Exception Handling Mechanisms in JSOM in SharePoint 2013 On-Premises

Question

Can anyone please provide how to handle the exceptions in JSOM in SharePoint 2013. Currently I am developing a SharePoint 2013 On-Premises portal having JSOM as the approach for coding and while coding I need to put several functions and have to handle exceptions.

Is there any exception handling mechanisms available in JSOM or javascript ? any free frameworks can I use ?

Answer 1

Everything in JSOM is client side. So the exceptions you get are not stored server side. You can use the on fail method as below to store & check exceptions in the console itself. Check below code snippet :

function getItems(camlQuery){

     var context = SP.ClientContext.get_current();
     var web = context.get_web();
     var list = context.get_web().get_lists().getByTitle('Test');
     var items = list.getItems(camlQuery, 'AllItems');

     context.load(items);
     context.executeQueryAsync(Function.createDelegate(this, onSuccess),   
     Function.createDelegate(this, onFailure));  

}

function onSuccess(sender, args) {
   //...success
   //execute your code
}

function onFailure(sender, args) {
    console.log('Request Failed. ' + args.get_message() + '\n' + args.get_stackTrace());    
}

This will give you the error message as well as the stack trace in the console. To check the message, press F12 (opens developer tools) and click on console tab.

onFailure method can be used across different functions.

Answer 2

Try catch does not work that well with async, you could use SP.ExceptionHandlingScope when you work against SharePoint data.

Simple example creating ClientContext against a none existing site:

var ctx = new SP.ClientContext("https://i-dont-exists");
ctx.load(ctx.get_web(), "Title");

var exceptionScope = new SP.ExceptionHandlingScope(ctx);  
var startScope = exceptionScope.startScope();  

var tryScope = exceptionScope.startTry();
       var web = ctx.get_web();
tryScope.dispose();  

var catchScope = exceptionScope.startCatch();  

    // DO stuff in catch
    ctx = SP.ClientContext.get_current()
    ctx.load(ctx.get_web(), "Title");

catchScope.dispose();  

var finallyScope = exceptionScope.startFinally();  
    // DO Stuff in finally                          

finallyScope.dispose();  

startScope.dispose();  

ctx.executeQueryAsync(function() { 
    console.log(ctx.get_web().get_title());
}, function(s, args) { 
    console.log('Err: ' + args.get_message()); 
});  

Answer 3

You can use:

try {
    ...
}
catch (Exception) {
    //Get error code and act
}
finally {
    ...
}

Good article here