CODEWITHSUNDEEP
javascriptnode.jscoffeescript
donald
donald

Reputation: 23737

Node.js: Make sure a piece of code is executed after another

Given this code:

 c = new Customer 
 c.entry phone,req #how to make sure it ends before the next piece of code?

 db.Entry.findOne {x: req.body.x}, (err,entry) ->

How do I make sure that db.Entry.findOne is only executed after c.entry completes?

class Customer
  entry: (phone,req) ->

Upvotes: 2

Views: 160

Answers (1)

mu is too short
mu is too short

Reputation: 434615

Presumably your entry method does something asynchronous and that something should have a callback that runs when it finishes. So, just add a callback to entry:

class Customer
  entry: (phone, req, callback = ->) ->
    some_async_call phone, req, (arg, ...) -> callback(other_arg, ...)

I don't know what the arguments for some_async_call's callback are or what you'd want to pass to entry's callback so I'm using arg, ... and other_arg, ... as illustrative placeholders. If the arguments for some_async_call and the entry callback were the same then you could (as Aaron Dufour notes in the comments) just say:

entry: (phone, req, callback = ->) ->
  some_async_call phone, req, callback

And then move the db.Entry.findOne call into the callback thusly:

c = new Customer 
c.entry phone, req, -> 
  db.Entry.findOne {x: req.body.x}, (err, entry) ->

The details inside entry and the callback arguments would, of course, depend on what entry is doing and what some_async_call really is.

Any time you need to wait for something to happen in async (Java|Coffee)Script, you almost always solve the problem by adding a callback.

Upvotes: 4

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