#Code Snippet

Cache tricks

Several years ago, long before Developer Community Portal was launched, I published a series of Caché tricks at one of Czech web sites. In this article, I’m posting translated version of one of them.

Capturing output of someone else’s methods or routines

Suppose you, or someone else created a useful method or routine, that was producing some computation that you’d like to benefit from, but the routine was writing output to process principal device.

You would like to use the data, but you need it not written to a device, but assigned to a variable. And, for any reason, you can’t modify the code. What can you do?

I want to show my script which I use for a completion in bash, for ccontrol and csession.

With this script bash helps to available (running or down) instances to ccontrol, or in csession

file
/usr/share/bash-completion/completions/ccontrol

The message viewer can resend messages but it is not suitable for resending a large number of messages (>100). For that, you should use Cache Object Script code such as the following:

Two fairly common requests we receive from HL7 customers are (1) how to remove all trailing delimiters for fields and segments in HL7 messages and (2) how to "find and replace" for an entire HL7 message (as opposed to one segment/field at a time). The code sample below shows a custom function that solves for item 1 and by extension item 2 above. In other words the same approach can be used for finding/replacing any sequence of chars in an entire HL7 message, with some tweaks to the custom function.

The topic of for/while loop performance in Caché ObjectScript came up in discussion recently, and I'd like to share some thoughts/best practices with the rest of the community. While this is a basic topic in itself, it's easy to overlook the performance implications of otherwise-reasonable approaches.

Hi!

Want to share with you code snippet of try catch block I usually use in methods which should return %Status.

{ 
 try {
  	$$$TOE(sc,StatusMethod())
 }
 catch e {
 	set sc=e.AsStatus()
 	do e.Log()
 }

Quit sc 
}

Here $$$TOE is a short form of $$$TROWONERROR macro.

Inside macro StatusMethod is any method you call which will return %Status value. This value will be placed into sc variable.

There have been a few use cases recently within InterSystems where we've needed to connect to Caché-based web services from PHP. The first of these was actually the Developer Community itself, which uses web services as part of Single Sign-On with other InterSystems sites/applications. The following example demonstrates how to connect to a Caché-based web service (particularly, the web service in the SAMPLES namespace) from PHP, using password authentication.

C:\data\backup.bat :

C:\InterSystems\Ensemble\bin\cache -s"C:\InterSystems\Ensemble\Mgr" -U%%SYS ##Class(Backup.General).ExternalFreeze() <C:\data\login.scr

echo %ERRORLEVEL%

rem note that we need to check errorlevel from highest to lowest here....

if errorlevel 5 goto OK

Question:

How do I get a list of files residing in a certain folder/directory, according to some wildcard/filter.

For example all '*.txt' files in 'C:\Temp'.

Answer:

In CACHE –

You can use the %Library.File's FileSet class query.

Here's some sample code using it (also attached):

The attached code package provides a simple implementation of a web service client that utilizes the USPS Shipping API to normalize an address.

This code requires the developer to obtain a USPS Shipping API user ID which can be obtained from the USPS shipping API website. The assigned User Id can either be passed into the web service call as a parameter or can be coded as a parameter into the Request object.