Tips & Tricks - Automatic removal of system methods from codebase

Recently I wrote about automatic removal of system methods from the codebase.

Today, I'm ready to present you a working solution (codename: SMR) for this task.

What it does?

For each class you wish to process SMR does the following

1. Replaces .$ with .<something of your choice> (.% by default)
2. (Optonally) Capitalizes the letter after the $
3. Replaces references from %Object to %DynamicObject and so on

User guide

Import classes and call one of the entry points, depending on what classes you want to process. There are entry points for:

• all user classes
• subclasses of some class
• classes with name matching LIKE SQL condition

Entry points are the following methods:

set st = ##class(SMR.Main).RemoveFromAllClasses(Replace, Capitalize)
set st = ##class(SMR.Main).RemoveFromSubclassesOf(Class, Replace, Capitalize)
set st = ##class(SMR.Main).RemoveFromMatchingClasses(Mask, Replace, Capitalize)

Arguments:

• Replace - what to replace $ with (% by default but, for example, you can specify $$$ if you have macros)
• Capitalize - capitalize the letter after $ (boolean, yse by default)
• Class - class which subclasses the utility would try to convert (including the class)
• Mask - passed into the SQL query SELECT ID FROM %Dictionary.ClassDefinition Where ID LIKE ?

More throughout documentation is available in the code.

Example

Here's SMR.A class

Class SMR.A
{
ClassMethod A()
{
    set obj = ##class(%Library.Object).%New()
    set obj = {}.$fromJSON("{""a"":1}")
    write obj.$toJSON()
}
}

If you don't care about 2016.1 compatibility, you can just call SMR with the defaults, like this:

write ##class(SMR.Main).RemoveFromMatchingClasses("SMR.A")

And SMR.A class would look like this:

Class SMR.A
{
ClassMethod A()
{
    set obj = ##class(%Library.DynamicObject).%New()
    set obj = {}.%FromJSON("{""a"":1}")
    w obj.%ToJSON()
}
}

If, however you do care about 2016.1 compatibility, you can use macro approach as described here. Lets say we want to replace $<system method name> with $$$json<System method name>. To do that, call SMR like this:

write ##class(SMR.Main).RemoveFromMatchingClasses("SMR.A", "$$$json")

It yields:

Class SMR.A
{

ClassMethod A()
{
    set obj = ##class(%Library.DynamicObject).%New()
    set obj = {}.$$$jsonFromJSON("{""a"":1}")
    write obj.$$$jsonToJSON()
}
}

If you don't want to capitalize the first letter of system method name, you can provide Capitalize argument:

write ##class(SMR.Main).RemoveFromMatchingClasses("SMR.A", "$$$json", 0)

It yields:

Class SMR.A
{

ClassMethod A()
{
    set obj = ##class(%Library.DynamicObject).%New()
    set obj = {}.$$$jsonfromJSON("{""a"":1}")
    write obj.$$$jsontoJSON()
}
}

Notes

• Call TSTART before calling SMR, then view results in Studio and call TCOMMIT or TROLLBACK to finalize or remove the changes
• Carefully check resulting commit. This tool is NOT a syntax analyzer of any kind, it just uses $find and regexp
• $compose/%Compose method is unavailable in 2016.2. Don't forget to remove it
• SMR can be easily  modified to do some general purpose find-replacing for arbitrary group of classes
• Works only in a current namespace
• Works only in 2016.2 Field Test or later
• SMR does not compile processed classes

Links

• GitHub