如何在文本框值不爲空時隱藏按鈕

Question

我無法找到有關如何隱藏按鈕的任何文檔，當它填充的字段有一個值。我發現的所有參考文章都指的是隱藏一個按鈕，如果值爲空。

我需要「rmabutton」被禁用或隱藏的，如果「helpdesk_ticket_custom_field_rma_210279」已經與價值

<input type="button" id="rmabutton" onclick="RMA()" value="Generate RMA #"> 
<script type="text/javascript"> 

function RMA(){ 
//formatted day 
    var date = new Date(); 
    var d = date.getDate(); 
    var day = (d < 10) ? '0' + d : d; 

//formatted month 
    var m = date.getMonth() + 1; 
    var month = (m < 10) ? '0' + m : m; 

//formatted year 
    var yy = date.getYear(); 
    var year = (yy < 1000) ? yy + 1900 : yy; 

//grab agent ID 
    var agent = $("helpdesk_ticket_responder_id").value; 

//Isolate agent ID last 5 digits for use in RMA as agent number 
    var agent_short = agent.slice(5,10) 

//grab ticket number and eliminate special characters 
    var ticket = $("ticket-display-id").innerHTML.replace(/[^a-zA-Z0-9 ]/g, ""); 

//parse new RMA # day-month-year-agent-ticket 
    var rma_number = ""+month+""+day+""+year+"-"+agent_short+"-"+ticket+""; 

//replace RMA field contents with new RMA # 
    $("helpdesk_ticket_custom_field_rma_210279").value = rma_number; 
} 
</script> 

Answer 1

使用keyup處理器上測試值的RMA輸入字段填充，並切換的知名度該按鈕取決於它。

$("#helpdesk_ticket_custom_field_rma_210279").keyup(function() { 
 
    $("#rmabutton").toggle(this.value == ''); 
 
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> 
 
<input type="text" id="helpdesk_ticket_custom_field_rma_210279"> 
 
<input type="button" id="rmabutton" value="Generate RMA #">

Answer 2

喜檢查了這一點http://jsfiddle.net/elviz/2z1nvg7y/

$("#helpdesk_ticket_custom_field_rma_210279").keyup(function(){ 

     $("#rmabutton").hide(); 

    });