Swift

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. Swift

func chilkatTest() {
    var success: Bool = false

    // This is the JavaScript we'll run:

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

    let sbScript = CkoStringBuilder()!
    sbScript.append(value: "console.log('Starting infinite loop...'); while(true) {};")

    let js = CkoJs()!

    // 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.timeoutSeconds = 2

    let result = CkoJsonObject()!
    result.emitCompact = false

    // Run the script..
    success = js.eval(jscript: sbScript, result: result)
    if success == false {
        // Examine the result for an exception.
        print("\(result.emit()!)")

        // 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!)")
        return
    }

    // We should never get here..
    print("Succeeded.")
    print("\(result.emit()!)")

}