Issue Unable to load local JSON file in a javascript file which is spun up with node.

Details

The question is straight forward but I am not serving the javascript file in a browser. I have a javascript file which has the logic, I then spin it up with:

node main.js

I googled a few solutions, they remend using JQuery or XMLHttpRequest but they appear to be running into issues related to the fact i am no serving this in a browser.

Project Background

I am using a raspberry PI to get data from an IR Temperature Sensor. I am using python to get calculate the voltage, convert to celsius, then export that as a JSON file. I then plan to load this file into my javascript file which then configures angular fire Database and pushes this data.

I have a front-end application that will then pull this down and display the end data to the user.

If I go with the JQuery:

Option 1

sample:

$.getJSON("test.json", function(json) {
    console.log(json); // this will show the info it in firebug console
});

Error

$.getJSON is not a function even though I am requiring jQuery.

Option 2

If I go with pure javascript, I see

sample

 function loadJSON(callback) {   

    var xobj = new XMLHttpRequest();
        xobj.overrideMimeType("application/json");
    xobj.open('GET', 'my_data.json', true); // Replace 'my_data' with the path to your file
    xobj.onreadystatechange = function () {
          if (xobj.readyState == 4 && xobj.status == "200") {
            // Required use of an anonymous callback as .open will NOT return a value but simply returns undefined in asynchronous mode
            callback(xobj.responseText);
          }
    };
    xobj.send(null);  
 }

Error

xobj.overrideMimeType is not a function

TL/DR

How do I load a local JSON file into a javascript file that is not loaded into a browser but instead spun up with node,

node main.js

Issue Unable to load local JSON file in a javascript file which is spun up with node.

Details

The question is straight forward but I am not serving the javascript file in a browser. I have a javascript file which has the logic, I then spin it up with:

node main.js

I googled a few solutions, they remend using JQuery or XMLHttpRequest but they appear to be running into issues related to the fact i am no serving this in a browser.

Project Background

I am using a raspberry PI to get data from an IR Temperature Sensor. I am using python to get calculate the voltage, convert to celsius, then export that as a JSON file. I then plan to load this file into my javascript file which then configures angular fire Database and pushes this data.

I have a front-end application that will then pull this down and display the end data to the user.

If I go with the JQuery:

Option 1

sample:

$.getJSON("test.json", function(json) {
    console.log(json); // this will show the info it in firebug console
});

Error

$.getJSON is not a function even though I am requiring jQuery.

Option 2

If I go with pure javascript, I see

sample

 function loadJSON(callback) {   

    var xobj = new XMLHttpRequest();
        xobj.overrideMimeType("application/json");
    xobj.open('GET', 'my_data.json', true); // Replace 'my_data' with the path to your file
    xobj.onreadystatechange = function () {
          if (xobj.readyState == 4 && xobj.status == "200") {
            // Required use of an anonymous callback as .open will NOT return a value but simply returns undefined in asynchronous mode
            callback(xobj.responseText);
          }
    };
    xobj.send(null);  
 }

Error

xobj.overrideMimeType is not a function

TL/DR

How do I load a local JSON file into a javascript file that is not loaded into a browser but instead spun up with node,

node main.js

• javascript
• node.js

• 4 const jsonData = require('./test.json'); – Explosion Pills Commented Dec 20, 2017 at 3:45
• what?!! I spent hours looking for this single line of code. *facepalm. Thank you very much – Bromox Commented Dec 20, 2017 at 4:16

1 Answer 1

Node.js can load JSON files through require. See the documentation here: https://nodejs/api/modules.html#modules_all_together

• If filename begins with './' or '/' or '../'
  • If filename.json is a file, parse filename.json to a JavaScript Object. STOP

Most likely what you want is const json = require('./test.json') assuming test.json is in the same directory as the code requiring it. Remember that require parses the JSON, so json in the example is a JavaScript Object.