使用wp_trim_excerpt将the_excerpt（）移出循环

自WP 3.3.0起,如果您能够获取要为其生成摘录的内容,则wp_trim_words()将很有帮助.希望这对某人有帮助,并且省去了创建自己的单词计数功能的麻烦.

http://codex.wordpress.org/Function_Reference/wp_trim_words

Since WP 3.3.0, wp_trim_words() is helpful if you're able to get the content that you want to generate an excerpt for. Hope that's helpful to someone and it saves creating your own word counting function.

http://codex.wordpress.org/Function_Reference/wp_trim_words

wp_trim_excerpt()有一些奇怪的机制-如果有任何东西传递给它,那么它什么也不做.

这是背后的基本逻辑:

• get_the_excerpt()检查手动摘录；
• wp_trim_excerpt()如果没有手动摘录并从内容或预告片中摘录,则会发出提示.

两者与全局变量紧密相关,因此Loop.

在循环之外,最好从wp_trim_excerpt()中取出代码并编写自己的修整函数.

wp_trim_excerpt() has a little curious mechanics - if anything is passed to it then it does nothing.

Here is basic logic behind it:

• get_the_excerpt() checks for manual excerpt;
• wp_trim_excerpt() chimes in if there is no manual excerpt and makes one from content or teaser.

Both are tightly tied to global variables and so Loop.

Outside the Loop you are better of taking code out of wp_trim_excerpt() and writing your own trim function.

更新:

这是我使用的wp_trim_excerpt()的派生词.完美运作.源自Wordpress版本3.0.4

 function my_excerpt($text, $excerpt)
{
    if ($excerpt) return $excerpt;

    $text = strip_shortcodes( $text );

    $text = apply_filters('the_content', $text);
    $text = str_replace(']]>', ']]>', $text);
    $text = strip_tags($text);
    $excerpt_length = apply_filters('excerpt_length', 55);
    $excerpt_more = apply_filters('excerpt_more', ' ' . '[...]');
    $words = preg_split("/[\n\r\t ]+/", $text, $excerpt_length + 1, PREG_SPLIT_NO_EMPTY);
    if ( count($words) > $excerpt_length ) {
            array_pop($words);
            $text = implode(' ', $words);
            $text = $text . $excerpt_more;
    } else {
            $text = implode(' ', $words);
    }

    return apply_filters('wp_trim_excerpt', $text, $raw_excerpt);
}
 

Update:

Here is a derivative of wp_trim_excerpt() which I used. Works perfectly. Derived from Wordpress version 3.0.4

function my_excerpt($text, $excerpt)
{
    if ($excerpt) return $excerpt;

    $text = strip_shortcodes( $text );

    $text = apply_filters('the_content', $text);
    $text = str_replace(']]>', ']]>', $text);
    $text = strip_tags($text);
    $excerpt_length = apply_filters('excerpt_length', 55);
    $excerpt_more = apply_filters('excerpt_more', ' ' . '[...]');
    $words = preg_split("/[\n\r\t ]+/", $text, $excerpt_length + 1, PREG_SPLIT_NO_EMPTY);
    if ( count($words) > $excerpt_length ) {
            array_pop($words);
            $text = implode(' ', $words);
            $text = $text . $excerpt_more;
    } else {
            $text = implode(' ', $words);
    }

    return apply_filters('wp_trim_excerpt', $text, $raw_excerpt);
}

这是我对以帖子对象或帖子ID为参数的"trim_excerpt"的看法.

显然是基于核心内容.不知道为什么这个(和get_the_author())没有非循环等效项.

 /**
     * Generates an excerpt from the content, if needed.
     *
     * @param int|object $post_or_id can be the post ID, or the actual $post object itself
     * @param string $excerpt_more the text that is applied to the end of the excerpt if we algorithically snip it
     * @return string the snipped excerpt or the manual excerpt if it exists         
     */
    function zg_trim_excerpt($post_or_id, $excerpt_more = ' [...]') {
        if ( is_object( $post_or_id ) ) $postObj = $post_or_id;
        else $postObj = get_post($post_or_id);

        $raw_excerpt = $text = $postObj->post_excerpt;
        if ( '' == $text ) {
            $text = $postObj->post_content;

            $text = strip_shortcodes( $text );

            $text = apply_filters('the_content', $text);
            $text = str_replace(']]>', ']]>', $text);
            $text = strip_tags($text);
            $excerpt_length = apply_filters('excerpt_length', 55);

            // don't automatically assume we will be using the global "read more" link provided by the theme
            // $excerpt_more = apply_filters('excerpt_more', ' ' . '[...]');
            $words = preg_split("/[\n\r\t ]+/", $text, $excerpt_length + 1, PREG_SPLIT_NO_EMPTY);
            if ( count($words) > $excerpt_length ) {
                array_pop($words);
                $text = implode(' ', $words);
                $text = $text . $excerpt_more;
            } else {
                $text = implode(' ', $words);
            }
        }
        return apply_filters('wp_trim_excerpt', $text, $raw_excerpt);
    }
 

Here's my take on a "trim_excerpt" that takes the post object or a post ID as a parameter.

Obviously based on what's in core. Don't know why this (and get_the_author()) don't have non-loop equivalents.

/**
     * Generates an excerpt from the content, if needed.
     *
     * @param int|object $post_or_id can be the post ID, or the actual $post object itself
     * @param string $excerpt_more the text that is applied to the end of the excerpt if we algorithically snip it
     * @return string the snipped excerpt or the manual excerpt if it exists         
     */
    function zg_trim_excerpt($post_or_id, $excerpt_more = ' [...]') {
        if ( is_object( $post_or_id ) ) $postObj = $post_or_id;
        else $postObj = get_post($post_or_id);

        $raw_excerpt = $text = $postObj->post_excerpt;
        if ( '' == $text ) {
            $text = $postObj->post_content;

            $text = strip_shortcodes( $text );

            $text = apply_filters('the_content', $text);
            $text = str_replace(']]>', ']]>', $text);
            $text = strip_tags($text);
            $excerpt_length = apply_filters('excerpt_length', 55);

            // don't automatically assume we will be using the global "read more" link provided by the theme
            // $excerpt_more = apply_filters('excerpt_more', ' ' . '[...]');
            $words = preg_split("/[\n\r\t ]+/", $text, $excerpt_length + 1, PREG_SPLIT_NO_EMPTY);
            if ( count($words) > $excerpt_length ) {
                array_pop($words);
                $text = implode(' ', $words);
                $text = $text . $excerpt_more;
            } else {
                $text = implode(' ', $words);
            }
        }
        return apply_filters('wp_trim_excerpt', $text, $raw_excerpt);
    }

+1到Rast.非常奇怪的是,在很明显应该没有get_the_excerpt($post-> ID)之类的东西的情况下.无论如何,这是wordpress版本3.0.4中的wp_trim_excerpt():

http://core.trac. wordpress.org/browser/tags/3.0.4/wp-includes/formatting.php

 function wp_trim_excerpt($text) {
1824            $raw_excerpt = $text;
1825            if ( '' == $text ) {
1826                    $text = get_the_content('');
1827    
1828                    $text = strip_shortcodes( $text );
1829    
1830                    $text = apply_filters('the_content', $text);
1831                    $text = str_replace(']]>', ']]>', $text);
1832                    $text = strip_tags($text);
1833                    $excerpt_length = apply_filters('excerpt_length', 55);
1834                    $excerpt_more = apply_filters('excerpt_more', ' ' . '[...]');
1835                    $words = preg_split("/[\n\r\t ]+/", $text, $excerpt_length + 1, PREG_SPLIT_NO_EMPTY);
1836                    if ( count($words) > $excerpt_length ) {
1837                            array_pop($words);
1838                            $text = implode(' ', $words);
1839                            $text = $text . $excerpt_more;
1840                    } else {
1841                            $text = implode(' ', $words);
1842                    }
1843            }
1844            return apply_filters('wp_trim_excerpt', $text, $raw_excerpt);
1845    }
 

您可以在第1826行上看到它通过get_the_contents链接到$post全局变量.是的,我不知道他们在想什么.但是从这里,在您自己的my_excerpt中将get_the_content替换为$text,它的行为应类似.

+1 to Rast. It is very weird that there is no such thing as get_the_excerpt($post->ID), when it should be quite obvious that it should. Anyway, here is wp_trim_excerpt() in wordpress version 3.0.4:

http://core.trac.wordpress.org/browser/tags/3.0.4/wp-includes/formatting.php

function wp_trim_excerpt($text) {
1824            $raw_excerpt = $text;
1825            if ( '' == $text ) {
1826                    $text = get_the_content('');
1827    
1828                    $text = strip_shortcodes( $text );
1829    
1830                    $text = apply_filters('the_content', $text);
1831                    $text = str_replace(']]>', ']]>', $text);
1832                    $text = strip_tags($text);
1833                    $excerpt_length = apply_filters('excerpt_length', 55);
1834                    $excerpt_more = apply_filters('excerpt_more', ' ' . '[...]');
1835                    $words = preg_split("/[\n\r\t ]+/", $text, $excerpt_length + 1, PREG_SPLIT_NO_EMPTY);
1836                    if ( count($words) > $excerpt_length ) {
1837                            array_pop($words);
1838                            $text = implode(' ', $words);
1839                            $text = $text . $excerpt_more;
1840                    } else {
1841                            $text = implode(' ', $words);
1842                    }
1843            }
1844            return apply_filters('wp_trim_excerpt', $text, $raw_excerpt);
1845    }

You can see on line 1826 that it is linked to the $post global variable via get_the_contents. And yes, I have no idea what were they thinking. But from here, replace the get_the_content with $text in your own my_excerpt, and it should behave in a similar fashion.

如果$more！=0,则get_the_content()函数将返回完整内容. 您必须将全局变量$more设置为0,以确保get_the_content()函数返回摘录.

修改后的wp_trim_excerpt()函数:

 function wp_trim_excerpt($text) {
    $raw_excerpt = $text;
    if ( '' == $text ) {
        global $more;
        $tmp = $more;
        $more = 0;
        $text = get_the_content('');
        $more = $tmp;

        $text = strip_shortcodes( $text );

        $text = apply_filters('the_content', $text);
        $text = str_replace(']]>', ']]>', $text);
        $text = strip_tags($text);
        $excerpt_length = apply_filters('excerpt_length', 55);
        $excerpt_more = apply_filters('excerpt_more', ' ' . '[...]');
        $words = preg_split("/[\n\r\t ]+/", $text, $excerpt_length + 1, PREG_SPLIT_NO_EMPTY);
        if ( count($words) > $excerpt_length ) {
            array_pop($words);
            $text = implode(' ', $words);
            $text = $text . $excerpt_more;
        } else {
            $text = implode(' ', $words);
        }
    }
    return apply_filters('wp_trim_excerpt', $text, $raw_excerpt);
}
 

The get_the_content() function would return full content if $more != 0. You have to set global variable $more to 0 to make sure get_the_content() function return excerpt.

Modified wp_trim_excerpt() function:

function wp_trim_excerpt($text) {
    $raw_excerpt = $text;
    if ( '' == $text ) {
        global $more;
        $tmp = $more;
        $more = 0;
        $text = get_the_content('');
        $more = $tmp;

        $text = strip_shortcodes( $text );

        $text = apply_filters('the_content', $text);
        $text = str_replace(']]>', ']]>', $text);
        $text = strip_tags($text);
        $excerpt_length = apply_filters('excerpt_length', 55);
        $excerpt_more = apply_filters('excerpt_more', ' ' . '[...]');
        $words = preg_split("/[\n\r\t ]+/", $text, $excerpt_length + 1, PREG_SPLIT_NO_EMPTY);
        if ( count($words) > $excerpt_length ) {
            array_pop($words);
            $text = implode(' ', $words);
            $text = $text . $excerpt_more;
        } else {
            $text = implode(' ', $words);
        }
    }
    return apply_filters('wp_trim_excerpt', $text, $raw_excerpt);
}

使用上面的其他答案,这是一个似乎很有效的简单答案:

 global $post;

$excerpt = apply_filters('get_the_excerpt', get_post_field('post_excerpt', $post->ID));

if ( $excerpt == '' ) {
    $excerpt = wp_trim_words( $post->post_content, 55 );
}
 

我在函数的<meta>标记中使用它来定义OpenGraph描述.因此,我只需添加:

 <meta property="og:description" content="<?php echo esc_html( $excerpt ); ?>" />
 

Using others' answers above, here's a simpler answer that seems to work well:

global $post;

$excerpt = apply_filters('get_the_excerpt', get_post_field('post_excerpt', $post->ID));

if ( $excerpt == '' ) {
    $excerpt = wp_trim_words( $post->post_content, 55 );
}

I'm using it in the <meta> tags in a function to define OpenGraph descriptions. So then I just add:

<meta property="og:description" content="<?php echo esc_html( $excerpt ); ?>" />