The attached file contains an example of code generation using ObjectGenerators which builds a very simple homemade RuleEngine.

Code generation is an excellent way of increasing performance moving run-time calculations to compile-time.

We could generate code creating routines or implemeting methods using ObjectGenerators. In this example we are using ObjectGenerators.

Update: Rule Engine is now on GitHub https://github.com/intersystems-ib/cache-iat-ruleengine

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Hello

I made for fun a bash script that creates csv files from a %GOGEN exported file.
%GOGEN, the utility for exporting globals for Cache 5.xx

First I thought it would be very simply with bash, but ...
- if I want a header in the csv file
- if you export with GOGEN more globals together not only one
- if I want a csv file for every global/indexes has the global ..

The simply bash script goes up 100 lines of code. If I will start again with this, I would use Python or Go, not bash.

Example:

For a EXPORTED.GLO file

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Article
· May 1, 2020 1m read
Code sample to concatenate JSON arrays

ObjectScript doesn't include any built-in method for appending one JSON dynamic array to another. Here's a code snippet I use that's equivalent to the JavaScript concat() method.

Call it with any number of arguments to concatenate them into a new array. If an argument is a dynamic array, its elements will be added. Otherwise the argument itself will be added.

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Points to remember before you start:

  1. It is not possible in a COS (Caché Object Script) job/process context to have multiple Named Pipes. It is a one Named Pipe per job/process limited line of communication.
  1. Named Pipes, in Caché, like most pipes on most operating systems are Unidirectional. That means you open them for either Read or Write, but not both.
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Hi, developers!

Currently, I'm working on a project that requires highly dynamic event management. In the context of the Java programming language, my first instinct should be to opt for the "Observer Pattern", which is an approach to managing interactions between objects by establishing a notification mechanism. It allows multiple observers to react to changes in the state of a subject autonomously, promoting code flexibility and modularity. If you are not familiar with this design pattern, check out Wikipedia to find more information about it.


While it's natural and commonly used in certain programming languages as Java and C++, in ObjectScript, it's quite a different story.

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Recently I wanted to get a list of all cached queries and their texts. Here's how to do that.

First create an SQL Procedure returning Cache Query text from a Cached Query routine name:

Class test.CQ
{

/// SELECT test.CQ_GetText()
ClassMethod GetText(routine As %String) As %String [ CodeMode = expression, SqlProc ]
{
##class(%SQLCatalog).GetCachedQueryInfo(routine)
}

}

And after that you can execute this query:

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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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I needed to know programmatically if last ran failed or not.

After some exploring, here's the code:

ClassMethod isLastTestOk() As %Boolean
{
  set in = ##class(%UnitTest.Result.TestInstance).%OpenId(^UnitTest.Result)
  for i=1:1:in.TestSuites.Count() {
    #dim suite As %UnitTest.Result.TestSuite
    set suite = in.TestSuites.GetAt(i)
    return:suite.Status=0 $$$NO
  }
  quit $$$YES
}

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A few years ago, I was teaching the basics of our %UnitTest framework during Caché Foundations class (now called Developing Using InterSystems Objects and SQL). A student asked if it was possible to collect performance statistics while running unit tests. A few weeks later, I added some additional code to the %UnitTest examples to answer this question. I’m finally sharing it on the Community.

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Article
· Sep 27, 2018 2m read
Method to Create a Class

The following class method "test" contains code that can create a new class, create new properties for classes, or create new methods for classes. "test" runs all three of these processes once, and the code that performs each action is labelled by comments in the method:


ClassMethod test() As %Status
{
    set sc = $$$OK
    
    // Create a class
    set class = ##class(%ClassDefinition).%New("MyClass")
    set class.Description = "This is my test class"_$c(13,10)_"testing %ClassDefinition"
    set class.Super = "%Persistent"

    // Create a property and add it
    set property = ##class(%PropertyDefinition).%New("MyClass.MyProperty")
    set property.Type = "%String"
    set property.Description="This is a property"
    set sc1 = class.Properties.Insert(property)
    do:$$$ISERR(sc1) $system.Status.DisplayError(sc1)
    set sc = $$$ADDSC(sc, sc1)
    
    // Create a method and add it
    set method = ##class(%MethodDefinition).%New("MyClass.MyMethod")
    set method.ReturnType = "%Integer"
    set method.FormalSpec = "x:%Integer,y:%Integer=10"
    set method.Description = "Return product of x and y"
    set method.CodeMode = "code"
    set method.Code = " new result"_$c(13,10)_" set result=x*y"_$c(13,10)_" quit result"
    set sc2 = class.Methods.Insert(method)
    do:$$$ISERR(sc2) $system.Status.DisplayError(sc2)
    set sc = $$$ADDSC(sc, sc2)
    
    // Save the class definition
    set sc3 = class.%Save()
    do:$$$ISERR(sc3) $system.Status.DisplayError(sc3)
    set sc = $$$ADDSC(sc, sc3)
    
    return sc
}

Here's a link to the code on GitHub

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This is a series of programming challenges for beginners and experienced Caché programmers.

For an introduction : go to article https://community.intersystems.com/post/advent-code-2016-day1-no-time-ta...

Today's challenge is about decompressing input that is compressed in an experimental format.
In the format, markers indicate how much time a number of characters need to be repeated.

For example :

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Hi guys!

Portrait of Madame X, Gustave Caillebotte.

One of the features I like in InterSystems ObjectScript is how you can process array transformations in a specific method or a function.

Usually when we say "process an array" we assume a very straightforward algorithm which loops through an array and does something with its entries upon a certain rule.

The trick is how you transfer an array to work with into a function.

One of the nice approaches on how to pass the information about an array is using $Name and Indirection operator.

Below you can find a very simple example which illustrates the thing.

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This code snippet provides a ZEN page that downloads a stream from its database directly:


/// We assume that you have stored your data within this schema:
/// MyApp.Model.Storage: Filename,FileSize,Content,ContentType
Class zen.downloadStream Extends (%ZEN.Component.page,%CSP.StreamServer)
{
 
    /// Wrapper to get the id of the download, we assume that the id is passed to this zen page
    /// as a URI parameter, i.e.: MyApp.Downloads.cls?OID=1234
    ClassMethod GetId()
    {
        Quit $Get(%request.Data("OID",1))
    }
     
    /// Set the appropriate header for the file.
    ClassMethod OnPreHTTP() As %Boolean
    {
        Set tId = ..GetId()
     
        If ##Class(MyApp.Model.Storage).%ExistsId(tId) {
            Set tStream = ##Class(MyApp.Model.Storage).%OpenId(tId)
            // You could "guess" the content type by its file extension
            // or you can store it (before) in the database separately (like in this example).
            // Set Extension = $Piece(tStream.Filename,".",$Length(tStream.Filename,"."))
            // Set ContentType = ..FileClassify(Extension)
     
            Set %response.ContentType = tStream.ContentType
            Do %response.SetHeader("content-disposition","attachment; filename="_tStream.Filename)
            Do %response.SetHeader("Content-Length",tStream.FileSize)
        }
        Else {
            Set %response.Status="404 File Not Found"
            Quit 0
        }
        Quit $$$OK
    }
     
    ClassMethod OnPage() As %Status
    {
        Set Download = ##Class(MyApp.Model.Storage).%OpenId(..GetId())
        Do Download.Content.OutputToDevice()
        Quit $$$OK
    }
 
}

Link to code on GitHub

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When you have more than ten thousand users in your database, it becomes time-consuming and inconvenient to assign group access rights through the standard IRIS interface. In this artilce I want to introduce you an application to automate this process.

I’ll show you how to assign and change the role lists for the users, selecting them by context, and I will also show you how to expand this application’s functionality. you know how to apply your work as an administrator and developer to the new features of the well-proven apptools software complex. With the addition of an adminLTE template, you can now quickly and easily create interface interactions for any entity and many functional modules.
The goal while developing this toolkit is to write as little JavaScript as possible as well as transfer and implement all the dynamics as much as possible in the ObjectScript.

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