Recently, a partner company started to develop an Angular client for their Cache application. Together, we decided to leverage the power of Caché dynamic objects to exchange JSON encoded data between client and server parts. However, we realized that currently there is a gap in Cache JSON implementation that prevents simple use of traditional registered and persistent classes to exposed their data with the same ease as with XML. I wrote a small JSON adapter, that does the job and bridgers the gap. It's purpose is simple expose data described by a regular Cache class in a one-to-one fashion to a %DynamicObject. On the other hand, when a serialized JSON data comes in, it can be easily deserialized into dynamic object and subsequently bound to regular class by the newly created adapter.

Last comment 13 hours 32 min ago
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This code snippet uses %ZEN.Auxiliary.jsonSQLProvider. The namespace and string of SQL can be edited for different situations. The class method "test" runs the code:


Class eduardlebedyuk.passQuestionParams
{
    classmethod test(pValue = 50) {
        s ns = $Namespace
        zn "samples"
        s tSQL = "SELECT ID, Name FROM Sample.Person WHERE Id > ?"
        s tPR = ##class(%ZEN.Auxiliary.jsonSQLProvider).%New()
        s tPR.sql = tSQL
        s tPR.%Format = "tw"
        s tPR.maxRows = 100
     
        s tParam = ##class(%ZEN.Auxiliary.parameter).%New()
        s tParam.value = pValue
        d tPR.parameters.SetAt(tParam,1)
      
        d tPR.%DrawJSON() 
        //d ##class(%ZEN.Auxiliary.jsonSQLProvider).%WriteJSONFromSQL(,,,,,tPR)  //same thing
        zn ns
    }
}

(Originally posted to Intersystems CODE by @Eduard Lebedyuk, 5/13/15)

Here's a link to the code on GitHub

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Google Cloud Platform (GCP) provides a feature rich environment for Infrastructure-as-a-Service (IaaS) as a cloud offering fully capable of supporting all of InterSystems products including the latest InterSystems IRIS Data Platform. Care must be taken, as with any platform or deployment model, to ensure all aspects of an environment are considered such as performance, availability, operations, and management procedures.  Specifics of each of those areas will be covered in this article.

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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

Last comment 9 days ago
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InterSystems products (IRIS, Caché, Ensemble) already include a built-in Apache web server. But the built-in server is designed for the development and administration tasks and thus has certain limitations. Though you may find some useful workarounds for these limitations, the more common approach is to deploy a full-scale web server for your production environment. This article describes how to set up Apache to work with InterSystems products and how to provide HTTPS access. We will be using Ubuntu, but the configuration process is almost the same for all Linux distributions.

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GraphQL is a standard for declaring data structures and methods of data access that serves as a middleware layer between the client and the server. If you’ve never heard about GraphQL, here is a couple of useful online resources: here, here and here.

In this article, I will tell you how you can use GraphQL in your projects based on InterSystems technologies.

Last comment 3 October 2018
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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

Last comment 27 September 2018
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The following code snippet includes a class method "test" that runs code to find a class based on the class's name. "test" takes one argument, which is the name of the table:


Class objectscript.findTable Extends %RegisteredObject
{
    classmethod test(name as %String="mytable")  
    {
            #Dim result as %ResultSet
            #Dim tName as %String
            #Dim contain as %Integer
     
            Set contain=0
            Set result = ##class(%ResultSet).%New("%Dictionary.ClassDefinition:Summary")
            Do result.Execute()

            While(result.Next()) 
            {
                Set tName=$get(result.Data("Name"))
                &sql(select position (:name in :tName) into :contain)
                Write:contain'=0 tName, " ... ", name, " (", contain,")", !
            }
            Return $$$OK
     }
}

Here's a link to the code on GitHub

Last comment 21 September 2018
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This code snippet determines the day of the week associated with a date. The class method "test" takes a date as a string in "mm/dd/yyyy" format, and returns an integer corresponding to a day of the week:


Class cartertiernan.getDayfromDate Extends %RegisteredObject
{
    classmethod test(date) as %Integer {
        //Set date = $ZDATE(date) //  Looks like: mm/dd/yyyy
     
        Set monthList = $LISTBUILD(0,3,3,6,1,4,6,2,5,0,3,5) // (Jan,Feb,Mar,Apr,...)
        Set centuryList = $LISTBUILD(6,4,2,0) // first two digits divisiable by 4, then subsequent centuries. EX (2000, 2100, 2200, 2300)
        Set dayList = $LISTBUILD("Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday") // Index goes from 0-6
         
        Set day = $PIECE(date,"/",2) // get the day 
        Set monthVal = $LIST(monthList,($PIECE( date,"/",1 ))) // get the month value
        Set first2DigsYear = $PIECE( date,"/",3 ) \ 100 // get the last 2 digits of the year
        Set last2DigsYear = $PIECE( date,"/",3 ) # 100 // get the first 2 digits of the year
         
        // Used for DEBUG perpouses
        /*write !,"day: ",day
        write !,"Month: ",monthVal
        write !,"last2: ",last2DigsYear
        write !,"first2: ",first2DigsYear
        write !,"cen Val: ",$LIST(centuryList,(first2DigsYear # 4) + 1),!!*/
         
        // Look here for formula explination (its the "Basic method for mental calculation")
        // http://en.wikipedia.org/wiki/Determination_of_the_day_of_the_week
        Set dayOfWeekVal = ( day + monthVal + last2DigsYear + (last2DigsYear\4) + $LIST(centuryList,(first2DigsYear # 4) + 1 ) ) # 7
     
        Quit dayOfWeekVal
    }
}

Here's a link to the code on GitHub

(originally posted to CODE by Carter Tiernan, 6/18/14)

Last comment 20 September 2018
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The following post outlines a more flexible architectural design for DeepSee. As in the previous example, this implementation includes separate databases for storing the DeepSee cache, DeepSee implementation and settings, and synchronization globals. This example introduces one new databases to store the DeepSee indices. We will redefine the global mappings so that the DeepSee indices are not mapped together with the fact and dimension tables.

Last comment 17 September 2018
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