mathoid/lib/api-util.js

Render TeX to SVG and MathML using MathJax. Based on svgtex.

'use strict';

const preq = require( 'preq' );
const sUtil = require( './util' );
const Template = require( 'swagger-router' ).Template;
const HTTPError = sUtil.HTTPError;

/**
 * Calls the MW API with the supplied query as its body
 *
 * @param {!Object} app the application object
 * @param {string} domain the domain to issue the request to
 * @param {?Object} query an object with all the query parameters for the MW API
 * @return {!Promise} a promise resolving as the response object from the MW API
 */
function mwApiGet( app, domain, query ) {

	query = Object.assign( {
		format: 'json',
		formatversion: 2
	}, query );

	const request = app.mwapi_tpl.expand( {
		request: {
			params: { domain },
			headers: { 'user-agent': app.conf.user_agent },
			query
		}
	} );

	return preq( request ).then( ( response ) => {
		if ( response.status < 200 || response.status > 399 ) {
			// there was an error when calling the upstream service, propagate that
			throw new HTTPError( {
				status: response.status,
				type: 'api_error',
				title: 'MW API error',
				detail: response.body
			} );
		}
		return response;
	} );

}

/**
 * Calls the REST API with the supplied domain, path and request parameters
 *
 * @param {!Object} app the application object
 * @param {string} domain the domain to issue the request for
 * @param {!string} path the REST API path to contact without the leading slash
 * @param {?Object} [restReq={}] the object containing the REST request details
 * @param {?string} [restReq.method=get] the request method
 * @param {?Object} [restReq.query={}] the query string to send, if any
 * @param {?Object} [restReq.headers={}] the request headers to send
 * @param {?Object} [restReq.body=null] the body of the request, if any
 * @return {!Promise} a promise resolving as the response object from the REST API
 *
 */
function restApiGet( app, domain, path, restReq ) {

	restReq = restReq || {};
	path = path[ 0 ] === '/' ? path.slice( 1 ) : path;

	const request = app.restbase_tpl.expand( {
		request: {
			method: restReq.method,
			params: { domain, path },
			query: restReq.query,
			headers: Object.assign( { 'user-agent': app.conf.user_agent }, restReq.headers ),
			body: restReq.body
		}
	} );

	return preq( request );

}

/**
 * Sets up the request templates for MW and RESTBase API requests
 *
 * @param {Object} app the application object
 */
function setupApiTemplates( app ) {

	// set up the MW API request template
	if ( !app.conf.mwapi_req ) {
		app.conf.mwapi_req = {
			uri: 'http://{{domain}}/w/api.php',
			headers: {
				'user-agent': '{{user-agent}}'
			},
			body: '{{ default(request.query, {}) }}'
		};
	}
	app.mwapi_tpl = new Template( app.conf.mwapi_req );

	// set up the RESTBase request template
	if ( !app.conf.restbase_req ) {
		app.conf.restbase_req = {
			method: '{{request.method}}',
			uri: 'http://{{domain}}/api/rest_v1/{+path}',
			query: '{{ default(request.query, {}) }}',
			headers: '{{request.headers}}',
			body: '{{request.body}}'
		};
	}
	app.restbase_tpl = new Template( app.conf.restbase_req );

}

module.exports = {
	mwApiGet,
	restApiGet,
	setupApiTemplates
};