Stretched link (ストレッチリンク)

CSSでネストされたリンクを「Stretched link (ストレッチリンク) にすることで、任意のHTML要素やBootstrapコンポーネントをクリックできるようにします。

リンクに .stretch-link を追加して、::after 擬似要素を使ってそのリンクの containing block がクリックが可能になるようにします。ほとんどの場合、これは、 .stretched-linkクラスのリンクを含むposition：relative;の要素がクリック可能であることを意味します。

Bootstrapではデフォルトでカードに position：relativeがあるため、この場合、他のHTMLを変更せずに、カード内のリンクに .stretched-linkクラスを安全に追加できます。

複数のリンクやタップターゲットは、ストレッチリンクでは推奨されません。しかし、必要に応じて position や z-index スタイルを利用することができます。

Card with stretched link

Some quick example text to build on the card title and make up the bulk of the card's content.

Go somewhere

<div class="card" style="width: 18rem;">
  <img src="..." class="card-img-top" alt="...">
  <div class="card-body">
    <h5 class="card-title">Card with stretched link</h5>
    <p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's content.</p>
    <a href="#" class="btn btn-primary stretched-link">Go somewhere</a>
  </div>
</div>

ほとんどのカスタムコンポーネントはデフォルトで position: relative を持っていないので、リンクが親要素の外に伸びないようにするためにここに .position-relative を追加する必要があります。

Custom component with stretched link

This is some placeholder content for the custom component. It is intended to mimic what some real-world content would look like, and we're using it here to give the component a bit of body and size.

Go somewhere

<div class="d-flex position-relative">
  <img src="..." class="flex-shrink-0 me-3" alt="...">
  <div>
    <h5 class="mt-0">Custom component with stretched link</h5>
    <p>This is some placeholder content for the custom component. It is intended to mimic what some real-world content would look like, and we're using it here to give the component a bit of body and size.</p>
    <a href="#" class="stretched-link">Go somewhere</a>
  </div>
</div>

Columns with stretched link

Another instance of placeholder content for this other custom component. It is intended to mimic what some real-world content would look like, and we're using it here to give the component a bit of body and size.

Go somewhere

<div class="row g-0 bg-light position-relative">
  <div class="col-md-6 mb-md-0 p-md-4">
    <img src="..." class="w-100" alt="...">
  </div>
  <div class="col-md-6 p-4 ps-md-0">
    <h5 class="mt-0">Columns with stretched link</h5>
    <p>Another instance of placeholder content for this other custom component. It is intended to mimic what some real-world content would look like, and we're using it here to give the component a bit of body and size.</p>
    <a href="#" class="stretched-link">Go somewhere</a>
  </div>
</div>

Identifying the containing block

伸びたリンクがうまくいかないようであれば、containing blockが原因ではないかと思います。

以下のCSSプロパティで要素を content blockにします。

A position value other than static
A transform or perspective value other than none
A will-change value of transform or perspective
A filter value other than none or a will-change value of filter (only works on Firefox)

Card with stretched links

Some quick example text to build on the card title and make up the bulk of the card's content.

Stretched link will not work here, because position: relative is added to the link

This stretched link will only be spread over the p-tag, because a transform is applied to it.

<div class="card" style="width: 18rem;">
  <img src="..." class="card-img-top" alt="...">
  <div class="card-body">
    <h5 class="card-title">Card with stretched links</h5>
    <p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's content.</p>
    <p class="card-text">
      <a href="#" class="stretched-link text-danger" style="position: relative;">Stretched link will not work here, because <code>position: relative</code> is added to the link</a>
    </p>
    <p class="card-text bg-light" style="transform: rotate(0);">
      This <a href="#" class="text-warning stretched-link">stretched link</a> will only be spread over the <code>p</code>-tag, because a transform is applied to it.
    </p>
  </div>
</div>