terminate a handler execution in JavaScript

I need to terminate a handler execution in JavaScript in order to allow methods/handlers to be executed in a Web page. For example, the following piece of code illustrates what I need:

function handler() {

    //doing many things 1

    internalProcess() 

    //doing many things 2 (it is not executed)

} 



function internalProcess() {

    //doing many things 3

    //terminate the handler execution

}

I have seen some solutions using throw but they are not working for me because sometimes other functions in the handler captures this exception and the handler continues its execution.

edited Nov 19 '18 at 17:15

j08691

166k20192213

asked Nov 19 '18 at 17:14

Naive Developer

13829

2

throw, is the correct way. sometimes other functions in the handler captures this exception then maybe they should not. It's hard to tell without a more concrete example.

– Keith
Nov 19 '18 at 17:17

I am not sure what you are asking.... If they catch the errors, not sure what you can do....

– epascarello
Nov 19 '18 at 17:17

Could just add a return; after internalProcess() in the first handler?

– apokryfos
Nov 19 '18 at 17:18

1

There is no mechanism that directly does what you're asking; throw is about as close as you can get.

– Pointy
Nov 19 '18 at 17:20

add a comment |

I need to terminate a handler execution in JavaScript in order to allow methods/handlers to be executed in a Web page. For example, the following piece of code illustrates what I need:

function handler() {

    //doing many things 1

    internalProcess() 

    //doing many things 2 (it is not executed)

} 



function internalProcess() {

    //doing many things 3

    //terminate the handler execution

}

I have seen some solutions using throw but they are not working for me because sometimes other functions in the handler captures this exception and the handler continues its execution.

edited Nov 19 '18 at 17:15

j08691

166k20192213

asked Nov 19 '18 at 17:14

Naive Developer

13829

2

throw, is the correct way. sometimes other functions in the handler captures this exception then maybe they should not. It's hard to tell without a more concrete example.

– Keith
Nov 19 '18 at 17:17

I am not sure what you are asking.... If they catch the errors, not sure what you can do....

– epascarello
Nov 19 '18 at 17:17

Could just add a return; after internalProcess() in the first handler?

– apokryfos
Nov 19 '18 at 17:18

1

There is no mechanism that directly does what you're asking; throw is about as close as you can get.

– Pointy
Nov 19 '18 at 17:20

add a comment |

I need to terminate a handler execution in JavaScript in order to allow methods/handlers to be executed in a Web page. For example, the following piece of code illustrates what I need:

function handler() {

    //doing many things 1

    internalProcess() 

    //doing many things 2 (it is not executed)

} 



function internalProcess() {

    //doing many things 3

    //terminate the handler execution

}

I have seen some solutions using throw but they are not working for me because sometimes other functions in the handler captures this exception and the handler continues its execution.

edited Nov 19 '18 at 17:15

j08691

166k20192213

asked Nov 19 '18 at 17:14

Naive Developer

13829

I need to terminate a handler execution in JavaScript in order to allow methods/handlers to be executed in a Web page. For example, the following piece of code illustrates what I need:

function handler() {

    //doing many things 1

    internalProcess() 

    //doing many things 2 (it is not executed)

} 



function internalProcess() {

    //doing many things 3

    //terminate the handler execution

}

I have seen some solutions using throw but they are not working for me because sometimes other functions in the handler captures this exception and the handler continues its execution.

javascript handler

edited Nov 19 '18 at 17:15

j08691

166k20192213

asked Nov 19 '18 at 17:14

Naive Developer

13829

edited Nov 19 '18 at 17:15

j08691

166k20192213

asked Nov 19 '18 at 17:14

Naive Developer

13829

edited Nov 19 '18 at 17:15

j08691

166k20192213

edited Nov 19 '18 at 17:15

j08691

166k20192213

edited Nov 19 '18 at 17:15

j08691

166k20192213

asked Nov 19 '18 at 17:14

Naive Developer

13829

asked Nov 19 '18 at 17:14

Naive Developer

13829

asked Nov 19 '18 at 17:14

Naive Developer

13829

2

throw, is the correct way. sometimes other functions in the handler captures this exception then maybe they should not. It's hard to tell without a more concrete example.

– Keith
Nov 19 '18 at 17:17

I am not sure what you are asking.... If they catch the errors, not sure what you can do....

– epascarello
Nov 19 '18 at 17:17

Could just add a return; after internalProcess() in the first handler?

– apokryfos
Nov 19 '18 at 17:18

1

There is no mechanism that directly does what you're asking; throw is about as close as you can get.

– Pointy
Nov 19 '18 at 17:20

add a comment |

2

throw, is the correct way. sometimes other functions in the handler captures this exception then maybe they should not. It's hard to tell without a more concrete example.

– Keith
Nov 19 '18 at 17:17

I am not sure what you are asking.... If they catch the errors, not sure what you can do....

– epascarello
Nov 19 '18 at 17:17

Could just add a return; after internalProcess() in the first handler?

– apokryfos
Nov 19 '18 at 17:18

1

There is no mechanism that directly does what you're asking; throw is about as close as you can get.

– Pointy
Nov 19 '18 at 17:20

throw, is the correct way. sometimes other functions in the handler captures this exception then maybe they should not. It's hard to tell without a more concrete example.

– Keith
Nov 19 '18 at 17:17

I am not sure what you are asking.... If they catch the errors, not sure what you can do....

– epascarello
Nov 19 '18 at 17:17

Could just add a return; after internalProcess() in the first handler?

– apokryfos
Nov 19 '18 at 17:18

There is no mechanism that directly does what you're asking; throw is about as close as you can get.

– Pointy
Nov 19 '18 at 17:20

add a comment |

1 Answer
1

active

oldest

votes

throw would be appropriate if you are handling errors in your internalProcess. You would simply need to try / catch in you handler:

function handler() {

  try {

    console.log('doing many things 1');

    internalProcess();

    console.log('doing many things 2');

  } catch (e) {

    console.log('interrupted:', e.message);

  }

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    throw new Error('a message');

}



handler();

If you just want to sometimes stop execution of handler() depending on computations that happen in internalProcess(), here's a way without using throw:

Simply make the return value of internalProcess() tell handler() whether to continue running or not:

function handler() {

    console.log('doing many things 1');

    const shouldContinue = internalProcess();

    if (!shouldContinue) {

      return;

    }

    console.log('doing many things 2');

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    return false;

}



handler();

answered Nov 19 '18 at 17:25

lucascaro

3,72611731

} catch (e) { you really need to be sure this is what you want,. eg. the function handler will now always succeed, as you don't re-throw. Generally speaking exception handling is something that's handled right at the root of your application,.

– Keith
Nov 19 '18 at 17:34

Thanks for the feedback! I think it really depends on your needs, I'm not sure what the use case is here, which is why I recommend the second option. There are definitely use cases where you want to handle known exceptions, for example on an event handler since there is no other function directly calling it. In this example, I assumed handler was an event handler, and wanted to do error handling within it, but yes, if you want to expose errors to users you would need to rethrow.

– lucascaro
Nov 19 '18 at 17:39

The second solution doesn't work for me, because I have to interrupt an execution. My only problem with the first one if the call of internalProcess (which triggers the exception) is inside of another function, foo, that captures this exception because foo uses catch(e). Maybe If creates a particular object exception, it is not captured.

– Naive Developer
Nov 19 '18 at 18:52

I see... you should try posting a Minimal, Complete, and Verifiable example, that would help us understand the specifics of your problem and provide better answers.

– lucascaro
Nov 20 '18 at 2:59

add a comment |

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1 Answer
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throw would be appropriate if you are handling errors in your internalProcess. You would simply need to try / catch in you handler:

function handler() {

  try {

    console.log('doing many things 1');

    internalProcess();

    console.log('doing many things 2');

  } catch (e) {

    console.log('interrupted:', e.message);

  }

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    throw new Error('a message');

}



handler();

If you just want to sometimes stop execution of handler() depending on computations that happen in internalProcess(), here's a way without using throw:

Simply make the return value of internalProcess() tell handler() whether to continue running or not:

function handler() {

    console.log('doing many things 1');

    const shouldContinue = internalProcess();

    if (!shouldContinue) {

      return;

    }

    console.log('doing many things 2');

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    return false;

}



handler();

answered Nov 19 '18 at 17:25

lucascaro

3,72611731

} catch (e) { you really need to be sure this is what you want,. eg. the function handler will now always succeed, as you don't re-throw. Generally speaking exception handling is something that's handled right at the root of your application,.

– Keith
Nov 19 '18 at 17:34

Thanks for the feedback! I think it really depends on your needs, I'm not sure what the use case is here, which is why I recommend the second option. There are definitely use cases where you want to handle known exceptions, for example on an event handler since there is no other function directly calling it. In this example, I assumed handler was an event handler, and wanted to do error handling within it, but yes, if you want to expose errors to users you would need to rethrow.

– lucascaro
Nov 19 '18 at 17:39

The second solution doesn't work for me, because I have to interrupt an execution. My only problem with the first one if the call of internalProcess (which triggers the exception) is inside of another function, foo, that captures this exception because foo uses catch(e). Maybe If creates a particular object exception, it is not captured.

– Naive Developer
Nov 19 '18 at 18:52

I see... you should try posting a Minimal, Complete, and Verifiable example, that would help us understand the specifics of your problem and provide better answers.

– lucascaro
Nov 20 '18 at 2:59

add a comment |

throw would be appropriate if you are handling errors in your internalProcess. You would simply need to try / catch in you handler:

function handler() {

  try {

    console.log('doing many things 1');

    internalProcess();

    console.log('doing many things 2');

  } catch (e) {

    console.log('interrupted:', e.message);

  }

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    throw new Error('a message');

}



handler();

If you just want to sometimes stop execution of handler() depending on computations that happen in internalProcess(), here's a way without using throw:

Simply make the return value of internalProcess() tell handler() whether to continue running or not:

function handler() {

    console.log('doing many things 1');

    const shouldContinue = internalProcess();

    if (!shouldContinue) {

      return;

    }

    console.log('doing many things 2');

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    return false;

}



handler();

answered Nov 19 '18 at 17:25

lucascaro

3,72611731

} catch (e) { you really need to be sure this is what you want,. eg. the function handler will now always succeed, as you don't re-throw. Generally speaking exception handling is something that's handled right at the root of your application,.

– Keith
Nov 19 '18 at 17:34

Thanks for the feedback! I think it really depends on your needs, I'm not sure what the use case is here, which is why I recommend the second option. There are definitely use cases where you want to handle known exceptions, for example on an event handler since there is no other function directly calling it. In this example, I assumed handler was an event handler, and wanted to do error handling within it, but yes, if you want to expose errors to users you would need to rethrow.

– lucascaro
Nov 19 '18 at 17:39

The second solution doesn't work for me, because I have to interrupt an execution. My only problem with the first one if the call of internalProcess (which triggers the exception) is inside of another function, foo, that captures this exception because foo uses catch(e). Maybe If creates a particular object exception, it is not captured.

– Naive Developer
Nov 19 '18 at 18:52

I see... you should try posting a Minimal, Complete, and Verifiable example, that would help us understand the specifics of your problem and provide better answers.

– lucascaro
Nov 20 '18 at 2:59

add a comment |

throw would be appropriate if you are handling errors in your internalProcess. You would simply need to try / catch in you handler:

function handler() {

  try {

    console.log('doing many things 1');

    internalProcess();

    console.log('doing many things 2');

  } catch (e) {

    console.log('interrupted:', e.message);

  }

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    throw new Error('a message');

}



handler();

If you just want to sometimes stop execution of handler() depending on computations that happen in internalProcess(), here's a way without using throw:

Simply make the return value of internalProcess() tell handler() whether to continue running or not:

function handler() {

    console.log('doing many things 1');

    const shouldContinue = internalProcess();

    if (!shouldContinue) {

      return;

    }

    console.log('doing many things 2');

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    return false;

}



handler();

answered Nov 19 '18 at 17:25

lucascaro

3,72611731

throw would be appropriate if you are handling errors in your internalProcess. You would simply need to try / catch in you handler:

function handler() {

  try {

    console.log('doing many things 1');

    internalProcess();

    console.log('doing many things 2');

  } catch (e) {

    console.log('interrupted:', e.message);

  }

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    throw new Error('a message');

}



handler();

If you just want to sometimes stop execution of handler() depending on computations that happen in internalProcess(), here's a way without using throw:

Simply make the return value of internalProcess() tell handler() whether to continue running or not:

function handler() {

    console.log('doing many things 1');

    const shouldContinue = internalProcess();

    if (!shouldContinue) {

      return;

    }

    console.log('doing many things 2');

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    return false;

}



handler();

function handler() {

  try {

    console.log('doing many things 1');

    internalProcess();

    console.log('doing many things 2');

  } catch (e) {

    console.log('interrupted:', e.message);

  }

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    throw new Error('a message');

}



handler();

function handler() {

  try {

    console.log('doing many things 1');

    internalProcess();

    console.log('doing many things 2');

  } catch (e) {

    console.log('interrupted:', e.message);

  }

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    throw new Error('a message');

}



handler();

function handler() {

    console.log('doing many things 1');

    const shouldContinue = internalProcess();

    if (!shouldContinue) {

      return;

    }

    console.log('doing many things 2');

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    return false;

}



handler();

function handler() {

    console.log('doing many things 1');

    const shouldContinue = internalProcess();

    if (!shouldContinue) {

      return;

    }

    console.log('doing many things 2');

} 



function internalProcess() {

    console.log('doing many things 3');

    //terminate the handler execution

    return false;

}



handler();

answered Nov 19 '18 at 17:25

lucascaro

3,72611731

answered Nov 19 '18 at 17:25

lucascaro

3,72611731

answered Nov 19 '18 at 17:25

lucascaro

3,72611731

answered Nov 19 '18 at 17:25

lucascaro

3,72611731

} catch (e) { you really need to be sure this is what you want,. eg. the function handler will now always succeed, as you don't re-throw. Generally speaking exception handling is something that's handled right at the root of your application,.

– Keith
Nov 19 '18 at 17:34

Thanks for the feedback! I think it really depends on your needs, I'm not sure what the use case is here, which is why I recommend the second option. There are definitely use cases where you want to handle known exceptions, for example on an event handler since there is no other function directly calling it. In this example, I assumed handler was an event handler, and wanted to do error handling within it, but yes, if you want to expose errors to users you would need to rethrow.

– lucascaro
Nov 19 '18 at 17:39

The second solution doesn't work for me, because I have to interrupt an execution. My only problem with the first one if the call of internalProcess (which triggers the exception) is inside of another function, foo, that captures this exception because foo uses catch(e). Maybe If creates a particular object exception, it is not captured.

– Naive Developer
Nov 19 '18 at 18:52

I see... you should try posting a Minimal, Complete, and Verifiable example, that would help us understand the specifics of your problem and provide better answers.

– lucascaro
Nov 20 '18 at 2:59

add a comment |

} catch (e) { you really need to be sure this is what you want,. eg. the function handler will now always succeed, as you don't re-throw. Generally speaking exception handling is something that's handled right at the root of your application,.

– Keith
Nov 19 '18 at 17:34

Thanks for the feedback! I think it really depends on your needs, I'm not sure what the use case is here, which is why I recommend the second option. There are definitely use cases where you want to handle known exceptions, for example on an event handler since there is no other function directly calling it. In this example, I assumed handler was an event handler, and wanted to do error handling within it, but yes, if you want to expose errors to users you would need to rethrow.

– lucascaro
Nov 19 '18 at 17:39

The second solution doesn't work for me, because I have to interrupt an execution. My only problem with the first one if the call of internalProcess (which triggers the exception) is inside of another function, foo, that captures this exception because foo uses catch(e). Maybe If creates a particular object exception, it is not captured.

– Naive Developer
Nov 19 '18 at 18:52

I see... you should try posting a Minimal, Complete, and Verifiable example, that would help us understand the specifics of your problem and provide better answers.

– lucascaro
Nov 20 '18 at 2:59

} catch (e) { you really need to be sure this is what you want,. eg. the function handler will now always succeed, as you don't re-throw. Generally speaking exception handling is something that's handled right at the root of your application,.

– Keith
Nov 19 '18 at 17:34

Thanks for the feedback! I think it really depends on your needs, I'm not sure what the use case is here, which is why I recommend the second option. There are definitely use cases where you want to handle known exceptions, for example on an event handler since there is no other function directly calling it. In this example, I assumed handler was an event handler, and wanted to do error handling within it, but yes, if you want to expose errors to users you would need to rethrow.

– lucascaro
Nov 19 '18 at 17:39

The second solution doesn't work for me, because I have to interrupt an execution. My only problem with the first one if the call of internalProcess (which triggers the exception) is inside of another function, foo, that captures this exception because foo uses catch(e). Maybe If creates a particular object exception, it is not captured.

– Naive Developer
Nov 19 '18 at 18:52

I see... you should try posting a Minimal, Complete, and Verifiable example, that would help us understand the specifics of your problem and provide better answers.

– lucascaro
Nov 20 '18 at 2:59

add a comment |

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