Validation pattern for strings

A Validation Pattern can be set in the App Builder to ensure the user is inputting a parameter setting in the proper format. This will be present for input parameters that are strings.

Validation patterns are regular expressions, as described here.

^ matches as the beginning of the string, $ matches at the end of the string. Using both will ensure the parameter value entered matches the entire string and not part of the string. + matches the previous pattern one or more times, * matches the previous pattern 0 or more times.

Here are some common examples:

• Alphanumeric characters with underscores or dashes, but no spaces: ^[a-zA-Z0-9]+[_][-][a-zA-Z0-9]*$

• Any file name with a fasta extension: ^\S+.fn?a(sta)?(.gz)?$

• Any file name with a GTF extension: ^\S+.gtf(.gz)?$

• A csv, tsv, or txt file: ^\S+.(csv|tsv|txt)$