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";