How to Generate an Array of JSON Objects in JavaScript on a Razor Page using a Custom ViewModel in MVC?

Attempting to populate the array within my script for future charting with D3.JS, I came across some issues. Following advice from this post, I used a specific syntax that unfortunately resulted in an error stating "Uncaught ReferenceError: WebSite is not defined." It appears this error stems from the namespace of the data being used (in this case, 'WebSite').

<script>
  var data = new Array();
  @foreach (var piece in @Model.DataPieces)
  {
    @:data.push(@piece);
  }
</script>

The problem seemed related to the data type of `piece`, as tweaking the code slightly helped alleviate the errors. By individually extracting fields from the `piece` object and creating a new object to push into the array, the process worked more smoothly.

<script>
  var data = new Array();
  @foreach (var piece in @Model.DataPieces)
  {
    @:data.push({'cat': '@piece.Category', 'key': '@piece.Key', 'val': '@piece.Value'});
  }
</script>

This manual approach, however, proves cumbersome, error-prone, and requires updates whenever the model changes. How can I automate the creation of JSON objects upon assignment, similar to the initial example?

The structure of the Razor page's viewmodel is outlined below.

namespace WebSite.Models
{
  public class DrillDataViewModel
  {
    public List<DataPiece> DataPieces { get; set; }

    public class DataPiece
    {
      public string Category { get; set; }
      public string Key { get; set; }
      public int Value { get; set; }
    }
  }
}

Answer №1

When the code @:data.push(@piece); is executed, it will generate the following output in the HTML:

data.push(<the result of calling ToString() on @piece>);

To ensure that @piece is evaluated as the JSON you desire, you can use the following code snippet:

@:data.push(@Html.Raw(Json.Encode(piece)));

Alternatively, you have the option to output the entire array at once like this:

var data = @Html.Raw(Json.Encode(Model.DataPieces));

Answer №2

Here is a method to pass data from a Razor page to JavaScript.

@Html.Raw(@JsonConvert.SerializeObject(Model.DataPieces)
  .Replace("{\"", "{")
  .Replace(",\"", ",")
  .Replace("\":", ":"))

The above code snippet removes invalid characters that are produced by the default converter, avoiding the need to work with streams or use additional libraries. It may not be pretty, but it gets the job done.

Sometimes, I also include an extra replace operation: .Replace("\"","'") to make the output look more like JavaScript. The wrapping method ensures that any issues with special characters, such as & within "e;, are avoided.

This solution is practical, but if there's a better approach out there, feel free to share your feedback!

Answer №3

Don't forget to use

var <a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="fc8593898eb69d8a9d8f9f8e958c88bd8e8e9d85c1bcb4889190d2ae9d8b">[email protected]</a>(Json.Encode(YouModel));

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

Is the div empty? Maybe jQuery knows the answer

I currently have a <div id="slideshow"> element on my website. This div is fully populated in the index.php file, but empty in all other pages (since it's a Joomla module). When the div is full, everything works fine. However, when it's emp ...

Submitting a detailed JSON object with Javax-RS and Java Persistence for a RESTful API

I want to start off by apologizing in advance if this question has already been asked, but after searching for the past two days, I still haven't found a solution to my problem. The issue at hand is related to a web service I've created where I ...

ArangoDB Export Tool for Generating JSON Files

If you're looking to generate a native backup and restore it, the tools arangodump and arangorestore are essential. For importing JSON (and CSV, TSV) files, the appropriate tool is arangoimp. Is there a specific method or tool available in ArangoDB ...

Discover a method to conceal an element within a <div> by monitoring mouseover events in a separate <div> container

<div id="one-id"> <div id="some">Information</div> <div id="control"> <div id="value-1"> <img id="image-one-id" /> <img id="image-two-id" /> ...

Creating a JSX.Element as a prop within a TypeScript interface

I need to create an interface for a component that will accept a JSX.Element as a prop. I have been using ReactNode for this purpose, but I am facing issues when trying to display the icon. How can I resolve this issue? export interface firstLevelMenuItem ...

How can I retrieve object data and store it in a variable using PHP?

I've gone through a lot of responses, but I'm still struggling with something. I have an object that fetches data from a file and formats it into an array. Now, I'm trying to pass this data into a variable in the calling file so that I can m ...

Is placing JavaScript on the lowest layer the best approach?

I'm facing a unique situation that I haven't encountered before and am unsure of how to address it. My website has a fixed top header and footer. On the left side, there is a Google Adsense ad in JavaScript. When scrolling down, the top header s ...

Struggling with adding headers in React application

When I try to include an h1 heading, either the heading doesn't show up if I comment out the buttons, or if I comment out the heading, then the buttons don't display. But when both are included, nothing is displayed. Any suggestions on how to fix ...

Is it possible to load a webpage in a WebBrowser control without displaying certain HTML elements by their IDs

Is there a way to load a specific page using the WebBrowser control without displaying unwanted advertisement banners in the 'tb' DIV element? I've searched online and came across an example that uses the mshtml reference, but I can't ...

Code executing twice instead of once in Javascript

Having trouble with a script in my demo below. When I enter "first input", submit, then click on the returned "first input", it alerts once as intended. However, upon refresh, if I enter "first input", submit, then add "second input", submit, and finally c ...

Retrieving data from a WebAPI in JSON format and then storing it in a Store

As I dive into learning ExtJS-4.2, I have been diligently following their MVC tutorial... I successfully constructed my controller, view, model, and store with hardcoded data. Additionally, I have set up a WebAPI for testing purposes which provides result ...

What is the reason for Jest attempting to resolve all components in my index.ts file?

Having a bit of trouble while using Jest (with Enzyme) to test my Typescript-React project due to an issue with an alias module. The module is being found correctly, but I believe the problem may lie in the structure of one of my files. In my jest.config ...

What is the best approach to dealing with a non-TypeScript project that is requesting the installation of @types for

With the project set up using create-react-app and custom-react-scripts to utilize decorators for MobX, I am aiming to incorporate the react-c3js library for data visualization. Surprisingly, everything is functioning correctly, but there's a warning ...

The CSS property overflow-x:hidden; is not functioning properly on mobile devices despite trying multiple solutions recommended online

Seeking help on a persistent issue, but previous solutions haven't worked for me. Looking to implement a hamburger menu that transitions in from offscreen. The design appears correctly on desktop and simulating mobile, but actual mobile view require ...

Clickable link in popup window using fancybox

When I try to use fancybox to open an iframe and scroll to an anchor tag, it works perfectly in IE but not consistently in other browsers. It stops at a different place than the anchor. I suspect the issue may be related to JavaScript based on information ...

The Best Way to Display Quad Wireframe in Three.js using OBJ Model

I am trying to display the wireframe of OBJ meshes using Three.js. However, Three.js can only render triangles, so I came up with the idea of creating a line for each edge of the model. After parsing the OBJ file and iterating through its vertices and fac ...

Displaying an image in AngularJS using a byte array received in the response

Dealing with a service that adds properties to a file and returns it as a byte array in the response. I'm struggling to display it properly since it's in byte form. Attempted converting it to base64 but still showing raw bytes. PNG IHDR&L ...

Tips for accessing a composition function in VueJS from another composition

I've been diving into the new composition-api within VueJS and have encountered a problem that I need help with. I am seeking advice on how to effectively tackle this issue. Previously, when everything was vuex-based, dispatching an action to another ...

Prevent Button Click in ASP.NET After Validating Regular Expression in Textbox

How can I ensure that the asp button is disabled only after the user submits the form with the correct regular expression? Below is the form code: <asp:TextBox ID="TextBox2" runat="server" placeholder="Email" class="form-control" type="email" Font-Siz ...

Having trouble with the position function in JavaScript?

I'm working on creating a small game, but I've encountered some difficulties at the start. Every time I attempt to obtain the position of track or trackCont, it consistently returns x: 0, y: 0. The DIV doesn't move to the correct position w ...