Regular Bootstrap supports animated progress bars.
Are you sure that you correctly imported Boostrap files? I think you might have included only the CSS file but not the JS. Take a look at the basic template to see which files you should include.
Take also a look at the uib-progressbar documentation. The code snippet you wrote seems to be correct. As I said, I think the reason for this problem is that you didn't include the JS file for Bootstrap.
EDIT: Oh, ui-bootstrap apparently doesn't need Bootstrap's JS, you're right.
Regarding the min-width part of your question: I noticed that you added the progress-bar class to the <uib-progressbar> element. According to the documentation, the progress-bar class should not be used (it will be added by ui-bootstrap to the <div> element that will be rendered inside <uib-progressbar>, and you can easily verify this by inspecting the progress bar width devtools).
Thus, the min-width property is to be applied to the internal <div>. However, since the rendering is managed by angular, the only way to change it is to add a CSS rule like this:
.setminwidth .progress-bar {
min-width: 20em;
}
And then add the new setminwidth class to the external <uib-element> like this:
<uib-progressbar class="progress-striped setminwidth" value="22" type="warning">22%</uib-progressbar>
I tested this but it doesn't seem to work. I think it's because min-width: 0; is hardcoded in the template, and it gets reset everytime ui-bootstrap re-renders the element.
I tried adding !important to the CSS rule, to avoid being overridden, but it doesn't work either.
I guess at this point you should consider why you need to add this min-width property, since ui-bootstrap likes to override it. Could it be because you don't want the progress bar to be "too empty" when the % is low? If that's the case, I think you should look up the changes recently introduced by Bootstrap: it seems that now they add a special min-width for 0%, 1% and 2%.
UPD: The Bootstrap folks apparently changed their mind and reverted the special min-width value. At this point, I think that ui-bootstrap should follow along and remove the hardcoded min-width: 0; as it's not needed anymore. I just sent a pull-request to them. If they merge it, you will be able to use the CSS I posted above.
