Microsoft Rolls Out New Visio JavaScript APIs

A New Version Of Visio JavaScript APIs is now available to enhance the Visio for the web and build rich mashup scenarios.

Recently, Microsoft announced the public preview of a new version of Visio JavaScript APIs. These APIs are used to extend Visio for the web and build rich mashup scenarios.
The highlight of the new version includes Custom HTML Overlay API, Disable Pan Zoom Window and Default zoom parameter.
The new version allows you to add custom HTML content on your shapes and build rich solutions. It enables you to show HTML content on various shape events, for example on shape hover or selection change, and extend the same diagram to fit into several scenarios.
Like: addOverlay(“html”, “”, 2, 2, 50, 50);
For example, Using Visio for the web, you can visualize the ordering system. Here, data can be fetched from various order entry sources, processing, and invoicing systems in real-time and can be overlaid on the process diagram. The diagram below provides the number of orders at every step with one HTML Overlay, and a drill-down of the status with another overlay.
Source: Microsoft 
The new version also allows you to customize Pan Zoom Window with the document view property to disable the Pan Zoom Window and allow users to consume the diagram without any disruptions. Like: documentView.disablePanZoomWindow = true;
Now, developers can set a default zoom level for diagrams opened in Visio by appending append wdzoom=<zoom value> in the file URL. The new version automatically adjusts to the zoom level you set.
Like: https://…-58A5-42CF-BFC7-E29E701D38D2%7D&wdzoom=300