JSON Implementation - Attempt to call global ‘jsonFile’ (a nil value)

Solar2D General Questions/Discussion
#1

Hello there,

I used this tutorial

http://www.coronalabs.com/blog/2011/08/03/tutorial-exploring-json-usage-in-corona/

and I’m getting the error “Attempt to call global ‘jsonFile’ (a nil value)”

I know that there are working JSON solutions out there, so what is wrong with that?

local path local source local t = {} [...] local Data = saveData:read("\*a") t = json.decode(Data) io.close(saveData)

After I say print(t.abc) whatever I always says that t is nil.

I just wonder what’s wrong with that?

Can anybody help?

#2

Did you add:

[lua]local json = require( “json” )[/lua]

to the top of the file?

#3

What’s saveData?

We won’t magicaly guess what is each variable and what it does. You must paste all essential parts for us to help you.

#4

Yes, I did.

My path is wrong I think,

How can I tell

local path =

the local project directory?

Does path = system.pathForFile(src, system.ResourceDirectory) work? I need something like this.

(Sorry about the code, wanted to focus on the important part, but I see you need all of it)

Here is the entire part:

local json = require("json") local src = "test.json" local t = {} local temp local path -- path = system.pathForFile(src, system.DocumentsDirectory) -- path = system.pathForFile(src, system.TemporaryDirectory) path = system.pathForFile(src, system.ResourceDirectory) local saveData = io.open(path, "r") local Data = saveData:read("\*a") t = json.decode(Data) io.close(saveData) print(t.abc) ----------------- test.json looks like this: { {"abc":"hello"} }

Any ideas?

#5

Can’t no one help me with this?

You could also give me a working sample, please.

#6

I don’t see anything obviously wrong with the code you pasted in your last post.  Are you still getting an error?  If so, what is it?

The tutorial blog post I think incorrectly calls a function jsonFile that doesn’t exist.  So if you worked off the tutorial directly, that would explain the error in your original post.

Since your new post (correctly) doesn’t call a non-existent function jsonFile, any error you’re getting now must be different.

  • Andrew
#7

 attempt to index local ‘t’ a nil value

Do you think, that print(t.abc) is wrong or my .json file is buggy?

Seems like the data is loaded, but can’t use it :frowning:

#8

As error states, “t” is nil —> jsonData is invalide so json.decode() fails

#9

–EDIT

 json file must be

{ "abc":"hello" }
#10

Thank you for your advice :).

I found the error. Loaded the sample.json and compared to my own .json file.

The syntax of my abc.json file was wrong.

My code was working at all.

Edit: Ah, now you’ve seen it, too. :slight_smile: Thanks.

#11

For future reference, if you’re editing JSON data by hand, it’s a good idea to use a validator like JSONLint (http://jsonlint.com/) to check that you don’t have any syntax errors.

  • Andrew
#12

Thanks, didn’t thought that for .JSON there is something like that. Used something similar always for HTML :).

#13

If you are using editor like notepad++ or sublime text then there are also plugins for friendly formatting json files, if it will help you :slight_smile:

#14

Did you add:

[lua]local json = require( “json” )[/lua]

to the top of the file?

#15

What’s saveData?

We won’t magicaly guess what is each variable and what it does. You must paste all essential parts for us to help you.

#16

Yes, I did.

My path is wrong I think,

How can I tell

local path =

the local project directory?

Does path = system.pathForFile(src, system.ResourceDirectory) work? I need something like this.

(Sorry about the code, wanted to focus on the important part, but I see you need all of it)

Here is the entire part:

local json = require("json") local src = "test.json" local t = {} local temp local path -- path = system.pathForFile(src, system.DocumentsDirectory) -- path = system.pathForFile(src, system.TemporaryDirectory) path = system.pathForFile(src, system.ResourceDirectory) local saveData = io.open(path, "r") local Data = saveData:read("\*a") t = json.decode(Data) io.close(saveData) print(t.abc) ----------------- test.json looks like this: { {"abc":"hello"} }

Any ideas?

#17

Can’t no one help me with this?

You could also give me a working sample, please.

#18

I don’t see anything obviously wrong with the code you pasted in your last post.  Are you still getting an error?  If so, what is it?

The tutorial blog post I think incorrectly calls a function jsonFile that doesn’t exist.  So if you worked off the tutorial directly, that would explain the error in your original post.

Since your new post (correctly) doesn’t call a non-existent function jsonFile, any error you’re getting now must be different.

  • Andrew
#19

 attempt to index local ‘t’ a nil value

Do you think, that print(t.abc) is wrong or my .json file is buggy?

Seems like the data is loaded, but can’t use it :frowning:

#20

As error states, “t” is nil —> jsonData is invalide so json.decode() fails