Class VmlHelper

java.lang.Object

dev.jcputney.mjml.render.VmlHelper

public final class VmlHelper
extends Object

Helper for generating Outlook VML (Vector Markup Language) for background images. Outlook doesn't support CSS background-image, so VML is needed for background images in sections, wrappers, and hero components.

MjSection and MjWrapper produce different VML output:

• MjSection uses percent-based origin formulas with auto/repeat/no-repeat modes
• MjWrapper always uses tile with simple keyword mapping (cssAxisToVml)

Method Summary

Modifier and Type	Method	Description
static String	buildSectionVmlRect(String widthStyle, String bgUrl, String bgColor, String bgPosition, String bgSize, String bgRepeat)	Builds VML rect markup for MjSection background image support in MSO/Outlook.
static String	buildWrapperVmlRect(String widthStyle, String bgUrl, String bgColor, String bgPosition, String bgSize)	Builds VML rect markup for MjWrapper background image support in MSO/Outlook.
static String	cssAxisToVml(String value)	Maps a CSS axis keyword to a VML coordinate value.
static double	cssPositionToPercent(String value, boolean isX)	Converts a CSS position keyword or percentage to a percentage value.
static String	formatVmlCoord(double value)	Formats a VML coordinate value.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

buildSectionVmlRect

public static String buildSectionVmlRect(String widthStyle,
 String bgUrl,
 String bgColor,
 String bgPosition,
 String bgSize,
 String bgRepeat)

Builds VML rect markup for MjSection background image support in MSO/Outlook. Follows the official MJML algorithm for computing VML origin/position/type.

Parameters:

widthStyle - the CSS width style (e.g. "600px" or "mso-width-percent:1000;")

bgUrl - the background image URL

bgColor - the fallback background color (may be null/empty)

bgPosition - resolved CSS background-position (e.g. "center top")

bgSize - CSS background-size value (e.g. "auto", "cover", "contain")

bgRepeat - CSS background-repeat value (e.g. "repeat", "no-repeat")

Returns:

the VML rect markup string for section background rendering in Outlook

buildWrapperVmlRect

public static String buildWrapperVmlRect(String widthStyle,
 String bgUrl,
 String bgColor,
 String bgPosition,
 String bgSize)

Builds VML rect markup for MjWrapper background image support in MSO/Outlook. Simpler than section: always uses tile type with keyword-based origin mapping.

Parameters:

widthStyle - the CSS width style (e.g. "600px" or "mso-width-percent:1000;")

bgUrl - the background image URL

bgColor - the fallback background color (may be null/empty)

bgPosition - resolved CSS background-position (e.g. "center top")

bgSize - CSS background-size value (e.g. "auto", "cover", "contain")

Returns:

the VML rect markup string for wrapper background rendering in Outlook

cssPositionToPercent

public static double cssPositionToPercent(String value,
 boolean isX)

Converts a CSS position keyword or percentage to a percentage value.

Parameters:

value - the CSS position keyword (e.g. "left", "center", "right") or percentage string

isX - true if this is for the X axis, false for Y axis

Returns:

the corresponding percentage value (0-100)

formatVmlCoord

public static String formatVmlCoord(double value)

Formats a VML coordinate value. Integers are rendered without decimals.

Parameters:

value - the numeric coordinate value to format

Returns:

the formatted coordinate string

cssAxisToVml

public static String cssAxisToVml(String value)

Maps a CSS axis keyword to a VML coordinate value.

Parameters:

value - the CSS axis keyword (e.g. "left", "center", "right", "top", "bottom")

Returns:

the VML coordinate string ("0", "0.5", or "1")