Workflow
The following image shows an overview of the workflow executed by the component to render a chart:
The process of rendering a chart using the Fusion Chant Pentaho Plugin starts with the load of two properties files and the load of request parameters. The parameters are managed by Properties Manager. For more information about parameters check Supported Parameters. The Properties Manager has one Global Properties Manager and two maps of properties. On the first request, the Global Properties Manager loads the global properties (called global properties) which are defined in the fusionCharts.properties file in the plugin's root folder. For each request, if the request parameters has the location of an xFusion file, the Properties Manager loads all the properties included in the file (called local properties). Finally the properties sent in the request are loaded (called instance properties).
All properties have an override order:
- Global Properties - Are the base properties
- Local Properties - Override Global Properties
- Instance Properties - Override Global Properties and Local Properties
After all properties are loaded, it's time to invoke the CDA to get data. CDA is used to get data to all types of charts and widgets. Some times the plugin has to execute more than one query depending on the type of the chart. All the results from the different queries are stored on a map for next steps.
If the data is already available on the initial request no need to use to CDA. This step converts the JSON data into Pentaho Result sets that are used from now on to build the chart.
Different types of charts require generating specific XML nodes. To make the design more modular a factory is used to obtain the correct Fusion Component class based on the chart type.
Each class knows how to correctly handle the chart properties and data to generate a valid xml. The xml is the output of the plugin.
The XML is the output of the plugin which is sent as a response to the browser. On the browser the javascript function renderChart() is called from file standaloneChartRender.js and the Fusion Chart is rendered.
This process is similar to the XDashFusionChartComponent the only difference is that in the chart properties you need to specify that you want to use the new XPFusionChartComponent. We also included a 'new' method to load properties to the chart by using the FusionCharts 'theme' property. So if you want to define properties to apply to all your charts, create a new theme and apply it to all of them.
Using the chart properties the triggerQuery method retrieves the chart that will be used to create the chart dataset.
After the retrieval of the data, the component generates the JSON structure that will be used as the chart dataset and gets the properties ready to render the chart.
After everything is ready the component renders the chart.