthMapper: field => { return -1; }, // Doesn't seem to get called except for compound types
            PropertyStringLengthMapper: field => { return -1; } // Doesn't seem to get called except for compound types
            ));

I dug into DatatypeMessage.Writing.cs, and wasn't able to trace out a way to get it to work.

Thanks

[Apollo3zehn]

You are right that it is currently not possible. I simply forgot to implement this and it is tracked here: #138. Unfortunately I have very limited time right now and it will be worse soon so I appreciate any pull requests to solve this :-)