How to word-break text in a flex display when the text is long?

Question

I need to make a responsive web, so that the width of parent is dynamic. There are two flex items, one is long (dynamic) and another one is short (static).

I hope the result can look like the second line, that the long text is broken (or hidden when overlap), and the short text is always displayed correctly.

I tried to use flex-shrink: 0 but seems there is always an overflow.

How can I get rid of the overflow in this case?

I do need flex layout, and the js should not be involved.

.parent {
  display: flex;
  flex-direction: row;
  width: 15rem;
  background: yellowgreen;
  padding: 10px;
  overflow: hidden;
}
.flex-item {
  width: 10em;
  padding: 10px;
  background: yellow;
  flex: 1 1 50%;
}
.block1 {
  background: red;
}
.block2 {
  background: orange;
}
.nos {
  flex-shrink: 0 !important;
}

<div class="parent">
  <div class="flex-item">
    <div class="block1">
      longlonglonglonglonglonglonglonglonglonglonglonglonglong
    </div>
  </div>
  <div class="flex-item nos">
    <div class="block2">
      Display
    </div>
  </div>
</div>
<br/>
<div class="parent">
  <div class="flex-item">
    <div class="block1">
      longlonglonglonglong...
    </div>
  </div>
  <div class="flex-item">
    <div class="block2">
      Display
    </div>
  </div>
</div>

https://jsfiddle.net/templefox/Lw3hhz8j/

Answer 1

just put word-break:break-all property to its parent div. You can see it live by clicking this JSFiddle link

Answer 2

.parent {
   display: flex;
   width: 15rem;
   padding: 10px;
   background: yellowgreen;
   /* overflow: hidden       <-- not necessary at this point */
   /* flex-direction: row    <-- default value; can be omitted */
}
.flex-item {
   /* width: 10em            <-- not necessary at this point */
   /* flex: 1 1 50%          <-- not necessary at this point */
   padding: 10px;
   background: yellow;
   display: flex;            /* new */
   min-width: 0;             /* see note #1 */

}
.block1 {
   width: 10em;
   overflow: hidden;         /* see note #2 */
   text-overflow: ellipsis;  /* see note #2 */
   white-space: nowrap;      /* see note #2 */
   background: red;
}
.block2 {
  background: orange;
}

/* .nos { flex-shrink: 0 !important; } */

<div class="parent">
  <div class="flex-item">
    <div class="block1">longlonglonglonglonglonglonglonglonglonglonglonglonglong</div>
  </div>
  <div class="flex-item">
    <div class="block2">Display</div>
  </div>
</div>
<br/>
<div class="parent">
  <div class="flex-item">
    <div class="block1">longlonglonglonglong...</div>
  </div>
  <div class="flex-item">
    <div class="block2">Display</div>
  </div>
</div>

revised fiddle

Notes:

1. Why doesn't flex item shrink past content size?
2. Applying an ellipsis to multiline text