Why am I getting "The component(s) below failed to render"?
wicket, wicket-1.5
Solution
Always start with the obvious and make sure the `wicket:id(s)` are defined in your markup. If you see the ID added in your markup, then chances are you have the following scenario:
- You are trying to render a Component that is a child of another Component. This means your trying to render a Page or a Panel that is a subclass of a another Page or Panel.
- e.g. Within a Page you try to call `add(new ChildPanel("myChildPanel"));`
- The Component you are extending has defined and add Components with it's own markup
- e.g. Within `AbstractParentPanel` you call `add(new Label("myCommonLabel"));`
- The markup in the child Component failed to included some required Wicket XHTML
- e.g. Within `ChildPanel.html`, you forgot to add `<wicket:extend>` tags or maybe even `<wicket:panel>` tags, or you have them not containing the components in question.
Problem
When I add a ChildPanel to a page, I get an error that states: ``` org.apache.wicket.WicketRuntimeException: The component(s) below failed to render. A common problem is that you have added a component in code but forgot to reference it in the markup (thus the component will never be rendered). 1. [Form [Component id = myForm]] 2. [DropDownChoice [Component id = referenceType]] 3. [TextField [Component id = referenceNumber]] 4. [CheckBox [Component id = referenceReqChk]] 5. [ [Component id = saveRefNumButton]] 6. [ [Component id = cancelRefNumButton]] at org.apache.wicket.Page.checkRendering(Page.java:693) at org.apache.wicket.Page.onAfterRender(Page.java:849) at org.apache.wicket.markup.html.WebPage.onAfterRender(WebPage.java:213) at org.apache.wicket.Component.afterRender(Component.java:950) at org.apache.wicket.Component.render(Component.java:2298) at org.apache.wicket.Page.renderPage(Page.java:1041) at org.apache.wicket.request.handler.render. WebPageRenderer.renderPage(WebPageRenderer.java:105) ``` I can clearly see the components in question are added in the markup in my AbstractParentPanel, which my ChildPanel extends. The odd thing is, if I make the AbstractParentPanel a non-abstract class, I'm able to add that panel with no issues. Why am I getting this error? NOTE: I have already found the answer to this question. I'm adding it to SO to help others since I wasted more time than I should have for such a simple check. If you got burned by this message and this answer helped you, consider voting up this JIRA ticket