在 Javascript 中使用 JSON 从 Google Search Ajax API 获取结果

Question

我正在尝试使用 javascript 从网页的 innerHTML 获取 url。

这就是我正在做的：

var goog = newTabBrowser.contentDocument.getElementsByTagName("pre")[0].innerHTML;
   alert(goog.responseData.results[0].url);

但它不会工作：S

我输出了 goog（使用警报）并将其复制到我的程序中，如下所示：

var goog =  {"responseData": {"results":[{"GsearchResultClass":"GwebSearch","unescapedUrl":"http://stackoverflow.com/","url":"http://stackoverflow.com/","visibleUrl":"stackoverflow.com","cacheUrl":"http://www.google.com/search?q\u003dcache:U1GC2GYOToIJ:stackoverflow.com","title":"\u003cb\u003eStack Overflow\u003c/b\u003e","titleNoFormatting":"Stack Overflow","content":"A language-independent collaboratively edited question and answer site for  programmers."},{"GsearchResultClass":"GwebSearch","unescapedUrl":"http://en.wikipedia.org/wiki/Stack_overflow","url":"http://en.wikipedia.org/wiki/Stack_overflow","visibleUrl":"en.wikipedia.org","cacheUrl":"http://www.google.com/search?q\u003dcache:mWu8b0BQAmwJ:en.wikipedia.org","title":"\u003cb\u003eStack overflow\u003c/b\u003e - Wikipedia, the free encyclopedia","titleNoFormatting":"Stack overflow - Wikipedia, the free encyclopedia","content":"In software, a \u003cb\u003estack overflow\u003c/b\u003e occurs when too much memory is used on the call  \u003cb\u003estack\u003c/b\u003e. In many programming languages the call \u003cb\u003estack\u003c/b\u003e contains a limited amount  \u003cb\u003e...\u003c/b\u003e"},{"GsearchResultClass":"GwebSearch","unescapedUrl":"http://blog.stackoverflow.com/","url":"http://blog.stackoverflow.com/","visibleUrl":"blog.stackoverflow.com","cacheUrl":"http://www.google.com/search?q\u003dcache:iqtvg9Ge1c0J:blog.stackoverflow.com","title":"Blog - \u003cb\u003eStack Overflow\u003c/b\u003e","titleNoFormatting":"Blog - Stack Overflow","content":"Apr 12, 2009 \u003cb\u003e...\u003c/b\u003e Apparently some users who really should know better are confused about the way  \u003cb\u003eStack Overflow\u003c/b\u003e works. I take this as a sweeping indictment of \u003cb\u003e...\u003c/b\u003e"},{"GsearchResultClass":"GwebSearch","unescapedUrl":"http://support.microsoft.com/kb/145799","url":"http://support.microsoft.com/kb/145799","visibleUrl":"support.microsoft.com","cacheUrl":"","title":"How to Troubleshoot Windows Internal \u003cb\u003eStack Overflow\u003c/b\u003e Error Messages","titleNoFormatting":"How to Troubleshoot Windows Internal Stack Overflow Error Messages","content":"This article lists steps to help you troubleshoot problems with \u003cb\u003estack overflow\u003c/b\u003e  errors in Windows. Stacks are reserved memory that programs use to process \u003cb\u003e...\u003c/b\u003e"}],"cursor":{"pages":[{"start":"0","label":1},{"start":"4","label":2},{"start":"8","label":3},{"start":"12","label":4},{"start":"16","label":5},{"start":"20","label":6},{"start":"24","label":7},{"start":"28","label":8}],"estimatedResultCount":"273000","currentPageIndex":0,"moreResultsUrl":"http://www.google.com/search?oe\u003dutf8\u0026ie\u003dutf8\u0026source\u003duds\u0026start\u003d0\u0026hl\u003den\u0026q\u003dStack+overflow"}}, "responseDetails": null, "responseStatus": 200};`

尝试过

alert(goog.responseData.results[0].url);

这成功了

Answer 1

innerHTML 返回一个字符串，而不是一个对象结构。您可能必须使用eval 或 JSON 解析库（取决于 JSON 数据的安全程度）将其从字符串转换为 JavaScript 对象。

例如，（使用json2.js JSON 库）：

var googString = newTabBrowser.contentDocument.getElementsByTagName("pre")[0].innerHTML;
var goog = JSON.parse(googString);

// This should give the correct result
alert(goog.responseData.results[0].url);

史蒂夫

Answer 2

看看这个someone has wrote jquery.google plugin我知道这个插件很小，它不支持分页或类似的。我想这会对你有帮助吗？ 只需检查它的源代码。

问候