javascript - How do I convert synchronous ajax to asynchronous? -

javascript - How do I convert synchronous ajax to asynchronous? -

what trying accomplish

i trying check server time , compare against preset closing time prevent user clicking on expired sale items (and display item has expired) hitting snag on how accomplish when it's mixed in synchronous call

i know async:false bad thought , won't work in firefox(works in chrome , ie) wanted. having hard time figuring out how convert code asynchronous. if alter part of code asynchronous other parts of code depends on falls apart because timing off.

previous code - phone call if sale_closed()

@get_server_time: (url) -> $.ajax( url: url + '/servertime' type: 'get' async: false ) @sale_closed: () -> if not @is_valid_user homecoming true if config.override_bid_closed? homecoming false if @get_server_time(url) > sale_end homecoming true homecoming false

what tried that's not working

coffeescript

@get_server_time: (url) -> $.ajax( url: url + '/servertime' type: 'get' ) @sale_closed: () -> @get_server_time(url).done (data) -> if not @is_valid_user homecoming true if config.override_bid_closed? homecoming false if info > sale_end homecoming true homecoming false

same code in

javascript:

function get_server_time (url) { homecoming $.ajax({ url: url + '/servertime', type: 'get' }); }; function sale_closed() { get_server_time(url).done(function(data) { if (!this.is_valid_user()) { homecoming true; } if (config.override_sale_closed != null) { homecoming false; } if (data > sale_end) { homecoming true; } homecoming false; }); };

is correct?

is expectation alter sale_close code from

foo: () -> if sale_closed() /* */

to

do_something: () -> /* */ foo: () - > sale_closed(do_something)

that's giant nightmare because have alter lot of code , create them asynchronous may break other functions phone call 'foo', 'foo2', etc. (which synchronous before).

is there guarantee variables do_something read in context , have same value when execute?

thanks help seek wrap head around this

is correct?

not really. cannot return asynchronous callbacks in synchronous code. instead, want utilize promises:

@get_server_time: (url) -> $.ajax( url: url + '/servertime' type: 'get' ) @sale_closed: () -> if not @is_valid_user homecoming $.when true if config.override_bid_closed? homecoming $.when false @get_server_time(url).then (data) -> info > sale_end

is expectation alter code calls sale_close?

yes, need alter callback style. promises, changes won't big though, , flow stays linear.

is there guarantee variables do_something read in context , have same value when execute?

you should declare do_something locally within foo function (or utilize function expression), guarantee variables need in scope. if need right this context, utilize fat arrow functions.

javascript jquery ajax asynchronous coffeescript