WebSockets look to be supported reasonably well in Cache. I have yet to use them in production so I am wondering how well it has worked for other developers.

In particular what happens when the browser does not support WebSockets, or when a firewall blocks the connection.

Have you had to write your own long polling fall-back?

I've read the documentation and found this interesting article...

https://community.intersystems.com/post/asynchronous-websockets-quick-tutorial

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Hi everyone,

This is:

Cache for UNIX (Red Hat Enterprise Linux for x86-64) 2016.2 (Build 736U) Fri Sep 30 2016 12:25:56 EDT

The server is on RedHat Linux while the browser is running on Windows (Firefox).

I am helping a partner build a complex modern HTML5 web application that talks with Caché using REST calls. They have been using %CSP.REST very successfully. Security works great as well. 

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0 11 6,807

So, one day you're working away at WidgetsDirect, the leading supplier of widget and widget accessories, when your boss asks you to develop the new customer facing portal to allow the client base to access the next generation of Widgets..... and he wants you to use Angular 1.x to read into the department's Caché server.   

There's only one problem:  You've never used Angular, and don't know how to make it talk to Caché.

This guide is going to walk through the process of setting up a full Angular stack which communicates with a Caché backend using JSON over REST.  

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5 10 5,149

So, one day you're working away at WidgetsDirect, the leading supplier of widget and widget accessories, when your boss asks you to develop the new customer facing portal to allow the client base to access the next generation of Widgets..... and he wants you to use Angular 1.x to read into the department's Caché server.   

There's only one problem:  You've never used Angular, and don't know how to make it talk to Caché.

This guide is going to walk through the process of setting up a full Angular stack which communicates with a Caché backend using JSON over REST.  

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3 23 3,827
Article
Michael Smart · Oct 7, 2016 4m read
Forwarding Requests in a REST Service

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.

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or "So you just got yelled at by your boss, for sending him an unformatted Hello World webpage"

Our previous lesson ended with us serving a Message value obtained from a Caché REST service to the client, using Angular as a runtime.  While there is a lot of moving parts involved in this process, the page is not especially exciting at the moment.  Before we can start adding new features, we should take a step back and review our tools.

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1 0 1,790
Article
Eduard Lebedyuk · Apr 17, 2017 4m read
Debugging Web

In this article I'll cover testing and debugging Caché web applications (mainly REST) with external tools. Second part covers Caché tools.

You wrote server-side code and want to test it from a client or already have a web application and it doesn't work. Here comes debugging. In this article I'll go from the easiest to use tools (browser) to the most comprehensive (packet analyzer), but first let's talk a little about most common errors and how they can be resolved.

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2 0 1,671
Question
Thembelani Mlalazi · Mar 12, 2019
String to date

I am trying to convert a string to date but can not get it to work I have  function that I would like to take in a date string and covert it to date object

here is the ezample so far can not get it to work any help appreciated 

 

set p="12/03/2019"
 
w $System.SQL.TODATE(p,"YYYY-MM-DD")
 
<ILLEGAL VALUE>todate+32^%qarfunc

if I try this still get the wrong value returned

set p="12/03/2019" 
w $ZDATE(p,3)
1841-01-12

 

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Hi-

I am trying to create a simple example of allowing binary (tiff) files to be selected and uploaded asynchronously to an IRIS for Health back-end.   I have managed to write the HTML and Javascript which works great with regular text / ascii files, but fails with binary files.

When I upload a binary file (tiff) image I get garbage like this on the database server 

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Hi,

I have been trying to implement SPA using routing between two components in a CSP page. 

If i use the line which i commented the page views and gets data from the vue instance (when not using the <route-view> and other 2 vue route functions below).

since i need to implement routing i am using as below, now the property "selectedYear" is not getting data from vue instane and i am getting the below error as well.

I dont know whether i am going down the right path.

please see my code below and help me

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1 0 1,321
Question
David Crawford · Jun 18, 2018
CSP Error Log

I thought I should be able to go to the application error log or look at d ^%ER when I get the following error in the browser when troubleshooting a CSP page:

An error occurred with the CSP application and has been logged to system error log (^ERRORS)

However nothing is being generated in these logs. Where are these logs being made?

Thank you

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1 9 1,306

We finished our last lesson with our Widgets Direct page iterating over a list of widgets, displaying an ID and a Name value.  While we have been able to achieve this with only a small amount of coding, the page itself is not the most visually appealing place to be.  The AngularJS framework is providing a powerful Model-View-Controller framework for our structure and logic, but it does not implement anything that will provide a nice UI experience.

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0 3 1,292

Hello Community,

I recently encountered a issue with Caché and I can't figure out where the problem is coming from.

I noticed that the license limit (200)  was reached whenever I was opening my Studio (so it seems). When this occurs, I restart Caché (with the Cube in the Taskbar), and the number of license used is back to 1%, but grows back after.  The time taken before the number of license  grows back again looks pretty random.

Here is a couple of screenshots :

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or "Didn't you say you would cover Persistent Objects in Part 5, Chris?"

Yes, that was the plan.  This is a pretty important topic, so it get's its own Article

Up until now, we've display widget JSON that has been created by a basic loop.  Clearly this isn't of much value.  Now we have our stack connected together, and we can see that the data is flowing to the Welcome page, it's time to complete the stack and start feeding our service from "real" data.

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Index to Articles

Published 2018-05-11 Last edit -

Hi All

I this article I detail some strategic issues that a new development UI will need to address - these are the ones that I can think of now - others may come to light during this journey.

See the webinar by Eduard Lebedyuk here from the last Global Summit describing  modern web development and Caché

And, as always, if I have missed something please comment....

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or "Things are going to break"

We left our application over the weekend, secure in the knowledge that it was returning data from our primary persistent class, User.Widget.  However, Widgets Direct are the premier supplier of both Widgets AND Widget Accessories, so we should really start working on adding these Accessories to our application. 

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0 3 995
Question
Tamara Lebedeva · Aug 22, 2016
$fromJSON and MAXSTRING

Hi, all.
I have CSP application and it needs to get and process data from ajax request with json-content. JSON can be very big.
In this case:
TRY
{
Set RequestObj = ##class(%Object).$fromJSON(%request.Content.Read())
} CATCH(Exception) {
Set Status=Exception.AsStatus()
}
I get just part of getting JSON and validate error in $fromJSON.
If I try to read it all in cycle:
TRY
{
While (%request.Content.AtEnd = 0) {

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Article
Peter Cooper · Mar 18, 2018 1m read
Replacing ZEN - Index to articles

Hi All
This is the index to a series of articles I hope to create over the coming months.

ZEN and ZEN Mojo are no longer being actively developed by Intesystems - this is a great shame as it is a fine product that works so well for business applications.
However ZEN is a 15 year old product and I need a path forward to replace the ZEN UI with a supported development framework.

This article is an index of the other articles I have, or plan to write. - the articles will be subject to change as I develop my thoughts and climb the learning curve.

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1 5 963