CODEWITHSUNDEEP
javascriptjsonnode.js
Ron van der Heijden
Ron van der Heijden

Reputation: 15070

JSON.stringify = illegal access

I have an array with objects in Javascript. I want to save this array to a .json file.

Before I added the objects to the file, I console.log the objects.

// Client
Object {id: "1", color: "#00FF00"}
Object {id: "2", color: "#FF7645"}
Object {id: "3", color: "#FF8845"}

Then I post the jsonArray to my nodejs server like this:

// Client
$.post('/savejson', 'json=' + JSON.stringify(jsonArray)) // This works

Catch the post and save the file in nodejs like this:

app.router.post('/savejson', function(data) {
    url = '/jsonfiles/something.json'
    // Nodejs Server
    fs.writeFile(url, data.body.json, function(error) {
        if(error) {
            console.log(error)
            return
    }
    console.log('Saved file: ' + url)
})

Now I have a json file with an array with objects like this:

something.json

[
    {"id":"1","color":"#00FF00"},
    {"id":"2","color":"#FF7645"},
    {"id":"3","color":"#FF8845"}
]

I read the file like this:

// Nodejs Server
jsonfile = fs.readFileSync(url, 'UTF-8')
// Output jsonfile: 
[{"id":"1","color":"#00FF00"},{"id":"2","color":"#FF7645"},{"id":"3","#FF8845"}]

Parse it

// Nodejs Server
jsonArray = JSON.parse(jsonfile)
// Output jsonArray: 
[{id: '1',color: '#00FF00'},{ id: '2',color: '#FF7645'},{ id: '3',color: '#FF8845'}]

And send back to the client

// Nodejs Server
window.newjson(jsonArray)

At my client I catch the file with:

// Client
window.newjson = function(jsonArray) {
    // Here foreach loop
}
// Output jsonArray:
undefined[3]
    0: 
        color: "#00FF00"
        id: "1"
        __proto__: 
    1: 
        color: "#FF7645"
        id: "2"
        __proto__: 
    2: 
        color: "#FF8845"
        id: "3"
        __proto__: 
    length: 3
    __proto__: undefined[0]

And for each object I console.log the object.

Output

// Client
{id: "1", color: "#00FF00"}
{id: "2", color: "#FF7645"}
{id: "3", color: "#FF8845"}

Noticed the Object word is difference.

Now I want the same file to be saved again like this:

// Client
$.post('/savejson', 'json=' + JSON.stringify(jsonArray)) // Not working anymore...

When I use JSON.stringify(jsonArray) at client side, I get the error: Uncaught illegal access

I also tried to use JSON.parse(jsonArray) at client side, but this one give me the error Uncaught SyntaxError: Unexpected token o

When I log the jsonArray BEFORE the second post:

// 1
console.log(jsonArray)

// Result
Array[3]
    0: 
        color: "#00FF00"
        id: "1"
        __proto__: 
    1: 
        color: "#FF7645"
        id: "2"
        __proto__: 
    2: 
        color: "#FF8845"
        id: "3"
        __proto__: 
    length: 3
    __proto__: Array[0] 


// 2
console.log(jsonArray.toString())

// Result
[object Object],[object Object],[object Object]


// 3
JSON.stringify(jsonArray)

// Result
Uncaught illegal access


// 4
JSON.parse(jsonArray)

// Result
Uncaught SyntaxError: Unexpected token o

What did I wrong? Why I'm missing the Object word?

Upvotes: 1

Views: 2504

Answers (2)

freakish
freakish

Reputation: 56467

You have to stringify jsonArray before sending it back to the client side.

Upvotes: 2

Andreas
Andreas

Reputation: 1150

The unexpected token problem could be because you are calling JSON.parse on a JavaScript Object as mentioned here: d3.js json uncaught syntax error unexpected token o . Then for JSON.stringify(jsonArray) at client side where you get the error "Uncaught illegal access", debug by checkking if jsonArray is null(as null is an object still):

if(variable==null){
// Do stuff console.log etc
}

(although it is very rare for this to be a problem .strigify should print null) If this fails your variable could also be undeclared. I think the problem could be what @Anthony Grist said initially

Upvotes: 0

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