Objective-C

Call a JavaScript Function Returning an Object

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Demonstrates how to call a JavaScript function that returns an object. Objective-C

#import <CkoStringBuilder.h>
#import <CkoJs.h>
#import <CkoJsonObject.h>

BOOL success = NO;

// This is the JavaScript function we'll call:

// function getSettings() {
//     return {
//         theme: "dark",
//         notifications: true,
//         version: 1.0
//     };
// }

CkoStringBuilder *sbScript = [[CkoStringBuilder alloc] init];
[sbScript Append: @"function getSettings() {"];
[sbScript Append: @"    return {"];
[sbScript Append: @"        theme: \"dark\","];
[sbScript Append: @"        notifications: true,"];
[sbScript Append: @"        version: 1.0"];
[sbScript Append: @"    };"];
[sbScript Append: @"}"];

CkoJs *js = [[CkoJs alloc] init];

CkoJsonObject *result = [[CkoJsonObject alloc] init];
result.EmitCompact = NO;

// Call Eval to add the function to the context's global object
success = [js Eval: sbScript result: result];
if (success == NO) {
    // Examine the result for an exception.
    NSLog(@"%@",[result Emit]);

    // Also examine the LastErrorText.
    NSLog(@"%@",js.LastErrorText);
    return;
}

// ------------------------------------------------------------------------------
// Call the function getSettings()

CkoJsonObject *funcCall = [[CkoJsonObject alloc] init];

// Create JSON specifying the function name and arguments
// The function has no arguments, so we only specify the name.

// {
//   "name": "getSettings",
// }

[funcCall UpdateString: @"name" value: @"getSettings"];

success = [js CallFunction: funcCall result: result];
if (success == NO) {
    // Examine the result for an exception.
    NSLog(@"%@",[result Emit]);

    // Also examine the LastErrorText.
    NSLog(@"%@",js.LastErrorText);
    return;
}

NSLog(@"%@",[result Emit]);

// Output:
// {
//   "type": "object",
//   "value": {
//     "theme": "dark",
//     "notifications": true,
//     "version": 1
//   }
// }

// Examine the object's members
NSLog(@"%@%@",@"theme: ",[result StringOf: @"value.theme"]);
NSLog(@"%@%d",@"notifications: ",[result BoolOf: @"value.notifications"]);
NSLog(@"%@%d",@"version: ",[[result IntOf: @"value.version"] intValue]);

// Output:
// theme: dark
// notifications: True
// version: 1