Rappid/Joint JS based diagram editor with custom elements and custom connectors

Rappid/Joint JS Diagram Editor with custom Elements, custom Connectors and HTML/JS integration Need a JS based component to create and view layouts. This should be done using Rappid/JointJS. - User is able to drag and drop the custom elements created and create a site layout. This functionality is already available with Rappid. However, the custom elements needs to be created. SVG images required for the custom element will be provided. - custom connectors may be used to connect the elements. - For these custom elements, user will be able to set properties. For some of the properties, application will query a web API to present the set of options available to select. e.g. Name of equipment which is property should be selected from a list that is queried using web api for the customer. - On save of the layout, invoke a service to save to DB. - In view mode, layout will be retrieved from the service and loaded in the view. When mouse-over/click is invoked on the selected element, the registered callback should be invoked to render the data associated with the element. Developer MUST have worked on multiple projects with Rappid/JointJS and should be able to demonstrate the expertise.