Ruby on Rails: how to render a string as HTML?

Security essentials: sanitization

The sanitize method is your shield against potential security threats when rendering HTML. This Rails method cleanses user-provided HTML, helping to defend against cross-site scripting (XSS) attacks:

<%= sanitize @your_string %>
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Also, to side-step problems associated with HTML attribute manipulation, replace unescaped double quotes:

<%== @str.gsub(/"/, '&quot;') %>
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When JavaScript enters the chat

JavaScript is potent for injecting dynamic HTML. Libraries, such as jQuery, are built to handle such tasks efficiently:

$('#element').html('<strong>Dynamic Content</strong>');
// If you can inject HTML code, you're probably a wizard. 🧙‍♀️
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Although JavaScript is a powerhouse, sometimes you might be looking for JS-free methods, which can outperform in specific use-cases.

Newlines to paragraphs: using simple_format

The simple_format helper is a pipeline, converting newlines (\n) into HTML paragraph tags:

<%= simple_format @your_string %>
// From '\n' to '<p>', a true Cinderella story. 👸
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This method is perfect for user-generated content where preserving basic formatting is critical.

Unleashing power with Erubis

The Erubis gem is a magical extension of Rails, furnishing you with advanced HTML rendering capabilities:

eruby = Erubis::Eruby.new("Your string: <%== @your_string %>")
puts eruby.result(binding())
// Print HTML like your life depends on it. 💃
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If you are dealing with complex rendering scenarios, exploratory voyages into such gem-specific features can yield exceptional results.

Principles of clarity in design

It's essential to keep your HTML and Ruby code distinct for readability and ease of modification. Rails gutters this boundary by using ERB tags such as <%= to output HTML:

<%= link_to 'Home', root_path %>
// Who knew HTML and Ruby could be friends?
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Handy Rails helpers, such as link_to, provide seamless integration of Ruby within HTML, ensuring safe rendering while avoiding spaghetti code.

Ensuring correct HTML display

If raw and simple_format helpers appear insufficient, perform manual escape of HTML for an accurate display:

<%= @your_string.gsub('<', '&lt;').gsub('>', '&gt;') %>
// '<' and '>' become '&lt;' and '&gt;', kindergarten level HTML magic 🎩 
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This manual intervention provides granular control and is necessary in intricate rendering contexts.

Exploring alternative solutions

The Rails community is incredibly diverse, providing diverse insights into HTML rendering. Exploring alternative solutions on forums like Stack Overflow can open doors to unique perspectives.