Vaadin-combo-box: Regression: calling render() before first open throws

Created on 11 Mar 2019 · 5Comments · Source: vaadin/vaadin-combo-box

Description

Calling combobox.render() throws in case combo-box has not yet been open:

Cannot read property 'querySelectorAll' of undefined

This is the line where is happens:
https://github.com/vaadin/vaadin-combo-box/blob/41f870912bdd872e3376b090e863641928568a24/src/vaadin-combo-box-mixin.html#L276

Expected outcome

Calling combobox.render() doesn't throw

Actual outcome

Error is thrown

Steps to reproduce

Put a vaadin-combo-box element in the page.
Assign the renderer, don't open combo-box
Run combobox.render()

bug good first issue

Source

web-padawan

👍1

Most helpful comment

Actual items wouldn't still be rendered before the dropdown is opened so this wouldn't invoke any renderers. From this point of view would make sense to not do anything unless _selector is there.

tomivirkki on 11 Mar 2019

👍2

All 5 comments

Note: this was reported for the dom-if version but should be still valid after disable-upgrade change as _selector isn't defined either until combo-box is opened for the first time.

web-padawan on 11 Mar 2019

Discussed in person that render() could actually call _initDropdown, if called before first opening of the combobox, so as it would trigger actual rendering as users might expect it to do.

web-padawan on 11 Mar 2019

Actual items wouldn't still be rendered before the dropdown is opened so this wouldn't invoke any renderers. From this point of view would make sense to not do anything unless _selector is there.

tomivirkki on 11 Mar 2019

👍2

After #782 is merged and build is green, I will rebase this fix on latest master to get this one to pass also.