(Ruby) Call a JavaScript Function Returning a Boolean

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Note: This example requires Chilkat v11.4.0 or greater.

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require 'chilkat'

success = false

# This is the JavaScript function we'll call:

# function isEven(number) {
#     return number % 2 === 0;
# }

sbScript = Chilkat::CkStringBuilder.new()
sbScript.Append("function isEven(number) { return number % 2 === 0; }")

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 isEven(8)

funcCall = Chilkat::CkJsonObject.new()

# Create JSON specifying the function name and arguments

# {
#   "name": "isEven",
#   "args": [ 8 ]
# }

funcCall.UpdateString("name","isEven")
funcCall.UpdateInt("args[0]",8)

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";

# Output:
# {
#   "type": "bool",
#   "value": true
# }

retval = result.BoolOf("value")
print retval.to_s() + "\n";

# Output:
# true