United States Department of Agriculture 美国农业部网站数据自动下载小脚本

帮对象写的自动点击页面的小脚本，如果有需要的可以试试，(#^.^#)

https://apps.fas.usda.gov/gats/ExpressQuery1.aspx

 var year = '1991';

 var box3 = document.querySelector("#ctl00_ContentPlaceHolder1_lb_Partners");
 box3.value='ALLRG';
 box3 = document.querySelector("#ctl00_ContentPlaceHolder1_lb_Products");
 box3.value='M1';
 box3 = document.querySelector("#ctl00_ContentPlaceHolder1_ddlValueUnit");
 box3.value='M';
 box3 = document.querySelector("#ctl00_ContentPlaceHolder1_ddlDateSeries");
 box3.value='Annual';
 box3 = document.querySelector("#ctl00_ContentPlaceHolder1_ddlOrderBy");
 box3.value='CODE';
 box3 = document.querySelector("#ctl00_ContentPlaceHolder1_ddlInDetail");
 box3.value='Product';
 box3 = document.querySelector("#ctl00_ContentPlaceHolder1_ddlCalculation");
 box3.value='';

 box3 = document.querySelector("#ctl00_ContentPlaceHolder1_ddlStartYear");
 box3.value= year;
 box3.dispatchEvent(new Event('change'));
 box3 = document.querySelector("#ctl00_ContentPlaceHolder1_ddlEndYear");
 box3.value= year;
 box3.dispatchEvent(new Event('change'));

 function clickStep()
  {
      if (document.querySelector("#overlay").style.display == 'block') {
          setTimeout("clickStep()", 1000);
          return;
      }
      console.log("触发点击事件")
      document.querySelector("#ctl00_ContentPlaceHolder1_btnRetrieveData").click();
  }
  setTimeout("clickStep()", 1000);

 String.prototype.startWith=function(str){
 var reg=new RegExp("^"+str);
 return reg.test(this);
 }
 var clicked = false;
 function doExpand() {
     box3 = document.querySelector("#ctl00_ContentPlaceHolder1_UltraWebTab1__ctl1_grdExpressQuery_GridView1");
     var rows = box3.rows;
     var inputs = [];
     for (var index in rows) {
         var length = rows[index].cells ? rows[index].cells.length : 0;
         if (length < 4) {
             continue;
         }
         var nodes = rows[index].cells[3].childNodes;
         if (nodes.length == 0) {
             continue;
         }
         if (nodes[0].nodeName == '#text') {
             continue;
         }
         var cell5Text = rows[index].cells[4].innerText;
         if (!cell5Text.startWith('Bulk Total') && !cell5Text.startWith('Intermediate Total') && !cell5Text.startWith('Consumer Oriented Total')) {
             continue;
         }

         var input = nodes[0];

         if(input.value == '-') {
             continue;
         }

         clicked = true;
         input.click();
         break;
     }
 }

 var index = 0;
 function expandStep()
  {
      if (document.querySelector("#overlay").style.display == 'block' || document.querySelector("#ctl00_ContentPlaceHolder1_UltraWebTab1") == null) {
          setTimeout("expandStep()", 1000);
          return;
      }
      console.log((index++) + "打开,total:" );
      doExpand();
      if (!clicked) {
          alert("展开完成，请下载")
          return;
      } else {
          clicked = false;
      }
      expandStep();
  }

  setTimeout("expandStep()", 5000);