Question

image_constrain_size_for_editor( int $width,  int $height,  string|array $size = 'medium',  string $context = null )

Scale down the default size of an image.

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description

This is so that the image is a better fit for the editor and theme.

The $size parameter accepts either an array or a string. The supported string values are ‘thumb’ or ‘thumbnail’ for the given thumbnail size or defaults at 128 width and 96 height in pixels. Also supported for the string value is ‘medium’, ‘medium_large’ and ‘full’. The ‘full’ isn’t actually supported, but any value other than the supported will result in the content_width size or 500 if that is not set.

Finally, there is a filter named ‘editor_max_image_size’, that will be called on the calculated array for width and height, respectively. The second parameter will be the value that was in the $size parameter. The returned type for the hook is an array with the width as the first element and the height as the second element.

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参数

$width

(int) (Required) Width of the image in pixels.

$height

(int) (Required) Height of the image in pixels.

$size

(string|array) (Optional) Image size. Accepts any valid image size, or an array of width and height values in pixels (in that order).

Default value: 'medium'

$context

(string) (Optional) Could be 'display' (like in a theme) or 'edit' (like inserting into an editor).

Default value: null

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返回值

(array) Width and height of what the result image should resize to.

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源代码

File: wp-includes/media.php

function image_constrain_size_for_editor( $width, $height, $size = 'medium', $context = null ) {
	global $content_width;

	$_wp_additional_image_sizes = wp_get_additional_image_sizes();

	if ( ! $context )
		$context = is_admin() ? 'edit' : 'display';

	if ( is_array($size) ) {
		$max_width = $size[0];
		$max_height = $size[1];
	}
	elseif ( $size == 'thumb' || $size == 'thumbnail' ) {
		$max_width = intval(get_option('thumbnail_size_w'));
		$max_height = intval(get_option('thumbnail_size_h'));
		// last chance thumbnail size defaults
		if ( !$max_width && !$max_height ) {
			$max_width = 128;
			$max_height = 96;
		}
	}
	elseif ( $size == 'medium' ) {
		$max_width = intval(get_option('medium_size_w'));
		$max_height = intval(get_option('medium_size_h'));

	}
	elseif ( $size == 'medium_large' ) {
		$max_width = intval( get_option( 'medium_large_size_w' ) );
		$max_height = intval( get_option( 'medium_large_size_h' ) );

		if ( intval( $content_width ) > 0 ) {
			$max_width = min( intval( $content_width ), $max_width );
		}
	}
	elseif ( $size == 'large' ) {
		/*
		 * We're inserting a large size image into the editor. If it's a really
		 * big image we'll scale it down to fit reasonably within the editor
		 * itself, and within the theme's content width if it's known. The user
		 * can resize it in the editor if they wish.
		 */
		$max_width = intval(get_option('large_size_w'));
		$max_height = intval(get_option('large_size_h'));
		if ( intval($content_width) > 0 ) {
			$max_width = min( intval($content_width), $max_width );
		}
	} elseif ( ! empty( $_wp_additional_image_sizes ) && in_array( $size, array_keys( $_wp_additional_image_sizes ) ) ) {
		$max_width = intval( $_wp_additional_image_sizes[$size]['width'] );
		$max_height = intval( $_wp_additional_image_sizes[$size]['height'] );
		// Only in admin. Assume that theme authors know what they're doing.
		if ( intval( $content_width ) > 0 && 'edit' === $context ) {
			$max_width = min( intval( $content_width ), $max_width );
		}
	}
	// $size == 'full' has no constraint
	else {
		$max_width = $width;
		$max_height = $height;
	}

	/**
	 * Filters the maximum image size dimensions for the editor.
	 *
	 * @since 2.5.0
	 *
	 * @param array        $max_image_size An array with the width as the first element,
	 *                                     and the height as the second element.
	 * @param string|array $size           Size of what the result image should be.
	 * @param string       $context        The context the image is being resized for.
	 *                                     Possible values are 'display' (like in a theme)
	 *                                     or 'edit' (like inserting into an editor).
	 */
	list( $max_width, $max_height ) = apply_filters( 'editor_max_image_size', array( $max_width, $max_height ), $size, $context );

	return wp_constrain_dimensions( $width, $height, $max_width, $max_height );
}

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更新日志

Version	description
2.5.0	Introduced.

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相关函数

Uses

• wp-includes/media.php: wp_get_additional_image_sizes()
• wp-includes/load.php: is_admin()
• wp-includes/plugin.php: apply_filters()
• wp-includes/option.php: get_option()
• wp-includes/media.php: wp_constrain_dimensions()
• wp-includes/media.php: editor_max_image_size
Show 1 more use Hide more uses

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Used By

• wp-includes/media.php: wp_prepare_attachment_for_js()
• wp-includes/media.php: image_get_intermediate_size()
• wp-includes/media.php: image_downsize()

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User Contributed Notes