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