Bootstrap4 make all input-group-addons same width

问题:

Is it possible to make all prepend add-ons same width?

i.e in this screenshot I would like Email, License Key 1 & License Key 2 to be the same length, is that possible.

If I did not use add-ons and just used regular labels and a form grid it would be possible but it seems to be the prepend addons look much nicer then regular labels.

Relevant Html is

<main class="container-fluid">
  <form action="/license.process" name="process" id="process" method="post">
      <div class="input-group mb-2">
          <div class="input-group-prepend">
              <label class="input-group-text" id="licenseEmaillabel">
                  Email
              </label>
          </div>
          <input type="text" name="licenseEmail" value="[e-mail]" class="form-control" aria-describedby="licenseEmaillabel">
      </div>
      <div class="input-group mb-2">
          <div class="input-group-prepend">
              <label class="input-group-text" id="licenseKey1label">
                  License Key 1
              </label>
          </div>
          <input type="text" name="licenseKey1" value="51302c021440d595c860233f136731865a12cfad2ce2cc2" class="form-control" aria-describedby="licenseKey1label">
      </div>
      <div class="input-group mb-2">
          <div class="input-group-prepend">
              <label class="input-group-text" id="licenseKey2label">
                  License Key 2
              </label>
          </div>
          <input type="text" name="licenseKey2" value="1e50214376557ba3e1dede6c490f33d07b738515c8c2a03" class="form-control" aria-describedby="licenseKey2label">
      </div>
      <h3 class="error" style="visibility:hidden;">
          &nbsp;
      </h3>
      <input type="submit" name="cancel" value="Cancel" class="btn btn-outline-secondary">
      <input type="submit" name="save" value="Save" class="btn btn-outline-secondary">
      <button onclick="j2html.tags.UnescapedText@d352d4f" type="button" class="btn btn-outline-secondary">
          Get License
      </button>
  </form>
</main>

回答1:

So this is actually pretty complicated, because each label is in it's own div and not part of a sibling chain. And afaik, Bootstrap does not support this type of sizing, only relative sizing form classes (which essentially only makes the font bigger). That kind of eliminates most possibilities that I can think of using flex/child properties. However, I think hard-coding is not the right word usage in this circumstance. But the idea is the same.

The example of using min-width is not right in this circumstance because min-width !== width=xx. For example, if you set min-width to 50px, but 1 string of text is longer than that, you still have the same problem as above. Essentially, if you don't want to set them all to one specific value, then your only other option is to use Javascript.

Here is my pure CSS workaround:

.input-group-prepend {
  width : 35%; /*adjust as needed*/
}

.input-group-prepend label {
  width: 100%;
  overflow: hidden;
}

---

Additionally you could use Boostrap specific inline styling classes, but that's arbitrary and one of the issues with Bootstrap (too many inline classes clutter code, and then you would have to manually add it to each element). Just offering it as an alternative

For example:

<div class="input-group-prepend w-50"> /* grows to 50% of parent*/
  <label class="input-group-text w-100" id="licenseEmaillabel"> /* grows to 100% of parent */

回答2:

Using jquery you could do something like this:

var biggest = Math.max.apply(Math, $('.input-group-text').map(function(){ return $(this).width(); }).get());
$('.input-group-text').width(biggest);

Math.max.apply reads all .input-group-text widths and returns the biggest one. The next line applies this width to all .input-group-text divs.

Sources: jquery-get-max-width-of-child-divs

回答3:

Just using the bootstrap classes:

<div class="input-group">
    <div class="input-group-prepend col-3">
        <span class="input-group-text col-12">Name:</span>
    </div>
    <input type="text" class="form-control" placeholder="Name">
</div>
<div class="input-group">
    <div class="input-group-prepend col-3">
        <span class="input-group-text col-12">Address 1:</span>
    </div>
    <input type="text" class="form-control" placeholder="Street Address">
</div>

Looks like this: