My suggestion would be to use domains. Careful use of domains should obviate the need for try/catch altogether, and will handle async errors in Express much better than the default error handler.
Getting Express / Connect up and running with domains is a little tricky, but if you check out the NodeConf slides ( https://othiym23.github.io/nodeconf2013-domains/#/), they have some example middleware functions that show you what's up. Forrest On Saturday, July 6, 2013, Tony Mobily wrote: > Hi, > > I have been writing a bit of code with nodejs, and am sort of "going back" > to brush things up, checking that I am doing things the right way. > I recently read this: > > http://geoff.greer.fm/2012/06/10/nodejs-dealing-with-errors/ > > After a bit of research, I got to this article: > > http://benno.id.au/blog/2011/08/08/nodejs-exceptions > > And to this SO answer: > > > http://stackoverflow.com/questions/7310521/node-js-best-practice-exception-handling > > At the moment, I am only ever throwing() if: > > 1) I am enclosing _async_ code with try/catch, like this: > > // Get the messages from Json, safely > try { > if( ! req.body.messages ) > throw( new Error("req.body.messages not there") ); > var messages = JSON.parse(req.body.messages); > } catch(e) { > var messages = []; > } > > 2) Something reeeeeeeeaaaaaaaalllllllyyyyyyy bad happens in terms of how > my module was used. For example a class constructor is missing a necessary > parameter, etc. > > In any other case, I am using next( err ). If something really bad > happens, for example mongodb dies and calls to the db start failing, I > handle it with an error manager in express: > > app.use( function( err, req, res, next){ > // ... > }); > > But... does this mean that if my application uses a library that has a > random throw(), my app will effectively die? > What's the "current" state of affairs? > > Looking at existing code, well, I seem to have gotten it right: nodejs > libraries tend to only throw when things really aren't supposed to happen. > For example in qs/lib/querystring.js: > > function stringifyString(str, prefix) { > if (!prefix) throw new TypeError('stringify expects an object'); > return prefix + '=' + encodeURIComponent(str); > } > > But... am I missing something? > Would this be correct: > > * throw() when the program really deserves to die, and not for external > causes (see: the db server goes down, etc.) > * Always use next( err ) if anything goes wrong (business as usual) > * Figure out if some libraries emit events, and listen to them if necessary > > Bye, > > Merc. > > -- > -- > Job Board: http://jobs.nodejs.org/ > Posting guidelines: > https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > You received this message because you are subscribed to the Google > Groups "nodejs" group. > To post to this group, send email to > nodejs@googlegroups.com<javascript:_e({}, 'cvml', 'nodejs@googlegroups.com');> > To unsubscribe from this group, send email to > nodejs+unsubscr...@googlegroups.com <javascript:_e({}, 'cvml', > 'nodejs%2bunsubscr...@googlegroups.com');> > For more options, visit this group at > http://groups.google.com/group/nodejs?hl=en?hl=en > > --- > You received this message because you are subscribed to the Google Groups > "nodejs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to nodejs+unsubscr...@googlegroups.com <javascript:_e({}, 'cvml', > 'nodejs%2bunsubscr...@googlegroups.com');>. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en --- You received this message because you are subscribed to the Google Groups "nodejs" group. To unsubscribe from this group and stop receiving emails from it, send an email to nodejs+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
