Question

尝试从getUrl函数获取返回值，但它返回未定义。
我将不胜感激任何帮助。

感谢
这是代码：

    function createXmlFicaRsi(xmlDoc,xmlFileName) {     
    var mystr = "<?xml version='1.0' encoding='utf-8'?><result><rows>"+strStor+"</rows></result>"
    jQuery(document).ready(function(){ 
      jQuery("#fRsiGrid").jqGrid({
        datatype: 'xmlstring',
        datastr : mystr,
        colNames:['Year','Earnings', 'Amt<br/>Needed <br/>1 QC','Amt<br/>Needed <br/>4 QC','#<br/>of<br/> QCs','Monthly<br/>Under FRA','Yearly<br/>Under FRA','Monthly<br/> Yearly of<br/> Attain.<br/> FRA','Year of<br/> Attain. of<br/> FRA','YOC*','Sum of<br/>Post-1977<br/>YOCs'],
        colModel :[ 
            {name:'yearRsi', index:'yearRsi', width:55, resizable:false, align:'center', sorttype:'int'},
            {name:'earnRsi', index:'earnRsi', width:65, resizable:false, align:'right', sortable:false}, 
            {name:'1qcRsi', index:'1qcRsi', width:65, resizable:false, align:'right', sortable:false}, 
            {name:'4qcRsi', index:'4qcRsi', width:65, resizable:false, align:'right', sortable:false}, 
            {name:'numqcRsi', index:'numqcRsi', width:40, resizable:false, align:'right', sortable:false}, 
            {name:'mfra', index:'mfra', width:65, resizable:false, align:'right', sortable:false}, 
            {name:'yfra', index:'yfra', width:65, resizable:false, align:'right', sortable:false},
            {name:'myafra', index:'myafra', width:85, resizable:false, align:'right', sortable:false},
            {name:'yafra', index:'yafra', width:65, resizable:false, align:'right', sortable:false},
            {name:'yoc', index:'yoc', width:65, resizable:false, align:'right', sortable:false},          
            {name:'sumpost', index:'sumpost', width:60, resizable:false, align:'right', sortable:false} ],     
        rowNum:-1,      
        hidegrid: false,
        width: 760, 
        height: 460,
        shrinkToFit: false,         
        caption: '<span id=fRsiGrid_caption>FICA Earnings, QC, AET and YOC amounts after 1977</span>'       
      });     

      $('.ui-jqgrid .ui-th-column').css('height', '40px');
      $('.ui-jqgrid .ui-jqgrid-htable th div').css('height', '40px'); 
      $('.ui-jqgrid-title').css('font-size', '.8em');//Font size for title
      $('.ui-jqgrid .ui-th-column').css('font-size', '.7em');//Font size for header content 
      $('#fRsiGrid_caption').append("<span id='whatLink' style='font-size:large;color:blue;text-decoration:none;cursor:pointer'>*</span>");     

    }); 
    $('#jqgh_1qcRsi').addClass("gridLink");
    $('#jqgh_4qcRsi').addClass("gridLink");
    $('#jqgh_mfra').addClass("gridLink");
    $('#jqgh_yfra').addClass("gridLink");
    $('#jqgh_myafra').addClass("gridLink");
    $('#jqgh_yafra').addClass("gridLink");
    $('#jqgh_yoc').addClass("gridLink");

    $("#jqgh_1qcRsi").click(function() {
        var nurl = getUrl("QueryView-QC");
        alert(nurl);        
    }); 
}

    function getUrl(urlNm){
    DWREngine._execute(_ajaxConfig._cfscriptLocation, null, 'getUrls', urlNm, doQueryResults);
    function doQueryResults(r){     
        xmlDoc = loadXMLString(r);      
        y = xmlDoc.getElementsByTagName("URL");

        for (i = 0; i < y.length; i++) {            
            url = y[i].attributes.getNamedItem("val").nodeValue;            
            if (url == urlNm)
            {                           
                url = y[i].childNodes[0];
                //alert(url.nodeValue);
                url = url.nodeValue;
                return url;
            }           
        }   
    }
}

Answer 1

您正在返回内部函数，但getURL函数没有任何内容。

function getUrl(urlNm){
DWREngine._execute(_ajaxConfig._cfscriptLocation, null, 'getUrls', urlNm, doQueryResults);
var returnVal = function doQueryResults(r){     
    xmlDoc = loadXMLString(r);      
    y = xmlDoc.getElementsByTagName("URL");

    for (i = 0; i < y.length; i++) {            
        url = y[i].attributes.getNamedItem("val").nodeValue;            
        if (url == urlNm)
        {                           
            url = y[i].childNodes[0];
            //alert(url.nodeValue);
            url = url.nodeValue;
            return url;
        }           
    }   
  }
  return returnVal;
}

Answer 2

我认为你在getUrl方法中发出了一个ajax请求，而doQueryResults是对处理响应的ajax方法的回调。

问题在于，ajax调用是异步进行的，javascript不会等待完全执行它，然后继续执行函数中提到的其他代码。

在您的代码中，您调用了getUrl

var nurl = getUrl("QueryView-QC"); // getUrl will trigger the ajax request and return nothing ie. undefined so the nurl is undefined.

您需要使用ajax回调来使用响应。以下代码可以帮助您

function getUrl(urlNm){
 DWREngine._execute(_ajaxConfig._cfscriptLocation, null, 'getUrls', urlNm, doQueryResults);
            function doQueryResults(r){     
                xmlDoc = loadXMLString(r);      
                y = xmlDoc.getElementsByTagName("URL");

                for (i = 0; i < y.length; i++) {            
                    url = y[i].attributes.getNamedItem("val").nodeValue;            
                    if (url == urlNm)
                    {                           
                        url = y[i].childNodes[0];
                        //alert(url.nodeValue);
                        url = url.nodeValue;

                        // perform your stuff with url
                       doWithUrl(url);
                    }           
                }   
            }

// function to handle the url 
function doWithUrl(url){
 alert(url);
}

Answer 3

js函数不会从for循环返回任何内容，需要初始化临时载体

function youFunction (){
    for(){
        if(true){
            return value; //wrong
        }
    }
}

这样做

function youFunction (){
    var carrier;
    for(){
        if(true){
            carrier = value; 
            return false; //end the loop
        }
    }
    return carrier;
}

函数的返回值返回undefined

3 个答案: