5. Monitoring Widget Tutorial

5.1: Introduction

The Monitoring Widget is a simple Web-based tool that allows the monitoring of the processes running on a remote server from a common Web browser. It is available since JOpera v2.3.6. This tool may be integrated and executed within any HTML web page by embedding a chunk of code within the page.

Figure 5.1: Monitoring a Running Process

The figure above shows an example where each instance of the {msg_example_asynch}ASYNCHProcessSupplier[1.0] process is described by the states of their tasks. Each task has a name on the left and a colored rectangle at the right. The color, that may change over time, defines the current state of the task. On the top there is a STOP button, that when clicked, terminates the execution of the monitoring widget, which may further be restarted by clicking again on the same button.

Note: Clicking on the STOP button will not stop the execution of the process but only pause its monitoring by the widget - the Stop button can be hidden using CSS

5.2: Adding a Monitoring Widget

In order to use the Monitoring Widget, you need to add some lines of code to your HTML Web page.

Note: Multiple Widgets can be added to the same page

  1. Load the widget API by adding the following line into the HTML head element:

    Figure 5.2: Include the widget API in the page header

    The jopera.js script is served by JOpera's embedded Web server
  2. Choose which process should be displayed:

    Figure 5.3: Load and configure the widget

  3. Create a div container where the widget will be placed:

    Figure 5.4: Widget container

    The id of the div element has to be the same as the first argument used to initialize the TaskDisplalyer widget object.

5.3: Example

Copy and Paste this example HTML code in your page to get started:

 <script src="http://localhost:8080/ui.v2/scripts/jopera.js"></script>
  function load() { new TaskDisplayer("process"); }
<body onload="load()">
 <div id="process"></div>

5.4: TaskDisplayer API

There are three ways for creating the Monitoring Widget depending if you want to display all process, or only a single process, and in this case, if you are interested in a particular instance or in all the instances.

  • Display all processes:

    Figure 5.5: All the processes

    Where the argument process is the id of the div element where the widget will be displayed.
  • Display a single process with all pf its instances:

    Figure 5.6: A single process

    Where the second argument is the name of the process.
  • Display a single process with a specific instance:

    Figure 5.7: A single instance

    Where the third argument is the instance number.