(RSS Feed) Uncaught TypeError: Cannot read property 'title' of undefined

Question

我正在尝试从 Google Blogger Feed 中选择内容 http://testdevchuli.blogspot.com/feeds/posts/default?redirect=false&orderby=published&alt=json-in-script&callback=exeRSSpostReader&max-results=500 through using the JavaScript code at http://testdevchuli.blogspot.com/ ，您可以通过 Inspect Element 部分看到错误，其中只有一个红色警告...

Uncaught TypeError: Cannot read property 'title' of undefined
exeRSSpostReaderMain @ (index):1342
exeRSSpostReader @ (index):1313
(anonymous function) @ default?redirect=false&orderby=published&alt=json-in-script&callback=exeRSSpostReader&max-results=5…:2

那么为什么会发生...？？？这是我上面 link...

的完整代码

<script>
function exeRSSpostReader(json){
//<![CDATA[ 
//exeRSSpostReaderMain(json, DivisionId, Label, PostsVisible, ImageVisibility, SummaryVisibility, SummaryCharcters);
//DivisionId: Id of the division in which the result should shown.
//Label: Specific Label, Set &quot;&quot; for all posts.
//PostsVisible: No of posts shown in final result.
//ImageVisibility: Set true if you want thumbnails else set false.
//SummaryVisibility: Set true if you want summary else set false.
//SummaryCharcters: No of character shown in summary.
exeRSSpostReaderMain(json, 'latest_post', '', 3, true, true, 150);
exeRSSpostReaderMain(json, 'first_label', 'Dashain Song', 3, true, true, 150);
exeRSSpostReaderMain(json, 'second_label', 'Modern Song', 6, true, true, 150);
exeRSSpostReaderMain(json, 'third_label', 'Nepali Movie', 4, true, true, 150);
exeRSSpostReaderMain(json, 'fourth_label', 'Nepali Movie', 4, true, true, 150);
exeRSSpostReaderMain(json, 'fifth_label', 'Nepali Movie', 4, true, true, 150);
exeRSSpostReaderMain(json, 'sixth_label', 'Nepali Movie', 5, true, true, 150);
}
//]]>
</script>
<script style='text/javascript'>
//<![CDATA[ 
function exeRSSpostReaderMain(json, postArea, labelTxt, visiblePosts, imageVisible, summaryVisible, summaryChar) {
    var noOfTotalPosts  = 500;
    var outputDiv = postArea;
    var postLabel = labelTxt;
    var numPosts = json.feed.openSearch$totalResults.$t;
    var indexPosts = new Array();
    var pstChk = 0;
    var resultStr = '';
    var resultStr = '<ul style="height:100%;background:#fff;">';
    for (var i = 0; i < numPosts; ++i) {
        indexPosts[i] = i;
    }
    if (noOfTotalPosts > numPosts) {
        noOfTotalPosts = numPosts;
    }
    for (i = 0; i < noOfTotalPosts; ++i) {
        var entry = json.feed.entry[indexPosts[i]];
        var postTitle =  entry.title.$t;
        for (var k = 0; k <  entry.link.length; k++) {
            if ( entry.link[k].rel == 'alternate') {
                postURL =  entry.link[k].href;
                break;
            }
        }
        if ("content" in entry) {
            var postContent = entry.content.$t
        }
        s = postContent;
        a = s.indexOf("<img");
        b = s.indexOf("src=\"", a);
        c = s.indexOf("\"", b + 5);
        d = s.substr(b + 5, c - b - 5);
        if ((a != -1) && (b != -1) && (c != -1) && (d != "")) {
            var imageUrl = d
        } else var imageUrl = 'https://lh6.googleusercontent.com/-cXUE46Oenac/U6rONTOCYuI/AAAAAAAAQTw/r_WI91TMLpk/s400/Images_no_image.gif';
        var img = '';
        if (imageVisible == true) {
        var img = '<a href="'+postURL+'"><img src="'+imageUrl+'" alt="' + postTitle + '" title="' + postTitle + '" /></a>';
        }
        var labels = '';
        if (!entry.category){
            var noLabel = "No Label In This Post";
        } else {
            for(var lblNo = 0; lblNo < entry.category.length; lblNo++){
                labels += entry.category[lblNo].term + ', ';
            }
        }
        if (labels.search(postLabel) >= 0 && pstChk < visiblePosts){
        resultStr += '<li><div id="exe_post_container">'  + img + '<h2 ><a href="'+postURL+'">' + postTitle + '</h2></a></h2><p>';
        var re = /<\S[^>]*>/g;
        postContent = postContent.replace(re, "");
        if (summaryVisible == true) {
            if (postContent.length < summaryChar) {
                resultStr += postContent + '</p>';
            } else {
                postContent = postContent.substring(0, summaryChar);
                var quoteEnd_gal = postContent.lastIndexOf(" ");
                postContent = postContent.substring(0, quoteEnd_gal);
                resultStr += postContent + '...</p>';
            }
        }
         resultStr += '</div></li>';
         pstChk++;
        }
    }
    resultStr += '</ul>';
    document.getElementById(outputDiv).innerHTML += resultStr;
}
function readMoreWidget() {
var var1 = document.getElementsByTagName('footer')[0].innerHTML;var var2 = var1.search('href="http://www.exeideas.net" target="_blank">EXEIdeas');if (var2 == '-1'){alert('This Template Is Designed By EXEIdeas(www.exeideas.net)');}
}
window.onload = readMoreWidget;
//]]>
</script>
<script src='http://testdevchuli.blogspot.com/feeds/posts/default?redirect=false&orderby=published&alt=json-in-script&callback=exeRSSpostReader&max-results=500'></script>

Answer 1

该错误是由于运行循环获取的帖子比您的 RSS 提要 link 多。例如，如果您的 RSS Feed 中有 100 个帖子，并且您是运行 101 的循环，那么当运行迭代没有 101 时，它将在尝试从 null [=] 获取数据时通过错误13=] 所以尽量减少你的循环次数。

(RSS Feed) Uncaught TypeError: Cannot read property 'title' of undefined

(RSS Feed) Uncaught TypeError: Cannot read property 'title' of undefined

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