Javascript Ajax Scope Inside Of $.each Scope

So I am trying to loop through some elements and change some text based on the result of an ajax call. the problem is I cannot get the data out of the ajax callback and I am not su

Solution 1:

$.ajax() runs asynchronously, so you can't really "wait" for the success in the previous scope. You can use jQuery promise and Deferred to do this though. Check out http://www.erichynds.com/jquery/using-deferreds-in-jquery/ and http://joseoncode.com/2011/09/26/a-walkthrough-jquery-deferred-and-promise/

EDIT: showing an alternate solution that doesn't require promise or deferred:

$(function(){
  var tweets = $('.tweet');
  var symbol_pat = /(^|\s\$)([a-z]+\b)/gi;
  $.each(tweets, function(){
       var that = this;

       var symbol = arguments[2];
       varYAHOO_API_URL = 'http://query.yahooapis.com/v1/public/yql'var format = 'json'var query = 'select * from yahoo.finance.quotes where symbol in ("'+symbol+'")';
       var env = "store://datatables.org/alltableswithkeys";

       $.ajax({
        'url':YAHOO_API_URL,
        'async':false,
        'method':'GET',
        'data': {
        'format':format,
        'q':query,
        'env':env
        },
        success: function(data){
        var quote = data.query.results.quote;
        var change = quote.Change;
        var change_pct = quote.ChangeinPercent;
        var quote_price = quote.LastTradePriceOnly;
        var html_str = "";

        if( change.indexOf("+") != -1 ){
            html_str = '<span class="symWrap up">'+arguments[0]+'</span>';
        }else{
            html_str = '<span class="symWrap down">'+arguments[0]+'</span>';
        }

            var tweet_html = $(that).html();
                var tweet_html = arguments[0].replace(html_str);
            tweet_html = tweet_html.replace(symbol_pat,html_str);
        $(that).html(tweet_html);
        }
       });

    });
  });

});

Solution 2:

so long as your replace code is correct, I believe the following rework of your code should work (or at least get you darn close, as this is untested and depends on the rest of your code):

$(function(){

    varYAHOO_API_URL = 'http://query.yahooapis.com/v1/public/yql'var tweets = $('.tweet');
    var symbol_pat = /(^|\s\$)([a-z]+\b)/gi;
    $.each(tweets, function(){
        var tweet_html = $(this).html();
        tweet_html = tweet_html.replace(symbol_pat, function(){
            var symbol = arguments[2];
            var format = 'json'var query = 'select * from yahoo.finance.quotes where symbol in ("'+symbol+'")';
            var env = "store://datatables.org/alltableswithkeys";
            var quoteHtml = getQuote(format, query, env, function(quote) {
                var change = quote.Change;
                var change_pct = quote.ChangeinPercent;
                var quote_price = quote.LastTradePriceOnly;
                var html_str = "";

                if( change.indexOf("+") != -1 ){
                    html_str = '<span class="symWrap up">'+arguments[0]+'</span>';
                }
                else{
                    html_str = '<span class="symWrap down">'+arguments[0]+'</span>';
                }
                returnarguments[0].replace(html_str);
            });
            return quoteHtml;
        });
        $(this).html(tweet_html);
    });

    var getQuote = function(format, query, env, successCallback) {
       $.ajax({
            'url':YAHOO_API_URL,
            'async':false,
            'method':'GET',
            'data': {
                'format': format,
                'q': query,
                'env': env
            },
            success: function(data){
                var quote = data.query.results.quote;
                if(successCallback !== undefined && typeof successCallback == 'function') {
                    successCallback(quote);
                }
            }
       });
    };
});