Creating a Venn diagram
1. Overview
The Venn Diagram was first introduced in 1880 by John Venn, and is designed to show all possible logical relations between a finite collection of different sets.
This sample will show how to integrate an external Javascript library such as the D3.js library into the Dundas BI Application using an HTML label.
2. Prerequisites
This sample requires:
- Basic knowledge of HTML, CSS and Javascript.
- Venn.js library which is the source for the D3 visual.
3. Sample data
Create a metric set from the main menu, selecting the different category intersections on Rows and the member counts on Measures.
Disable totals from the toolbar or from the dialog shown when clicking the Edit button in the Data Analysis Panel.
A sample metric set looks like this:
4. Integrating D3
Add the Venn.js file in the Dundas BI Javascript override folder located at [BIWebsite]/Scripts/Override.
Download and unzip this file and add the dundasVennLib.js to the override folder located at [BIWebsite]/Scripts/Override.
Create a new CSS file with the following code:
.venntooltip {
position: absolute;
text-align: center;
width: 128px;
height: 16px;
background: #000;
color: #FFF;
padding: 2px;
border: 0px;
/*border-radius: 8px;*/
opacity: 0;
z-index: 10000;
}
Rename this file to venn.css and add it to the override folder located at [BIWebsite]/Content/Override. This css file adds formatting to the tooltip displayed when hovering over the Venn diagram.
Now, navigate to the [BIWebsite]/Override folder and add the following to the Html.Override.html file
<link rel="stylesheet" type="text/css" href="/Content/Override/venn.css"> <script src="/Scripts/Override/venn.js"></script> <script src="/Scripts/Override/dundasVennLib.js"></script>
5. Dashboard setup
On a new or existing dashboard, add an HTML Label component.
Under the Text properties of the HTML Label, add the following to the HTML Label Text:
<div id="venn"></div>
On the Ready event of the dashboard, add the script to call window.dundasVennLib.generateVenn
var div = d3.select("#venn");
var viewParameter1 = this.baseViewService.currentView.control.viewParameters.filter(function(vp){
return vp.name === "viewParameter1";})[0];
/*
//htmlLabel: reference to the htmlLabel containing the div where the diagram is to be shown
//div: reference to the div where the diagram will be shown as returned by the d3 selector
//metricSetID: id of the metricSet to get data from
//categoryHierarchy: name of the hierarchy that identifies the categories
//memberMeasure: name of the measure that indicates the number of members of each category
//viewParameterMappings (optional): array of mappings between view parameters and metric set elements,
//for when you want to use filters. The mappings would use this format:
// {targetElementName: "<name_of_element_to_filter>",
// parameter: <view_parameter_used_to_filter_the_element>}
*/
window.dundasVennLib.generateVenn(htmlLabel1, div,
'2c344485-cad0-427b-bcec-9afd221d7eb2',
"IntersectionName","Students"
);
Optional: If you intend to use filters on the Venn Diagram, you will need to add a script that refreshes the Venn Diagram. This script should be added on the Parameter Value Changed event of those filters.
htmlLabel1.refreshVenn();
6. Result
The result of this sample is a Venn Diagram that displays how many students are enrolled in the courses provided.
