Lianja

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. Lianja

llSuccess = .F.

// This is the JavaScript we'll run:

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

loSbScript = createobject("CkStringBuilder")
loSbScript.Append("console.log('Starting infinite loop...'); while(true) {};")

loJs = createobject("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.
loJs.TimeoutSeconds = 2

loResult = createobject("CkJsonObject")
loResult.EmitCompact = .F.

// Run the script..
llSuccess = loJs.Eval(loSbScript,loResult)
if (llSuccess = .F.) then
    // Examine the result for an exception.
    ? loResult.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.
    ? loJs.LastErrorText
    release loSbScript
    release loJs
    release loResult
    return
endif

// We should never get here..
? "Succeeded."
? loResult.Emit()


release loSbScript
release loJs
release loResult