PHP + 表单选择选项
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PHP + form select options
提问by sea_1987
I have a select that looks like this, it is written in in HTML and is not rendered via any php,
我有一个看起来像这样的选择，它是用 HTML 编写的，不是通过任何 php 呈现的，
<select name="position">
<option value="left">Left</option>
<option value="right">Right</option>
<option value="centre">Centre</option>
</select>
The value gets sent to database and later on gets returned from the database as a variable in the form of $v['position'], using this and my original form how can I make the option that matches the varibale the default selection?
该值被发送到数据库，然后从数据库中作为变量以 的形式返回$v['position']，使用这个和我的原始形式如何使与变量匹配的选项成为默认选择？
采纳答案by Ahmed Aman
try this
尝试这个
<select name="position">
<option value="left" <?php echo $v['position']=='left'?'selected="selected"':'' ?> >Left</option>
<option value="right" <?php echo $v['position']=='right'?'selected="selected"':'' ?>>Right</option>
<option value="centre" <?php echo $v['position']=='centre'?'selected="selected"'?:'' >>Centre</option>
</select>
回答by fabrik
You didn't specify when the form displayed again. If immediately when user is submitted the form, you need to insert this snippet to every option:
您没有指定表单何时再次显示。如果在用户提交表单时立即，您需要将此代码段插入到每个选项中：
<option value="left"<?php echo $v['position'] == 'left' ? ' selected' : ''; ?>>Left</option>
<option value="right"<?php echo $v['position'] == 'right' ? ' selected' : ''; ?>>Right</option>
<option value="centre"<?php echo $v['position'] == 'centre' ? ' selected' : ''; ?>>Centre</option>
OR:
或者：
You must iterate through variables via PHP :(
您必须通过 PHP 迭代变量:(
$html = '<select name="position">';
$opts = array('left', 'right', 'centre');
foreach($opts as $option)
{
$html .= '<option value="' . $option . '"';
$html .= $option == $v['position'] . ' selected' : '';
$html .= '>' . ucfirst($option) . '</option>';
}
$html .= '</select>';
print $html;
回答by Felix Kling
You can create the options in a loop and check whether the current element equals the value in $v['position']and set the selectedattribute accordingly.
您可以在循环中创建选项并检查当前元素是否等于中的值$v['position']并相应地设置selected属性。
<?php
$options = array('left'=>'Left', 'right'=>'Right', 'centre'=>'Centre');
?>
<select name="position">
<?php foreach($options as $value=>$text):?>
<option value="<?php echo $value ?>"
<?php echo ($v['position'] == $value) ? 'selected="selected"' : '' ?> >
<?php echo $text ?>
</option>
<?php endforeach; ?>
</select>
回答by Gordon
You can do it with DOMwithout having to touch your HTML. If this is your HTML:
您可以使用DOM来完成，而无需接触您的 HTML。如果这是您的 HTML：
$template = <<< TPL
<select name="position">
<option value="left">Left</option>
<option value="right">Right</option>
<option value="centre">Centre</option>
</select>
TPL;
And this is the value that was selected:
这是选择的值：
$value = 'right';
You can do
你可以做
$dom = new DOMDocument;
$dom->loadXml($template);
$xPath = new DOMXPath($dom);
$node = $xPath->query(sprintf('//option[@value = "%s"]', $value));
if($node->item(0)) {
$node->item(0)->setAttribute('selected', 'selected');
}
echo $dom->saveXML($dom->documentElement);
And that will output:
这将输出：
<select name="position">
<option value="left">Left</option>
<option value="right" selected="selected">Right</option>
<option value="centre">Centre</option>
</select>
回答by Mark Baker
<select name="position">
<option value="left"<?php echo ($v['position'] == 'left') ? ' selected="selected" : ''; ?>>Left</option>
<option value="right"<?php echo ($v['position'] == 'right') ? ' selected="selected" : ''; ?>>Right</option>
<option value="centre"<?php echo ($v['position'] == 'centre') ? ' selected="selected" : ''; ?>>Centre</option>
</select>
