Question

我正在寻找添加if / else语句，根据需要显示不同的HTML。我的问题是如何改进这段代码？是否有更精确的方式来呈现此代码？

<?php if ('Images' == get_post_meta($post->ID, 'project_type', true)) { ?>
                  <h1>Images</h1>
<div class="images">...</div>
                <? } elseif ('Slideshow' == get_post_meta($post->ID, 'project_type', true)) { ?>
                  <h1>Slideshow</h1>
<div class="slideshow">...</div>
                <? } elseif ('Video' == get_post_meta($post->ID, 'project_type', true)) { ?>
                    <h1>Video</h1>
<div class="video">...</div>
                <? } elseif ('Audio' == get_post_meta($post->ID, 'project_type', true)) { ?>
                    <h1>Audio</h1>
<div class="audio">...</div>
                <?php } ?>

Answer 1

<?php

// Only call the function once (performance)
$post_id = get_post_meta($post->ID, "project_type", true);

// Use a whitelist to validate
$whitelist = array("Images", "Slideshow", "Video", "Audio");

// Check if given post ID is valid
if (in_array($post_id, $whitelist) === true) { ?>
    <h1><?= $post_id ?></h1>
    <div class="<?= strtolower($post_id) ?>">...</div>
<?php } ?>

是的，此方法未考虑<div>元素中可能发生的情况。因为这不是你问题的一部分。如果有很多事情发生，我会提出一种面向对象的方法。另一个坏方法是switch语句。

<?php

switch (get_post_meta($post->ID, "project_type", true)) {
    case "Images": ?>
        <h1>Images</h1>
        <div class="images">...</div>
        <?php break;

    case "Slideshow": ?>
        <!-- Same story again ... -->
        <?php break;
} // End switch

使用OOP，我们可以创建如下内容：

<?php

namespace Stackoverflow;

abstract class MyBaseTemplate {

    protected $title;

    protected $class;

    protected $content;

    public function __toString() {
        return "<h1>{$this->title}</h1><div class='{$this->class}'>{$this->content}</div>";
    }

}

class Images extends MyBaseTemplate {

    public function __construct() {
        $this->title   = "Images";
        $this->class   = "images";
        $this->content = "...";
    }

}

class Slideshow extends MyBaseTemplate {

    // Init

}

// In the other file instead of if/else and switch

$post_id = get_post_meta($post->ID, "project_type", true);
$class   = "\\Stackoverflow\\{$post_id}";

if (class_exists($class) === true) {
    echo new $class();
}

Answer 2

有时将所有标记放在echo语句中会更清晰，但只有它是简单的标记，并且结果实际上比在上面的php语句中混合更具可读性。例如：

<?php
if (...) {
    echo "<h1>Images</h1>"
    echo "<div class=\"images\">...</div>"
} else if(...) {
    echo "<h1>...</h1>"
}
?>

Answer 3

Fleshgrinder是对的，你可以通过一次只使用get_post_meta来改善它。

如果每个html的内容不同，我可能会使用开关而不是else / elseif / etc ......

$project_type = get_post_meta($post->ID, 'project_type', true);
switch ( $project_type ) {

case 'Images':
    echo '<h1>Images</h1>';
    echo '<div class="images">...</div>';
    break;

case 'Slideshow':
    echo '<h1>Slideshow</h1>';
    echo '<div class="slideshow">...</div>';
    break;

case 'Video':
    echo '<h1>Video</h1>';
    echo '<div class="video">...</div>';
    break;

case 'Audio':
    echo '<h1>Audio</h1>';
    echo '<div class="audio">...</div>';
    break;
}

WordPress / PHP - 优化if / else语句

3 个答案: