Hi Peter, During creation of DropDownList component in MDL I have experienced Null Pointer Exception in HorizontalFlexLayout. [1]
Issue: My DropDownList contains 3 elements: Div with selected text, Material icon (i) and Menu. Case 1: If I create DropDownList in MXML - MDL library handle properly upgrading. Menu is a simple ul, but once upgrade is done MDL library surround it by additional div [2] "mdl-menu__container". HorizontalFlexLayout is going through the children of View in function "layout". Array contains 3 elements from my DropDownList - the last one is menu - in moment of layout perform it contains "ul" not "mdl-menu__container". <http://apache-flex-development.2333347.n4.nabble.com/file/n61437/horizontalflex_layout.png> This "ul" has been created by FlexJS and has element.flexjs_wrapper. and function getElementAt returns child one by one. Case 2 - ISSUE: I would like to create DropDownList dynamically: var dropDown:DropDownList = new DropDownList(); addElement(dropDown); In order to do this Menu inside DropDownList need to be "upgraded" manually - I need to tell MDL library that I've created Menu component - I have bead for that purpose which doing his job: UpgradeElement. Upgrade is completed successfully and MDL is surrounding "ul" by "mdl-menu__container". Now HorizontalFlexLayout is doing "layout" and trying to go through the children. In array for some reason there is no "ul" MDL Menu, but this "mdl-menu__container" which wasn't created by FlexJS. In that case it doesn't have element.flexjs_wrapper, so getElementAt returns null. And we are getting NPE. It look like everything what HorizontalFlexLayout is doing in Case 1 happened before upgrading - in case 2 I'm doing upgrade during whole life cycle performance. I hope this long explanation help you understand issue and provide some feedback. I'm attaching simple project where you can reproduce this issue [3] [1] https://paste.apache.org/9oRP [2] https://paste.apache.org/iN4K [3] https://1drv.ms/u/s!ApVpLyjpHDC2zTehS-kv_1g0cgSY Piotr ----- Apache Flex PMC piotrzarzyck...@gmail.com -- View this message in context: http://apache-flex-development.2333347.n4.nabble.com/FlexJS-MDL-Null-Pointer-Exception-in-HorizontalFlexLayout-tp61437.html Sent from the Apache Flex Development mailing list archive at Nabble.com.
