Question

我有以下代码从github获取JSON对象，我想将某些部分添加到数组中。

function getTree(hash) {
    var pathToTree, returnedJSON;
    pathToTree = 'https://api.github.com/repos/myaccount/myrepo/git/trees/' + hash;
    $.ajax({
        accepts: 'application/vnd.github-blob.raw',
        dataType: 'jsonp',
        url: pathToTree,
        success: function (json) {
            returnedJSON = json;
        },
        error: function (error) {
            console.debug(error);
        }
    });
    return returnedJSON;
}

function parseTree(hash) {
    var objectedJSON, objectList = [], i, entry;
    objectedJSON = getTree(hash, function () {
        console.debug(objectedJSON);                    // this is not appearing in console
        for (i = 0;  i < objectedJSON.data.tree.length; i += 1) {
            entry = objectedJSON.data.tree[i];
            console.debug(entry);
            if (entry.type === 'blob') {
                if (entry.type.slice(-4) === '.svg') {     // we only want the svg images not the ignore file and README etc
                    objectList.append(i.content);
                }
            } else if (entry.type === 'tree') {
                    objectList.append(parseTree(getTree(entry.sha)));
            }
        }

    });
    return objectList;
}

$(document).ready(function () {
    var objects = parseTree('master', function () {
        console.debug(objects);
    });
});

我有检索JSON对象的代码很好但是在尝试解析它时遇到了麻烦（也就是拉出我想要的位）。我正在使用的回调似乎没有进行，并且想知道是否有人可以查看它并帮助我。

具体来说，我可以为我选择的任何功能添加回调吗？我是否必须对该功能做任何事情？

Answer 1

据我所知，你没有将回调传递给你的函数：

function getTree(hash) {

你正在使用：

objectedJSON = getTree(hash, function () {

同样，这个函数没有回调参数：

function parseTree(hash) {

你正在使用：

var objects = parseTree('master', function () {

修改你的功能：

function getTree(hash, fn) {  ...  }
function parseTree(hash, fn) {  ...  }

然后在需要时使用fn致电fn()。

Answer 2

我已修复代码以说明您将如何处理它。

function getTree(hash, cb) {
    // notice that I copy the callback and hash references to have access to them in this 
    // function's closure and any subsequent closures, like the success and error
    // callbacks.
    var pathToTree, returnedJSON, cb = cb, hash = hash;
    pathToTree = 'https://api.github.com/repos/myaccount/myrepo/git/trees/' + hash;
    $.ajax({
        accepts: 'application/vnd.github-blob.raw',
        dataType: 'jsonp',
        url: pathToTree,
        success: function (json) {
            returnedJSON = json;
            // if anything was passed, call it.
            if (cb) cb(json);
        },
        error: function (error) {
            console.debug(error);
            // an error happened, check it out.
            throw error;
        }
    });
    return returnedJSON;
}

function parseTree(hash) {
    var objectedJSON, objectList = [], i, entry;
    objectedJSON = getTree(hash, function (objectedJSON) {
        console.debug(objectedJSON);                    // this is not appearing in console
        for (i = 0;  i < objectedJSON.data.tree.length; i += 1) {
            entry = objectedJSON.data.tree[i];
            console.debug(entry);
            if (entry.type === 'blob') {
                if (entry.type.slice(-4) === '.svg') {     // we only want the svg images not the ignore file and README etc
                    objectList.append(i.content);
                }
            } else if (entry.type === 'tree') {
                    objectList.append(parseTree(getTree(entry.sha)));
            }
        }

    });
    return objectList;
}

$(document).ready(function () {
    var objects = parseTree('master', function () {
        console.debug(objects);
    });
});

Answer 3

添加第二个参数o getTree函数。像

这样的东西

function getTree(hash, callback)

在Ajax选项中使用“jsopCallback”参数

$.ajax({
      ...
      jsopCallback: callback,
      ...

回调函数似乎没有执行

3 个答案: