documentationfor yFiles for HTML 3.0.0.1

The GraphMLIOHandler

The central class for reading and writing GraphML is the GraphMLIOHandler. Besides its methods for reading and writing graphs, it offers several customization hooks.

readFromDocument(graph: IGraph, document: Document): Promise<IGraph>
readFromGraphMLText(graph: IGraph, data: string): Promise<IGraph>
readFromURL(graph: IGraph, url: string): Promise<IGraph>
Parses GraphML from different sources and populates the given graph.
write(graph: IGraph): Promise<string>
Returns a promise with the given graph as GraphML string.

By default, the GraphMLIOHandler reads and writes GraphML, which encodes all structural, visual, and geometric information of a graph. You can easily configure the GraphMLIOHandler to write additional business data that is associated with graph elements or the graph itself. This data can be of a simple type like string, for example, encoding a tooltip or a link. It is also possible, though, to encode complex data like objects that model the entire business data behind a graph item.

Events for Reading and Writing

GraphMLIOHandler provides events that are fired at different stages of reading or writing a graph. The most common use case is to perform an action after a graph is loaded. For example, you might want to apply a layout algorithm to the loaded graph.

writing
Fired when the writing of a document is about to start.
written
Fired when the document has been written successfully.
parsing
Fired when the parsing of the document is about to start.
parsed
Fired when the document has been parsed successfully.