\echo Use "CREATE EXTENSION supascript CASCADE" to load this file. \quit

SET PLV8.START_PROC = 'supascript_init';

ALTER DATABASE POSTGRES SET PLV8.START_PROC TO 'supascript_init';

CREATE TABLE IF NOT EXISTS SUPASCRIPT_JS_MODULES (MODULE text UNIQUE PRIMARY KEY,

AUTOLOAD BOOL DEFAULT FALSE,

SOURCE text);

CREATE OR REPLACE FUNCTION supascript_init() RETURNS VOID

AS $$

/* plv8.execute('set search_path to "$user", public, auth, extensions'); */

this.moduleCache = {};

// execute a Postgresql function

// i.e. exec('my_function',['parm1', 123, {"item_name": "test json object"}])

this.exec = function(function_name, parms) {

var func = plv8.find_function(function_name);

return func(...parms);

}

this.load = function(key, source) {

var module = {exports: {}};

try {

eval("(function(module, exports) {" + source + "; })")(module, module.exports);

} catch (err) {

plv8.elog(ERROR, `eval error in source: ${err} (SOURCE): ${source}`);

}

// store in cache

moduleCache[key] = module.exports;

return module.exports;

};

// execute a sql statement against the Postgresql database with optional args

// i.e. sql('select * from people where first_name = $1 and last_name = $2', ['John', 'Smith'])

this.sql = function(sql_statement, args) {

if (args) {

return plv8.execute(sql_statement, args);

} else {

return plv8.execute(sql_statement);

}

};

// emulate node.js "require", with automatic download from the internet via CDN sites

// optional autoload (boolean) parameter allows the module to be preloaded later

// i.e. var myModule = require('https://some.cdn.com/module_content.js', true)

this.require = function(module, autoload) {

if(moduleCache[module])

return moduleCache[module];

var rows = plv8.execute(

'select source from supascript_js_modules where module = $1',

[module]

);

if (rows.length === 0 && module.substr(0,4) === 'http') {

try {

source = plv8.execute(`SELECT content FROM http_get('${module}');`)[0].content;

} catch (err) {

plv8.elog(ERROR, `Could not load module through http: ${module}`, JSON.stringify(err));

}

try {

/* the line below is written purely for esthetic reasons, so as not to mess up the online source editor */

/* when using standard regExp expressions, the single-quote char messes up the code highlighting */

/* in the editor and everything looks funky */

const quotedSource = source.replace(new RegExp(String.fromCharCode(39), 'g'), String.fromCharCode(39, 39));

plv8.execute(`insert into supascript_js_modules (module, autoload, source) values ('${module}', ${autoload ? true : false}, '${quotedSource}')`);

} catch (err) {

plv8.elog(ERROR, `Error inserting module into supascript_js_modules: ${err} ${module}, ${autoload ? true : false}, '${plv8.quote_literal(source)}'`);

}

return load(module, source);

}

else if(rows.length === 0) {

plv8.elog(NOTICE, `Could not load module: ${module}`);

return null;

} else {

return load(module, rows[0].source);

}

};

// Grab modules worth auto-loading at context start and let them cache

var query = `select module, source from supascript_js_modules where autoload = true`;

plv8.execute(query).forEach(function(row) {

this.load(row.module, row.source);

});

$$ LANGUAGE PLV8;