aaworker

An Extensible Web Worker for Hoplon

1. Introduction
2. Client API
3. Worker API
4. Change Log

Introduction

Some things, like IndexedDB and crypto tasks, may interfere with the responsiveness of a web page. These tasks then are best run using a web worker.

Responses from a web worker are typically an updated state. Hoplon is a nice solution for processing updated state for a reactive web page cells.

AAWorker's deflpc and mklocal have been modeled after Castra's defrpc and mkremote. A mechanism like castra's is necessary here as aaworker does not use shared web workers.

Demos: tworker duracell

Client API

(aaworker.lpc/new-worker! "worker.js")

Create a web worker that executes the worker.js file.

(aaworker.lpc/mklocal! 'click "worker.js" state error loading)

(aaworker.lpc/mklocal! 'click "worker.js" state error loading counter)

(aaworker.lpc/mklocal! 'click "worker.js" state error loading counter req-key)

Returns a RPC function to call the click method in the web worker that is executing worker.js, while also associating the state/error/loading cells with the name of the function for the given worker.

The state cell is where the results of calling click are returned, assuming no exception was raised.

The error cell is set to the exception raised when click was called in the web worker.

The loading cell contains a text message while the click method is executing, otherwise it is nil.

The optional counter cell is incremented on completion of a request, successful or otherwise.

The optional req-key identifies the particular request, allowing multiple requests with different state cells to the same worker api. When not present, (keyword fn-name)--:click in this case--is used.

(aaworker.lpc/register-notice-processor! "worker.js" :alert (fn [msg] (js/alert msg)))

The register-notice-processor! is creates a handler for one type of notice from a worker. In this case it creates a handler for alerts coming from the web worker executing worker.js. And this particular call to register-notice-processor! occurs when new-worker! is called, so that any worker can send an :alert notice to the client.

Worker API

(aaworker.api/process-requests)

Processes requests sent by the client.

Once request processing is initiated, a :ready notice is sent back to the client.

(aaworker.worker-macros/deflpc! click [] body)

Defines the click function and registers it to process click requests from the client.

(aaworker.worker-macros/deflapc! idb-read [key] body)

Defines the idb-read asynchronous function and registers it to process idb-read requests from the client.

Two arguments are pre-pended to the function's arguments, success and failure. These are callback functions which take a single argument, a result or an error message, respectively.

(aaworker.api/send-notice :alert "Something somewhere has gone wrong!")

Sends a notice, in this case an :alert, to the client. The client must have already registered a handler for the given type of notice, or the notice will be ignored. Arguments after the notice type, e.g. after the :alert in this case, must match the arguments of the registered handler function.

Change Log

0.1.4 - Updated dependencies.

0.1.3 - Updated dependencies.

0.1.2 - Added mkreq! for when multiple cells use the same worker api. Fixed error handling and argument passing bugs. Added optional completion counter.

0.1.1 - Added deflapc! for asynchronous functions. Added the :ready notice.

0.1.0 - Dropped async.core, added worker notifications, added ! to the end of the names of funchtions which alter state.

0.0.1 - Initial release.