ServerEventService

ServerEventService

new ServerEventService(server, route, wait_intervalopt)

Description:

  • Implements a mechanism to react to events from the server.

    • A POST service is attached to the given route.

    • This is the server side of a simple client/server mechanism for persistent data.

    • The local service is attached to an express web mechanism, using a construct of the form:

    // Loads required packages
const express = require("express");
const server = express();
const ServerEventService = require("./ServerEventService.js");

// Defines a minimal persistantdata service
new ServerEventService(server, "/_serverevent");
server.listen(8080);
Parameters:
Name Type Attributes Default Description
server express

The express server mechanism.
route string /_serverevent

The route, both :

  • The URL route to this service and
  • The local root directory path.
wait_interval uint <optional>
 10

The waiting interval between scanning the event queue, minimal value is 10.

Methods

(inner) doQuery()

Description:

  • Implements the event server management query. The even server management queries are:

    • action=clear :
      • Purges all pending events.

add(value)

Description:

  • Appends an event to the event queue.

Parameters:
Name Type Description
value string

The event value, it might be a JSON string.

clear()

Description:

  • Clears the event queue.

addClock(period, count)

Description:

  • Generates a periodic event (mainly for debugging purpose).

    • The event value writes $index, the occurence index, starting from 0.
Parameters:
Name Type Description
period uint

The clock period in millisecond, 0 to stop the clock.
count uint

The maximal number of event, 0 if no bound.