CODEWITHSUNDEEP
jsonxmlxqueryexist-db
Mark Miller
Mark Miller

Reputation: 3096

eXistdb JSON serialization

I have created an XQuery against http://www.w3schools.com/xsl/books.xml

xquery version "3.0";
for $x in collection("/db/books")//book
return 
    <book title="{$x/title}">
    {$x//author}
    </book>

If I evaluate it in eXistdb's eXide, I get reasonable output in the preview pane. 

<book title="Everyday Italian">
   <author>Giada De Laurentiis</author>
etc.

If I try to "run" it, I get the following error in the web browser:

This page contains the following errors:

error on line 4 at column 1: Extra content at the end of the document
Below is a rendering of the page up to the first error.

Giada De Laurentiis

I thought maybe I should serialize it as JSON. Based on a quick reading of http://exist-db.org/exist/apps/wiki/blogs/eXist/JSONSerializer, I added the following two lines after the xquery version line:

declare namespace json="http://www.json.org";
declare option exist:serialize "method=json media-type=text/javascript";

But I get the same acceptable xml preview result and same browser error.

How can I get my output in a web browser, either as XML or JSON?

I looked at https://stackoverflow.com/questions/35038779/json-serialization-with-exist-db-rest-api but didn't see how to use that as a starting point.

Upvotes: 0

Views: 1128

Answers (2)

Joe Wicentowski
Joe Wicentowski

Reputation: 5294

I'm glad you figured out that the original issue was that the browser expects well-formed XML, whereas eXide is happy to show you arbitrary nodes.

On the topic of JSON serialization, briefly (I'm on my phone), see http://exist-db.org/exist/apps/wiki/blogs/eXist/XQuery31 in the section entitled "Serialization". Make sure you're running eXist 3.0 RC1.

Upvotes: 1

Mark Miller
Mark Miller

Reputation: 3096

A top level tag and some additional curly braces are required:

xquery version "3.0";
declare namespace json="http://www.json.org";
declare option exist:serialize "method=json media-type=text/javascript";
<result> 
{for $x in collection("/db/books")//book
return 
    <book title="{$x/title}">
    {$x//author}
    </book>
}
</result>

Or, for well-formed XML serialization:

xquery version "3.0";
<result> 
{for $x in collection("/db/books")//book
return 
    <book title="{$x/title}">
    {$x//author}
    </book>
}
</result>

Credit: http://edutechwiki.unige.ch/en/XQuery_tutorial_-_basics

Upvotes: 0

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