在帖子>上出现JSON错误的Blogger Javascript 500 [英] Blogger Javascript with JSON error on Posts > 500
问题描述
我想向我的博客显示随机帖子.
我从谷歌搜索中获取了一个javascript并进行了尝试，但是随机帖子的数量不正确(应为10，但有时为4，有时为2，依此类推).我试图检查发生了什么，发现json.feed.entry [500]引发错误.
这是我使用的javascript
<script type="text/javascript">
function randomposts(json) {
var randarray = new Array();
var l=0;
var flag;
var numofpost=10;
var total = parseInt(json.feed.openSearch$totalResults.$t,10);
for(var i=0;i < numofpost;) {
flag=0;
randarray.length=numofpost;
l=Math.floor(Math.random()*total);
for(j in randarray){
if(l==randarray[j]){
flag=1;}
}
if(flag==0&&l!=0){
randarray[i++]=l;
}
}
// correct output
// alert(randarray);
document.write('<ul>');
// dummy for testing 500 limit
//for (var x = 0; x < numofpost; x++) {
// randarray[x]= 495 + x;
//}
for(var n in randarray){
var p=randarray[n];
var entry=json.feed.entry[p-1];
var posttitle = entry.title.$t;
for(var k=0; k < entry.link.length; k++){
if(entry.link[k].rel=='alternate'){
document.write('<li> ' + posttitle.link(entry.link[k].href) + '</li>');
}
}
}
document.write('</ul>');
}
</script>
<script src="/feeds/posts/default?alt=json-in-script&start-index=1&max-results=1000&callback=randomposts" type="text/javascript"></script>
当前，我将var total = 500;设置为使随机仅适用于前500个帖子.
如何解决此问题?
更新: 我添加了try catch块，错误为 TypeError:无法读取未定义的属性'title'
更新2: 下图是控制台的快照. json.feed.entry 500未定义.
因此，似乎随机索引处的供稿条目为空，在这种情况下，要添加另一个条件以确保随机索引中的每个条目都不为空./p>
替换:
if(flag==0&&l!=0){
具有:
if(flag==0&&l!=0&&json.feed.entry[l-1]!=null){
randarray[i++]=l;
}
我希望能解决您的问题.
此致
PP
然后，您可以两次调用供稿网址，这是一种快速而又肮脏的方法:
<script type="text/javascript">
var a=0;
var b=0;
var entries = new Array();
function randomposts(json) {
for (var i in json.feed.entry) {
var entry = json.feed.entry[i];
if (entry != null) {
entries[b++] = entry;
}
}
a++;
if (a < 2) return;
var randarray = new Array();
var l=0;
var flag;
var numofpost=10;
var total = entries.length;
for(var i=0;i < numofpost;) {
flag=0;
randarray.length=numofpost;
l=Math.floor(Math.random()*total);
for(j in randarray){
if(l==randarray[j]){
flag=1;}
}
if(flag==0&&l!=0){
randarray[i++]=l;
//alert(l);
}
}
// correct output
// alert(randarray);
document.write('<ul>');
// dummy for testing 500 limit
//for (var x = 0; x < numofpost; x++) {
// randarray[x]= 495 + x;
//}
for(var n in randarray){
var p=randarray[n];
var entry=entries[p-1];
var posttitle = entry.title.$t;
for(var k=0; k < entry.link.length; k++){
if(entry.link[k].rel=='alternate'){
document.write('<li> ' + posttitle.link(entry.link[k].href) + '</li>');
}
}
}
document.write('</ul>');
}
</script>
<script src="/feeds/posts/default?alt=json-in-script&start-index=1&max-results=500&callback=randomposts" type="text/javascript"></script>
<script src="/feeds/posts/default?alt=json-in-script&start-index=501&max-results=500&callback=randomposts" type="text/javascript"></script>
I would like to show random posts to my blogger.
I got a javascript from googling and tried it, but the number of random posts are not correct (should be 10 but sometimes 4, sometimes 2, etc). I tried to check what's happening and found out that json.feed.entry [500] throws error.
Here is the javascript that I used
<script type="text/javascript">
function randomposts(json) {
var randarray = new Array();
var l=0;
var flag;
var numofpost=10;
var total = parseInt(json.feed.openSearch$totalResults.$t,10);
for(var i=0;i < numofpost;) {
flag=0;
randarray.length=numofpost;
l=Math.floor(Math.random()*total);
for(j in randarray){
if(l==randarray[j]){
flag=1;}
}
if(flag==0&&l!=0){
randarray[i++]=l;
}
}
// correct output
// alert(randarray);
document.write('<ul>');
// dummy for testing 500 limit
//for (var x = 0; x < numofpost; x++) {
// randarray[x]= 495 + x;
//}
for(var n in randarray){
var p=randarray[n];
var entry=json.feed.entry[p-1];
var posttitle = entry.title.$t;
for(var k=0; k < entry.link.length; k++){
if(entry.link[k].rel=='alternate'){
document.write('<li> ' + posttitle.link(entry.link[k].href) + '</li>');
}
}
}
document.write('</ul>');
}
</script>
<script src="/feeds/posts/default?alt=json-in-script&start-index=1&max-results=1000&callback=randomposts" type="text/javascript"></script>
Currently I set var total = 500; so that the random works only for first 500 posts.
How to solve this issue?
UPDATE: I added try catch block and the error is TypeError: Cannot read property 'title' of undefined
UPDATE 2: The following picture is snapshot of console. The json.feed.entry 500 is undefined.
So it seems that the feed entry at the randomized index is null, in that case add another condition to ensure that every entry in randomized indexes is not null.
Replace:
if(flag==0&&l!=0){
with:
if(flag==0&&l!=0&&json.feed.entry[l-1]!=null){
randarray[i++]=l;
}
I hope that solves your problem.
Regards,
PP
EDIT: Then you can call the feed url twice, this is the quick and dirty way to achieve so:
<script type="text/javascript">
var a=0;
var b=0;
var entries = new Array();
function randomposts(json) {
for (var i in json.feed.entry) {
var entry = json.feed.entry[i];
if (entry != null) {
entries[b++] = entry;
}
}
a++;
if (a < 2) return;
var randarray = new Array();
var l=0;
var flag;
var numofpost=10;
var total = entries.length;
for(var i=0;i < numofpost;) {
flag=0;
randarray.length=numofpost;
l=Math.floor(Math.random()*total);
for(j in randarray){
if(l==randarray[j]){
flag=1;}
}
if(flag==0&&l!=0){
randarray[i++]=l;
//alert(l);
}
}
// correct output
// alert(randarray);
document.write('<ul>');
// dummy for testing 500 limit
//for (var x = 0; x < numofpost; x++) {
// randarray[x]= 495 + x;
//}
for(var n in randarray){
var p=randarray[n];
var entry=entries[p-1];
var posttitle = entry.title.$t;
for(var k=0; k < entry.link.length; k++){
if(entry.link[k].rel=='alternate'){
document.write('<li> ' + posttitle.link(entry.link[k].href) + '</li>');
}
}
}
document.write('</ul>');
}
</script>
<script src="/feeds/posts/default?alt=json-in-script&start-index=1&max-results=500&callback=randomposts" type="text/javascript"></script>
<script src="/feeds/posts/default?alt=json-in-script&start-index=501&max-results=500&callback=randomposts" type="text/javascript"></script>
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