No. You can just add two RT in the CMS Collection List Item and link them to the same field. You can limit the height of the first one to break the text, and use a custom code with the CSS property {text-overflow:ellipsis;}
so you get an automatic ellipsis ("…") where the text breaks.
If you had to add a field, you would name this field “Teaser text” and craft a special short text for this need to prevent it to break. IMHO that’s better than having a text to overflow, but for as we’re talking about reproducing the Quora thing…
You’ll pay attention to give both RT fields the same paddings and margin, so that when one replaces the other, it’s seamless and doesn’t provoke a “jump” of the design.
Also I forgot to account for the “read more” link in my scenario, here is an update:
- hide the limited RT element, hide the “read more link”, and show the full RT element instead, all at the same time
- at the same time too, make the teaser image change dimensions (don’t scale it, make its dimensions change, so the content below takes its size into account) and change its alignment (from position absolute to position relative.
Yes, you wouldn’t be able to easily control an image in the RT (you could, with CSS custom code, target it to style it, with a CSS rule such as “target the next image inside the RT”, but you wouldn’t be able to target it with IX without advanced and counter productive JS). Anyway, having a CMS image field for a teaser image in an article-based site is really a good practice. It allows you to illustrate teasers.
So in the teaser mode, you have the image set at position absolute and you manually place it there, and in the full node view you change its position to static or relative and it goes back in the flow of elements, that is just before the RT. Don’t forget to select the image element, the one you’ll target with the IX, and give it Transition on position, in the Style tab. I don’t know if it’s really going to animate… I have to check a few things with IX2.
Oh, and you have to think about your structure. When you will click on read more, you don’t want all the teaser items of the page to unfold, so you have to somehow limit the interaction effect. You must be able to limit it to siblings of the trigger, which in our case is the case (“read more” is at the same level than your image and your Rts)