如何从动态html表读取输入值？

Question

i have the following code to read the values from a regular input,

HTML:

     <tr>
  <th>Email:</th>     
    <td><input id="email"  name="email" onchange="EmailValidate()" maxlength="50"></td>
  </tr>

PHP:

      file_put_contents($file, "\nEMAIL:", FILE_APPEND | LOCK_EX);

  $ret = file_put_contents($file, $_POST['email'], FILE_APPEND | LOCK_EX);

in the same way, i am trying to read the input values from a dynamically generated html table, but i am getting an error,

HTML:

     <table>
  <tr>
  <th>Number of Models:<title="Number of Models"></th>

  <td><select id="numbermodels" name="numbermodels"       onchange="buildTable(this.value); buildTable4(this.value);">

  <option value="1">1</option >
  <option value="2">2</option >
  <option value="3">3</option >
  <option value="4">4</option >
  <option value="5">5</option >
  <option value="6">6</option >
  </select></td>
  </tr>

  <tr>
  <th>Number of heads per model:</th>
  <td>
  <table id="contentTable" border="1" name="contentTable">
    <!-- Fill table programmatically -->
      </table></td>
  </tr>

Javascript:

      function buildTable(val)
      {
     var myTable =document.getElementById("contentTable");
    var j=val;
        var rows = [];
    var cells = [];

     while (myTable.hasChildNodes()) {
     myTable.removeChild(myTable.lastChild);
      }


      for( var i = 0; i < 1; i++ )
       {
       rows[i] = myTable.insertRow(i);
       if(i%3==2)rows[i].addClass("every3rdrow");
         cells[i] = [];

       for( var x = 0; x < j ; x++ )
      {
        cells[i][x] =document.createElement((x==0)?"th":"td");
        cells[i][x].innerHTML = (x==0)?"<input id=t onchange=ty() name=t>":"<input     id=t onchange=ty()>";
        rows[rows.length - 1].appendChild(cells[i][x]);
        }
        }

         }
             buildTable();  

         function ty(){
      $ad = document.getElementById("t").value;
      if(!/^-?\d*$/.test($ad)) {
       alert("Number of heads per model value must be numeric!");
       } 
       } 

for this also i wrote the similar PHP code, but i am getting the error Undefined index t, PHP:

      file_put_contents($file, "\n Number of Heads per Model:", FILE_APPEND | LOCK_EX);

$ret = file_put_contents($file, $_POST['t'], FILE_APPEND | LOCK_EX);

what is the reason for this, what modifications can be done to be able to successfully read the input values from the dynamic html table ?

Answer 1

A few suggestions:

1. Element IDs must be unique. You shouldn't use "t" for each input ID. You could change it to id="t_$i_$x" or something like that to make it unique.

2. You need to let your server side script know that t is an array. To get all of the values from the form submitted, change the name=t in the <input> element templates to name="t[]" .

3. Step 2 will break your validation function. I would change onchange=ty() to onchange="ty(this)" . You will then have to change your ty() function implementation to:

    function ty(el) { if(!/^-?\\d*$/.test(el.value)) { alert("Number of heads per model value must be numeric!"); } } 

   This consequently simplifies your function by removing the need to get the element again (you simply pass an instance of it in when you call it in the onchange event).

4. This isn't necessarily required, but it's a good practice to always enclose your HTML tag attribute values in quotations, as I've shown in my suggestions above.