How To

17 Feb 202224 minutes to read

Customize the header for treemap drilldown

Yon can add a header element as <div> and customize it to show the population of a particular country or continent on treemap drill-down.

To customize the header for treemap drill-down, follow the given steps:

Step 1:

Initialize the treemap and enable the drill-down option.

 @Html.EJS().TreeMap("container").WeightValuePath("Population").Format("n").UseGroupingSeparator(true).WeightValuePath("Population").Palette(new string[] { "#9999ff", "#CCFF99", "#FFFF99", "#FF9999", "#FF99FF", "#FFCC66" }).LeafItemSettings(leaf =>
          leaf.LabelPath("Name").ShowLabels(false)).EnableDrillDown(true).Levels(level =>
          {
              level.GroupPath("Continent").Fill("#336699").Border(br => br.Color("black").Width(0.5)).Add();
              level.GroupPath("States").Fill("#336699").Border(br => br.Color("black").Width(0.5)).Add();
              level.GroupPath("Region").Fill("#336699").Border(br => br.Color("black").Width(0.5)).Add();
          }).Render()

Step 2:

Show the population of a particular continent in the treemap loaded event. In this event, you can get the header element.

    loaded: function (args: ILoadedEventArgs) {
        var header = document.getElementById('header');
        var population = 0;
        for (var i = 0; i < args.treemap.layout.renderItems[0]['parent'].Continent.length; i++) {
            population += +(args.treemap.layout.renderItems[0]['parent'].Continent[i]['data'].Population);
        }
        header.innerHTML = 'Continent - Population : ' + population
    }

Step 3:

Customize the population for drilled countries or states in the header element when drill-down the treemap. The drillEnd event will be triggered when treemap is drilled.

CSHTML
Header.cs
@using Syncfusion.EJ2;
<div id="header" style="background-color: #179bd7"></div>
<div id="container">
       @Html.EJS().TreeMap("container").Load("load").DrillEnd("drillEnd").Loaded("loaded").WeightValuePath("Population").Format("n").UseGroupingSeparator(true).WeightValuePath("Population").Palette(new string[] { "#9999ff", "#CCFF99", "#FFFF99", "#FF9999", "#FF99FF", "#FFCC66" }).LeafItemSettings(leaf =>
          leaf.LabelPath("Name").ShowLabels(false)).EnableDrillDown(true).Levels(level =>
          {
              level.GroupPath("Continent").Fill("#336699").Border(br => br.Color("black").Width(0.5)).Add();
              level.GroupPath("States").Fill("#336699").Border(br => br.Color("black").Width(0.5)).Add();
              level.GroupPath("Region").Fill("#336699").Border(br => br.Color("black").Width(0.5)).Add();
          }).Render()
</div>
<script>
function loaded(args) {
        var header = document.getElementById('header');
        var population = 0;
        for (var i = 0; i < args.treemap.layout.renderItems[0]['parent'].Continent.length; i++) {
            population += +(args.treemap.layout.renderItems[0]['parent'].Continent[i]['data'].Population);
        }
    header.innerHTML = 'Continent - Population : ' + population
    }
    function drillEnd(args) {
        var header = document.getElementById('header');
        var layout = document.getElementById("container_TreeMap_Squarified_Layout");
        var population = 0;
        if (args.treemap.layout.renderItems[0]['isDrilled']) {
            for (var i = 0; i < args.treemap.layout.renderItems.length; i++) {
                population += +(args.treemap.layout.renderItems[i]['data'].Population);
            }
            header.innerHTML = layout.children[0].children[1].innerHTML.split(']')[1] + ' - ' + population;
        }
        else if (args.treemap.layout.renderItems[0]['parent'].Continent) {
            for (var i = 0; i < args.treemap.layout.renderItems[0]['parent'].Continent.length; i++) {
                population += +(args.treemap.layout.renderItems[0]['parent'].Continent[i]['data'].Population);
            }
            header.innerHTML = 'Continent - Population : ' + population;
        } else {
            population = args.treemap.layout.renderItems[0]['data'].Population;
            header.innerHTML = layout.children[0].children[1].innerHTML.split(']')[1] + ' - Population : ' + population;
        }
    }
    function load(args)
    { 
        var data = [
    { Continent:[
       { Name: "Africa",Population: 1216130000, States: [
            { Name: "Eastern Africa",Population:410637987, Region:[				
                { Name:"Ethiopia", Population: 107534882},
				{ Name:"Tanzania", Population: 59091392},
				{ Name:"Kenya", Population: 50950879},
				{ Name:"Uganda", Population: 44270563},
				{ Name:"Mozambique", Population: 30528673},
				{ Name:"Madagascar", Population: 26262810},
				{ Name:"Malawi", Population: 19164728},
				{ Name:"Zambia", Population: 17609178},
				{ Name:"Zimbabwe", Population: 16913261},
				{ Name:"Somalia", Population: 15181925},
				{ Name:"South, Sudan", Population: 12919053},
				{ Name:"Rwanda", Population: 12501156},
				{ Name:"Burundi", Population: 11216450},
				{ Name:"Eritrea", Population: 5187948},
				{ Name:"Mauritius", Population: 1268315},
				{ Name:"Djibouti", Population: 971408},
				{ Name:"Réunion", Population: 883247},
				{ Name:"Comoros", Population: 832347},
				{ Name:"Mayotte", Population: 259682},
				{ Name:"Seychelles", Population: 95235},
            ]  },
            { Name: "Middle Africa",Population:158562976, Region:[
				{ Name:"Democratic, Republic of the Congo", Population: 84004989},
				{ Name:"Angola", Population: 30774205},
				{ Name:"Cameroon", Population: 24678234},
				{ Name:"Chad", Population: 15353184},
				{ Name:"Congo", Population: 5399895},
				{ Name:"Central African, Republic", Population: 4737423},
				{ Name:"Gabon", Population: 2067561},
				{ Name:"Equatorial Guinea", Population: 1313894},
				{ Name:"Sao Tome and Principe", Population: 208818},
			] },
            { Name: "Northern Africa",Population:229385603, Region: [
				{ Name:"Egypt", Population: 99375741},
				{ Name:"Algeria", Population: 42008054},
				{ Name:"Sudan", Population: 41511526},
				{ Name:"Morocco", Population: 36191805},
				{ Name:"Tunisia", Population: 11659174},
				{ Name:"Libya", Population: 6470956},
				{ Name:"Western, Sahara", Population: 567421},
			] },
            { Name: "Southern Africa",Population:64292365, Region:[
				{ Name:"South Africa", Population: 57398421},
				{ Name:"Namibia", Population: 2587801},
				{ Name:"Botswana", Population: 2333201},
				{ Name:"Lesotho", Population: 2263010},
				{ Name:"Swaziland", Population: 1391385},
			] },
            { Name: "Western Africa", Population:362201579, Region:[
				{ Name:"Nigeria", Population: 195875237},
				{ Name:"Ghana", Population: 29463643},
				{ Name:"Côte d'Ivoire", Population: 24905843},
				{ Name:"Niger", Population: 22311375},
				{ Name:"Burkina Faso", Population: 19751651},
				{ Name:"Mali", Population: 19107706},
				{ Name:"Senegal", Population: 16294270},
				{ Name:"Guinea", Population: 13052608},
				{ Name:"Benin", Population: 11485674},
				{ Name:"Togo", Population: 7990926},
				{ Name:"Sierra Leone", Population: 7719729},
				{ Name:"Liberia", Population: 4853516},
				{ Name:"Mauritania", Population: 4540068},
				{ Name:"Gambia", Population: 2163765},
				{ Name:"Guinea-Bissau", Population: 1907268},
				{ Name:"Cabo Verde", Population: 553335},
				{ Name:"Saint Helena", Population: 4074},
			] },
        ]
       }]
    },
	
	
	
	{ Continent:[
        {
		Name: "Asia", Population:4436224000, States:[
			{Name: "Central Asia", Population: 69787760, Region:[
				{ Name:"Uzbekistan", Population: 32364996 },
				{ Name:"Kazakhstan", Population: 18403860 },
				{ Name:"Tajikistan", Population: 9107211 },
				{ Name:"Kyrgyzstan", Population: 6132932 },
				{ Name:"Turkmenistan", Population: 5851466 },
			] },
			{Name: "Eastern Asia", Population:1641908531, Region:[
				{ Name:"China", Population: 1415045928}, 
				{ Name:"Japan", Population:	 127185332 },
				{ Name:"South Korea", Population:	51164435 },
				{ Name:"North Korea", Population:25610672 },
				{ Name:"Taiwan", Population: 23694089 },
				{ Name:"Hong Kong", Population: 7428887 },
				{ Name:"Mongolia", Population: 3121772}, 
				{ Name:"Macao", Population: 632418 },
			]  },
			{Name: "Southeastern Asia", Population:641775797, Region: [
				{ Name:"Indonesia", Population:	 266794980 },
				{ Name:"Philippines", Population:	 106512074 },
				{ Name:"Viet Nam", Population:	 96491146 },
				{ Name:"Thailand", Population:	 69183173 },
				{ Name:"Myanmar", Population:	 53855735 },
				{ Name:"Malaysia", Population:	 32042458 },
				{ Name:"Cambodia", Population:	 16245729 },
				{ Name:"Laos", Population:	 6961210 },
				{ Name:"Singapore", Population:	 5791901}, 
				{ Name:"Timor-Leste", Population:	 1324094}, 
				{ Name:"Brunei Darussalam", Population:	 434076}, 
			]  },
			{Name: "Southern Asia", Population: 1846266634, Region: [
				{ Name:"India", Population:	 1354051854},
				{ Name:"Pakistan", Population:	 200813818},
				{ Name:"Bangladesh", Population:	 166368149},
				{ Name:"Iran", Population:	 82011735},
				{ Name:"Afghanistan", Population:	 36373176},
				{ Name:"Nepal", Population:	 29624035},
				{ Name:"Sri Lanka", Population:	 20950041},
				{ Name:"Bhutan", Population:	 817054},
				{ Name:"Maldives", Population:	 444259},
			]},
			{Name: "Western Asia", Population:262938009, Region: [
				{ Name:"Turkey", Population: 81916871},
				{ Name:"Iraq", Population: 39339753},
				{ Name:"Saudi Arabia", Population: 33554343},
				{ Name:"Yemen", Population: 28915284},
				{ Name:"Syria", Population: 18284407},
				{ Name:"Azerbaijan", Population: 9923914},
				{ Name:"Jordan", Population: 9903802},
				{ Name:"United Arab Emirates", Population: 9541615},
				{ Name:"Israel", Population: 8452841},
				{ Name:"Lebanon", Population: 6093509},
				{ Name:"State of Palestine", Population: 5052776},
				{ Name:"Oman", Population: 4829946},
				{ Name:"Kuwait", Population: 4197128},
				{ Name:"Georgia", Population: 3907131},
				{ Name:"Armenia", Population: 2934152},
				{ Name:"Qatar", Population: 2694849},
				{ Name:"Bahrain", Population: 1566993},
				{ Name:"Cyprus", Population: 1189085},
			] },
       ]
        }]
    },
 
 
	{ Continent:[
        {
		Name: "North America", Population:579024000, States:[
			
		{Name:"Central America", Population:174988756 , Region:[
			{ Name:"Mexico", Population: 130759074 },
			{ Name:"Guatemala", Population: 17245346 },
			{ Name:"Honduras", Population: 9417167 },
			{ Name:"El, Salvador", Population: 6411558}, 
			{ Name:"Nicaragua", Population: 6284757 },
			{ Name:"Costa, Rica", Population: 4953199}, 
			{ Name:"Panama", Population: 4162618 },
			{ Name:"Belize", Population: 382444 },
	   ]},
		{ Name:"Northern America", Population:358593810, Region:[
			{ Name:"U.S.", Population:3267667480 }, 
			{ Name:"Canada", Population:36953765},
			{ Name:"Bermuda", Population:61070	},
			{ Name:"Greenland", Population:56565},
			{ Name:"Saint Pierre & Miquelon", Population:6342	},
		]},
      ]
        }]
    },
 
 
	{
        Continent:[
            {
		Name:"South America", Population: 422535000, States:[
			{Name:"Brazil", Population:204519000},
			{Name:"Colombia", Population:48549000 },
			{Name:"Argentina", Population:43132000 },
			{Name:"Peru", Population:31153000 },
			{Name:"Venezuela", Population:30620000},
			{Name:"Chile", Population:18006000 },
			{Name:"Ecuador", Population:16279000},
			{Name:"Bolivia", Population:10520000},
			{Name:"Paraguay", Population:7003000},
			{Name:"Uruguay", Population:3310000},
			{Name:"Guyana", Population:747000},
			{Name:"Suriname", Population:560000 },
			{Name:"French Guiana", Population:262000},
			{Name:"Falkland Islands", Population:3000 },
        ]},
    ]},
        

	{ Continent:[
        {
        Name: "Europe", Population:738849000, States:[
		{Name:"Eastern Europe", Population:291953328, Region:[
			{Name:"Russia", Population:143964709 },
			{Name:"Ukraine", Population: 44009214},
			{Name:"Poland", Population:38104832 },
			{Name:"Romania", Population:19580634 },
			{Name:"Crech, Republic", Population:10625250 },
			{Name:"Hungary", Population:9688847 },
			{Name:"Belarus", Population:9452113 },
			{Name:"Bulgaria", Population: 7036848},
			{Name:"Slovakia", Population: 5449816},
			{Name:"Moldova", Population:4041065 },
		] },
		{Name:"Northern Europe", Population:103642971, Region:[
			{ Name:"United Kingdom", Population: 66573504},
			{ Name:"Sweden", Population: 9982709},
			{ Name:"Denmark", Population: 5754356},
			{ Name:"Finland", Population: 5542517},
			{ Name:"Norway", Population: 5353363},
			{ Name:"Ireland", Population: 4803748},
			{ Name:"Lithuania", Population: 2876475},
			{ Name:"Latvia", Population: 1929938},
			{ Name:"Estonia", Population: 1306788},
			{ Name:"Iceland", Population: 337780},
			{ Name:"Channel Islands", Population: 166083},
			{ Name:"Isle of Man", Population: 84831},
			{ Name:"Faeroe Islands", Population: 49489},
		] },
		{Name:"Southern Europe", Population:152172107, Region:[
			{ Name:"Italy",Population:  59290969 },
			{ Name:"Spain",Population:  46397452}, 
			{ Name:"Greece",Population:  11142161 },
			{ Name:"Portugal",Population:  10291196}, 
			{ Name:"Serbia",Population:  8762027 },
			{ Name:"Croatia",Population:  4164783 },
			{ Name:"Bosnia and Herzegovina",Population:  3503554 },
			{ Name:"Albania",Population:  2934363 },
			{ Name:"Macedonia",Population:  2085051 },
			{ Name:"Slovenia",Population:  2081260 },
			{ Name:"Montenegro",Population:  629219}, 
			{ Name:"Malta",Population:  432089 },
			{ Name:"Andorra",Population:  76953 },
			{ Name:"Gibraltar",Population:  34733 },
			{ Name:"San Marino",Population:  33557 },
			{ Name:"Holy, See",Population:  801 },
		]},
		{Name:"Western Europe", Population:92746859, Region:[
			{ Name:"Germany", Population: 82293457 },
			{ Name:"France", Population: 65233271 },
			{ Name:"Netherlands", Population: 17084459 },
			{ Name:"Belgium", Population: 11498519 },
			{ Name:"Austria", Population: 8751820 },
			{ Name:"Switzerland", Population: 8544034 },
			{ Name:"Luxembourg", Population: 590321 },
			{ Name:"Monaco", Population: 38897 },
			{ Name:"Liechtenstein", Population: 38155 },
		]},
      ]
    }]
    }
 ];
        args.treemap.dataSource = data;
    }
</script>
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using EJ2_Core_Application.Models;
using Newtonsoft.Json;

namespace EJ2_Core_Application.Controllers
{
    public class HomeController : Controller
    {
        public IActionResult Index()
        {
            return View();
        }
    }
}

Sample reference

treemap sample.

Screenshot

Screenshot for your reference

Add label template with drill down

Yon can add a label template as <div> element to the treemap control when using the label template. To add a label template to the treemap control, you have to hide another labels by setting the showLabels property to false in leafItemSettings to show only the label template.

To add label template to treemap drilldown, follow the given steps: