Is hard coding custom metadata type name in Apex a good practice?

Question

I am new to custom metadata types (CMDT). With the Winter'22 maintenance, I learned that there is no longer a need to write Salesforce Object Query Language (SOQL) to access custom metadata records in Apex. There are new methods similar to accessing Custom Settings. This removes any SOQL limits, making the code cleaner and faster.

However, the example shown for this on the trailhead module uses

Games__mdt mc = Games__mdt.getInstance('FirstRecord');

to return a single record sObject. FirstRecord is the developerName for the CMDT named Games_mdt

I am interested in learning good practices with Apex and I am curious to know:

• Is hard coding CMDT names in Apex a good practice?
  • If so, please explain why?
  • If not, how do I avoid hard coding CMDT name?

Answer 1

Generic or specific coding structures are tools. Knowing when to use which is part of the art involved in being a good developer.

In this case, the name of your Custom Metadata Type is Games__mdt, and the only alternative would be to use Dynamic SOQL which would be an awkward fit for this situation. In all likelihood, trying to be more generic in this dimension would make your code harder to read and therefore less maintainable. It may also have worse performance as far as CPU consumption.