Supporting multilevel hierarchies

Flexmonster supports creating multilevel hierarchies from non-hierarchical data out of the box. To use this feature for the custom data source API, you need to handle certain request scenarios on your server.

This guide describes how to support multilevel hierarchies on your server and configure them in the component.

Step 1. Implement advanced hierarchical filters

Hierarchies are composed on the client side while the server's task is to filter them. For this purpose, your back end has to implement advanced hierarchical filters.

Flexmonster sends filters in the /members request and the /select requests for the pivot table, the flat table, and the drill-through view. The filters' structure is described by the FilterGroupObject.

Step 2. Notify Flexmonster about implementing advanced filters

When the server implements hierarchical filters, it should inform the component about that.

For this purpose, set the advanced property to true in the response to the /fields request. The component will ignore multilevel hierarchies if the advanced property is set to false.

Step 3. (optional) Handle the additional /select request

The component sends the additional /select request when the levelName property is defined in the slice. This request extracts members from the hierarchy level specified in levelName.

If you need the levelName property in your slice, handle the /select request for loading the required hierarchy levels.

Step 4. Configure the multilevel hierarchies

There are two ways to compose multilevel hierarchies:

On the client side

The MappingObject is responsible for grouping data into hierarchies. Specify hierarchy and parent properties to structure the data.

The example below illustrates how to compose multilevel hierarchies in the report. Here, we create the "Item" hierarchy with the "Category" field as a first level and the "Color" field as a second level:

report: {
  dataSource: {
    type: "api",
    url: "your_url",
    index: "your_index",
    mapping: {
      "Category": {
        type: "string",
        hierarchy: "Item"
      },
      "Color": {
        type: "string",
        hierarchy: "Item",
        parent: "Category"
      }
    }
  },
  slice: {
    // Your slice
  }
}

Live example

On the server side

As an alternative to the MappingObject, you can configure hierarchies right in the response to the /fields request. To do so, specify hierarchy and parent properties for the necessary fields.

Here is an example of a /fields response where the "Category" and "Color" fields are grouped under the "Item" hierarchy (with "Category" as the top level of the hierarchy):

{  
  "fields":[
    {
      "uniqueName": "Category",
      "type": "string",
      "hierarchy": "Item"
    },
    {
      "uniqueName": "Color",
      "type": "string",
      "hierarchy": "Item",
      "parent": "Category"
    },
    // ...
  ],
  "aggregations":{
    // ...
  },
  "filters":{
    // ...
  } 
}

Now run your project and open the webpage with Flexmonster - multilevel hierarchies should appear in the component.

What’s next?

You may be interested in the following articles:

Changes to Flexmonster Software License Agreement