Re: Is JSON Schema simpler than XML Schema?

From: Pete Cordell <pete++xmldev@codalogic.com>
To: "Costello, Roger L." <costello@mitre.org>,"xml-dev@l..." <xml-dev@l...>
Date: Thu, 2 Aug 2018 14:51:27 +0100

Play the video

Hi Roger,

...

On 02/08/2018 11:29, Costello, Roger L. wrote:

Neat!

How is the following XML Schema complexType expressed using JCR? Note that the complexType specifies mixed content.

<xs:complexType name="InternationalString" mixed="true">
     <xs:choice minOccurs="0" maxOccurs="unbounded">
         <xs:element name="bdo" type="bdoType" />
         <xs:element name="bdi" type="bdiType" />
     </xs:choice>
     <xs:attribute name="direction" type="directionType" />
</xs:complexType>

Next, suppose the above complexType is extended (derive-by-extension) with an attribute, as shown below. How is this second complexType expressed in JCR?

<xs:complexType name="PedigreeStringType">
     <xs:complexContent mixed="true">
         <xs:extension base="InternationalString">
             <xs:attribute name="pedigree" type="xs:string" />
         </xs:extension>
     </xs:complexContent>
</xs:complexType>

**Currently** we're investigating using mixins for compositional relationships. We're hoping that, in general, this will be more flexible than pure-OO style extension relationships.

Naturally JSON doesn't support mixed types by default or the distinction between elements and attributes, and JCR offers nothing 'out-the-box' to change that. (JCR is intended for data-oriented applications, not text-oriented.)

But to use the mixin approach, you would currently have to define a 'group' to be your mixin (such as "InternationalStringMixin") and then use that in your instances of "InternationalString" and "PedigreeStringType". So something like:

$InternationalStringMixin = ( ; Note round brackets -> a group def
"content" : [
{
(
"bdo" : $bdoType |
"bdi" : $bdoType
),
"text" : string
} *
],
"direction" : $directionType
)

$InternationalString = { ; Braces -> an object definition
$InternationalStringMixin
}

$PedigreeStringType = {
$InternationalStringMixin,
"pedigree" : string
}

**Going forwards** we might be able to consider an object referenced inside another object (without a preceding name) to be automatically converted to a group. So, instead of the above, we'd just have:

$InternationalString = { ; Note braces
"content" : [
{
(
"bdo" : $bdoType |
"bdi" : $bdoType
),
"text" : string
} *
],
"direction" : $directionType
}

$PedigreeStringType = {
$InternationalString,
"pedigree" : string
}

-----------

I don't think my original message made it to the list, so here's the links for more info again for those that missed it:

Latest official spec:

http://json-content-rules.org/drafts/draft-newton-json-content-rules-09.txt

More info (including syntax checker):
http://json-content-rules.org/

I hope at some point we can indulge this lists wisdom for some more feedback on JCR once we've got a new draft out.

Thanks again,

Pete.
--
---------------------------------------------------------------------
Pete Cordell
Codalogic Ltd
C++ tools for C++ programmers, http://codalogic.com
Read & write XML in C++, http://www.xml2cpp.com
---------------------------------------------------------------------

References:
- Is JSON Schema simpler than XML Schema?
  - From: "Costello, Roger L." <costello@mitre.org>
- RE: Is JSON Schema simpler than XML Schema?
  - From: "Costello, Roger L." <costello@mitre.org>

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index]

PURCHASE STYLUS STUDIO ONLINE TODAY!

Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced!

Download The World's Best XML IDE!

Accelerate XML development with our award-winning XML IDE - Download a free trial today!

Subscribe in XML format

RSS 2.0
Atom 0.3

Stylus Studio has published XML-DEV in RSS and ATOM formats, enabling users to easily subcribe to the list from their preferred news reader application.

Stylus Studio Sponsored Links are added links designed to provide related and additional information to the visitors of this website. they were not included by the author in the initial post. To view the content without the Sponsor Links please click here.

XML Editor - Download a 15 Day Free Trial Now >

See What's New in Stylus Studio >

Buy Stylus Studio - XML Editor - Now >