How to put nested json into d3.js table?

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by rollin , in category: Javascript , a month ago

How to put nested json into d3.js table?

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1 answer

by darrion.kuhn , 21 days ago

@rollin 

To display nested JSON data in a d3.js table, you can follow these steps:

  1. Parse the nested JSON data: First, you will need to parse the nested JSON data into a format that d3.js can work with. You can use the d3.nest() function to group the data by a key or multiple keys to create a nested structure.
  2. Create a table structure: Next, create an HTML table structure using d3.js selection methods. You can create the table headers based on the keys of the nested data and add rows for each nested object.
  3. Bind the data to the table: Use the d3.js data() and enter() methods to bind the nested JSON data to the table rows. You can then append table cells to display the values from the nested JSON objects.
  4. Update the table: Use the d3.js update pattern to update the table when the data changes. You can use the exit() method to remove any rows that are no longer needed and update the text content of the cells with the new data values.


Here is an example code snippet to demonstrate how to put nested JSON into a d3.js table:

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// Sample nested JSON data
var data = [
  {
    name: "John",
    age: 30,
    children: [
      {name: "Alice", age: 5},
      {name: "Bob", age: 8}
    ]
  },
  {
    name: "Jane",
    age: 28,
    children: [
      {name: "Charlie", age: 4},
      {name: "Diana", age: 6}
    ]
  }
];

// Parse the nested JSON data
var nestedData = d3.nest()
  .key(function(d) { return d.name; })
  .entries(data);

// Create a table structure
var table = d3.select("body").append("table");
var thead = table.append("thead").append("tr");
var tbody = table.append("tbody");

// Create table headers
thead.selectAll("th")
  .data(["Name", "Age", "Children"])
  .enter().append("th")
  .text(function(d) { return d; });

// Bind nested data to the table
var rows = tbody.selectAll("tr")
  .data(nestedData)
  .enter().append("tr");

// Add table cells and display nested values
var cells = rows.selectAll("td")
  .data(function(d) {
    return [d.key, d.values[0].age, d.values.map(function(child) {
      return child.name;
    }).join(",")];
  })
  .enter().append("td")
  .text(function(d) { return d; });


By following these steps, you should be able to display nested JSON data in a d3.js table effectively. Feel free to customize the code as needed to fit your specific data structure and requirements.