NewBie's Corner Session 22 Parameters Part III

Welcome to NewBie's Corner, a weekly or biweekly post covering basic Caché Material.

Parameters

In Sessions’ 20 and 21 on Parameters we saw how to call one routine from another with parameters as well as calling one Label from another with parameters. In these examples, the data was passed through the parameters from the calling routine or label to the called routine or label.

Now suppose you wanted the called routine or label to pass data back?

This article will describe and include an example of how to embed an external PDF file into an HL7 segment, specifically ADT_A01:2.3.1 OBX(). This can be useful when attempting to insert pictures or other external data into an HL7 message. In this example, the name of the PDF file to be embedded is provided in the incoming HL7 message in OBX(1):ObservationValue field.

This is a beginner’s guide to the design of a “MicroService” implemented in Ensemble. “MicroService” is a popular phrase these days which has a broad interpretation. My interpretation is: “MicroService” is a “NoSQL Service”. A what? The answer is in the article.

We learnt what the difference is between SQL and NoSQL databases. For me the difference is nearly the same between a SOA Web Service and a “MicroService”. I am going to explain it through an example.

In this article I would like to tell you about macros in InterSystems Caché. A macro is a symbolic name that is replaced with a set of instructions during compilation. A macro can “unfold” in various instruction sets each time it is called, depending on the parameters passed to it and activated scenarios. This can be both static code and the result of ObjectScript execution. Let's take a look at how you can use them in your application.

This is the third article (see Part 1 and Part 2) where I continue to introduce you to the internal structure of Caché databases. This time, I will tell you a few interesting things and explain how my Caché Blocks Explorer project can help make your work more productive.

Each business component in Ensemble picks up its allocated jobs from a pool, and the Pool Size setting for each component determines how many jobs each component can work on each time. In this article we will be specifically discussing different Pool Size settings for Business Processes.

Pool Size = 1

Interesting anecdote I want to share. Not 100% Caché related, but I hope it would be useful.

When CSP Gateway is configured on IIS, opening CSP Gateway Configuration page is prohibited by default -- as IIS blocks URLs with '/bin' in it.

In our documentation we advise to add <remove segment="bin" /> to applicationHost.config file.
That is correct.

The goal of this writing was to illustrate how to restore backup before the patch would be applied. The alert notes that:

The risk can be avoided by applying journals from the beginning of the journal file that was switched to at the start of the backup, rather than accepting the default of starting from the journal marker position.

Having non-patched Caché 2015.1.4, I ran sample database backup and restore just to get where I should answer "No". Collecting journal info from the backup log:

This text is a continuation of my article where I explained the structure a Caché database. In this article, I described the types of blocks, connections between them and their relation to globals. The article was purely theoretical. I made a project that helps visualize the block tree - and this article will explain how it works in great detail.

One useful feature of our REST framework is the ability for a dispatch class to identify request prefixes and forward them to another dispatch class. This approach of modularizing your URL map will improve code readability, enable you to easily maintain separate versions of an interface, and provide a means to protect API calls that only certain users will be allowed to access.

A beginner’s guide to Exception Handling in RESTful web services. The article gives an example how the various error conditions during processing a service request can be handled.

We expect our client – server communication working in a flawless operational condition, running error free software. But we are prepared to handle exceptions. Are we? So far in the examples of the previous sessions were not. We did not care about exceptions. The result? In any error incident it took ages to figure out what the problem is and more importantly how to fix it.

This article gives a brief introduction how a RESTful service consumer and a RESTful service provider exchange data. It is a beginner’s guide. Data is transferred from a consumer to a provider as parameters of the service. Parameters are part of a service request. The result of the service action a response is returned from a provider to a consumer. Both the service request and response are standard HTTP messages. Since HTTP is a flexible standard regarding to the message contents, RESTful services also enjoy the versatility of data transfer methods.

How to parse a URL in Caché:

Let's pretend you are working on a project where you may be retrieving a URL for some purpose and you have the need to be easily able to parse apart that URL to get the various components that make up the URL.

Here's how to do that:

InterSystems Caché globals provide very convenient features for developers. But why are globals so fast and efficient?

Theory

Basically, the Caché database is a catalog having the same name as the database and containing the CACHE.DAT file. On Unix systems, the database can also be an ordinary disk partition.