Allow UTF-8 Encodings for SVGs in add_menu_page

[sahil-gidwani]

Trac Ticket: https://core.trac.wordpress.org/ticket/55543

Allow Additional Encodings for SVGs in add_menu_page

This PR improves the handling of SVGs in add_menu_page by allowing additional encoding formats beyond Base64. Previously, the function only checked for data:image/svg+xml;base64,, but SVGs don’t need to be Base64-encoded. This update introduces support for data:image/svg+xml;utf8, encoding and provides a more flexible approach to validating and sanitizing SVGs.

Changes Introduced

• Extended Encoding Support:

  • Added support for data:image/svg+xml;utf8, SVG encoding.
  • Ensures proper sanitization and rendering of inline SVGs.

• Enhanced SVG Sanitization:

  • Created a more comprehensive list of allowed SVG attributes and elements, including common tags like <g>, <path>, <circle>, <text>, and gradients.
  • Uses wp_kses_allowed_html( 'post' ) as the base and extends it with the new SVG attributes.

• Improved Rendering & Styling:

  • Introduced a wrapper <div class="inline-svg-container"> to encapsulate the inline SVGs.
  • Added CSS styles to ensure proper scaling and display inside the WordPress admin menu.

Why This Change?

• More Efficient & Flexible SVG Handling:

  • Avoids unnecessary Base64 encoding, which increases the file size and reduces readability.
  • Ensures WordPress menus can support different encoding methods for SVGs.

• Security & Compatibility:

  • The SVG sanitization method (wp_kses) ensures safe and controlled rendering of inline SVGs.
  • Maintains backward compatibility while expanding support for other encoding types.

Potential Impact & Compatibility

• No breaking changes—existing Base64-encoded SVGs will continue to work.
• Enhances compatibility for developers using inline SVGs in WordPress menus.

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