paper-dropdown-menu | Dropdown wrapper for paper-menu | Menu library

Edit: Turns out, it helps if you import paper-listbox before using it in another element. For some reason I thought it was being imported as a dependency on another element I was importing, but no. As soon as I added the explicit import, it began working correctly. Original question follows.

To start, this problem only happens when using paper-dropdown-menu (with paper-listbox inside) in a lit-element. We're using the component in almost the exact same way in multiple PolymerElement(s) with no issues.

Basically, I'm seeing two issues with paper-dropdown-menu. The first is that it never displays a value of any type, whether the label attribute or an actual selected value, nor does its value property ever change, even when the paper-listbox inside has a set value. The second problem is that it appears to be impossible to select any value from the dropdown menu - you can click on them, but the list doesn't close, and the selected option name doesn't show up in the menu's text display.

Due to the nature of the issues, it appears as though the problem is that the paper-dropdown-menu and the paper-listbox inside of it aren't communicating properly... but I'll be damned if I can figure out why.

Here's the markup in question from the element's render method:

I've started the Polymer 3.0 Getting started tutorial and decided to play with it a bit. I have started a new project and I'm trying to add a paper-dropdown-menu to view1 that grabs data from an array.

view1.js:

after importing these:

I've been learning Polymer since 3 days ago and I'm stucked with Polymer Behaviours.

I've defined a Behaviour as you can see in the following code:

I recently updated my angular application from 2.0.1 to 4.0.0. The application is running but not displayed on browser. The errors seems to indicate Polymer issue. I tried to update bower dependencies but still got errors like following:

I have a web dev project that is built using the polymer-cli. On my local machine, when I run polymer build within the project folder, I am able to build the project successfully.

However, if I try to build the project on Jenkins, it fails with an 'Unable to load import' error. Here is the piece of console output that outlines the error

I am trying to fire a simple listen function on an iron-select event based on the selection of a value in a paper-dropdown-menu.

Here is my HTML's head

I am trying to round the corners of a paper-listbox, which is contained in a paper-dropdown-menu. However, the following CSS doesn't change the border radius as I would've expected:

I have a dropdown like this :