递归setTimeout
函数getRandomProducts在html body标签中称为onload
,因此不断进行迭代。从嵌套导航栏的ul中的链接调用setCategoryTree函数。然后,此函数将变量mainCategory传递给getRandomProducts,在该变量中全局声明该变量以维护其初始化。并通过点击的链接传递类别名称。但是,onclick
似乎不起作用,因此迭代发生的频率更高,因为此时有多个递归循环同时执行,不仅如此,而且我的全局变量未按预期存储setCategoryTree的数据(基本上我正在尝试使用类似于静态变量的全局变量)。我已经用注释掉的clearTimeout
识别了所有这些行为。以下是相关的Javascript代码:
var mainCategory = ""; // initialized from setCategoryTree
var category = mainCategory;
function getRandomProducts(category)
{
//window.alert(category);
if(typeof category == "undefined")
category = "all";
else
clearTimeout(t);
var req = new XMLHttpRequest();
var products = document.getElementById("products");
req.onreadystatechange = function()
{
if( (req.readyState == 4) && (req.status == 200) )
{
var result = req.responseText;
products.innerHTML = result;
}
}
req.open("GET", "default.php?category=" + category, true);
req.send(null);
var t = setTimeout("getRandomProducts()", 1000);
}
function setCategoryTree(link)
{
var categoryTree = document.getElementById("categoryTree");
/* climbing the DOM-tree to get the category name (innerHTML of highest "a" tag) */
mainCategory = link.parentNode.parentNode.parentNode.getElementsByTagName("a")[0].innerHTML;
var subcategory = link.innerHTML;
categoryTree.innerHTML = "-- " + mainCategory + " -- " + subcategory;
getRandomProducts(mainCategory);
}
最佳答案
您正在函数中设置变量t
。下次调用此函数时,var t
将不可用。
因此,请将变量设置在函数上方(不在其中)
var randomProductsTimeout = false;
function getRandomProducts(category){
randomProductsTimeout = setTimeout()[..]