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Nikita Savchenko · Jun 3, 2016 go to post

[UPD fixed] Got you. Incredible! It seems that this is what I needed:

USER>set string = $lb($C(1),$c(2),$c(3),",",$c(0))
USER>w $a($LISTGET(a,1))
1
USER>w $a($LISTGET(a,2))
2
USER>w $a($LISTGET(a,3))
3
USER>w $LISTGET(a,4)
,
USER>w $a($LISTGET(a,5))
0

Until the list values may contain any set of characters here this is the best solution, thank you, Jon!

Nikita Savchenko · Jun 2, 2016 go to post

Don't understand what are $lts and $lfs. I need to convert this string back to the structure, so I can read it's elements. The delimiter needs to be escaped somehow.

Nikita Savchenko · May 10, 2016 go to post

John, you are right, in general any temporary namespace change should be new'd, as Timothy mentioned.

But both inside CreateProjection and RemoveProjection methods not changing the namespace back to the original one at the end of the methods doesn't have any side effects as I discovered.

Nikita Savchenko · May 10, 2016 go to post

The general approach here is to use COS' write command to output any user-readable result. This result will be visible during and after class import for any of three cases described in the article (importing with Caché Studio, Management Portal and terminal).

Nikita Savchenko · May 10, 2016 go to post

Thank you, Evgeny!

Showing the logs has a lot of use cases, but the most common of the top of my head are:

  1. To notify user that no errors occurred during installation and to help track any errors if any happened;
  2. To show the user what happened and what was configured;
  3. And even to collect installations statistics and catch any unpredictable error logs during setup, as I do in my VisualEditor project.
Nikita Savchenko · May 9, 2016 go to post

Daniel, 

Also, in many cases, when you compile a class, you only want to perform changes only once, not with every compilation.

This can be easily held in the case of Projections. For example, by testing whether the compiled installer exists in the system, or, as I do in my project, by checking if the project's global exists, whatever. The only thing you need to write all of this pure COS code to perform the checks and build the whole installation logic.

Not sure if %Installer gives more control, except of the moment when you trigger the installation process. It looks for me as a kind of framework with a lot of useful things.

The ideal variant here would be to trigger %Installer's setup from CreateProjection method I think.

Nikita Savchenko · May 9, 2016 go to post

After some additional editing the article is finally published. Moving to developer community feedback page to leave an issue about wrong publishing date (the date of draft creation is displayed instead of the date of actual article publishing), which causes wrong sorting order on site pages.

Nikita Savchenko · May 9, 2016 go to post

Oops! Thanks for catching this up. Somehow I missed to copy the correct version of the code.

UPD fixed.

Thank you!

Nikita Savchenko · Apr 18, 2016 go to post

write a.$toJSON() is always vulnerable for <MAXSTRING> error, which was unacceptable for my case. For some cases while cycle can solve this problem, but even with this known bug an empty write command followed by do statement looks shorter and more reliable I think.

Nikita Savchenko · Apr 17, 2016 go to post

Thanks for the great article! It made a good introduction to the new JSON capabilities in Caché for me.

But it seems like there is one super strange issue with $toJSON method.

Check this simple REST application:

Class JSON.Mystery Extends %CSP.REST
{
XData UrlMap
{
<Routes>
   <Route Url="/test" Method="GET" Call="Test"/>
</Routes>
}

ClassMethod Test() As %Status
{
set a = { "test": 1 }
do a.$toJSON()
quit $$$OK
}

}

Guess what you get by querying "http://hostname/webAppName/test"? You get nothing. And now, by adding a pointless change to the Test method:

ClassMethod Test() As %Status
{
set a = { "test":1 }
write ""  // Right. This one.
do a.$toJSON()
quit $$$OK
}

Everything works as expected, string '{"test":1}' is outputted. Tested on Caché 2016.2.0.590.0.

Any ideas on why this happens? Doesn't $toJSON function initialize the output aswrite does?

Nikita Savchenko · Apr 11, 2016 go to post

Thank you Wolf for the good suggestions! Especially about UML associations.

As Timur mentioned, you can fill the issue or feature request on GitHub's Class Explorer issue tracker, but don't expect it to be implemented fast if only it is not critical for you. Just left the suggestions there to keep things organized, if you have some time.

Thanks for your interest on the project!

Nikita Savchenko · Apr 7, 2016 go to post

Thanks!

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Nikita Savchenko · Dec 18, 2015 go to post

Alex, the current WebTerminal version (3.1.4) supports only VT100/Caché TERM applications. The VT440 support was not in the close future todo list, but may become true anytime.

We had tried to run some "dinosaurs" in WebTerminal and some of them worked really well, but moslty it was all about the issue with the Caché command "USE": it breaks WebSocket connection and should be used properly considering that WebTerminal is an "over-TCP device". I believe one day we will find a way to make no difference between the common Terminal and WebTerminal behavior at this point, but today these application maybe should include a little fix to any usage of "USE" commands inside terminal applications.