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John Hotalen · Sep 22, 2025 go to post

One additional note (that I thought of after seeing the DC AI Bot response):  The DC AI Bot explains that the lock can be "manually" released by logging into terminal window and forcing the lock.  And while that is true, the goal of my post is to allow our support team to be able to use our LIS web-based application to remove the locks and NOT have to waste time logging in to another piece of software to perform the task that should be able to be done via our LIS application.  And as you can imagine, there is a whole separate support process including creation/updating/assignment/etc... of a support ticket if the support team is unable to use the LIS application for certain pre-defined/verified workflows.  So it is not cost-effective to have to deal with support tickets every time an orphaned lock needs to be removed.   So please keep this item in mind when offering feedback/suggestions for how to allow the LIS web-based application to remove the lock for another Cache process.   Best Regards.

John Hotalen · Jun 30, 2025 go to post

If you have an install of Cache, then any of the COS commands should work with your Cache Terminal or whatever terminal emulator you are using for your instance/namespace.

In regard to the "class does not exist" or the "method does not exist" errors, those would happen if you tried to call/reference a class (or method within the class) that does not exist.   You might want to confirm that you do not have a typo, as class names and method names are case sensitive (i.e. Filename versus FileName)

Hope that helps on your Cache journey!

If there are specific questions or issues you are having, feel free to post more details to the Dev Community and there are lots of Cache Devs willing to help.

Best Regards.

John Hotalen · Sep 23, 2024 go to post

Thanks Enrico.   I look forward to being able to use the new features of Cache and IRIS someday.  The company I work for is still running Cache 2017.1.3, so those new JSON features are not available.  But I sincerely appreciate the information.  Because once we upgrade to IRIS, then I will be able to leverage/use the information you shared.

Best Regards!

John Hotalen · Sep 18, 2024 go to post

Exactly!    I updated my code based on your suggestion and it worked like a charm.   It looks just like what you demonstrated above.    I really appreciate the information you provided.

Side Note:   The one thing that I noticed (that was a little annoying from the Cache perspective) is my XML Export uses the XMLNAME keyword values, but the JSON Export does not.

Here is an example of my real property names from the Slide class with the XMLNAME keyword values:

Property SlideSequence As %Integer(XMLNAME = "slideSeq");
Property BarcodeText As %String(MAXLEN = 100, XMLNAME = "barcodeID");
Property StainType As %String(MAXLEN = 200, XMLNAME = "stainType");
Property StainTypeMapped As %String(MAXLEN = 200, XMLNAME = "mappedStainType");
Property Block As %String(XMLNAME = "blockNumber");

The XML Export uses the XMLNAME value.   But the JSON Export uses the class property name.   I looked in the documentation to see if there was a JSONNAME keyword - but no luck.   So that is a little nuance and inconsistency with Cache.  I like how we can encapsulate the real property name with an alias using XMLNAME (we use the XMLNAME mainly for downstream systems, and to keep the real property names hidden (for lack of a better word) in the projected data formats).    But at least you got me to where I needed to be.    So you are the Cache Developer Community Hero of the Week - at least for me :)

Best Regards and GO TEAM!

John Hotalen · Sep 18, 2024 go to post

Wow!  Thank you for the timely reply.   I will go and try that right now.   If that works, then you will be my hero!   I wasted several hours over the past few days trying a bunch of different things and looking for some secret hidden feature such as a keyword like XMLKEYNAMEASELEMENT = 1 or something like that where the built-in Cache code might have allowed XML attributes to be instead exported as an element (which would have been a really cool hidden feature if it existed).   But I will definitely try your suggestion today.

This is why I like the InterSystems Developer Community so much.  There are folks like you who have many years of knowledge and experience, as well as, those who have run into similiar issues, so all of you always have so many wonderful ideas, thoughts, and suggestions to help fellow Cache programmers.

Thanks again for your time and advice.   Go Team!!!!

John Hotalen · Jun 14, 2022 go to post

Thanks Rich for the feedback.   Do you have any advice or experience about what value to use for the Maximum Server Connections?   Or is there any rule-of-thumb to follow when picking a value?

John Hotalen · Jan 26, 2022 go to post

I accidentally had the  enableToggleSelect property set to true - which was couteracting the second click of the double-click.   Once I got rid of that property it worked as expected.

John Hotalen · Jan 26, 2022 go to post

Hello to all.  You can disregard this post.  I found the solution/answer myself through more research/debugging. 

John Hotalen · Apr 27, 2020 go to post

Question:   Is there certain permissions that your Cache User Account must have to use the %Library/Global query that you show in your ObjectScript example above?   I tried this example and got an error message that my account was not privileged for the operation.  I used your first ObjectScript example and just substituted my namespace, global name, and value I was searching for.

Thanks.

John Hotalen · Jan 25, 2018 go to post

(sitting here amazed that someone was kind enough to build in VMS support for the open source product - I have found that is VERY rare)

Thank you very much Dmitry for this additional information.  I will discuss options with our internal infrastructure teams to see what the process is for installing the VMS libraries for ImageMagick.  It would be really cool to have those types of image handling libraries for VMS.

Thanks again - You Rock!

John Hotalen · Jan 25, 2018 go to post

Hi Jorge,  Thank you for the response/suggestion.  While the ZEN Report would be an option, our lab application interfaces with a reporting system that generates the report.  Our lab application provides all the report data (including images) to the reporting system.  Since the report has limited real estate for where/how the images are displayed, I was looking for a way to resize the raw images from our lab application image repository when sending the report data and images to the reporting system.   Thanks again for the feedback. 

John Hotalen · Jan 25, 2018 go to post

Hi Dmitry,  Thank you for the quick response/suggestion.  I checked out the imagemagick web site and it appears that the software is primarily used on Windows and has some Linux distributions.  The challenge for me is that my company is using Cache with the VMS 8.4 operating system, so when the user (running Win7/Win10 PC) saves the image files to the image directory, the file is actually being saved to an underlying VMS operating system directory.  And our web application is running on Cache which is installed on VMS (the users interact with the web application via a web browser).   So I am not sure if that software would work.  Do you know if there are any image resize capabilities built into Cache?

John Hotalen · Sep 26, 2017 go to post

When it comes to creating development/coding standards for your company, there are a few key things to keep in mind.  First the standards document should account for both development standards, as well as, coding standards.

Here are some thoughts/suggestions to consider:   Disclaimer:  The content listed below is just ideas and not necessarily a proposal of what your development/coding standards should be.

  1. The document should consider code that will be added/modified to existing legacy code versus new code that is being added to the application.  My recommendation for the legacy code is to insure any new code added to the legacy code try to maintain the coding style of the legacy code so the code does not become hard to read.  Example:  If the legacy code uses the old Mumps style of coding with line tags, goto, short variable names (i.e. X, Y, Z, I, J, K, PN, etc...), then I do not recommend adding Cache ObjectScript (COS) procedure blocks within the legacy code, because if added within code that contains things like structured DOs, then it could have impact on process flow, variable scoping, etc...;  If you do decide that new code (i.e. new methods) added to legacy code should follow COS standards, then consider having a coding standards rule telling programmers to add new COS style code at the end of the legacy routine - to keep all the COS style coding at the end of the routine, so the core legacy code looks consistent - it helps with reading the code for support and maintenance.   And it would be ok to allow the legacy code to call to classes/methods or to use new intrinsic functions ($Case, $Replace, etc...)
  2. The document should outline the recommended Development Standards vs. Coding Standards
    • Development Standards would be things like how to implement the various frameworks for things like error handling, database maintenance auditing, web services, handing of I/O, each definition page must have a corresponding inquiry, rules around creating custom components/composites/data types, etc...
    • Coding Standards would be things like:
      • naming conventions for packages, classes, routines, properties
      • type of comments to use
      • allow use of blank lines for readability
      • Commands should be in mixed case (or all uppercase or all lowercase - whatever is preferred for your company)
      • all Commands should be expanded (or collapsed)
      • maybe a rule about line length
      • rules around use of streams
      • rules around use of triggers
      • rules around SQL queries (dynamic? class? embedded?)
      • date/time formats
      • control structures
        • IF - comma versus double ampersand or exclamation point versus double vertical bar
        • Do-While
        • For
        • While
      • transaction processing (be careful not to mix old Mumps based TP with Cache Objects TP)
      • Should Xecute be allowed?  Can be hard to debug/support
      • Post Conditionals
      • locking (this can have information in both the development standards and the coding standards)
      • and on...
      • and on....
  3. Depending on the type of applications that your company has, there may need to be standards for the old type of UI (green screen/roll-n-scroll) versus UI for web-based applications.   There would be a whole separate list of recommendations around web-based development standards versus older Mumps based applications.
  4. When considering things such as Error Handling - there should be standards for how to deal with error handling for web-based applications, web services, and old Mumps based applications.  As you know, error handling for web-based applications can be more challenging because of the number of layers that could be involved (client, middleware (could be many layers), server (could also be many layers))
  5. Standards around database design
  6. Standards around MVC
  7. code should be modular and methods should perform a specific task.  Do not try and create methods that do everything (UI layout, validation, database updates, etc...) in a single method.
  8. There may need to be a separate standards sub-section on use of procedure blocks, since there are many things to consider when using procedure blocks
  9. and on....
  10. and on....

Any development/coding standards document could be fairly lengthy.  But as everyone can agree, standards are very important to insure applications are implemented in a consistent manner, where the code is supportable, maintainable, and reusable.  But it is also important to allow some flexibility with the standards to allow programmers the opportunity to be innovative with how they develop code.  The challenge is finding the perfect balance.

Hope this helps and Have a Great Day!!!  Go Team!!

Happy Coding!!

John Hotalen · Sep 26, 2017 go to post

There are multiple options you can choose from when implementing automated actions as part of your application.  In the end, it all comes down to what solution fits best for your business use case.  Here are a few examples:

  • (automated option) You could implement a database trigger that would fire when a record is inserted or updated to your database table, where the trigger could perform some action, such as call a method to evaluate the record data and to auto-send a notification based on some business rule (i.e.  the debut date is greater than some date then auto-send the notification).  You will want to give thought to the business logic fired with the trigger to minimize performance impacts to your database transactions - but there are options for how to achieve that.
  • (automated option) You could setup a scheduled task to run at certain times of the day that would query your database table(s) for specific things and if those things (business rules) are true, then auto-send the notification
  • (manual option)  If you want a user to be the one who determines whether a notification should be sent out, then you could have a web portal application that would query your database table(s) and display key data values to the user.  Based on the data displayed, the user could manually select one or more rows and click a button or perform some action to cause the notifications to be sent.
  • and on....
  • and on....

Bottom line, it comes down to what option works best for your company/applications.

P.S.  Also, based on the size of your database tables, be sure to review the SQL Query Plans for each of your SQL Queries to insure your queries are performing optimally.  If necessary, add the appropriate indexes to the tables to help improve the query plans (and the query performance).

Hope this helps and Have a Great Day!!!   Go Team!!

John Hotalen · Jan 30, 2017 go to post

If you are familiar with XSL, then you can create your XSL stylesheet manually via any text editor.  Then there are some free online XML/XSL transform testing tools so you can see if your XSL is transforming the XML as expected.

Good luck and Happy Coding......

John Hotalen · Jan 30, 2017 go to post

Also, I recommend using caution for when the cached queries are purged "dynamically".   Purging cached queries dynamically can add risk to users running the application, such as incorrect/incomplete data and/or application errors.   It is not a good practice to purge cached queries while users are actively using the application.  If the cached query routines are deleted while a user is in the middle of having resultset data retrieved that could cause unwanted behavior.   From what I understand of Cache Database Management, things like purging of cached queries should be done during slow/down times when users are not active on the system.    Please feel free to confirm this with the InterSystems team.

Best of luck and Happy Coding....

John Hotalen · Dec 19, 2016 go to post

Hi Sebastian,

If you add an  onloadHandler() method (which gets called when the page is first loaded), this method could call to the GetMessages class method to load your page property named Messages with the message content you want displayed on the page.  Then, a little later in the ZEN page creation processing when the server processing renders the ZEN page components, the <html> component will call to the DrawMessages method to load the message data on the page.

Hope this helps and Have a Great Day!!!

John

John Hotalen · Nov 14, 2016 go to post

Hi Marc,

As a starting point, I recommend that you have the developers review the Cache ObjectScript (COS) documentation at the InterSystems web site:  http://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls

The documentation has many reference guides and tutorials that will be helpful for any developer (new or experienced).

The developers will quickly see a lot of similar comparisons between the basic Java commands and COS commands.  Cache has various looping structures, such as For, While, and Do..While looping commands.  COS procedure blocks has local variable scoping.  COS works hand-in-hand with Cache Objects and can call class methods, instance methods, etc...

The great news is that COS is very easy to learn and use for any developer.  Also, in addition to the online Cache documentation, there is the InterSystems Cache Developer Community that has tons of wonderful information.  After your developers start using COS/Cache Objects, have them join this community, so they can ask questions about specific design or coding issues they might encounter.  There is a whole international community of Cache Developers always willing to help out.

Best of luck to you and your developers.

Best Regards,

John Hotalen

John Hotalen · Oct 14, 2016 go to post

So to make sure I understand, what would the global structure look like if the [NoExtent] keyword is added?

I am guessing since the Person class is abstract - that the data would be stored in 

^USA.President - contains records for presidents

^USA.Senator - contains records for senators

^USA.Representative - contains records for representatives

But what happens if someone forgets to add [NoExtent] to the USA.Person class?

Then would the data be stored as

^USA.Person(seq,"President")

^USA.Person(seq,"Senator")

^USA.Person(seq,"Representative")

And if the [NoExtent] keyword is omitted, then would bitmap indexes need to be added for president, senator, and representative, since I am guessing the data would be stored within ^USA.Person?    Another question:  If the number of people in one of these sub-grouping would exceed 10,000, then would a bitmap index still be used?  Or should another type of index be used?

John Hotalen · Oct 7, 2016 go to post

Also, you could use a simple javascript method to retrieve the value for a specified request parameter from a URL.  Hope this helps and Happy Coding!!!

Example:

ClientMethod getRequestParameter(sParameterName) [ Language = javascript ]
{
    var sRegexPattern='[\\?&]'+sParameterName+'=([^&#]*)';
    var oRegex=new RegExp(sRegexPattern);
    var aParms = oRegex.exec(window.location.href);
    if (aParms == null) {
        return "";
    } else {
        return aParms[1];
    }
}
John Hotalen · Oct 7, 2016 go to post

You can use the example method (parseURLquery) that Sergei posted to get at the query (request params) information.  You might also consider applying the $zconvert code that Tomas recommended as a good practice to account for any possible encoding and or use of different character sets.   Also, Fabian was kind enough to post a link to InterSystems documentation that discusses the built-in (%Net.URLParser) Parse method - which would be useful/helpful, as well.

John Hotalen · Oct 3, 2016 go to post

General question:  Is this available for all versions of Cache?  Or just from 2016.1 and beyond?

John Hotalen · Oct 3, 2016 go to post

Two quick questions regarding the Server Side section:

1.  In the Server() method in the error handling for when the CSP web socket is closed, there is code that is doing "kill ^CacheTemp.ChatWebSockets(..WebSocketID)" - shouldn't this actually be:  "kill ^CacheTemp.Chat.WebSockets(..WebSocketID)"? <-- notice the period I added between "Chat" and "WebSockets" in global name.

2.  In the Server() method in the error handling for when the CSP web socket is closed, shouldn't the code that is doing the kill of "kill ^CacheTemp.Chat.WebSockets(..WebSocketID)" also be doing a kill on "^CacheTemp.Chat.Room(..WebSocketID)"?

Thanks.    And this was a good article!

John Hotalen · Sep 29, 2016 go to post

Correct :)   I was just offering an alternate example for those developers who like/prefer While loops versus For loops.  From working with a vast array of Cache Developers over the years, I found that looping structures are one of those topics that provide "good discussion/debate" over which is better, faster, more useful, etc.... :)   Personally, I do not have a preference - I use both While loops and For loops. Which one I use is based on the content I am implementing.

John Hotalen · Sep 29, 2016 go to post

Quick comment/Note regarding the statement "A disadvantage of the 'While' structure is first you need to repeat the iteration construct, e.g. 'Set Sub1=$O(^Trans(Sub1))' before entering the loop and at the end." - this is a common perception for many newer Cache Developers.  

My suggestion for new folks would be to use a simplified structure, such as follows:

Set someVariable=""

While(1) {

     Set someVariable=$Order(^MyGlobal(someVariable))

     If (someVariable="") { Quit }

     // Do your processing here

}

The above structure keeps the looping construct at the start of the loop and is only needed once.  Within your processing logic, you can easily skip to the next iteration of the loop (if needed) via use of the Continue command.  Or if you need to exit the while loop, then you can do so via use of the Quit command.

Hope this was helpful!  And Happy Coding!!!

John Hotalen · Sep 29, 2016 go to post

Excellent Article.   I have a question about options for running pButtons.   Please Note:  It has been awhile since I last used pButtons.   But I can attest that it is a very useful tool.   My question:  Is there an option to run pButtons in "basic mode" versus "advanced mode"?   I thought I recalled such a feature, but cannot seem to remember how to select the run mode.   And from what I recall, basic mode collects less data/information than advanced mode.  This can be helpful for support teams and others when they only need the high-level details.

Thanks!  And I look forward to reading the next 5 articles in this series.