dpd-event

Event Resource

This custom resource type allows you to write an event that will run when the resource's route receives a GET or POST request.

Installation

In your app's root directory, type npm install dpd-event into the command line or download the source. This should create a dpd-event directory in your app's node_modules directory.

See Installing Modules for details.

Usage

The On POST event will be executed when the resource's route (or a subroute) receives a POST request, and likewise with the On GET event.

It is strongly recommended that you reserve the On GET event for operations that return a value, but don't have any side effects of modifying the database or performing some other operation.

If your resource is called /add-follower, you can trigger its POST event from dpd.js:

dpd.addfollower.post('320d6151a9aad8ce', {userId: '6d75e75d9bd9b8a6'}, function(result, error) {
    // Do something
})

And over HTTP:

POST /add-follower/320d6151a9aad8ce
Content-Type: application/json
{
    "userId": "6d75e75d9bd9b8a6"
}

Event API

In addition to the generic custom resource event API, the following functions and variables are available while scripting the Event resource:

setResult(result)

Sets the response body. The result argument can be a string or an object.

// On GET /top-score
dpd.scores.get({$limit: 1, $sort: {score: -1}}, (result) => {
    setResult(result[0]);
});

getHeader(header)

Gets a request header. header is case insensitive.

if (getHeader('x-api-key') != 'mysecretapikey') cancel(401, 'bad api key');

setHeader(header, value)

Set a response header.

setHeader('Content-Type', 'text/javascript');
setResult('typeof myCallback === "function" && myCallback("hello world")');

setStatusCode(statusCode)

Sets the response http status code.

// temporary redirect to somewhere else
setStatusCode(302);
setHeader('Location', 'https://somesite/someotherplace');

url

The URL of the request, without the resource's base URL. If the resource is called /add-follower and receives a request at /add-follower/320d6151a9aad8ce, the url value will be /320d6151a9aad8ce.

// On GET /statistics
// Get the top score
if (url === '/top-score') {
    dpd.scores.get({$limit: 1, $sort: {score: -1}}, function(result) {
    setResult(result[0]);
    });
}

parts

An array of the parts of the url, separated by /. If the resource is called /add-follower and receives a request at /add-follower/320d6151a9aad8ce/6d75e75d9bd9b8a6, the parts value will be ['320d6151a9aad8ce', '6d75e75d9bd9b8a6'].

// On POST /add-score
// Give the specified user (/add-score/:userId) 5 points
var userId = parts[0];
if (!userId) cancel("You must provide a user");
 
dpd.users.put({id: userId}, {score: {$inc: 5}}, function(result, err) {
    if (err) cancel(err);
});

query

The query string object.

// On GET /sum
// Return the sum of the a and b properties (/sum?a=5&b=1)
 
setResult(Number(query.a) + Number(query.b));

body

The body of the request.

// On POST /sum
// Return the sum of the a and b properties {a: 5, b: 1}
 
setResult(Number(body.a) + Number(body.b));