JSON

As Bill has mentioned earlier in his post, we have carefully reviewed the JSON capabilities and made some adjustments to ensure they deliver the best benefit to you. In this post, I am going to describe the modifications in more detail and provide guidance for you to understand the implication for your code base.

In our last lesson, we added some formatting and validation to our Edit Widget form.  So, now we are ready to add the ability to add new Widgets to our application.  However, the great Widget Wars have come to an abrupt end, as Widget Direct has purchased its biggest competitor, WorldWideWidgets.  In order to maintain some continuity, we need to display their catalog on our new application.

So, we have good news and bad news.  The good news is at that WorldWideWidgets also use Caché, but the bad news is that their Widget table has different properties with different names than our Widget class, and we need to keep the catalogs seperate for the time being.  WorldWideWidgets don't have a WidgetAccessory catalog (and they wonder why they lost the Widget War), so we don't need to worry about Accessories for no

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.  For that we need to implement a UI toolkit.  We have numerous options here; the leading toolkits are BootStrap from Twitter and Angular Material from Google.  There are advantages and drawbacks to each choice.  It is well worth exploring demos of each toolkit to see which would fit your need

Hi All,

I use SQL function JSON_OBJECT to get data as a JSON object.

However, sometimes I get error with function JSON_OBJECT when values contain [, ], { or }.

Error:

[SQLCODE: <-400>:<Fatal error occurred>]

Unexpected error occurred in JSON_OBJECT() function execution of <JSON_OBJECT>.%FromJSON().Parsing error

For example,

Query: SELECT JSON_OBJECT('idSQL':id, 'content':content) FROM DocBook.block

For demonstration, I used Management Portal, System Explorer – SQL, Execute Query

This text was in Content:

{&quot;Info&quot;:{&quot;Error&quot;:&quot;ErrorCode&quot;:&quot;5001&quot;,&quot;ErrorMessage&quot;:&quot;ERROR #5001: Cannot find Subject Area: &#39;SampleCube&#39;&quot;} } }

If I delete all { and } from Content, I don’t get this erro

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.

This tutorial is using the JSON functionality built into 2016.2+ versions of Caché.  This functionality is partially available in 2016.1 but utilizes a different syntax which will not be forward compatible. �

here is my $ZV string "Cache for Windows (x86-64) 2016.2.1 (Build 803) Wed Oct 26 2016 12:43:35 EDT"

 two questions

1. How do i convert any Persistent object to JSON String ?

2. How do i convert an y Register object to JSON string ?

3. Do i need to extend from any adaptor class for 1 & 2 ?

Hi community,

I am having a hard time figuring out how to properly use %ZEN.Auxiliary.jsonProvider to serialize a %RegisteredObject to JSON. Would be anyone so kind to share some simple usage example?

Thanks

Jiri

How can I prevent large number truncation when using the DynamicObject and DynamicArray classes to create JSON in objectscript and then parsing the result in javascript. Are there any global settings that configure the output when using these classes?

I am looking at converting to the new DynamicObject and DynamicArray classes to build JSON. Our current (homegrown) JSON library forces string representation of numbers too long because of errors we were seeing with long numbers being truncated on the client, I am hoping to accomplish the same with the new classes.

USER>set longNum = 1234567890123456789
 
USER>w longNum
1234567890123456789   //valid cache  number, 19 digits
USER>s arr = [(longNum)]  
 
USER>w arr.%ToJSON()
[1234567890123456789]   //Valid JSON, however I would like this to be a quoted string so it can be parsed in javascript

//Parsed in javascrip

Is there any way that I can check the native type of an object script variable? (similar to the typeof check in javascript)

I see that the DynamicArray class uses the type of the variable for its output, I would like to do something similar when I receive a value as an argument to my method.

USER>s var1 = 123  //No quotes, number type
 
USER>s var2 = "123" //quotes, string type
 

//DynamicArray can tell the difference
USER>s arr = []
 
USER>d arr.%Push(var1)
 
USER>d arr.%Push(var2)
 
USER>w arr.%ToJSON()
[123,"123"] //first value is output without quotes, second value is quoted

I'm working on a REST service which will include a binary stream as a request property. I'm currently encoding the stream as BASE64 and passing it as a string value, but I was wondering if there is anything in the Caché JSON support that may be a better fit for encoding this data? Thanks Chris

My organization has been tasked with parsing raw EDI 271 messages into JSON strings in order to feed a downstream application.  A few key details about the task:

• The raw EDI 271 will be coming across as a standard format from a single outbound upstream system
• The EDI 271 messages adhere to the 5010 standard
• We do not need EVERY field from the EDI message, only a select number of fields.  However some of the fields we need (e.g. coverage details) are dynamic in size and will be variable in # of segments both on the EDI side as well as the receiving JSON side.
• We will be looking to build one incoming business operation for the stream of 271 messages which will then be parsed into Medicare and non-Medicare
• The JSON output has a static format per class of payor (sample can be referenced below for both Medicare and non-Medicare payors):

Medicare Example JSON

Background

Caché 2016.1 introduced some very powerful JSON features.  Unfortunately, the syntax used in the 2016.1 release is going to be changed in the 2016.2 release to bring it closer to Caché ObjectScript syntax.  This will mean that code that works in 2016.1 may not be forwards compatible.   See this announcement and this article for more details about the changes.

In order to try to minimize the volume of code which would not work in future Caché versions, the following recommendations and tools are being used internally within InterSystems for internal application JSON code being written in 2016.1.�

Hi all,

We're creating a series of RESTful APIs that output data from a Cache database (made up of global storage that we've mapped to classes). I'm running into some problems with object-to-JSON conversions when relationships are involved. Eg:

ParentClass has children relationship to ChildClass

ChildClass has parent relationship to ParentClass

If you %WriteJSONFromObject on an instance of ChildClass, it will retrieve the instance of ChildClass you're asking for, and it will retrieve the ParentClass as a JSON sub object, via the parent relationship (this part is OK), AND it will retrieve EVERY other instance of ChildClass as sub-sub objects, via the children relationship of ParentClass (not OK).

I totally understand why it is doing this, as it's simply retrieving every related object, but for our database this ends up retrieving almost every instance of a given object, and more, when you're only asking for one!

What to do? Here's my thoughts

A beginners guide to develop Ensemble RESTful web services.

Background

Before you start reading this short introduction please go through the on-line documentation of Ensemble with special attention to chapter “Creating REST services and clients with Ensemble”.

The approach in the documentation is undisputable the fastest and easiest way to create RESTful services. As a beginner I went through the documentation and I had several questions. This short article is listing those questions plus my humble answers.

When I refer to documentation I mean Ensemble 2016.2 and onwards