Objective-C

Call a JavaScript Function Passing an Array Argument

See more JavaScript Examples

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]);