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image_downsize › WordPress Function

Since2.5.0
已弃用n/a
image_downsize ( $id, $size = 'medium' )
参数: (2)
  • (int) $id Attachment ID for image.
    Required: Yes
  • (string|int[]) $size Optional. Image size. Accepts any registered image size name, or an array of width and height values in pixels (in that order). Default 'medium'.
    Required: No
    默认: 'medium'
返回:
  • (array|false) { Array of image data, or boolean false if no image is available. @type string $0 Image source URL. @type int $1 Image width in pixels. @type int $2 Image height in pixels. @type bool $3 Whether the image is a resized image. }
定义在:
文档:

Scales an image to fit a particular size (such as 'thumb' or 'medium').

The URL might be the original image, or it might be a resized version. This function won't create a new resized copy, it will just return an already resized one if it exists. A plugin may use the {@see 'image_downsize'} filter to hook into and offer image resizing services for images. The hook must return an array with the same elements that are normally returned from the function.


源码

function image_downsize( $id, $size = 'medium' ) {
	$is_image = wp_attachment_is_image( $id );

	/**
	 * Filters whether to preempt the output of image_downsize().
	 *
	 * Returning a truthy value from the filter will effectively short-circuit
	 * down-sizing the image, returning that value instead.
	 *
	 * @since 2.5.0
	 *
	 * @param bool|array   $downsize Whether to short-circuit the image downsize.
	 * @param int          $id       Attachment ID for image.
	 * @param string|int[] $size     Requested image size. Can be any registered image size name, or
	 *                               an array of width and height values in pixels (in that order).
	 */
	$out = apply_filters( 'image_downsize', false, $id, $size );

	if ( $out ) {
		return $out;
	}

	$img_url          = wp_get_attachment_url( $id );
	$meta             = wp_get_attachment_metadata( $id );
	$width            = 0;
	$height           = 0;
	$is_intermediate  = false;
	$img_url_basename = wp_basename( $img_url );

	/*
	 * If the file isn't an image, attempt to replace its URL with a rendered image from its meta.
	 * Otherwise, a non-image type could be returned.
	 */
	if ( ! $is_image ) {
		if ( ! empty( $meta['sizes']['full'] ) ) {
			$img_url          = str_replace( $img_url_basename, $meta['sizes']['full']['file'], $img_url );
			$img_url_basename = $meta['sizes']['full']['file'];
			$width            = $meta['sizes']['full']['width'];
			$height           = $meta['sizes']['full']['height'];
		} else {
			return false;
		}
	}

	// Try for a new style intermediate size.
	$intermediate = image_get_intermediate_size( $id, $size );

	if ( $intermediate ) {
		$img_url         = str_replace( $img_url_basename, $intermediate['file'], $img_url );
		$width           = $intermediate['width'];
		$height          = $intermediate['height'];
		$is_intermediate = true;
	} elseif ( 'thumbnail' === $size && ! empty( $meta['thumb'] ) && is_string( $meta['thumb'] ) ) {
		// Fall back to the old thumbnail.
		$imagefile = get_attached_file( $id );
		$thumbfile = str_replace( wp_basename( $imagefile ), wp_basename( $meta['thumb'] ), $imagefile );

		if ( file_exists( $thumbfile ) ) {
			$info = wp_getimagesize( $thumbfile );

			if ( $info ) {
				$img_url         = str_replace( $img_url_basename, wp_basename( $thumbfile ), $img_url );
				$width           = $info[0];
				$height          = $info[1];
				$is_intermediate = true;
			}
		}
	}

	if ( ! $width && ! $height && isset( $meta['width'], $meta['height'] ) ) {
		// Any other type: use the real image.
		$width  = $meta['width'];
		$height = $meta['height'];
	}

	if ( $img_url ) {
		// We have the actual image size, but might need to further constrain it if content_width is narrower.
		list( $width, $height ) = image_constrain_size_for_editor( $width, $height, $size );

		return array( $img_url, $width, $height, $is_intermediate );
	}

	return false;
}