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Perl

Call a JavaScript Function Returning a Boolean

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Demonstrates how to call a JavaScript function that returns a boolean.

Chilkat Perl Downloads

Perl
use chilkat();

$success = 0;

# 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(0);

# Call Eval to add the function to the context's global object
$success = $js->Eval($sbScript,$result);
if ($success == 0) {
    # Examine the result for an exception.
    print $result->emit() . "\r\n";

    # Also examine the LastErrorText.
    print $js->lastErrorText() . "\r\n";
    exit;
}

# ------------------------------------------------------------------------------
# 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 == 0) {
    # Examine the result for an exception.
    print $result->emit() . "\r\n";

    # Also examine the LastErrorText.
    print $js->lastErrorText() . "\r\n";
    exit;
}

print $result->emit() . "\r\n";

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

$retval = $result->BoolOf("value");
print $retval . "\r\n";

# Output:
# 1