The issue is that there’s no perfect lossless translation in both directions. (If there were, we’d have implemented that across the board.) Some complicating factors: XML namespaces, mixed content, JSON arrays, allowable characters in JSON keys, etc. The use case for json:transform-to-json, is about getting a semantically similar representation of a JSON document in the XML data model, for search and manipulation in MarkLogic. The default translation used by the REST API is lossless, so you can get the JSON (semantically, not byte-for-byte) back that you put in. If you need more control over the JSON serialization, there are configuration options for json:transform-to-json. However, if you need to generate a very specific JSON representation json:object and json:array allow you the lowest-level control.
TL;DR: If you want to persist some JSON and search it, use json:transform-to-json, as the REST API does. If you need precise control over the JSON representation, use json:object/json:array (either through the built-ins or by generating an XML representation) along with xdmp:to-json. Some extra color on Stack Overflow <http://stackoverflow.com/a/17707377/563324>. Justin Justin Makeig Director, Product Management MarkLogic Corporation [email protected]<mailto:[email protected]> www.marklogic.com<http://www.marklogic.com/> On Jul 22, 2013, at 12:22 PM, Steve Spigarelli <[email protected]<mailto:[email protected]>> wrote: Thank you for your responses. I'm trying to write a REST extension that can create a JSON object with some objects previously uploaded using the REST interface. What I see to be the problem is that the REST interface translates the JSON into one format, and the json:map and json:array functions generate completely different internal XML structures. The files ingested with the REST interface require json:transform-to-json and json:map and json:array require xdmp:to-json to translate from XML to JSON. Starting with JSON of {"hello": "world"} I see the following: REST Interface (after upload): <json type="object" xmlns="http://marklogic.com/xdmp/json/basic";> <hello type="string">world</hello> </json> and using json:object() I get: json:object( <json:object xmlns:xs="http://www.w3.org/2001/XMLSchema"; xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; xmlns:json="http://marklogic.com/xdmp/json";> <entry key="hello"> <json:value xsi:type="xs:string">world</json:value> </entry> </json:object> ) I would expect them to be the same. Is there a way to convert from one to the other? Thanks Steve -- Steve On Mon, Jul 22, 2013 at 12:47 PM, Danny Sokolsky <[email protected]<mailto:[email protected]>> wrote: You can try looking through this section of the doc for a little more info too: http://docs.marklogic.com/guide/app-dev/json -Danny From: [email protected]<mailto:[email protected]> [mailto:[email protected]<mailto:[email protected]>] On Behalf Of David Lee Sent: Monday, July 22, 2013 11:44 AM To: MarkLogic Developer Discussion Subject: Re: [MarkLogic Dev General] json:object json:object is the in-memory representation of maps used for json. The only difference between map:map and json:object is that the keys are ordered (which actually is not something JSON guarentees ... but we do). Your "magic function" is xdmp:to-json(). You dont do a transformation on json:object TO JSON ... its already in the form needed ... You can turn it into a JSON string using xdmp:to-json() but thats not a transformation. Transformations occur between XML <-> JSON Did that answer your question ? ----------------------------------------------------------------------------- David Lee Lead Engineer MarkLogic Corporation [email protected]<mailto:[email protected]> Phone: +1 812-482-5224<tel:%2B1%20812-482-5224> Cell: +1 812-630-7622<tel:%2B1%20812-630-7622> www.marklogic.com<http://www.marklogic.com/> From: [email protected]<mailto:[email protected]> [mailto:[email protected]<mailto:[email protected]>] On Behalf Of Steve Spigarelli Sent: Monday, July 22, 2013 2:39 PM To: [email protected]<mailto:[email protected]> Subject: [MarkLogic Dev General] json:object I'm having a difficult time understanding what good the json:object() function is. From what I can tell after using it, it is a specialized map:map object. I have tried using json:transform-to-json on the object but the transform function doesn't like that. So, what is the proper way to create a json:object and receive back the actual JSON string? For example: let $json-obj := json:object() let $_ := map:put($json-obj, "key", "value") return magic-function($json-obj) which would return {"key": "value"} What I get instead by calling json:transform-to-json($json-obj) is an invalid coercion error. Even wrapping the object and passing the node doesn't work. Any ideas? Has anyone actually used this function? From the comments in the documentation it doesn't have many comments. (http://docs.marklogic.com/json:transform-to-json) -- Steve _______________________________________________ General mailing list [email protected]<mailto:[email protected]> http://developer.marklogic.com/mailman/listinfo/general _______________________________________________ General mailing list [email protected]<mailto:[email protected]> http://developer.marklogic.com/mailman/listinfo/general
_______________________________________________ General mailing list [email protected] http://developer.marklogic.com/mailman/listinfo/general
