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Why JSON will continue to push XML out of the picture

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Re: Why JSON will continue to push XML out of the picture

#41

Post by mindslight »

jerf wrote: post #40
Joeri wrote: post #35

Earlier quoted context omitted.

That's an impressively succinct way of mapping types to JSON, but it's still a mapping. There's one step for the developer between obtaining the JSON and using its data. In weakly typed languages there is no such step, the JSON data is the object you interact with in your business logic.

There's always a serialization step. The type of the resulting data is a consequence of the serialization technique, not the data format. I demonstrated the part you seemed to most strongly claim didn't exist, JSON strong typing, but I can show you "weakly-typed" XML too. In addition to the DOM, which is a standardized "weak type" XML representation, you also have things like ElementTree http://effbot.org/zone/elemen…

I think part of the reason "weakly typed" is ambiguous is because it's a bit pejorative, and "sloppy type" certainly isn't helping that. Maybe just "less typed" ? It really is an engineering tradeoff of how many assumptions you want to make explicit.

Re: Why JSON will continue to push XML out of the picture

#42

Post by AdrianRossouw »

mahmoudimus wrote: post #14
mtrimpe wrote: post #12

Earlier quoted context omitted.

I don't understand why JSON schemas and the OJMs (Object-JSON-Mappers ;) it would enable aren't being developed more heavily. I love JSON, but when working on APIs between large companies / departments the "we'll just send JSON like this and email you when we change stuff" really won't cut it.

Let me state that for the record, I believe JSON is a fantastic data interchange format, especially when compared with the current state of XML. However, the point you've touched on is exactly my gripe with JSON. I just might not know enough, which is completely adequate, but afaik all the JSON schemas are either extremely complicated (I'm looking at you json-schema) or way too simple (jschema). When working with ser…

with json-schema, the instance objects would have a $schema property referring to the schema of the document.

the schema has a links section, where you can define all the various related paths to use.

a 'suitably intelligent validator' should be able to resolve the links for you.

[1] http://tools.ietf.org/html/draft-zyp-json-schema-03#section-...

Re: Why JSON will continue to push XML out of the picture

#43

Post by 6ren »

jerf wrote: post #40
Joeri wrote: post #35

Earlier quoted context omitted.

That's an impressively succinct way of mapping types to JSON, but it's still a mapping. There's one step for the developer between obtaining the JSON and using its data. In weakly typed languages there is no such step, the JSON data is the object you interact with in your business logic.

There's always a serialization step. The type of the resulting data is a consequence of the serialization technique, not the data format. I demonstrated the part you seemed to most strongly claim didn't exist, JSON strong typing, but I can show you "weakly-typed" XML too. In addition to the DOM, which is a standardized "weak type" XML representation, you also have things like ElementTree http://effbot.org/zone/elemen…

In another sense, XML is strongly typed, in that it has a schema language (XML Schema - and DTDs are part of the XML spec itself).

Re: Why JSON will continue to push XML out of the picture

#44

Post by pumba_lt »

JSON is not a silver-bullet. Actually I think JSON-only APIs suck -- an API should have an equivalent XML alternative as well. Let me explain.

Web APIs are not only consumed by client-side Javascript-based AJAX apps -- they are also used by server-side (web)apps where Javascript is much less widespread. If the primary application language is not Javascript for which JSON is a native format, but PHP or Java for example, then its value is much lower.

There are established industries such as publishing that use complex XML workflows -- I don't think JSON will push them out.

XML family so far has much better standard specifications and tool support. Some of the most useful are XPath and XSLT. There are also advanced features -- too complex for some, useful for others -- like namespaces and schemas. If JSON is to expand its use, it will have to go to the same interoperability issues XML addressed, and develop similar features with similar problems. That's why the idea of JSON schemas sounds funny to me.

Let me give an example. I've developed a semantic tool that lets me import 3rd part API data as RDF. If it is available in XML, I can apply a GRDDL (basically XSLT) transformation to get RDF/XML -- and boom, it's there. RDF/XML serves as the bridge format between XML and RDF.

Now if the data is JSON-only, what do I do? I could download an API client, try to write some Java or PHP code, but that would be much less generic and extensible than XSLT. I could probably try a pivotal conversion via JSON-LD somehow, but oh, bummer -- there's no JSON transformation language? Or is there... Javascript? Thanks, I would prefer XSLT anyday since it is designed specifically for these kind of tasks.

My point is, by offering JSON-only you cut off all the useful tools from the XML world, which is pretty well established. I see JSON as an alternative syntax to XML, which is easier to use with Javascript -- but by no means THE "right tool" to all data serialization problems.

Re: Why JSON will continue to push XML out of the picture

#45

Post by clarkevans »

TazeTSchnitzel wrote: post #18
clarkevans wrote: post #8

I think this article has done a great job enumerating trends that show JSON is beating XML for data serialization applications. I think these points are evidence of a shift in thinking, but not the reason for shift itself. Why JSON over XML? Because people need data serialization format and XML is a Markup Language. JSON is gaining widespread adoption for data serialization applications since it's the correct tool. X…

It also sounds like the right tool for making something like SVG. The vast majority of SVG data isn't text.

In SGML land, you wouldn't have implemented SVG using tags, you would have created a NOTATION with syntax specific to the problem at hand. In XML land, everything is XML; for example, schemas are XML (in SGML they are DTDs, that are _not_ SGML), transforms are in XML (in SGML, they are DSSSL, a lisp variant). The XML approach is one-size-fits-all, not the use-the-best-tool/syntax for the job.

Re: Why JSON will continue to push XML out of the picture

#46

Post by clarkevans »

tptacek wrote: post #23
clarkevans wrote: post #8

I think this article has done a great job enumerating trends that show JSON is beating XML for data serialization applications. I think these points are evidence of a shift in thinking, but not the reason for shift itself. Why JSON over XML? Because people need data serialization format and XML is a Markup Language. JSON is gaining widespread adoption for data serialization applications since it's the correct tool. X…

This makes sense, but from what I can tell, in virtually no major XML-based systems is the basis for XML files an underlying text extended with markup. Most XML systems, since the dawn of XML, have been top-to-bottom structured data.

You're correct that almost no XML formats, with exception of XHTML, have an underlying text. This is the core problem, since the underlying information model inherited SGML presumes one. XML brings with it significant overhead for dealing with textual data, and most data isn't textual. Why is there an element vs tag debate? Wrong information model -- it's a difference without a distinction when you're doing data serialization. This is why XML was the shoe that never quite fit and why JSON will displace it so easily.

In 98/99, the XML bandwagon was something no one wanted to miss, it was the Web 2.0 and everyone knew it was the future. It was Java/WORA ("Write Once Run Anywhere") for data interchange and promised that you wouldn't be locked into a proprietary application. The marketing hype was simply outstanding. Even for technical people that hated XML itself, the promise of open formats was something you couldn't ignore and had to support even if you had to hold your nose. Open formats have since won -- holding your nose isn't needed anymore.

Now that the marketing hype of XML doesn't shut down the technical debate... JSON will soon dominate for data serialization tasks.

Re: Why JSON will continue to push XML out of the picture

#47

Post by 6ren »

clarkevans wrote: post #8

I think this article has done a great job enumerating trends that show JSON is beating XML for data serialization applications. I think these points are evidence of a shift in thinking, but not the reason for shift itself. Why JSON over XML? Because people need data serialization format and XML is a Markup Language. JSON is gaining widespread adoption for data serialization applications since it's the correct tool. X…

ON vs ML, nice

But there's also the stack. XML has XSD for validation and documentation; XSLT and XQuery for transformation; and most people seem to like XPath. The overwhelming response to analogues for JSON is horror - don't pollute our simplicity! - and acknowledgement that while some tasks do indeed need these features, the XML stack already has them. The corruption of XML is what keeps JSON clean.

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