How do I preserve line breaks when getting text from a textarea?

Ensuring compatibility and safety across browsers

Catering to good-old browsers

Simpler, supported methods like appendChild() and insertBefore() can handle things gracefully when dealing with text manipulation in older browsers:

var div = document.createElement('div');  // a home for our content
div.innerHTML = content;  // decorate the home!
document.body.appendChild(div); // release into the wild, go forth!
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Guarding against HTML injection

Protection against malicious HTML injections is crucial. Use .textContent instead of .innerHTML when appending user-generated content:

var textNode = document.createTextNode(content); // innocuous content turned into a text node
containerElement.appendChild(textNode); // like adopting one more pet
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Controlling whitespace and newline characters

Fine-grained control over white space (spaces, tabs, newlines) is possible via the CSS white-space property:

pre {
  white-space: pre; /* Put white space in the corner, don't let it run around carelessly */
}
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Preserving formatting upon copying

Make use of a button with an onclick event to copy formatted content from the <textarea> to a display element:

<button onclick="keepTheBeauty()">Copy The Beautiful Text</button>
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Embed this in your JavaScript code:

function keepTheBeauty() {
  var textareaStory = document.getElementById('textareaID').value;
  var formattedStory = textareaStory.replace(/\n/g, '<br>'); // beautify the story
  document.getElementById('storyDisplayID').innerHTML = formattedStory; // storytelling time
}
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Dicing text into lines

Occasionally, we need to handle text one line at a time. Thanks to split('\n') combined with a loop, you can do just that:

var lines = textareaStory.split('\n'); // chop 'textareaStory' into lines
lines.forEach(function(line) {
  // enjoy each line like a slice of cheesecake
});
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This approach gives granular control, ideal for sophisticated text processing.

Alternatives and special considerations

Utilizing <pre> instead of replacements

Rather than converting newlines to <br>, consider embedding the output within the <pre> tags:

<pre id="output"></pre>
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Set the textContent as the value of the textarea:

document.getElementById('output').textContent = textareaStory;
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Keeping format in real-time

Preserving live formatting requires attaching event listeners to the textarea, activated on the user's input:

document.getElementById('textareaID').addEventListener('input', function() {
  // Function to preserve formatting
});
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Considering trade-offs

Depending on the scenario, <pre>, regular expressions, and JavaScript .replace() each have their own strengths and weaknesses:

• Readability: <pre> tag can be a more readable solution.
• Performance: Regular expressions can provide better performance for large text bodies.
• Maintainability: It's always a good idea to keep solutions simple and straightforward for future updates.

Test the different solutions across browsers and scenarios to ensure robust implementation.