SF ID-Generator

Generates a custom ID for your Contact records

The requirement

One of my clients asked me to implement a solution that automatically assigns a custom non-SF ID to all Contacts upon creation or update of the record.

The custom ID should be alphanumeric and look like the following: AB1231

Generating the ID

1. randomly generate 2 letters
2. randomly generate 3 digits
3. calculate and append a verification number

Building the verification number

1. replace letters with their alphabetical index
2. all digits with modulo 10
3. multiply all digits alternately by 1 and 2
4. calculate the check sum from each product
5. add check sums together
6. sum modulo 10

Example:

If we randomly generated KW940, then the verification number must be 4

1. K = 11, W = 23 ==> Therefore, the sequence is 11 23 9 4 0
2. with modulo ==> 1 3 9 4 0
3. multiplied by 1s or 2s ==> 1 6 9 8 0
4. with check sum ==> 1 6 9 8 0
5. all added together ==> 24
6. modulo of 24 ==> 4 The ID therefore is KW9404.