javascript - ajax调用中的厄运金字塔

Question

我有一个 javascript 应用程序，我想在其中进行 ajax 调用，并且如果需要，根据之前的 ajax 响应进行其他 ajax 调用。我成功地用一个漂亮的厄运金字塔做到了这一点:

    function startParentArray(id) {
    getIssueDetail(id).success(function(data) {
    var source = $("#parenttemplate").html();
    var tpl = Handlebars.compile(source);
    if(data.issue.parent) {
        nextparent = data.issue.parent.id;
        getIssueDetail(nextparent).success(function(data1) {
            $("#parenttable").append(tpl(data1.issue));
            if(data1.issue.parent) {
                nextparent = data1.issue.parent.id;
                getIssueDetail(nextparent).success(function(data2) {
                    $("#parenttable").append(tpl(data2.issue));
                    if(data2.issue.parent) {
                        nextparent = data2.issue.parent.id;
                        getIssueDetail(nextparent).success(function(data3) {
                            $("#parenttable").append(tpl(data3.issue));
                            if(data3.issue.parent) {
                                nextparent = data3.issue.parent.id;
                                getIssueDetail(nextparent).success(function(data4) {
                                    $("#parenttable").append(tpl(data4.issue));
                                    if(data4.issue.parent){
                                        nextparent = data4.issue.parent.id;
                                        getIssueDetail(nextparent).success(function(data5) {
                                            $("#parenttable").append(tpl(data5.issue));
                                        });
                                    }
                                });
                            }
                        });
                    }
                });
            }
        });
    }
});

}

getIssueDetail 返回 ajax 响应。有没有其他更漂亮的方法来做到这一点，例如在 while 循环中？

Answer 1

promise 就是你正在寻找的，我正在考虑this one 。但 jQuery 也有一个 ($.Deferred 即使它没有实现所谓的 A+ promises

这来自 kris kowal 的 q

On the first pass, promises can mitigate the “Pyramid of Doom”: the situation where code marches to the right faster than it marches forward.