fh-webapp is part one of a two-part replacement for fh-nodeapp. Webapp is the "'"hostapp" part of fh-nodeapp, that which makes public endpoints from exported functions in cloud/main.js. It also hosts some system-level piping to help the studio determine if an app is online, the endpoints it exposes), and introduces a new namespace - /mbaas.
Usage
Add the following to the 'dependencies' section of your 'cloud/package.json' file:
"fh-webapp" : "*",
"fh-api" : "*",
"express" : "3.3.4"
Add a file to your FeedHenry app 'cloud/application.js', with the following contents:
var webapp = require('fh-webapp');
var express = require('express');
$fh = require('fh-api');
var mainjs = require('main.js');
var app = express();
app.use('/sys', webapp.sys(mainjs));
app.use('/mbaas', webapp.mbaas);
app.use('/cloud', webapp.cloud(mainjs));
// You can define custom URL handlers here, like this one:
app.use('/', function(req, res){
res.end('Your Cloud App is Running');
});
module.exports = app.listen(process.env.FH_PORT || process.env.VCAP_APP_PORT || 8001);
Customising & Extending
The above application.js is just an Expressjs application - it's easily extensible.
Custom APIs
You can create custom API handlers in the Express format by doing:
app.use('/myapi', function(req, res){
res.end('My custom response');
});
Serving Static Files
Express has a built-in static file server. In this example, we host files under the public directory:
app.use(express.static(__dirname + '/public'));
REST API
Cloud
(POST | GET | PUT) /cloud/:someFunction
Authentication : Optional - can be enabled globally or on a per-endpoint basis under "Endpoints" section of the studio. Response formats : JSON, binary, plain text
Headers
x-fh-auth-app : API key of your application, found under the "details" section of the studio.
Body:
JSON format - paramaters to be passed to the exported function, see 'Writing API Functions'.
Response:
Result as passed to the callback function of the exported function - see 'Writing API Functions'.
Writing API functions
The cloud namespace exposes the public functions of a javascript file of your choice (traditionally 'main.js') as public endpoints under the cloud URL namespace. :someFunction is the name of a function attached to the 'exports' object. These functions take two paramaters - the first is the data sent in the POST, the second is the callback function to call.
exports.getConfig = function (params, callback){
// Do some work here, then return data
var err = false;
// Check if some error condition happened first
if (err){
return callback(err);
}
return callback(null, res);
}
mBaaS
POST /mbaas/db
Authentication : Required - App API key goes here. Response format : JSON
Headers
x-fh-auth-app : API key of your application, found under the "details" section of the studio.
POST Body:
JSON body - same as $fh.db params. A summary of body options follows - For more, see $fh.db docs
{
"act": "create|update|list|delete|deleteall",
"type": "collectionName",
"guid": "GUID of object operating on - not required for list or deleteall",
"fields": "JSON definition of fields - required for create|update",
"eq|ne|in" : "JSON definition of query to match - supported for list only"
}
Response:
As per $fh.db
Sys
GET /sys/info/ping
Authentication : None Response formats : Plaintext
Headers
None
Response:
"OK"
if application is running as expected. Will respond with a 404 otherwise
GET /sys/info/endpoints
Authentication : None Response formats : JSON
Headers
None
Response:
{
endpoints : ['array of endpoints exported as public functions']
}
GET /sys/info/memory
Authentication : None Response formats : JSON
Headers
None
Response:
{
rss: 13721600, // Resident set size
heapTotal: 7195904, // V8's total available memory
heapUsed: 2369744 // V8's used memory
}
GET /sys/info/memory
Authentication : None Response formats : Plaintext
Headers
None
Response:
0.1.0