Re: Fw: [GENERAL] PLV8 and JS exports / referencing

On Sat, Nov 8, 2014 at 12:13 PM, Jon Erdman
<postgresql(at)thewickedtribe(dot)net> wrote:
>
> So, I was trying to use mustache.js in PG by defining a V8 function that imports it. Older versions worked fine, but in newer versions they use a class factory and I can't figure out how to reference the mustache stuff that it creates. Apparently I need to know how our V8 implementation does exports.

If you define a variable named "exports" before the Mustache factory
code then it'll make it think it's loading in a CommonJS environment
and the "exports" variable will be populated with the Mustache
methods.

I'm not too familiar with PLV8 (so I'm not sure if there's a
better/direct way to support modules) but the following works fine:

CREATE OR REPLACE FUNCTION mustache(template text, view json)
RETURNS TEXT
LANGUAGE plv8
IMMUTABLE
STRICT
AS $BODY$
var exports = {};
// Copy/paste https://raw.githubusercontent.com/janl/mustache.js/master/mustache.js
var Mustache = exports;
return Mustache.render(template, view);
$BODY$;

test=> SELECT mustache('test: {{foo}}', '{"foo": "bar"}'::json);
mustache
-----------
test: bar
(1 row)

Regards,
-- Sehrope Sarkuni
Founder & CEO | JackDB, Inc. | https://www.jackdb.com/