Server-side functions

Functions run into a custom JavaScript runtime we’ve created. It means that you do not have a full Node environment. You have a sandboxed runtime similar to what browsers offer but without the window and document objects.

How to trigger functions

When you create a function, you must specify a trigger. At this time, we support two trigger types: web and topic or message type.

StaticBackend already publishes messages when database documents are created, updated, or deleted. So those are all valid topics you can have functions be triggered and execute some logic on the server.

A function that triggers via web can be invoked directly via its URL.

Function’s entry point

The function entry point is named handle. You’re required to have a function with that name to have a valid executable function.

function handle(body, qs, headers) {
  // implement your logic here
}

Built-in message type (topic)

join: When a user joins a real-ime channel.

chan_out: When a message was send in a real-time channel.

db_created: When a document is created.

db_updated: When a document is updated.

db_deleted: When a document is deleted.

We will add multiple system topics in the following weeks for all StaticBackend resources. For instance, a new user creates an account when files are uploaded, forms are submitted, etc. This will allow your application to react to those events in a server-side function and perform other important tasks.

Built-in runtime functions

Those are the functions we provide to help you interact with your StaticBackend resources from your functions.

Helper functions

log(“item 1”, item2, true, …)

The log function allows you to keep records of what’s happening during the execution of your function. When viewing the execution history, you will see all output produced by the log function.

You may specify multiple objects and they’ll all get printed.

Database releated functions

create(col, doc)

Creates the document inside the specified collection.

Arguments:

Returns: The created document

list(col, [params])

List all documents in a collection.

Arguments:

List parameter object:

{
  "page": 1,
  "size": 25
}

Returns:

{
  "result": [{your doc}, ...],
  "page": 1,
  "size": 25,
}

getById(col, id)

Get a document by id.

Returns: The matching document

query(col, filter, [params])

Query a database collection for documents.

Returns:

{
  "result": [{your doc}, ...],
  "page": 1,
  "size": 25,
}

update(col, id, doc)

Update a document.

Returns: Updated document

del(col, id)

Delete a document.

Returns: Count of deleted document(s)

Event/messages/cache functions

send(type, data, channel)

Publish a message to a specific channel.

Returns: A boolean