5

让我先说我已经尝试将下面的代码剪得尽可能小：

        <?php
        // required variables (make them explciit no need for foreach loop)

        $getyear       = (isset($_POST['year'])) ? $_POST['year'] : '';
        $getpass       = (isset($_POST['studentpass'])) ? $_POST['studentpass'] : '';
        $getretypepass = (isset($_POST['retypepass'])) ? $_POST['retypepass'] : '';
        $errormsg      = (isset($errormsg)) ? $errormsg : '';

        $validSubmission = isset($_POST['registerbtn']) && $_POST['year'] && $_POST['studentpass'] && $_POST['retypepass'];

        $min_year = 1;
        $max_year = 10;
        $years    = range($min_year, $max_year); // returns array with numeric values of 1900 - 2012
        $yearHTML = '';
        $yearHTML .= '<select name="year" id="yearDrop">' . PHP_EOL;
        $yearHTML .= '<option value="">Please Select</option>' . PHP_EOL;
        foreach ($years as $year) {
            if (!$validSubmission && isset($_POST['year']) && $year == $_POST['year']) {
                $yearHTML .= "<option value='" . $year . "' selected='selected'>$year</option>" . PHP_EOL;
            } else {
                $yearHTML .= "<option value='" . $year . "'>$year</option>" . PHP_EOL;
            }
        }

        $yearHTML .= '</select>';


        if ((isset($_POST['registerbtn']))) {
            if (in_array($_POST['year'], $years) === true) {
                $getyear = (int) $_POST['year'];
            }
            $getpass       = $_POST['studentpass'];
            $getretypepass = $_POST['retypepass'];


            if ($getyear) {
                if ($getpass) {
                    if (strlen($getpass) <= 5) {
                        $errormsg = "The Password must be a minimum of 6 characters or more";
                    } else {
                        if ($getretypepass) {
                            if ($getpass === $getretypepass) {
                                //perform 2 queries, one query contains $aliasnumrows and other contains $numrows

                                if ($aliasnumrows == 0) {
                                    if ($numrows == 0) {
                                        //perform query which contains $numrows


                                        if ($numrows == 1) {
                                            $errormsg = "<span style='color: green'>Student has been Registered</span>";

                                            $getyear = "";


                                        } else {
                                            $errormsg = "An error has occured, Student has not been Registered";

                                        }

                                    }

                                    else {
                                        $errormsg = "There is already a Student with that Username";
                                    }
                                }

                                else {
                                    $errormsg = "There is already a Student with that Alias";
                                }
                            }

                            else {
                                $errormsg = "Your Passwords did not match";
                            }
                        }

                        else {
                            $errormsg = "You must retype your Password to Register";
                        }
                    }
                } else {
                    $errormsg = "You must enter in a Password to Register";
                }

            }

        else{
    $errormsg = "You must enter in Student's current Academic Year to Register";
    }

    }

$form = "
<form action='" . htmlentities($_SERVER["PHP_SELF"]) . "' method='post'>
  <table>
  <tr>
  <td></td>
  <td id='errormsg'>$errormsg</td>
</tr>
  <tr>
  <td>Year:</td>
  <td>{$yearHTML}</td>
  </tr>
  <tr>
  <td>Password:</td>
  <td><input type='password' name='studentpass' value='' /></td>  
  </tr>
  <tr>
  <td>Retype Password:</td>
  <td><input type='password' name='retypepass' value='' /></td>  
  </tr>
  <tr>
  <tr>
  <td></td>
  <td><input type='submit' value='Register' name='registerbtn' /></td>
  </tr>
  </table>
  </form>";

  echo $form;

好的，这就是我遇到的问题。多年来，我有一个下拉菜单和两个用于输入密码和重新输入密码的文本输入。现在，如果用户从下拉菜单中选择年份并提交表单，则会显示错误消息，指出必须输入密码，并且年份下拉菜单仍显示用户从年份下拉菜单中选择的选项。

我遇到的问题是，如果出现以下任一消息，则下拉选项将返回显示“请选择”。我的问题是，当出现以下错误消息时，如何阻止下拉菜单返回“请选择”选项？

$errormsg = "There is already a Student with that Username";
$errormsg = "There is already a Student with that Alias";
$errormsg = "Your Passwords did not match";
$errormsg = "You must retype your Password to Register";

我认为需要更改的代码行在这里：

    $validSubmission = isset($_POST['registerbtn']) && $_POST['year'] && $_POST['studentpass'] && $_POST['retypepass'];
4

3 回答 3

1

我认为您正在寻找的是：

// This is just a suggestion, but I would set these to null instead of an empty string:
    $getyear       = (isset($_POST['year'])) ? $_POST['year'] : null;
    $getpass       = (isset($_POST['studentpass'])) ? $_POST['studentpass'] : null;
    $getretypepass = (isset($_POST['retypepass'])) ? $_POST['retypepass'] : null;
    $errormsg      = (isset($errormsg)) ? $errormsg : null;
// You have already defined these, so no need to use $_POST here
// Also, I like to compare it to an actual value rather than just doing if ($variable)
// to avoid unforseen circumstances. Note, isset() returns false if $var == null.
$validSubmission = (isset($_POST['registerbtn']) && isset($getyear) && isset($getpass) && isset($getretypepass));

然后我认为您稍后会倒退逻辑：

    foreach ($years as $year) {
        if ($validSubmission && $year == $getyear) {
            $yearHTML .= "<option value='" . $year . "' selected='selected'>$year</option>" . PHP_EOL;
        } else {
            $yearHTML .= "<option value='" . $year . "'>$year</option>" . PHP_EOL;
        }
    }
于 2012-12-08T00:19:26.283 回答
1

在重新填充年份下拉列表时，您可能实际上并不关心提交的任何部分是否有效，您只想重新填充它。只需放弃逻辑即可。

foreach ($years as $year) {
    if (isset($_POST['year']) && $year == $_POST['year']) {
        $yearHTML .= "<option value='" . $year . "' selected='selected'>$year</option>" . PHP_EOL;
    } else {
        $yearHTML .= "<option value='" . $year . "'>$year</option>" . PHP_EOL;
    }
}
于 2012-12-08T00:42:55.790 回答
0

问题是您正在回发到服务器，而服务器正在重新呈现页面。为了正确执行此操作并且以适用于所有浏览器的方式执行此操作，您需要将 $_POST 结果（在正确转义它们之后）回显到输入元素中。

同样，您需要使用选择框的 $_POST 值来确定option应该selected="selected"设置哪个标签的属性。

于 2012-12-08T00:19:02.930 回答