How to get SimplePie fetch_feed without stripping iframe code?

Question

How to get SimplePie fetch_feed without stripping iframe code?

johnh10

2021年2月8日 05:58

I'm grabbing a remote feed in my plugin and some entries have iframe code I want to keep. However, SimplePie fetch_feed keeps stripping it out. Here is my code and what I've tried already:

kses_remove_filters(); # remove kses filters but SimplePie strips codes anyway
$rss = fetch_feed( 'http://www.someblog.com/feed/' );
$rss_items = $rss-get_items( 0, 2 );  # get two entries for this example
foreach ( $rss_items as $item ) {
    # just dump to screen:
    echo "div id='message' class='updated'p" .  $item-get_content() . "/p/div";
}
kses_init_filters(); # remove kses filters but SimplePie strips codes anyway


# also tried adding iframe to kses_allowed_html filter:
function se87359_add_filter( $feed, $url ) {
    add_filter('wp_kses_allowed_html', 'se87359_add_allowed_tags');
}
add_filter( 'wp_feed_options', 'se87359_add_filter', 10, 2 );
function se87359_add_allowed_tags($tags) {
    // Ensure we remove it so it doesn't run on anything else
    remove_filter('wp_kses_allowed_html', 'se87359_add_allowed_tags');
    $tags['iframe'] = array(
    'src' = true,
    'width' = true,
    'height' = true,
    'class' = true,
    'frameborder' = true,
    'webkitAllowFullScreen' = true,
    'mozallowfullscreen' = true,
    'allowFullScreen' = true
    );
    return $tags;
}

# also made sure not to cache the feed (for testing only):
function do_not_cache_feeds($feed) {
    $feed-enable_cache(false);
}
add_action( 'wp_feed_options', 'do_not_cache_feeds' );

# in case above doesn't work, set transient lifetime to 1 second:
add_filter( 'wp_feed_cache_transient_lifetime', create_function( '$a', 'return 1;' ) );

Topic wp-kses iframe feed rss Wordpress

Category Web

Cubakos · Accepted Answer · 2021年2月8日 05:58

From the SimplePie docs here: there is a strip_htmltags property in the SimplePie object, which among others it has the iframe tag we want to keep.

So, apart from the wp_kses, probably we want to remove the tag from the above property.

For instance, the $rss = fetch_feed( 'http://www.someblog.com/feed/' ); gives us the SimplePie object.

If we var_dump($rss)

or even better "pretty print" it by using:

highlight_string("<?php\n\$rss =\n" . var_export($rss, true) . ";\n?>");

we will see all fetched entries and all properties of the $rss object. Among those there is the one we are looking for, and we can isolate it by using:

highlight_string("<?php\n\$rss->strip_htmltags =\n" . var_export($rss->strip_htmltags, true) . ";\n?>");

this will give us something like the below:

<?php
    $rss->strip_htmltags =
      array (
        0 => 'base',
        1 => 'blink',
        2 => 'body',
        3 => 'doctype',
        4 => 'embed',
        5 => 'font',
        6 => 'form',
        7 => 'frame',
        8 => 'frameset',
        9 => 'html',
       10 => 'iframe',
       11 => 'input',
       12 => 'marquee',
       13 => 'meta',
       14 => 'noscript',
       15 => 'object',
       16 => 'param',
       17 => 'script',
       18 => 'style',
     );
?>

From the above we note that the key of the iframe entry is 10. So we use array_splice to remove the entry, like:

// Remove these tags from the list
$strip_htmltags = $rss->strip_htmltags; //get a copy of the strip entries array
array_splice($strip_htmltags, 10, 1); //remove the iframe entry
$rss->strip_htmltags = $strip_htmltags; // assign the strip entries without those we want

Now the iframe entry is out and of the $strip_htmltags property and probably we are set.

Notice: I couldn't find a "test" rss feed containing some iframe to test the above. So if anyone can verify it, please provide some feedback.

How to get SimplePie fetch_feed without stripping iframe code?

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