Refilling drop down menu selection after form subm

问题:

I'm working on a sign up/registration form in php that resubmits/retains the users input if everything doesn't validate properly. I've got text box, password input, and radio buttons all working but these drop down menus have been more trouble. The php code I used works for the text boxes but not these select/options, is there a better way to do this? I've cut out the majority of the options just to save space, but each goes from 0-11 months, 1-31 days, and 1900-2013 years respectively.

<select id="month" name="month" value="<?php
    if(isset($_POST['month']))
        echo htmlspecialchars($_POST['month'])?>">

    <option value="default">Month</option>
    <option value="0">January</option>
    ...
    <option value="11">December</option>

</select>
<select id="formDay" name="day" value="<?php
    if(isset($_POST['day']))
        echo htmlspecialchars($_POST['day'])?>">

    <option value="default">Day</option>
    <option value="1">1</option>
    ...
    <option value="31">31</option>

</select>
<select id="formYear" name="year" value="<?php
    if(isset($_POST['year']))
        echo htmlspecialchars($_POST['year'])?>">

    <option value="default">Year</option>
    <option value="2013">2013</option>
    ...
    <option value="1900">1900</option>

 </select>                    

回答1:

You may try this, generate values dynamically

Day:

echo "<select name='day'>";
for( $i = 1; $i <= 31; $i++ )
{
    $selectedDay = isset($_POST['day']) && $_POST['day'] == $i ? 'selected="selected"' : ''; 
    echo "<option $selectedDay value=$i>$i</option>";
}
echo "</select>";

Month:

$months = array('Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec');
echo "<select name='month'>";
for( $i = 0; $i <= 11; $i++ )
{
    $m = $months[$i];
    $selectedMonth = isset($_POST['month']) && $_POST['month'] == $i ? 'selected="selected"' : ''; 
    echo "<option $selectedMonth value=$i>$m</option>";
}
echo "</select>";

Year:

echo "<select name='year'>";
for( $i = 2013; $i >= 1900; $i-- )
{
    $selectedYear = isset($_POST['year']) && $_POST['year'] == $y ? 'selected="selected"' : ''; 
    echo "<option $selectedYear value=$i>$i</option>";
}
echo "</select>";

Demo Normal and Demo Selected

回答2:

You are doing in the wrong way.

please make the condition inside the each option like below

<option value="2013" <?php if(isset($_POST['year']) && $_POST['year']==2013){ echo "selected";}?>>2013</option>

in same manner for month.

回答3:

With selects you can't set a value ... instead you have to add a selected attribute to the selection option element.

I usually use a function like this to build out my selects

function showSelect($name, $options, $selected, $attr = array()){
    $str = "<select name='".$name.'"';
    foreach($attr as $name=>$val){
        $str.= " ".$name."='".$val."'";
    }
    $str.=">";
    foreach($options as $k=>$val){
        $str.= "<option value='".$val."'".($val==$selected?" selected='selected'":"").">".$k.'</option>';
    }
    $str.="</select>";
}

$name is the name of the element $options is an array in the form "option_value"=>"option_label" $selected is the value of the selection option $attr is an array of the additional attributes to put on the select element (style id etc.)

For example

$days = array();
for($d = 1; $x<=31; $x++){
     $days[(string)$d] = (string)$d;
}

echo showSelect("formDays", $days, $_POST["formDays"], array("id"=>"formDays"));