Article
Lily Taub · Mar 19, 2019 9m read
A Tutorial On WebSockets

Intro

Most server-client communication on the web is based on a request and response structure. The client sends a request to the server and the server responds to this request. The WebSocket protocol provides a two-way channel of communication between a server and client, allowing servers to send messages to clients without first receiving a request. For more information on the WebSocket protocol and its implementation in InterSystems IRIS, see the links below.

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Hi Community!

We are glad to invite every developer who uses ObjectSript and VSCode plugin to the upcoming "Introduction to VSCode-ObjectScript" webinar on April 14, 2020 at 11:00 EDT.

Speaker: @Dmitry Maslennikov, InterSystems Developers Advocate, CTO at CaretDev.

You will learn how convenient the development process can be already right now and what we are going to do next to make it even better.

Please check the agenda below.

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Article
Vitaliy Serdtsev · May 20, 2017 10m read
Localization in Caché DBMS

This is a translation of the following article. Thanks @Evgeny Shvarov for the help in translation.

Let's assume that you wrote a program that shows "Hello World!", for example:

  write "Hello, World!"

The program works and everyone is happy.

With time, however, your program becomes more complex, gets more features and you eventually need to show the same string in different languages. Moreover you don't know the number and names of these languages.

The spoiler below contains a description of how the task of multi-language localization is solved in Caché.

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Discussion
John Murray · Mar 3, 2016
Anyone using Visual Studio Code?

Is anyone in the fine community of developers who work with ISC technologies looking at Microsoft's Visual Studio Code offering?

One of Bill McCormick's recent posts about Atelier referred to Visual Studio being considered the best IDE. Granted, Code is far less of a tool than VS, and probably always will be. But it claims to be open source and cross-platform, i.e. Linux and OS X as well as Windows.

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Article
Robert Cemper · Jul 20, 2020 1m read
IRIS-NativeAPI-Nodejs-compact

This is a follow-up to my previous article WebSocket Client JS with IRIS Native API as Docker Micro Server

Installation is now much simpler as all pieces are now assembled in a single Docker image.
That makes life easier. But of course, the principle of the Micro Service is not so obvious anymore.
An All-in-1 bundled package. Therefore compact.

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Article
Joel Solon · Dec 23, 2015 1m read
Caché ObjectScript Quick Reference

In the Caché Foundations course, students are learning about Caché Development and ObjectScript syntax at the same time. To help students complete the exercises, we provide an ObjectScript Quick Reference (aka "the Cheat Sheet").

It is not a reference for all of ObjectScript! It is a list of the ObjectScript commands and functions that students use during the course, along with common syntax for objects, collections, etc. It also contains some useful macros.

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Article
Vitaliy Serdtsev · Jul 7, 2017 19m read
Indexing of non-atomic attributes

Quotes (1NF/2NF/3NF)ru:

Every row-and-column intersection contains exactly one value from the applicable domain (and nothing else).
The same value can be atomic or non-atomic depending on the purpose of this value. For example, “4286” can be
  • atomic, if its denotes “a credit card’s PIN code” (if it’s broken down or reshuffled, it is of no use any longer)
  • non-atomic, if it’s just a “sequence of numbers” (the value still makes sense if broken down into several parts or reshuffled)

This article explores the standard methods of increasing the performance of SQL queries involving the following types of fields: string, date, simple list (in the $LB format), "list of <...>" and "array of <...>".

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Hi Developers!

Sometimes we need to import CSV data programmatically to InterSystems IRIS either from CSV or from URL. And we expect the class with proper datatypes to be created and the data to be imported.

I published a module csvgen on Open Exchange which does exactly that.

If you just need the CSV file be imported into IRIS you can do the following:

USER>do ##class(community.csvgen).Generate("/usr/data/titanic.csv",,"Data.Titanic")

Class name: Data.Titanic
Header: PassengerId INTEGER,Survived INTEGER,Pclass INTEGER,Name VARCHAR(250),Sex VARCHAR(250),Age INTEGER,SibSp INTEGER,Parch INTEGER,Ticket VARCHAR(250),Fare MONEY,Cabin VARCHAR(250),Embarked VARCHAR(250)
Records imported: 891
USER>

Or if you have the CSV on the internet, e.g. COVID-19 Data on Github you can get the data in the following way:

USER>d ##class(community.csvgen).GenerateFromURL("https://raw.githubusercontent.com/CSSEGISandData/COVID-19/master/csse_covid_19_data/csse_covid_19_daily_reports/05-29-2020.csv",",","Data.Covid19")

Class name: Data.Covid19
Header: FIPS INTEGER,Admin2 VARCHAR(250),Province_State VARCHAR(250),Country_Region VARCHAR(250),Last_Update DATE,Lat MONEY,Long_ DOUBLE,Confirmed INTEGER,Deaths INTEGER,Recovered INTEGER,Active INTEGER,Combined_Key VARCHAR(250),Incidence_Rate DOUBLE,Case-Fatality_Ratio DOUBLE
Records imported: 3522
USER>

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The DeclarativeCOS project is a heartfelt cry about programming in the COS language.

The purpose of the project is to draw attention of the public to improving the inner core of COS.

The idea of the project is the support of a laconic syntax for cycles and collections.

So what is this laconic something that I have come up with? Welcome to the examples below!

Examples

The key concept underlying the project is the declarative approach to writing code. You need to specify WHAT should be used and HOW.

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Article
Kurro Lopez · Mar 4, 2022 4m read
How to become a time lord - Time travel

Time travel is like visiting Paris. You can't just read the guide, you have to throw yourself into it. Eat the food, use the wrong verbs, get double the charges, and end up kissing complete strangers.

The Doctor

We are now going to travel through time, that is, we are going to see future and past dates and how to calculate them in different formats. The TARDIS doesn't wait, take the controls and hold on tight.

Travel in TARDIS

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Moving over from Studio To VSCode like many other will do now the ObjectScript plugin reached version 1.0, I noticed I was missing some items in the objectscript explorer. For example when creating a Rest API using the spec first approach, 3 classes are generated, an application.impl, application.disp and application.spec class, but the disp class was missing in the Object Explorer.

As the application.disp is a generated class, for showing these classes you need to turn this on by hitting the switch on the object explorer:

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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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Article
David Crawford · Jul 26, 2019 3m read
Dynamic SQL to Dynamic Object

Hello community! I have to work with queries using all kinds of methods like embedded sql and class queries. But my favorite is dynamic sql, simply because of how easy it is to manipulate them at runtime. The downside to writing a lot of these is the maintenance of the code and interacting with the output in a meaningful way.

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This morning on the old Caché Google Group, someone posed the following question, which I've decided to answer here, because it's interesting!

Is there a way to iterate ClassMethod's params, and get param's names and values?

The first answer I can come up with is: it's not easy! In any method, you could try to write code like this (where methodName is the name of your method):

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So I know it's been a while, and I hate to let my adoring fans down... just not enough to actually start writing again. But the wait is over and I'm back! Now bask in my beautiful ginger words!

For this series, I am going to look at some common problems we see in the WRC and discuss some common solutions. Of course, even if you find a solution here, you are always welcome to call in and expression you gratitude, or just hear my voice!

This week's common problem: "My query returns no data."

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Some weeks ago, I was reading a book by Stephen Hawking and Leonard Mlodinow, The Grand Design. At a certain point, trying to define why do we exist? , why do we use the models we use in physics?, ...those kind of things you know... they pointed at the Game of Life example invented by the mathematician John Coward in 1970... Basically he wanted to show that a system with really basic fundamental laws (Physics) could evolve and "live" to become a more complex system (Chemistry) in which "something" (humans) could work out its own model and complex rules to explain its reality… the rules for this deterministic model that he exposed were so basic that I thought it could be funny to implement them in ObjectScript when I had some spare time... there are others implementations in JavaScript and other languages... but not in ObjectScript... and that had to be corrected!!… so here you are!

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Here are a few examples of conversions and operations you might need, along with links to documentation where you can learn more.

At the time I wrote this, Eastern Daylight Time was in effect for my Caché system.

How Caché keeps the time and date

Caché has a simple time format, with a longer range of recognized dates compared to some other technologies.

The current time is maintained in a special variable $HOROLOG ($H):

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