Ruby

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. Ruby

require 'chilkat'

success = false

#  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;
#  }

sbScript = Chilkat::CkStringBuilder.new()
success = sbScript.LoadFile("js_function_array_arg.js","utf-8")
if (success == false)
    print sbScript.lastErrorText() + "\n";
    exit
end

js = Chilkat::CkJs.new()

result = Chilkat::CkJsonObject.new()
result.put_EmitCompact(false)

#  Call Eval to add the function to the context's global object
success = js.Eval(sbScript,result)
if (success == false)
    #  Examine the result for an exception.
    print result.emit() + "\n";

    #  Also examine the LastErrorText.
    print js.lastErrorText() + "\n";
    exit
end

#  ------------------------------------------------------------------------------
#  Call the function calculateTotal(numbers)

funcCall = Chilkat::CkJsonObject.new()
funcCall.put_EmitCompact(false)

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

funcCall.UpdateString("name","calculateTotal")

#  Create the arguments array.
argsArray = Chilkat::CkJsonArray.new()

#  The 1st argument in the arguments array is itself an array.
#  Passing -1 indicates to append to the array.
arg = Chilkat::CkJsonArray.new()
argsArray.AddArrayAt2(-1,arg)

#  Fill in the values for the 1st argument.
arg.AddNumberAt(-1,"10.50")
arg.AddNumberAt(-1,"20.00")
arg.AddNumberAt(-1,"5.25")

#  Add the "args" array to the funcCall.
funcCall.AppendArrayCopy("args",argsArray)

print funcCall.emit() + "\n";

#  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)
if (success == false)
    #  Examine the result for an exception.
    print result.emit() + "\n";

    #  Also examine the LastErrorText.
    print js.lastErrorText() + "\n";
    exit
end

print result.emit() + "\n";

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

#  The function also emitted text to the console.

sbOut = Chilkat::CkStringBuilder.new()
js.ConsoleOutputSb(sbOut)
print sbOut.getAsString() + "\n";

#  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","calculateTotal")
funcCall.UpdateNumber("args[0][0]","10.50")
funcCall.UpdateNumber("args[0][1]","20.00")
funcCall.UpdateNumber("args[0][2]","5.25")
print funcCall.emit() + "\n";

JavaScript

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;
}