104 lines
3.7 KiB
JavaScript
104 lines
3.7 KiB
JavaScript
// Copyright IBM Corp. 2016,2018. All Rights Reserved.
|
|
// Node module: strong-error-handler
|
|
// This file is licensed under the MIT License.
|
|
// License text available at https://opensource.org/licenses/MIT
|
|
|
|
'use strict';
|
|
var accepts = require('accepts');
|
|
var debug = require('debug')('strong-error-handler:http-response');
|
|
var sendJson = require('./send-json');
|
|
var sendHtml = require('./send-html');
|
|
var sendXml = require('./send-xml');
|
|
var util = require('util');
|
|
|
|
module.exports = negotiateContentProducer;
|
|
|
|
/**
|
|
* Handles req.accepts and req.query._format and options.defaultType
|
|
* to resolve the correct operation
|
|
*
|
|
* @param req request object
|
|
* @param {Function} logWarning a logger function for reporting warnings
|
|
* @param {Object} options options of strong-error-handler
|
|
* @returns {Function} Operation function with signature `fn(res, data)`
|
|
*/
|
|
function negotiateContentProducer(req, logWarning, options) {
|
|
var SUPPORTED_TYPES = [
|
|
'application/json', 'json',
|
|
'text/html', 'html',
|
|
'text/xml', 'xml',
|
|
];
|
|
|
|
options = options || {};
|
|
var defaultType = 'json';
|
|
|
|
// checking if user provided defaultType is supported
|
|
if (options.defaultType) {
|
|
if (SUPPORTED_TYPES.indexOf(options.defaultType) > -1) {
|
|
debug('Accepting options.defaultType `%s`', options.defaultType);
|
|
defaultType = options.defaultType;
|
|
} else {
|
|
debug('defaultType: `%s` is not supported, ' +
|
|
'falling back to defaultType: `%s`', options.defaultType, defaultType);
|
|
}
|
|
}
|
|
|
|
// decide to use resolvedType or defaultType
|
|
// Please note that accepts assumes the order of content-type is provided
|
|
// in the priority returned
|
|
// example
|
|
// Accepts: text/html, */*, application/json ---> will resolve as text/html
|
|
// Accepts: application/json, */*, text/html ---> will resolve as application/json
|
|
// Accepts: */*, application/json, text/html ---> will resolve as application/json
|
|
// eg. Chrome accepts defaults to `text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*`
|
|
// In this case `resolvedContentType` will result as: `text/html` due to the order given
|
|
var resolvedContentType = accepts(req).types(SUPPORTED_TYPES);
|
|
debug('Resolved content-type', resolvedContentType);
|
|
var contentType = resolvedContentType || defaultType;
|
|
|
|
if (options.negotiateContentType === false) {
|
|
if (SUPPORTED_TYPES.indexOf(options.defaultType) > -1) {
|
|
debug('Forcing options.defaultType `%s`',
|
|
options.defaultType);
|
|
contentType = options.defaultType;
|
|
} else {
|
|
debug('contentType: `%s` is not supported, ' +
|
|
'falling back to contentType: `%s`',
|
|
options.defaultType, contentType);
|
|
}
|
|
}
|
|
|
|
// to receive _format from user's url param to overide the content type
|
|
// req.query (eg /api/Users/1?_format=json will overide content negotiation
|
|
// https://github.com/strongloop/strong-remoting/blob/ac3093dcfbb787977ca0229b0f672703859e52e1/lib/http-context.js#L643-L645
|
|
var query = req.query || {};
|
|
if (query._format) {
|
|
if (SUPPORTED_TYPES.indexOf(query._format) > -1) {
|
|
contentType = query._format;
|
|
} else {
|
|
// format passed through query but not supported
|
|
var msg = util.format('Response _format "%s" is not supported' +
|
|
'used "%s" instead"', query._format, defaultType);
|
|
logWarning(msg);
|
|
}
|
|
}
|
|
|
|
debug('Content-negotiation: req.headers.accept: `%s` Resolved as: `%s`',
|
|
req.headers.accept, contentType);
|
|
return resolveOperation(contentType);
|
|
}
|
|
|
|
function resolveOperation(contentType) {
|
|
switch (contentType) {
|
|
case 'application/json':
|
|
case 'json':
|
|
return sendJson;
|
|
case 'text/html':
|
|
case 'html':
|
|
return sendHtml;
|
|
case 'text/xml':
|
|
case 'xml':
|
|
return sendXml;
|
|
}
|
|
}
|