Use Apex Functions in String format within Apex code

Question

I have text box to input apex function names. For example text box may have DateTime.Today(). I want to read this Text box String value in apex code and use as the standard function. Is there any way we can do that? The issue is the value comes as a String and cannot use it.

Answer 1

There is no (simple) mechanism to run arbitrary Apex code and if there was it would represent a serious security problem as code such as delete [select Id from Account]; could be executed.

(JavaScript has an eval function that allows arbitrary JavaScript code to be executed so that has to be blocked to make Lightning Components secure - see Eval() and Function() under LockerService.)

If you have a distinct set of operations you can offer those as a picklist and execute locked down code for each one. Beyond that, it is possible to write an expression parser and create your own (safe) mini-language but that is a lot of work.

Answer 2

The closest that you can get to today is to call "execute anonymous", which requires administrative privileges to avoid security problems.

You would call it like this:

req.setEndpoint('http://***instance***.salesforce.com/services/data/v42.0/'+
    'tooling/executeAnonymous/?anonymousBody='+
    EncodingUtil.urlEncode(sourceCode,'utf-8'));
req.setMethod('GET');

There is no concept of "reflection" in the world of Apex Code, so it's not trivially possible to execute random code on the fly.