Mostly I have just used XML files to store config info and to provide elementary data persistence. Now I am building a website where I need to store some XML type data. However I am already using JSON extensively throughout the whole thing. Is it bad to store JSON directly instead of XML, or should I store the XML and introduce an XML parser.

Mostly I have just used XML files to store config info and to provide elementary data persistence. Now I am building a website where I need to store some XML type data. However I am already using JSON extensively throughout the whole thing. Is it bad to store JSON directly instead of XML, or should I store the XML and introduce an XML parser.

• javascript
• xml
• json

• Why must you store JSON in XML opposed to storing it in its own file? XML is not a data storage device, so you may need to evaluate your reasons for why you use XML and JSON. – austin cheney Commented Sep 22, 2009 at 2:00
• 2 YOu didn't understand the question. – DevDevDev Commented Sep 22, 2009 at 2:13
• @DevDevDev - may the inquiring minds know why none of these answers tickled your fancy enough to accept one? :) – DVK Commented Oct 8, 2009 at 3:07

6 Answers 6

Not bad at all. Although there are more XML editors, so if you're going to need to manually edit the files, XML may be better.

Differences between using XML and JSON are:

• A lot easier to find an editor supporting nice way to edit XML. I'm aware of no editors that do this for JSON, but there might be some, I hope :)

• Extreme portability/interoperability - not everything can read JSON natively whereas pretty much any language/framework these days has XML libraries.

• JSON takes up less space

• JSON may be faster to process, ESPECIALLY in a JavaScript app where it's native data.

• JSON is more human readable for programmers (this is subjective but everyone I know agrees so).

Now, please notice the common thread: any of the benefits of using pure XML listed above are 100% lost immediately as soon as you store JSON as XML payload.

Therefore, the gudelines are as follows:

• If wide interoperability is an issue and you talk to something that can't read JSON (like a DB that can read XML natively), use XML.

• Otherwise, I'd recommend using JSON

• NEVER EVER use JSON as XML payload unless you must use XML as a transport container due to existing protocol needs AND the cost of encoding and decoding JSON to/from XML is somehow prohibitively high as compared to network/storage lossage due to double encoding (I have a major trouble imagining a plausible scenario like this, but who knows...)

UPDATED: Removed Unicode bullets as per info in comments

It's just data, like XML. There's nothing about it that would preclude saving it to disk.

Define "bad". They're both just plain-text formats. Knock yourself out.

If your storing the data as a cache (meaning it was in one format and you had to process it programatically to "make" it JSON. Then I say no problem. As long as the consumer of your JSON reads native JSON then it's standard practice to save cache data to disk or memory.

However if you're storing a configuration file in JSON which needs human interaction to "process" then I may reconsider. Using JSON for simple Key:Value pairs is cool, but anything beyond that, the format may be too compact (meaning nested { and [ brackets can be hard to decipher).

one potential issue with JSON, when there is deep nesting, is readability, you may actually see ]]]}], making debugging difficult