plugin-development.md

Plugin development

This is an important step to enjoy all flexibility and features that this framework provides.

Steps

1. In visualizer.cfg add the plugin to the list of desired plugins:

Example:

[general]
host = 0.0.0.0
port = 6001
plugins = my_new_visualizer
debug = True
retries = 5

[my_new_visualizer]
var1 = 
var2 = 
var3 = 

In this tutorial, we will use MyNewVisualizer to represent a new visualizer plugin.

2. Create a new if statement condition in the file visualizer/service/api/init.py that will recognize if the new plugin added is informed in the configuration file (visualizer.cfg). If this condition is true, then the necessary variables to execute the plugin needs to be informed in the visualizer.cfg file and computed in the visualizer/service/api/init.py.

Example:

import ConfigParser

try:

[...]
    
    if 'my_new_visualizer' in plugins:
        var1 = config.get('my_new_visualizer', 'var1')
        var2 = config.get('my_new_visualizer', 'var2')
        var3 = config.get('my_new_visualizer', 'var3')

[...]

3. Create a new folder under visualizer/plugins with the desired plugin name and add init.py.

4. Write a new python class under visualizer/plugins/mynewvisualizer. This class must extend visualizer.plugins.base and implement only four methods: init, start_visualization, stop_visualization, get_visualizer_url.

• Example:

  •   class MyNewVisualizer:
    
      	def __init__(self, app_id, plugin_info, collect_period, retries=100):
      	# set things up
      	   pass
      
      	def start_visualization(self):
      	# visualizing logic
      	   pass
    
            def stop_visualization(self):
            # stop the visualizing logic
               pass
    
            def get_visualizer_url(self):
            # returns the visualizer url
               pass
    
    

5. Edit the VisualizerBuilder class adding a new condition to check the plugin name in the start_visualization. Instantiate the plugin in the conditional case.

• Example:

  •   ...
      elif plugin_name == "mynewvisualizer":
              plugin = MyNewVisualizer(app_id, plugin_info, collect_period, retries=retries)
      ...