Question
· Aug 28, 2020

List of custom items in %SYS namespace

Dear community

I'm using HealthShare on Cache 2017.2.  I'm trying to find out how I can get a list of all the custom classes, routines and globals in %SYS namespace (if it's even possible).

We're about to perform an upgrade, and in the docs it mentions needing to check for anything custom in %SYS to avoid important stuff being overwritten.  Some of our solutions have been developed by an external consultancy and we want to make sure that none of their code or data will be affected by the upgrade.

In TSQL there is an "is_ms_shipped" column, and I'm wondering if Cache has anything which does a similar job, or that gives required results.

Thanks

Marcus

Discussion (2)1
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Hi

It has been a generally understood convention for many many years that software houses and developers should not write classes or routines in the MGR (%SYS) database/namespace. The reason for this is that %SYS contains all of the Cache/Ensemble/IRIS system management classes and routines. By default any class or routine that is prefixed with the '%' character are mapped to all other namespaces in the Cache/Ensemble/IRIS Instance. In earlier versions of Cache many of the system configuration, security, operation utilities were written as Cache Objectscript routines. Over the years almost all of those routines and classes have been grouped into packages such as %SYSTEM and are accessed via the Cache Management Portal or through $system. $system is a shorthand way of referring to ##class(%System.{Classname}).{MethodName}(). Any classes or routines that are not prefixed with a '%' character are not mapped to other namespaces and can only be run in %SYS. 

The InterSystems developers used class or routine names that typically reflected the functionality of the class/routine, for example ^LOCKTAB, ^DATABASE, ^JOURNAL are routines that allow you to manage the Lock Table, Database utilities and Journalling utilities. Therefore it was always considered to be unwise to write classes or routines in %SYS due to the possibility that InterSystems might introduce a new class or routine that coincidentally has the same name as the routine or class your developers have written.

The general advise given to developers was as follows:

1)  If you need a routine or class to be accessible across many or all namespaces then create a database and namespace named "{Application}System" i.e. "MyCompanySystem" and then use the Namespace Routine and Package mapping feature of Namespace definitions to map those routines and/or classes to the desired namespaces where access to those routines/classes is required

2) If you absolutely have to write the classes and/or routines in %SYS then prefix the routine/class name with a 'z' (specifically lowercase 'z') as in ^%zMyRoutine or ^zMyOtherRotuine. InterSystems developers in turn would never write system classes/routines with a 'z' prefix

3) All InterSystem routines and classes will contain comments right at the start of the routine/class specifically saying that the code has been written by InterSystems and typically reads as follows:

LOCKTAB  ; LOCKTAB Utility  ; JO2010, 2/19/06
         /*
         +--------------------------------------------------------+
         | Copyright 1986-2015 by InterSystems Corporation,       |
         | Cambridge, Massachusetts, U.S.A.                       |
         | All rights reserved.                                   |
         |                                                        |
         | Confidential, unpublished property of InterSystems.    |
         |                                                        |
         | This media contains an authorized copy or copies       |
         | of material copyrighted by InterSystems and is the     |
         | confidential, unpublished property of InterSystems.    |
         | This copyright notice and any other copyright notices  |
         | included in machine readable copies must be reproduced |
         | on all authorized copies.                              |
         +--------------------------------------------------------+
         */

4) Use the %Dictionary.ClassDefinition class queries and methods to identify all classes in the %SYS namespace and when you open a class definition of a system class you will see that there is a property 'System' which if 'True' indicates that it is an InterSystems system class.

5) You can run the utility ^%ROU which will create a list of all routines in a namespace in a temporary global ^CacheTempUtil("ROU",{Name}) .  The entry point is the label DIR as in do DIR^%ROU({directory_name})

6) The databases 'CACHELIB", which  contains all of the Cache class Utility classes and 'ENSLIB' which contains the Ensemble utility classes are READ ONLY databases and therefore you cannot create routines or classes in them. %SYS on the otherhand has READ/WRITE permissions and so it was not untypical for developers to write routines in %SYS particularly in very early versions of cache that did not support Namespace Package Mapping.

I trust this helps

Nigel