Generate a unique IBM i object id

The shortid Nuget package generates unique, short ids. Out of the box is it is effective, but its default behavior doesn't generate unique ids that work as IBM i object names.

This wrapper function adds the constraints needed to generate a unique IBM i object name:

Using ShortId 
Using ShortId.Configuration 

...

BegFunc GenerateUniqueId Type(*Char) Len(10) 
    // ShortId class comes from this nuget package: https://www.nuget.org/packages/shortid

    DclFld Id Type(*Char) Len(10)

    DclFld Options Type(GenerationOptions) New()
    Options.Length = 10
    // ShortId needs at least 50 unique characters. 
    ShortId.SetCharacters('ABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890$#@abcdefghijklmnopqrstuvwxyz')

    Id = ShortId.Generate(Options).ToUpper()
    // Result cannot contain _, -, or start with a digit
    DoWhile Id.Contains('_') OR Id.Contains('-') OR Regex.IsMatch(Id, "^\d") 
        Id = ShortId.Generate(Options)
    EndDo             

    LeaveSr Id
EndFunc

...

DclFld ObjectId Type(*Char) Len(10)

ObjectId = GenerateUniqueId() 
// ObjectId is now a unqiue 10 char IBM i object id.

Every call to GenerateUniqueId() returns a unique 10-character IBM i object id. To ensure the added constraints don't affect ShortId's unique random capabilities, I used this repo to generate 1m ids and check each for uniqueness.

The test took a long time (each unique id is stashed in a string collection -- that gets very large before the test is completed.) Despite taking a long time, the GenerateUniqueId() function did indeed return 1m unique object ideas -- no duplicates.

To use the ShortID package in Visual RPG

Download the shortid package from the "Download package" link on the right side of this page.

Despite the download's .nupkg extension, Nuget packages are zip files. Use your favorite zip utility to unzip the package. After unzipping, set a reference to this file in the package

\lib\netstandard1.0\netstandard1.0\shortid.dll

in your Visual Studio project. Then, add these two Using statements:

Using ShortId 
Using ShortId.Configuration 

The GenerateUniqueId function (as shown above) compiles successfully after doing that setup.