css - Use justify-content: flex-end and to have vertical scrollbar

Question

I have chat and I need to scroll all content to bottom. I want to use justify-content: flex-end and to have vertical scrollbar.

.session-textchat {
  height: 320px;
  background: #fff;
  display: -webkit-flex;
  display: flex;
  -webkit-align-items: flex-end;
  align-items: flex-end;
  -webkit-justify-content: space-between;
  justify-content: space-between;
  -webkit-flex-direction: column;
  flex-direction: column;
}
.session-textchat .past-messages {
  width: 100%;
  max-width: 980px;
  margin: 0 auto;
  height: 83.92%;
  overflow-y: auto;
  padding: 30px 0 0;
  display: -webkit-flex;
  display: flex;
  -webkit-align-items: flex-end;
  align-items: flex-end;
  -webkit-justify-content: flex-end;
  justify-content: flex-end;
  -webkit-flex-direction: column;
  flex-direction: column;
}
.session-textchat .past-messages .receiver,
.session-textchat .past-messages .sender {
  width: 100%;
  min-height: 47px;
  margin: 0 0 20px;
  display: -webkit-flex;
  display: flex;
  -webkit-flex-direction: row;
  flex-direction: row;
}
.session-textchat .past-messages .receiver .message,
.session-textchat .past-messages .sender .message {
  position: relative;
  padding: 17px;
  -moz-border-radius: 4px;
  -webkit-border-radius: 4px;
  border-radius: 4px;
}
.session-textchat .past-messages .receiver {
  text-align: left;
  -webkit-justify-content: flex-start;
  justify-content: flex-start;
}
.session-textchat .past-messages .receiver .message {
  background: #f4f4f4;
  color: #535353;
}
.session-textchat .past-messages .sender {
  text-align: right;
  -webkit-justify-content: flex-end;
  justify-content: flex-end;
}
.session-textchat .past-messages .sender .message {
  background: url('../img/rgbapng/0050ff26.png');
  background: rgba(0, 80, 255, 0.15);
  color: #0050ff;
}

<div class="session-textchat">
  <div class="past-messages">
    <div class="receiver">
      <span class="message">
            Good afternoon David. Welcome to your appointment! How are you today?
          </span>
    </div>
    <div class="sender">
      <span class="message">
            Hello doctor. I feel terrible to be honest.
          </span>
    </div>
    <div class="receiver">
      <span class="message">
            I can see from your notes that you've been having some ear ache - can you tell me a bit more about your symptoms?
          </span>
    </div>
    <div class="sender">
      <span class="message">
            Hello doctor. I feel terrible to be honest.
          </span>
    </div>
    <div class="receiver">
      <span class="message">
            I can see from your notes that you've been having some ear ache - can you tell me a bit more about your symptoms?
          </span>
    </div>
  </div>
</div>

Answer 1

I just had to face this issue myself and, after concluding it is a bug, I came up with a workaround.

In summary, don't use justify-content: flex-end but rather put a margin-top: auto on the first child. Unlike flex-end this doesn't break the scrollbar functionality, and it bottom-aligns the contents when they're not overflowing the container.

Example based on @SrdjanDejanovic's fiddle is at https://jsfiddle.net/peter9477/4t5r0t5b/

In case the example isn't available, here's the relevant CSS:

#container {
    overflow-y: auto;
    display: flex;
    flex-flow: column nowrap;
    /* justify-content: flex-end; DO NOT USE: breaks scrolling */
}
#container > :first-child {
    margin-top: auto !important;
    /* use !important to prevent breakage from child margin settings */
}

An alternative workaround that I believe I've also used is to add an extra container for the scrollbar. Use the flex-end on the inner container and have the outer container handle the scrolling. I generally dislike workarounds that require adding dummy elements though, so I prefer my CSS-only solution above.