I am trying to parse the json data from an input field on my node.js server. If I simply have the value 16 as a value in the input field, I can simply read it out with request.body.id (<input type="hidden" id="id" name="id" value="16"/>). But when I stringify a json as a value of the input field and parse the data of json, I always get an error SyntaxError: Unexpected end of JSON input at JSON.parse (<anonymous>). But I can see in the browser console my json data <input type="hidden" id="id" name="id" value="{" a":0.3,"b":0.5,"c":1.3}"> Why can't I read the value of the input field with request.body.id?
CodePudding user response：
You need to send only the JSON data to the server while calling the respective endpoint in the front-end application. You should not send the html directly to the node js end-point
CodePudding user response：
The tag
<input type="hidden" id="id" name="id" value="{" a":0.3,"b":0.5,"c":1.3}">
contains the attributes
type="hidden"
id="id"
name="id"
value="{"
and some garbage
a":0.3,"b":0.5,"c":1.3}"
because the first quote in your JSON closes the attribute.
You have to masquerade the quotes
<input type="hidden" id="id" name="id" value="{" a":0.3,"b":0.5,"c":1.3}">
After clarification in the comments here is a working example:
const json = JSON.stringify({" a":0.3,"b":0.5,"c":1.3});
document.body.innerHTML = `<input value="${json.replaceAll('"', '"')}">`;
const input = document.querySelector('input');
console.log(JSON.parse(input.value));