You can easily get the node/link attributes from a json file using the d3.js library. Is it possible to get the graph attributes ? Sample JSON file:
{"directed": true, "graph":
[["name", "()"], ["label", "Graph Attribute"]],
"nodes": [
{"node_attr": 1.0, "id": "001"},
{"node_attr": 0.5, "id": "002"}
...