[英]How to display correct options in drop down menu AND keep option displayed
[英]How to state whether option is selected and display correct values in drop down menu
在下方,我有一个下拉菜单,如果表单中存在验证错误,它将保持下拉菜单中所选选项的显示,否则,如果表单没有错误,则下拉菜单将返回显示“请选择“选项:
$validSubmission = isset($_POST['registerbtn']) isset($getyear);
$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 && $year == $_POST['year'] && $numrows != 1) {
$yearHTML .= "<option value='" . $year . "' selected='selected'>$year</option>" . PHP_EOL;
} else {
$yearHTML .= "<option value='" . $year . "'>$year</option>" . PHP_EOL;
}
}
$yearHTML .= '</select>';
上述下拉列表的值为:
1
2
3
4
5
...
10
但是我在下面的下拉菜单中使用相同的方法时遇到问题,因为下拉菜单包含两种类型的选项,其中包含一个年份的单个数字,以及那些显示一年中多个值且之间带有/的选项:
1
1/2
2
2/3
3
3/4
4
4/5
5
....
10
我的问题是,如果表单中有错误,如何将上面的格式用于下面的下拉菜单代码,以便使选定的选项保持选中状态;否则,如果表单没有错误,则返回显示“请选择”值在下拉菜单中?
$validSubmission = (isset($_POST['createbtn']) && isset($getcourseid) && isset($getcoursename) && isset($getduration));
$durationHTML = '';
$durationHTML .= '<select name="duration" id="durationDrop">'.PHP_EOL;
$durationHTML .= '<option value="">Please Select</option>'.PHP_EOL;
foreach ($years as $year) {
$durationHTML .= "<option>$year</option>".PHP_EOL;
if ($year != $max_year) {
$nextYear = $year + 1;
$durationHTML .= "<option>$year/$nextYear</option>".PHP_EOL;
}
}
$durationHTML .= '</select>';
尝试这样:
foreach ($years as $year)
{
$nextYear = $year + 1;
//check for the "simple years"
if ($validSubmission && $year == $_POST['duration'])
{
$durationHTML .= "<option selected>$year</option>".PHP_EOL;
}
else
{
$durationHTML .= "<option>$year</option>".PHP_EOL;
}
//check for the timespans
if ($year != $max_year)
{
$nextYear = $year + 1;
if ($validSubmission && ($year . "/" . $nextYear) == $_POST['duration'])
{
$durationHTML .= "<option selected>$year/$nextYear</option>".PHP_EOL;
}
else
{
$durationHTML .= "<option>$year/$nextYear</option>".PHP_EOL;
}
}
}
即使未经测试,它也可以帮助您入门。 希望能帮助到你!
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