68 lines
2.3 KiB
JavaScript
68 lines
2.3 KiB
JavaScript
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/** This module defines a express.Router() instance
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* - checking Accept-Version header to be 1.0
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* - body-data to be JSON on POST/PUT/PATCH
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* - body to be not empty on POST/PUT/PATCH
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* - Request accepts JSOn as reply content-type
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*
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* @author Johannes Konert
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* @licence CC BY-SA 4.0
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*
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* @module restapi/request-checks
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* @type {Router}
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*/
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// remember: in modules you have 3 variables given by CommonJS
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// 1.) require() function
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// 2.) module.exports
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// 3.) exports (which is module.exports)
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"use strict";
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const router = require('express').Router();
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// API-Version control. We use HTTP Header field Accept-Version instead of URL-part /v1/
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router.use((req, res, next) => {
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// expect the Accept-Version header to be NOT set or being 1.0
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const versionWanted = req.get('Accept-Version');
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if (versionWanted !== undefined && versionWanted !== '1.0') {
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// 406 Accept-* header cannot be fulfilled.
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res.status(406).send('Accept-Version cannot be fulfilled').end();
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} else {
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next(); // all OK, call next handler
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}
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});
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// request type application/json check
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router.use((req, res, next) => {
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if (['POST', 'PUT', 'PATCH'].indexOf(req.method) > -1 &&
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(!( /multipart\/form-data/.test(req.get('Content-Type'))) &&
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!( /application\/json/.test(req.get('Content-Type'))))) {
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// send error code 415: unsupported media type
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res.status(415).send('wrong Content-Type'); // user has SEND the wrong type
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} else if (!req.accepts('json')) {
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// send 406 that response will be application/json and request does not support it by now as answer
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// user has REQUESTED the wrong type
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res.status(406).send('response of application/json only supported, please accept this');
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}
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else {
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next(); // let this request pass through as it is OK
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}
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});
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// request POST, PUT check that any content was send
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router.use((req, res, next) => {
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let err = undefined;
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if (['POST', 'PUT', 'PATCH'].indexOf(req.method) > -1 && parseInt(req.get('Content-Length')) === 0) {
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err = new Error("content in body is missing");
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err.status = 400;
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next(err);
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} else if ('PUT' === req.method && !(req.body.id || req.body._id)) {
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err = new Error("content in body is missing field id");
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err.status = 400;
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next(err);
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}
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next();
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});
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module.exports = router;
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