Javascript 将警报设置为空文本字段

我需要一个函数来发送警报，然后在文本字段为空时返回。带有文本字段的我的js列表是：

var filterList = [{name: "filterStartTime", type: "date", label: "Alguskuupäev"},
                  {name: "filterEndTime", type: "date", label: "Lõppkuupäev"},
                  {name: "filterDoctorCode", type: "text", label: "Dokumendi koostaja arstikood", upper:true},
                  {name: "filterDoctorSpecialityCode", type: "select", label: "Dokumendi koostaja erialakood", upper:true},
                  {name: "filterDocIdAndOid", type: "sub", label: "Dokumendi identifikaator", sub: [
                      {name: "filterDocIdOid",  type: "text", label: "OID", size: 35, noCheckbox: true},
                      {name: "filterDocId",     type: "text", label: "ID", noCheckbox: true}],
                      noCheckbox: false
                  },
                  {name: "filterCompanyCode", type: "text", label: "Koostaja asutuse registrikood"},
                  {name: "filterDocumentType", type: "select", label: "Dokumendi tüüp"}
                ];

调用它们的jsp文件是：

String filterDoctorCode = request.getParameter("filterDoctorCode");
            if(filterDoctorCode != null) filterDoctorCode = filterDoctorCode.trim();

            String filterDoctorSpecialityCode = request.getParameter("filterDoctorSpecialityCode");
            if(filterDoctorSpecialityCode != null) filterDoctorSpecialityCode = filterDoctorSpecialityCode.trim();

            String filterDocIdOid = request.getParameter("filterDocIdOid");
            if(filterDocIdOid != null) filterDocIdOid = filterDocIdOid.trim();
            String filterDocId = request.getParameter("filterDocId");
            if(filterDocId != null) filterDocId = filterDocId.trim();

            String filterCompanyCode = request.getParameter("filterCompanyCode");
            if(filterCompanyCode != null) filterCompanyCode = filterCompanyCode.trim();

            if(statusCode == null) statusCode = "deliveredResponse";
            dlPatDocs.setProcedure(statusCode, filterDoctorCode, filterStartTime, filterEndTime, filterDocIdOid, filterDocId, filterCompanyCode, filterDoctorSpecialityCode);


            sendId = dlPatDocs.send();

所以我知道用我的拙劣描述很难理解，但我希望有人能理解并能提供帮助

在JS中，我想我需要在这里添加警报：

    else if(filterList[i].type == "text"){
        if (!filterList[i].size) filterList[i].size = 20;
        filterInnerHtml += "<input type=\"text\" id=\"" + filterList[i].name + "_input\" ";
        if (filterList[i].upper) filterInnerHtml += " onchange='javascript:fieldValToUpperCase(this);' "
        filterInnerHtml += " class=\"txt_left\" value=\"\" maxlength=\""+ filterList[i].size + "\" size=\""+ filterList[i].size + "\" />";
    }

但我不太确定

抱歉，我忘了提到列表在第三个文件中调用：

<td>
                <!-- Will be built by JS in FilterBank.js#addFilterBank() -->
                <div id = "filtripank"></div>
            </td>
        </tr>
        <tr>
            <td>
                <img src="images/progress.gif" alt="" border="0" id="progressIndicator" style="display:none" />

                <input type="button" class="button" value="Saada päring" onClick="javascript:startDocumentListUpdate()" id="updateButton" />
            </td>

因此，我需要当我单击updateButton时，它检查文本值是否为空，如果为空，它将返回一条消息，并且不会执行onClick javascript:startDocumentListUpdate…..希望它有意义

在Out test field:

  <input type="text" name="checking" id="checking" onblur="checkTextField(this);" />

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这里有一个用于检查空文本字段的实时示例：

var filterList=[{name:filterStartTime，type:date，label:alguskupäev}， {名称：filterEndTime，类型：date，标签：Lõppkuupäev}， {name:filterDoctorCode，type:text，label:Dokumendi-koostaja-arstikood，大写：true}， {名称：filterDoctorSpecialityCode，类型：select，标签：Dokumendi koostaja-erialakood，大写：true}， {名称：filterDocIdAndOid，类型：sub，标签：Dokumendi Identificator，sub:[ {name:filterDocIdOid，type:text，label:OID，size:35，noCheckbox:true}， {name:filterDocId，type:text，label:ID，noCheckbox:true}]， noCheckbox：错误 }, {名称：filterCompanyCode，类型：text，标签：Koostaja asutuse registrikood}， {名称：filterDocumentType，类型：select，标签：Dokumendi tüp} ]; 函数checkEmptylist{ var i； 因为我在名单上{ 如果列表[i]。类型==文本{ 变量名称=列表[i]。名称； 如果$input[name=+name+].val=={ alertname+为空！； } } 如果列表[i].sub{ checkEmptylist[i].sub； } } } $function{ $button.clickfunction{ checkEmptyfilterList； }; }; filterDoctorCode： filterDocIdOid： filterDocId： 过滤器公司代码：

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检查空你的页面中是否加载了jQuery？是的，它加载正确我忘了一件事，我更新了我的问题…不清楚，我没有多少时间。我试图帮助您检查空文本输入功能，就像您将标题设置为空文本字段…

function checkTextField(field) {
    if (field.value == '') {
        alert("Field is empty");
    }
}