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sirdaiz
Asked: 2020-01-25 03:58:24 +0800 CST 2020-01-25 03:58:24 +0800 CST

Validate a JSON and print it formatted

  • 772

Suppose I copy a string into a textarea for example:

var str = "{ hello: 'world', places: ['Africa', 'America', 'Asia', 'Australia'] }";

So I JSON.parse(str)parse the string in JSON format, but I would like to display the result in a textarea or something similar and formatted-

Also, if you modify something in there and it's wrong, that's an error. Something similar to this website: https://jsonformatter.org/

My handler:

$scope.toParseJson= function (str) {
   $scope.jsonValue = str;
}

$scope.validateJson= function (str) {
   $scope.errors= JSON.parse(str);
}

my html

<textarea ng-change="toParseJson(str)" ng-model="str"></textarea><br>
{{errors}}<br>
<textarea ng-change="validateJson(str)" ng-model="jsonValue "></textarea>

1- How do I get that in the second textarea it appears ordering with its tabulations and differentiating?

2- Is there another elegant way to display the errors?

javascript

1 Answers

  1. Best Answer

    Validate a JSON

    The JSON.parse() method throws a SyntaxError if the syntax is invalid:

    let textoJSON = '{ "hello": "world" <<<ERROR>>> "places": ["Africa", "America", "Asia", "Australia"] }',
    objeto;

try {
    objeto = JSON.parse(textoJSON);
    console.log('Sintaxis Correcta');
}
catch (error) {
    if(error instanceof SyntaxError) {
        let mensaje = error.message;
        console.log('ERROR EN LA SINTAXIS:', mensaje);
    } else {
        throw error; // si es otro error, que lo siga lanzando
    }
}


    Print a formatted JSON

    The JSON.stringify() method converts an object to JSON, and accepts a third parameter with the number of spaces to use for each tab. I printed the result in a container that respects whitespace (eg: a <pre>or a <textarea>).

    let textoJSON = '{ "hello": "world", "places": ["Africa", "America", "Asia", "Australia"] }',
    objeto;
    
//Teniendo un objeto...
objeto = JSON.parse(textoJSON);

//Lo convertimos a JSON formateado con 2 espacios
let textoFormateado = JSON.stringify(objeto, undefined, 2);

//Imprimimos
document.write('<pre>' + textoFormateado + '</pre>');

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