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#Tips & Tricks

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Pieces of experience in InterSystems Technology which solve some particular problem in elegant or unusual way.

We're developing Ensemble PoC and one day our frontend developer (who doesn't have Ensemble production running) said that Populate just doesn't cut it and he needs to see the real data. He needed only one object, but the problem was - it's a big object. Still, I checked ids of everything related and wrote this command (parts omitted, but you get the idea):

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Article
· Sep 10, 2020 3m read
How To Create "Write-Only" Code

One of the leading benefits of ObjectScript is the speed and efficiency it allows for an experienced developer. Let's look at an example of how you can benefit from ObjectScript today.

Suppose you have a class that stores the names of your users. We'll call the class Data.User, and give it a string property Name. Next, we will need a method to create a new user or update an existing one. A naive, simplistic approach might look like this example:

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For some years I missed being able to offer, to everybody interested in ObjectScript, a tutorial more or less complete, to start with ObjectScript. Something that could help more and make things easier to those new developers that come to our technology... something intermediate, halfway between the common "Hello World!", that doesn't really get you further, and the "Advanced Training", that is unaffordable because of lack of time,etc.

If there were something truly helpful not only as an introduction to the ecosystem, but as a starting point, as a boost, to really start to walk into ObjectScript and move forward by yourself... wouldn't that be awesome?

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InterSystems IRIS currently limits classes to 999 properties.

But what to do if you need to store more data per object?

This article would answer this question (with the additional cameo of Community Python Gateway and how you can transfer wide datasets into Python).

The answer is very simple actually - InterSystems IRIS currently limits classes to 999 properties, but not to 999 primitives. The property in InterSystems IRIS can be an object with 999 properties and so on - the limit can be easily disregarded.

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Article
· Mar 1, 2022 5m read
How to become a time lord - The birth

Good men don’t need rules.

The Doctor.

It's not an easy task to be a master of dates and times, it is always a problem and sometimes confusing in any programming language, we are going to clarify and put a few tips to make this task as simple as possible.

Get on the TARDIS and I'm going to turn you into a Time lord

Tardis

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I was recently troubleshooting a problem on a Linux (RHEL) instance of 2016.1 at a site. For policy reasons their sysadmins wanted to update the Caché installation so it used network accounts for its cacheusr and iscagent users and groups instead of the locally-created ones that had been set up during original install of Caché.

To do this they ran various commands including chown

Afterwards non-root users couldn't obtain a terminal session using the csession command. Instead they receive this message:

cache: Permission denied

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Hi Devs!

For me, one of the most painful things about ObjectScript is ##class(Class).Method() typing to call a class method in code or in a terminal. I even submitted an idea to simplify it in ObjectScript.

But! There is a new feature in VSCode ObjectScript that was just introduced to the plugin - Copy Invocation!

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What is %SQLRESTRICT

%SQLRESTRICT is a special %FILTER clause for use in MDX queries in InterSystems IRIS Business Intelligence. Since this function begins with %, it means this is a special MDX extension created by InterSystems. It allows users to insert an SQL statement that will be used to restrict the returned records in the MDX Result Set. This SQL statement must return a set of Source Record IDs to limit the results by. Please see the documentation for more information.

Why is this useful?

This is useful because there are often times users want to restrict the results in their MDX Result Set based on information that is not in their cubes. It may be the case that this information may not make sense to be in the cube. Other times this can be useful when there is a large set of values you want to restrict. As mentioned before, this is not a standard MDX function, it was created by InterSystems to handle cases were queries were not performing well or cases that were not easily solved by existing functions.

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Hi developers!

Just want to share an old but always relevant best practice on namespaces changing @Dmitry Maslennikov shared with me (again).

Consider method:

classmethod DoSomethingInSYS() as %Status

{

set sc=$$$OK

set ns=$namespace

zn "%SYS"

// try-catch in case there will be an error

try {

// do something, e.g. config change

}

catch {}

 zn ns    ; returning back to the namespace we came in the routine

return sc

}

And with new $namespace the method could be rewritten as:

classmethod DoSomethingInSYS() as %Status

{

set sc=$$$OK

new $namespace

set $namespace="%SYS"

// do something

return sc

}

So! The difference is that we don't need to change the namespace manually as it will be back automatically once we return the method.

and we don't need try-catch (at least for this purpose) too.

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In Studio you could open a class directly via it's name, without having to traverse the package tree with multiple clicks until arriving at the desired class.

You would Ctrl + O or (File -> Open) and be able to simply type in the class name, for example:

You press Enter, and viola - the class is opened.

How do you achieve this in VSCode?

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Article
· Feb 14, 2017 1m read
Portal tip: The inconspicuous Menu button

Amongst the large fonts and chunky icons of Portal's pages, the Menu button in the top left corner is easily overlooked:

When clicked, it often produces the following menu:

When I remember it's there, I find the "View Console Log" option particularly handy.

I wrote "often" above because I've also noticed that the Menu contents change when I'm on a page within the Ensemble section of Portal:

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[Background]

InterSystems IRIS family has a nice utility ^SystemPerformance (as known as ^pButtons in Caché and Ensemble) which outputs the database performance information into a readable HTML file. When you run ^SystemPerformance on IRIS for Windows, a HTML file is created where both our own performance log mgstat and Windows performance log are included.

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Hi developers!

As you probably noticed in IRIS 2021 the names of globals are random.

And if you create IRIS classes with DDL and want to be sure what global was created you probably would want to provide a name.

And indeed you can do it.

Use WITH %CLASSPARAMETER DEFAULTGLOBAL='^GLobalName' in CREATE Table to make it work. Documentation. See the example below:

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Article
· Sep 28, 2017 1m read
Terminal license expire message

If you are facing out the license expire warning message on your terminal ("*** Warning: This Cache license will expire in 3 days ***") and you do not want that message to be displayed, you can disable/enable that by rinning the following commands:

Do ExpirationMessageOff^%SYS.LICENSE - Disable

Do ExpirationMessageOn^%SYS.LICENSE - Enable

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Article
· Mar 27, 2021 3m read
IRIS easy ECP workbench

Testing ECP-based applications often take quite some effort for setup and preparation.
I have created a Docker-based workbench that allows you to have it quick at hands.
And if you crash it? You just give your containers a fresh start.
The whole setup runs code-based during the start-up of your instance.
In that sense, it is also a portable coding example using ZPM and the objectscript-docker-template

see Video

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