embed.js

// Edits an image with drawio class on double click
document.addEventListener('dblclick', function(evt)
{
	var url = 'https://test.draw.io/?dev=1&embed=1&ui=atlas&spin=1&modified=unsavedChanges&proto=json';
	var source = evt.srcElement || evt.target;
	
	if (source.nodeName == 'IMG' && source.className == 'drawio')
	{
		// Checks if the elt is inside a content editable element
		var parent = source;
		
		while (parent != null && parent.nodeType == 1 &&
			parent.getAttribute('contentEditable') != 'true')
		{
			parent = parent.parentNode;
		}
	
		if (parent != null && parent.nodeType == 1 && parent.getAttribute('contentEditable') == 'true')
		{
			if (source.drawIoWindow == null || source.drawIoWindow.closed)
			{
				// Implements protocol for loading and exporting with embedded XML
				var receive = function(evt)
				{
					if (evt.data.length > 0 && evt.source == source.drawIoWindow)
					{
						var msg = JSON.parse(evt.data);

						// Received if the editor is ready
						if (msg.event == 'init')
						{
							// Sends the data URI with embedded XML to editor
							source.drawIoWindow.postMessage(JSON.stringify({action: 'load', xmlpng: source.getAttribute('src')}), '*');
						}
						// Received if the user clicks save
						else if (msg.event == 'save')
						{
							// Sends a request to export the diagram as XML with embedded PNG
							source.drawIoWindow.postMessage(JSON.stringify({action: 'export', format: 'xmlpng', spinKey: 'saving'}), '*');
						}
						// Received if the export request was processed
						else if (msg.event == 'export')
						{
							// Updates the data URI of the image
							source.setAttribute('src', msg.data);
						}
		
						// Received if the user clicks exit or after export
						if (msg.event == 'exit' || msg.event == 'export')
						{
							// Closes the editor
							window.removeEventListener('message', receive);
							source.drawIoWindow.close();
							source.drawIoWindow = null;
						}
					}
				};

				// Opens the editor
				window.addEventListener('message', receive);
				source.drawIoWindow = window.open(url);
			}
			else
			{
				// Shows existing editor window
				source.drawIoWindow.focus();
			}
		}
	}
}, true);