JavaScript动态拼接表单Action参数实现文件上传与数据提交

本文分享一个JavaScript实例，演示如何获取表单值并将其拼接到表单的action属性中。内容仅供参考，欢迎读者交流使用。

动态拼接Action参数的需求背景

在实际开发中，常遇到包含文件上传input的form表单。需要在点击提交按钮时，提取所有非文件类型的input值，将其格式化为name=value的形式，并追加到action参数之后，从而实现数据的统一提交。

<form id="myform" name="myform" method="post" action="http://www.yoursiteweb.com:8080/justsy/Dolet?type=ws_justsy_webclips_policy_update" enctype="multipart/form-data"> 
<!-- 后台生成json --> 
<script type="text/javascript"> 
var data = [{label:"基本信息",type:"title",tag:"h1"}, 
{label:"Name",type:"input",input:"text",optional:false,name:"policyName",id:"policyName",value:""}, 
{label:"Description",type:"input",input:"text",optional:false,name:"policyDescription",id:"policyDescription",value:""}, 
{label:"",type:"title",tag:"h1"}, 
{label:"Label(Required)",type:"input", input:"text", optional:true, name:"Label",id:"Label",value:""}, 
{label:"URL(Required)",type:"input", input:"text", optional:true, name:"URL",id:"URL",value:""}, 
{label:"Removeable",type:"input", input:"checkbox", optional:false,name:"IsRemovable",id:"IsRemovable",value:"",accept:"image/* "}, 
{label:"Icon",type:"input", input:"file", optional:true, name:"picurl",id:"IconFile",value:""}, 
{label:"Precomposed Icon",type:"input", input:"checkbox",optional:false,name:"Precomposed",id:"Precomposed",value:""}, 
{label:"Full screen",type:"input", input:"checkbox",optional:false,name:"FullScreen",id:"FullScreen",value:""}, 
{type:"hidden",name:"policyID",id:"policyID",value:""}, 
{type:"hidden",name:"PayloadDescription",id:"PayloadDescription",value:""}, 
{type:"hidden",name:"PayloadDisplayName",id:"PayloadDisplayName",value:""}, 
{type:"hidden",name:"PayloadIdentifier",id:"PayloadIdentifier",value:""}, 
{type:"hidden",name:"PayloadOrganization",id:"PayloadOrganization",value:""}, 
{type:"hidden",name:"PayloadType",id:"PayloadType",value:""}, 
{type:"hidden",name:"PayloadUUID",id:"PayloadUUID",value:""}, 
{type:"hidden",name:"PayloadVersion",id:"PayloadVersion",value:""}, 
//{type:"hidden",name:"Icon",id:"Icon",value:""}, 
{type:"submit",optional:true,func:""} 
]; 
inputs(data);//在需要显示输入框的地方调用该方法 
</script> 
<div class="btn-bar"> 
<input type="button" onClick="submitForm()" value="保存"> 
</div> 
</form>

核心JavaScript实现逻辑如下：

function getParams() 
{ 
var docList=document.getElementById("inputList").getElementsByTagName("input"); 
var str="";
//alert(docList.length) ; 
for(var i=0;i<docList.length-1;i++) 
{   
  if(docList[i].getAttribute("type")=="checkbox"){ 
    if(docList[i].checked) 
      str+=getParam(docList[i].getAttribute("name"),"1") 
    else 
      str+=getParam(docList[i].getAttribute("name"),"0") 
  } 
  else 
    str+=getParam(docList[i].getAttribute("name"),docList[i].value);
} 
return str; 
} 
function getParam(key,value) 
{ 
  return "&"+key+"="+value; 
} 
function submitForm(){ 
  if(document.getElementById("policyID").value == "")
  { 
   alert("该公司没有创建策略"); 
   return false; 
  } 
  else{ 
  document.getElementById("IconFile_error").innerHTML="正在提交……"; 
 /*获取文件上传的文件名称并且判断扩展名是否为JPG*/ 
  var testmsg=document.getElementById("IconFile").value; 
  var filename=testmsg.replace(/.*(\/|\\)/, ""); 
  var fileExt=(/[.]/.exec(filename)) ? /[^.]+$/.exec(filename.toLowerCase()) : ''; 
   if(fileExt!='jpg'){ 
    document.getElementById("IconFile_error").innerHTML=""; 
    alert("请上传图片");   
   return false; 
   } 
  document.getElementById("myform").action+=getParams(); 
  document.getElementById("myform").submit(); 
  } 
}

通过上述方式即可成功拼接参数。该方法不仅适用性广，还能有效验证checkbox的值：选中状态记为1，未选中状态记为0。

希望本文提供的JavaScript程序设计思路能对大家有所帮助。