Cannot load JSON file from Visual Studio 2013

Question

Cannot load JSON file from Visual Studio 2013

I am currently working on building a drag-able network diagram using d3.js, and I've come across an unusual issue. Whenever I try to run the page from Visual Studios 2013, I encounter the following error:

"Unhandled exception at line 25, column 13 in http://localhost:58771/HtmlPage1.html

0x800a138f - Microsoft JScript runtime error: Unable to get value of the property 'links': object is null or undefined"

However, when I move both the HTML page and the .json file to my local drive, the page opens without any issues.

Below is a snippet of the d3 code that is causing the problem:

     d3.json("graph.json", function (error, graph) {
        graph.links.forEach(function (d) {
            d.source = graph.nodes[d.source];
            d.target = graph.nodes[d.target];
        });

The json file is too large to be included here. My main question is why does it work when accessed from my local drive, but not when within the ASP project in Visual Studio. The network diagram will be part of an ASP.net application, so changing the website's format is not an option.

Any assistance with this issue would be greatly appreciated. Thank you.

javascript asp.net json d3.js

Answer 1

Answer №1

When running the ASP.NET project on IIS Web Server, it may encounter issues with Windows directories. To resolve this, ensure that the d3.json() URL property matches the location of the json file URL. Since the project is running on a virtual server, follow these steps:

Include the following code within the web.config file's

<configuration></configuration>

tag to allow IIS to serve the json file. Without this code, IIS may consider the json file as a part of the URL path:

<system.webServer>
 <handlers>
   <remove name="BlockViewHandler"/>
   <add name="BlockViewHandler" path="*" verb="*" preCondition="integratedMode" type="System.Web.HttpNotFoundHandler" />
   </handlers>
    <staticContent>
     <mimeMap fileExtension=".json" mimeType="application/json" />
    </staticContent>
    </system.webServer>

Obtain the URL of the json file and provide it to the d3.json() function.

If you are using the Razor View Engine, retrieve the URL as follows:

'I recommend storing graph.json within a folder named Data'
```
 var url = "@Url.Content("~/Data/graph.json")";
 d3.json(url, function (error, graph) {
       graph.links.forEach(function (d) {
        d.source = graph.nodes[d.source];
        d.target = graph.nodes[d.target];
    });
```
If you are using ASP.NET Webforms, adjust the d3.json() function:
```
   d3.json("~/Data/graph.json", function (error, graph) {
       graph.links.forEach(function (d) {
        d.source = graph.nodes[d.source];
        d.target = graph.nodes[d.target];
       });
```
Navigate through the solution explorer to locate the graph.json file and save it as if it were in a Windows directory. I typically use ~ to eliminate the path and start from the top.

Hope this guidance proves useful.

Answer 2

When running the ASP.NET project on IIS Web Server, it may encounter issues with Windows directories. To resolve this, ensure that the d3.json() URL property matches the location of the json file URL. Since the project is running on a virtual server, follow these steps:

Include the following code within the web.config file's

<configuration></configuration>

tag to allow IIS to serve the json file. Without this code, IIS may consider the json file as a part of the URL path:

<system.webServer>
 <handlers>
   <remove name="BlockViewHandler"/>
   <add name="BlockViewHandler" path="*" verb="*" preCondition="integratedMode" type="System.Web.HttpNotFoundHandler" />
   </handlers>
    <staticContent>
     <mimeMap fileExtension=".json" mimeType="application/json" />
    </staticContent>
    </system.webServer>

Obtain the URL of the json file and provide it to the d3.json() function.

If you are using the Razor View Engine, retrieve the URL as follows:

'I recommend storing graph.json within a folder named Data'
```
 var url = "@Url.Content("~/Data/graph.json")";
 d3.json(url, function (error, graph) {
       graph.links.forEach(function (d) {
        d.source = graph.nodes[d.source];
        d.target = graph.nodes[d.target];
    });
```
If you are using ASP.NET Webforms, adjust the d3.json() function:
```
   d3.json("~/Data/graph.json", function (error, graph) {
       graph.links.forEach(function (d) {
        d.source = graph.nodes[d.source];
        d.target = graph.nodes[d.target];
       });
```
Navigate through the solution explorer to locate the graph.json file and save it as if it were in a Windows directory. I typically use ~ to eliminate the path and start from the top.

Hope this guidance proves useful.

Answer 3

Answer №2

Here is the complete code for your review:

!DOCTYPE html>
<html>
<head>
<title></title>
<script src="http://d3js.org/d3.v2.js"></script>
<style>
    .link {
        stroke: #ccc;
    }

    .nodetext {
        pointer-events: none;
        font: 10px sans-serif;
    }
</style>
</head>
<body>
<script type="text/javascript">

    var w = 1280,
        h = 1024;

    var color = d3.scale.category20();

    var vis = d3.select("body").append("svg:svg")
        .attr("width", w)
        .attr("height", h);

    d3.json("graph3-copy.json", function (json) {
        var force = self.force = d3.layout.force()
            .nodes(json.nodes)
            .links(json.links)
            .gravity(.05)
            .distance(100)
            .charge(-100)
            .size([w, h])
            .start();

        var link = vis.selectAll("line.link")
            .data(json.links)
            .enter().append("svg:line")
            .attr("class", "link")
           .attr("x1", function (d) { return d.source.x; })
           .attr("y1", function (d) { return d.source.y; })
           .attr("x2", function (d) { return d.target.x; })
           .attr("y2", function (d) { return d.target.y; });

        var node_drag = d3.behavior.drag()
            .on("dragstart", dragstart)
            .on("drag", dragmove)
            .on("dragend", dragend);

        function dragstart(d, i) {
        force.stop() // stops the force auto positioning before you  start dragging
        }

        function dragmove(d, i) {
            d.px += d3.event.dx;
            d.py += d3.event.dy;
            d.x += d3.event.dx;
            d.y += d3.event.dy;
            tick(); // this is the key to make it work together with updating both px,py,x,y on d !
        }

        function dragend(d, i) {
            d.fixed = true; // of course set the node to fixed so the force doesn't include the node in its auto positioning stuff
            tick();
            force.resume();
        }

        var node = vis.selectAll("g.node")
            .data(json.nodes)
          .enter().append("svg:g")
            .attr("class", "node")
            .call(node_drag);

        node.append("svg:image")
            .attr("class", "circle")
            .attr("xlink:href", "https://github.com/favicon.ico")
            .attr("x", "-8px")
            .attr("y", "-8px")
            .attr("width", "16px")
            .attr("height", "16px");

        node.append("svg:text")
            .attr("class", "nodetext")
            .attr("dx", 12)
            .attr("dy", ".35em")
            .text(function (d) { return d.name });

        force.on("tick", tick);

        function tick() {
            link.attr("x1", function (d) { return d.source.x; })
                .attr("y1", function (d) { return d.source.y; })
                .attr("x2", function (d) { return d.target.x; })
                .attr("y2", function (d) { return d.target.y; });

            node.attr("transform", function (d) { return "translate(" + d.x + "," + d.y + ")"; });
        };


    });

</script>
</body>
</html>

The error message in Firefox console suggesting the JSON file is empty seems incorrect. I have verified that the data is present and the webpage runs properly outside of Visual Studio environment.

Answer 4

Here is the complete code for your review:

!DOCTYPE html>
<html>
<head>
<title></title>
<script src="http://d3js.org/d3.v2.js"></script>
<style>
    .link {
        stroke: #ccc;
    }

    .nodetext {
        pointer-events: none;
        font: 10px sans-serif;
    }
</style>
</head>
<body>
<script type="text/javascript">

    var w = 1280,
        h = 1024;

    var color = d3.scale.category20();

    var vis = d3.select("body").append("svg:svg")
        .attr("width", w)
        .attr("height", h);

    d3.json("graph3-copy.json", function (json) {
        var force = self.force = d3.layout.force()
            .nodes(json.nodes)
            .links(json.links)
            .gravity(.05)
            .distance(100)
            .charge(-100)
            .size([w, h])
            .start();

        var link = vis.selectAll("line.link")
            .data(json.links)
            .enter().append("svg:line")
            .attr("class", "link")
           .attr("x1", function (d) { return d.source.x; })
           .attr("y1", function (d) { return d.source.y; })
           .attr("x2", function (d) { return d.target.x; })
           .attr("y2", function (d) { return d.target.y; });

        var node_drag = d3.behavior.drag()
            .on("dragstart", dragstart)
            .on("drag", dragmove)
            .on("dragend", dragend);

        function dragstart(d, i) {
        force.stop() // stops the force auto positioning before you  start dragging
        }

        function dragmove(d, i) {
            d.px += d3.event.dx;
            d.py += d3.event.dy;
            d.x += d3.event.dx;
            d.y += d3.event.dy;
            tick(); // this is the key to make it work together with updating both px,py,x,y on d !
        }

        function dragend(d, i) {
            d.fixed = true; // of course set the node to fixed so the force doesn't include the node in its auto positioning stuff
            tick();
            force.resume();
        }

        var node = vis.selectAll("g.node")
            .data(json.nodes)
          .enter().append("svg:g")
            .attr("class", "node")
            .call(node_drag);

        node.append("svg:image")
            .attr("class", "circle")
            .attr("xlink:href", "https://github.com/favicon.ico")
            .attr("x", "-8px")
            .attr("y", "-8px")
            .attr("width", "16px")
            .attr("height", "16px");

        node.append("svg:text")
            .attr("class", "nodetext")
            .attr("dx", 12)
            .attr("dy", ".35em")
            .text(function (d) { return d.name });

        force.on("tick", tick);

        function tick() {
            link.attr("x1", function (d) { return d.source.x; })
                .attr("y1", function (d) { return d.source.y; })
                .attr("x2", function (d) { return d.target.x; })
                .attr("y2", function (d) { return d.target.y; });

            node.attr("transform", function (d) { return "translate(" + d.x + "," + d.y + ")"; });
        };


    });

</script>
</body>
</html>

The error message in Firefox console suggesting the JSON file is empty seems incorrect. I have verified that the data is present and the webpage runs properly outside of Visual Studio environment.

Cannot load JSON file from Visual Studio 2013

Answer №1

Answer №2

Similar questions

Tips for resizing a Textbox by dragging in asp.net?

Ensuring the correctness of phone numbers by validating them with country codes through the use of

The send_keys() function in Selenium version 3.141.0 works perfectly on Windows, but unfortunately, it is not functioning correctly on Linux Debian 11

Angular binding causing decimal inaccuracies

Tips for transferring data from one asynchronous function to another in AngularJS

What are the steps to utilizing the $document service in AngularJS?

Verifying that a parameter is sent to a function triggering an event in VueJS

Issue: Unhandled ReferenceError - onChangeAssignedGroup function is not declared within scope at HTMLSelectElement.onchange

What is the relationship between $.when, apply(), and $.done() within the scope of this function?

Dealing with Memory Issues in Google Apps Scripts

Execute a function for each template or controller when the page loads

Maintaining accurate type-hinting with Typescript's external modules

Is it possible to examine my API request URL from the API's perspective using a Linux Command Line Utility?

Symfony JSON responses with the field name included in the output

Updating the object in router.get and res.render in Node.js and Express after loading

What is the process of combining a JSON bundle with a Jade template?

Tips for automatically updating a MaterialUI DataGrid in a React JS application

What is the Next.js equivalent of routing with rendering capability for nested component paths?

reverting the effects of a javascript animation

VueJS, when used in conjunction with Vuetify, might require an extra loader to handle scoped css