Add example to export to JSON and import it again. (#2152)

Networks are exported as a JSON array containing an array of objects representing each node in the network. Each node contains an Id, it's x and y coordinates and the nodes it is connected to. Import converts the JSON to a vis DataSet and then regenerates the network using each node's attributes, inserting it in the same coordinates and with the same number of connections as before. fixes #2073
8 years ago · ea859d4c79
--- a/examples/network/other/saveAndLoad.html
+++ b/examples/network/other/saveAndLoad.html
@ -0,0 +1,177 @@
 <!doctype html>
 <html>
    <head>
        <meta content="text/html;charset=utf-8" http-equiv="Content-Type">
        <meta content="utf-8" http-equiv="encoding">
        <title>Network | Saving and loading networks</title>

        <style type="text/css">
            body {
              font: 10pt sans;
            }
            #network {
                float:left;
                width: 600px;
                height: 600px;
                margin:5px;
                border: 1px solid lightgray;
            }
            #config {
                float:left;
                width: 400px;
                height: 600px;
            }
            #input_output {
                height: 10%;
                width: 15%;
            }

            p {
                font-size:16px;
                max-width:700px;
            }
        </style>

        <script type="text/javascript" src="../exampleUtil.js"></script>
        <script type="text/javascript" src="../../../dist/vis.js"></script>
        <link href="../../../dist/vis.css" rel="stylesheet" type="text/css" />

        <script src="../../googleAnalytics.js"></script>
    </head>

    <body>
        <p>
            In this example, the network data can be exported to JSON and imported back into the network.

            Try this out by exporting the network to JSON, clearing the network and then importing it again. The nodes will all appear in the same position as they were before the network was destroyed.
        </p>

        <div id="network"></div>

        <div>
            <textarea id=input_output></textarea>
            <input type="button" id="import_button" onclick="importNetwork()" value="import"></input>
            <input type="button" id="export_button" onclick="exportNetwork()" value="export"></input>
            <input type="button" id="destroy_button" onclick="destroyNetwork()" value="destroy"></input>
        </div>

        <script type="text/javascript">
            var network;
            var container;
            var exportArea;
            var importButton;
            var exportButton;

            function init() {
                container = document.getElementById('network');
                exportArea = document.getElementById('input_output');
                importButton = document.getElementById('import_button');
                exportButton = document.getElementById('export_button');

                draw();
            }

            function addContextualInformation(elem, index, array) {
                addId(elem, index);
                addConnections(elem, index);
            }

            function addId(elem, index) {
                elem.id = index;
            }

            function addConnections(elem, index) {
                // need to replace this with a tree of the network, then get child direct children of the element
                elem.connections = network.getConnectedNodes(index);
            }

            function destroyNetwork() {
                network.destroy();
            }

            function clearOutputArea() {
                exportArea.value = "";
            }

            function draw() {
                // create a network of nodes
                var data = getScaleFreeNetwork(5);

                network = new vis.Network(container, data, {manipulation:{enabled:true}});

                clearOutputArea();
            }

            function exportNetwork() {
                clearOutputArea();

                var nodes = objectToArray(network.getPositions());

                nodes.forEach(addContextualInformation);

                // pretty print node data
                var exportValue = JSON.stringify(nodes, undefined, 2);

                exportArea.value = exportValue;

                resizeExportArea();
            }

            function importNetwork() {
                var inputValue = exportArea.value;
                var inputData = JSON.parse(inputValue);

                var data = {
                    nodes: getNodeData(inputData),
                    edges: getEdgeData(inputData)
                }

                network = new vis.Network(container, data, {});

                resizeExportArea();
            }

            function getNodeData(data) {
                var networkNodes = [];

                data.forEach(function(elem, index, array) {
                    networkNodes.push({id: elem.id, label: elem.id, x: elem.x, y: elem.y});
                });

                return new vis.DataSet(networkNodes);
            }

            function getEdgeData(data) {
                var networkEdges = [];

                data.forEach(function(node, index, array) {
                    // add the connection
                    node.connections.forEach(function(connId, cIndex, conns) {
                        networkEdges.push({from: node.id, to: connId});

                        var elementConnections = array[connId].connections;

                        // remove the connection from the other node to prevent duplicate connections
                        var duplicateIndex = elementConnections.findIndex(function(connection) {
                            connection === node.id;
                        });

                        elementConnections = elementConnections.splice(0, duplicateIndex - 1).concat(elementConnections.splice(duplicateIndex + 1, elementConnections.length))
                        });
                });

                return new vis.DataSet(networkEdges);
            }

            function objectToArray(obj) {
                return Object.keys(obj).map(function (key) { return obj[key]; });
            }

            function resizeExportArea() {
                exportArea.style.height = (1 + exportArea.scrollHeight) + "px";
            }

            init();
        </script>
    </body>
 </html>