Is it not possible to store function as JSON key value in .json file in angular 5

Question

We have an Angular 5 project in which we have a .json file which we're loading in a .ts file using XMLHttpRequest.

The .json file have the following content:

{
    stringKey: "stringValue",
    functionKey: function() {
        console.log('function called!')
    }
}

It throws the error: [json] value expected

If I open Chrome Devtool and set the above object as value - it works fine but not in the project

var obj = {
  stringKey: "stringValue",
  functionKey: function() {
    console.log('function called!')
  }
}

obj.functionKey();

Edit:

Is there a work around for storing functions in pure JSON?

https://stackoverflow.com/questions/8294088/javascript-object-vs-json — Adrian, Aug 01 '18 at 13:01
Not possible. JSON values can only be scalars and literal object or array declarations. — marekful, Aug 01 '18 at 13:01

score 2 · Answer 1 · answered Aug 01 '18 at 13:09

2

You can't put a function inside a json file because it is a data format language, but you can do it in a js file with a JS Object like you did:

var obj = {
  functionKey: function() {
    console.log('function called!')
  }
}
obj.functionKey();

answered Aug 01 '18 at 13:09

score 1 · Answer 2 · answered Aug 01 '18 at 13:01

1

There is no function data type in JSON.

See the documentation. JSON supports objects, arrays, strings, numbers, booleans and null.

It is a data format, not a programming language. It doesn't make much sense for it to support functions.

answered Aug 01 '18 at 13:01

Quentin

How is it possible in DevTool console then? – Zameer Ansari Aug 01 '18 at 13:02
@student — Because that is JavaScript (which **is** a programming language) and not JSON. – Quentin Aug 01 '18 at 13:03
Looking clear to me, so how do I handle this scenario then? Any suggestions please? – Zameer Ansari Aug 01 '18 at 13:04
Store your functions in your program. Use the data in your data file to decide which functions to call. – Quentin Aug 01 '18 at 13:06
Thanks for the clarifications, For my specific project needs - I still need some work around for storing functions in JSON. Anyways thanks! – Zameer Ansari Aug 01 '18 at 13:09

score 0 · Answer 3 · answered Aug 01 '18 at 13:12

var obj = {
  stringKey: "stringValue",
  functionKey: function() {
    console.log('function called!')
  }
}

obj.functionKey();

Here you are just creating an Object obj not JSON.

Just try to convert this Object to JSON using JSON.stringify(obj) it will remove the functionKey as its not a string.

score 0 · Accepted Answer · answered Aug 01 '18 at 15:13

See if that helps (functionKey needs to be a string, you would then use eval to get result)

var obj =  {
stringKey : "stringValue",
functionKey: "(function() { console.log('function called')})()"
}

var result = eval(obj.functionKey);

4 Answers4