Objective-C

Call a JavaScript Function Passing an Array Argument

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Demonstrates how to call a JavaScript function with an argument that is an array. Objective-C

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

BOOL success = NO;

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

// function calculateTotal(numbers) {
//   console.log(numbers);
//   let total = 0;
//   
//   // Loop through every number in the array
//   for (const num of numbers) {
//     console.log(num);
//     total += num;
//   }
//   
//   return total;
// }

CkoStringBuilder *sbScript = [[CkoStringBuilder alloc] init];
success = [sbScript LoadFile: @"js_function_array_arg.js" charset: @"utf-8"];
if (success == NO) {
    NSLog(@"%@",sbScript.LastErrorText);
    return;
}

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 calculateTotal(numbers)

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

// Create JSON specifying the function name and arguments
// In this case, there is only 1 argument, and it is an array.

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

// Create the arguments array.
CkoJsonArray *argsArray = [[CkoJsonArray alloc] init];

// The 1st argument in the arguments array is itself an array.
// Passing -1 indicates to append to the array.
CkoJsonArray *arg = [[CkoJsonArray alloc] init];
[argsArray AddArrayAt2: [NSNumber numberWithInt: -1] jarr: arg];

// Fill in the values for the 1st argument.
[arg AddNumberAt: [NSNumber numberWithInt: -1] numericStr: @"10.50"];
[arg AddNumberAt: [NSNumber numberWithInt: -1] numericStr: @"20.00"];
[arg AddNumberAt: [NSNumber numberWithInt: -1] numericStr: @"5.25"];

// Add the "args" array to the funcCall.
[funcCall AppendArrayCopy: @"args" jarr: argsArray];

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

// The funcCall is as follows.  Notice that the 1st (and only) argument is an array.

// {
//   "name": "calculateTotal",
//   "args": [
//     [
//       10.50,
//       20.00,
//       5.25
//     ]
//   ]
// }

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]);

// Result:
// {
//   "type": "double",
//   "value": 35.75
// }

// The function also emitted text to the console.

CkoStringBuilder *sbOut = [[CkoStringBuilder alloc] init];
[js ConsoleOutputSb: sbOut];
NSLog(@"%@",[sbOut GetAsString]);

// Output:
// 10.5,20,5.25
// 10.5
// 20
// 5.25

// -----------------------------------------------------------
// Note: If the array argument is simple, this is an alternative
// and simpler way of creating the funcCall:

[funcCall Clear];
[funcCall UpdateString: @"name" value: @"calculateTotal"];
[funcCall UpdateNumber: @"args[0][0]" numericStr: @"10.50"];
[funcCall UpdateNumber: @"args[0][1]" numericStr: @"20.00"];
[funcCall UpdateNumber: @"args[0][2]" numericStr: @"5.25"];
NSLog(@"%@",[funcCall Emit]);