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?

stackoverflow.com/questions/8294088/javascript-object-vs-json — Adrian
– Adrian, Commented Aug 1, 2018 at 13:01
Not possible. JSON values can only be scalars and literal object or array declarations. — marekful
– marekful, Commented Aug 1, 2018 at 13:01

عبدالرحمان · Accepted Answer · 2018-08-01 13:09:46Z

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();

Quentin · Accepted Answer · 2018-08-01 13:01:25Z

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 1, 2018 at 13:01

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5 Comments

How is it possible in DevTool console then?

@student — Because that is JavaScript (which is a programming language) and not JSON.

Looking clear to me, so how do I handle this scenario then? Any suggestions please?

Store your functions in your program. Use the data in your data file to decide which functions to call.

Thanks for the clarifications, For my specific project needs - I still need some work around for storing functions in JSON. Anyways thanks!

mike123 · Accepted Answer · 2018-08-01 15:13:51Z

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);

Atul Sharma · Accepted Answer · 2018-08-01 13:12:54Z

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.