PHP Extension

Prevent JavaScript Infinite Loops

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Demonstrates how prevent infinite loops or prevent the JavaScript from running for a longer amount of time than allowed. PHP Extension

<?php

include("chilkat.php");

$success = false;

// This is the JavaScript we'll run:

// console.log('Starting infinite loop...'); while(true) {};

$sbScript = new CkStringBuilder();
$sbScript->Append('console.log('Starting infinite loop...'); while(true) {};');

$js = new CkJs();

// Set a limit on the amount of time (in seconds) the script is allowed to run.
// If the JavaScript takes longer than this amount of time, then Chilkat kills the script without crashing the host program.
// The default value of TimeoutSeconds is 0, which indicates no limit.
// For this example, set a limit of 2 seconds.
$js->put_TimeoutSeconds(2);

$result = new CkJsonObject();
$result->put_EmitCompact(false);

// Run the script..
$success = $js->Eval($sbScript,$result);
if ($success == false) {
    // Examine the result for an exception.
    print $result->emit() . "\n";

    // The result contains this:

    // 	{
    // 	  "exception": {
    // 	    "message": "interrupted - JavaScript exceeded the Chilkat.Js.TimeoutSeconds",
    // 	    "stack": [
    // 	      {
    // 	        "func": "<eval>",
    // 	        "file": "<input>",
    // 	        "line": 1,
    // 	        "col": 8
    // 	      }
    // 	    ]
    // 	  }
    // 	}

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

// We should never get here..
print 'Succeeded.' . "\n";
print $result->emit() . "\n";

?>