Pen Settings

HTML

CSS

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

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JavaScript

Babel is required to process package imports. If you need a different preprocessor remove all packages first.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

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Behavior

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Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

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Visit your global Editor Settings.

HTML

              
                <h2>Basic Code Block</h2>
<div class="highlight">
  <pre class="chroma">
    <code class="language-python" data-lang="python">
def test_new_user(db, email, password):
    new_user = User(email=email, password=password)
    db.session.add(new_user)
    db.session.commit()
    user_exists = User.query.filter_by(email=email).first()
    assert user_exists
    </code>
  </pre>
</div>

<h2>Code Block with Line Numbers</h2>
<div class="highlight">
  <div class="chroma">
    <table class="lntable">
      <tbody>
        <tr>
          <td class="lntd">
            <pre class="chroma"><code>1
2
3
4
5
6
7
8
9
10</code></pre>
          </td>
          <td class="lntd">
            <pre class="chroma">
              <code class="language-python" data-lang="python">
import os

from flask_api_tutorial import create_app, db

app = create_app(os.getenv("FLASK_ENV", "development"))


@app.shell_context_processor
def shell():
    return {"db": db}</code>
            </pre>
          </td>
        </tr>
      </tbody>
    </table>
  </div>
              
            
!

CSS

              
                .highlight-wrapper {
  display: block;
}

.highlight {
  position: relative;
  z-index: 0;
  padding: 0;
  margin: 0;
  border-radius: 4px;
}

.highlight > .chroma {
  color: #d0d0d0;
  background-color: #212121;
  position: static;
  z-index: 1;
  border-radius: 4px;
  padding: 10px;
}

.chroma {
  overflow: auto;
}

.chroma .lntable {
  display: table;
  width: 100%;
  padding: 0 0 5px;
  margin: 0;
  border-spacing: 0;
  border: 0;
  overflow: auto;
}

.chroma .lntd:first-child {
  padding: 7px 7px 7px 10px;
  margin: 0;
}

.chroma .lntd:last-child {
  padding: 7px 10px 7px 7px;
  margin: 0;
}

.copy-code-button {
  position: absolute;
  z-index: 2;
  right: 0;
  top: 0;
  font-size: 13px;
  font-weight: 700;
  line-height: 14px;
  width: 65px;
  color: #232326;
  background-color: #7f7f7f;
  border: 1.25px solid #232326;
  border-top-left-radius: 0;
  border-top-right-radius: 4px;
  border-bottom-right-radius: 0;
  border-bottom-left-radius: 4px;
  white-space: nowrap;
  padding: 4px 4px 5px 4px;
  margin: 0 0 0 1px;
  cursor: pointer;
  opacity: 0.6;
}

.copy-code-button:hover,
.copy-code-button:focus,
.copy-code-button:active,
.copy-code-button:active:hover {
  color: #222225;
  background-color: #b3b3b3;
  opacity: 0.8;
}

.copyable-text-area {
  position: absolute;
  height: 0;
  z-index: -1;
  opacity: 0.01;
}

              
            
!

JS

              
                function createCopyButton(highlightDiv) {
  const button = document.createElement("button");
  button.className = "copy-code-button";
  button.type = "button";
  button.innerText = "Copy";
  button.addEventListener("click", () =>
    copyCodeToClipboard(button, highlightDiv)
  );
  addCopyButtonToDom(button, highlightDiv);
}

async function copyCodeToClipboard(button, highlightDiv) {
  const codeToCopy = highlightDiv.querySelector(":last-child > .chroma > code")
    .innerText;
  try {
    result = await navigator.permissions.query({ name: "clipboard-write" });
    if (result.state == "granted" || result.state == "prompt") {
      await navigator.clipboard.writeText(codeToCopy);
    } else {
      copyCodeBlockExecCommand(codeToCopy, highlightDiv);
    }
  } catch (_) {
    copyCodeBlockExecCommand(codeToCopy, highlightDiv);
  } finally {
    codeWasCopied(button);
  }
}

function copyCodeBlockExecCommand(codeToCopy, highlightDiv) {
  const textArea = document.createElement("textArea");
  textArea.contentEditable = "true";
  textArea.readOnly = "false";
  textArea.className = "copyable-text-area";
  textArea.value = codeToCopy;
  highlightDiv.insertBefore(textArea, highlightDiv.firstChild);
  const range = document.createRange();
  range.selectNodeContents(textArea);
  const sel = window.getSelection();
  sel.removeAllRanges();
  sel.addRange(range);
  textArea.setSelectionRange(0, 999999);
  document.execCommand("copy");
  highlightDiv.removeChild(textArea);
}

function codeWasCopied(button) {
  button.blur();
  button.innerText = "Copied!";
  setTimeout(function () {
    button.innerText = "Copy";
  }, 2000);
}

function addCopyButtonToDom(button, highlightDiv) {
  highlightDiv.insertBefore(button, highlightDiv.firstChild);
  const wrapper = document.createElement("div");
  wrapper.className = "highlight-wrapper";
  highlightDiv.parentNode.insertBefore(wrapper, highlightDiv);
  wrapper.appendChild(highlightDiv);
}

document
  .querySelectorAll(".highlight")
  .forEach((highlightDiv) => createCopyButton(highlightDiv));

              
            
!
999px

Console