Exception caught: Cannot set a new parent without first clearing the old parent

[youncta-dev]

I'm using 2.0-SNAPSHOT in my project and since a few days I'm observing a nasty exception on Chrome developer console. I'm sure it was not happening on 21st of April but now it is popping up frequently.

How can I select a snapshot of a given day in the pom ?

This is the exception:

gwtmaterialylct-0.js:5485 Thu May 04 16:21:18 GMT+200 2017 com.google.gwt.logging.client.LogConfiguration
SEVERE: Exception caught: Cannot set a new parent without first clearing the old parent
com.google.gwt.user.client.ui.AttachDetachException: Exception caught: Cannot set a new parent without first clearing the old parent
	at Unknown.RuntimeException_1(gwtmaterialylct-0.js)
	at Unknown.UmbrellaException(gwtmaterialylct-0.js)
	at Unknown.UmbrellaException_0(gwtmaterialylct-0.js)
	at Unknown.AttachDetachException(gwtmaterialylct-0.js)
	at Unknown.tryCommand(gwtmaterialylct-0.js)
	at Unknown.doAttachChildren_0(gwtmaterialylct-0.js)
	at Unknown.$onAttach(gwtmaterialylct-0.js)
	at Unknown.onAttach(gwtmaterialylct-0.js)
	at Unknown.$setParent(gwtmaterialylct-0.js)
	at Unknown.$add_2(gwtmaterialylct-0.js)
	at Unknown.$add_7(gwtmaterialylct-0.js)
	at Unknown.add_8(gwtmaterialylct-0.js)
	at Unknown.$add_1(gwtmaterialylct-0.js)
	at Unknown.$add_6(gwtmaterialylct-0.js)
	at Unknown.add_7(gwtmaterialylct-0.js)
	at Unknown.setInSlot(gwtmaterialylct-0.js)
	at Unknown.$setInSlot(gwtmaterialylct-0.js)
	at Unknown.execute_19(gwtmaterialylct-0.js)
	at Unknown.runScheduledTasks(gwtmaterialylct-0.js)
	at Unknown.$flushPostEventPumpCommands(gwtmaterialylct-0.js)
	at Unknown.execute_2(gwtmaterialylct-0.js)
	at Unknown.execute_1(gwtmaterialylct-0.js)
	at Unknown.apply_1(gwtmaterialylct-0.js)
	at Unknown.entry0(gwtmaterialylct-0.js)
	at Unknown.anonymous(gwtmaterialylct-0.js)
	at Unknown.callback(gwtmaterialylct-0.js)
Caused by: java.lang.IllegalStateException: Cannot set a new parent without first clearing the old parent
	at Unknown.Exception(gwtmaterialylct-0.js)
	at Unknown.RuntimeException_0(gwtmaterialylct-0.js)
	at Unknown.IllegalStateException_0(gwtmaterialylct-0.js)
	at Unknown.$setParent(gwtmaterialylct-0.js)
	at Unknown.$add_2(gwtmaterialylct-0.js)
	at Unknown.$add_7(gwtmaterialylct-0.js)
	at Unknown.add_8(gwtmaterialylct-0.js)
	at Unknown.$add_1(gwtmaterialylct-0.js)
	at Unknown.$add_6(gwtmaterialylct-0.js)
	at Unknown.initialize_4(gwtmaterialylct-15.js)
	at Unknown.$onLoad_0(gwtmaterialylct-0.js)
	at Unknown.onLoad_7(gwtmaterialylct-0.js)
	at Unknown.$onAttach(gwtmaterialylct-0.js)
	at Unknown.onAttach(gwtmaterialylct-0.js)
	at Unknown.execute_5(gwtmaterialylct-0.js)
	at Unknown.tryCommand(gwtmaterialylct-0.js)
	at Unknown.doAttachChildren_0(gwtmaterialylct-0.js)
	at Unknown.$onAttach(gwtmaterialylct-0.js)
	at Unknown.onAttach(gwtmaterialylct-0.js)
	at Unknown.$setParent(gwtmaterialylct-0.js)
	at Unknown.$add_2(gwtmaterialylct-0.js)
	at Unknown.$add_7(gwtmaterialylct-0.js)
	at Unknown.add_8(gwtmaterialylct-0.js)
	at Unknown.$add_1(gwtmaterialylct-0.js)
	at Unknown.$add_6(gwtmaterialylct-0.js)
	at Unknown.add_7(gwtmaterialylct-0.js)
	at Unknown.setInSlot(gwtmaterialylct-0.js)
	at Unknown.$setInSlot(gwtmaterialylct-0.js)
	at Unknown.execute_19(gwtmaterialylct-0.js)
	at Unknown.runScheduledTasks(gwtmaterialylct-0.js)
	at Unknown.$flushPostEventPumpCommands(gwtmaterialylct-0.js)
	at Unknown.execute_2(gwtmaterialylct-0.js)
	at Unknown.execute_1(gwtmaterialylct-0.js)
	at Unknown.apply_1(gwtmaterialylct-0.js)
	at Unknown.entry0(gwtmaterialylct-0.js)
	at Unknown.anonymous(gwtmaterialylct-0.js)
	at Unknown.callback(gwtmaterialylct-0.js)

[kevzlou7979]

What specific GMD components you've used in order to reproduce this issue? Thanks in advance

[youncta-dev]

ApplicationView.ui.xml.gz
SystemSummaryView.ui.xml.gz

Second time I click to show SystemSummaryView I get the exception. Probably the navigation side bar is causing the problem. You can see it in this video:

https://youtu.be/x86PwZfOio4

[youncta-dev]

I'm also using gwt-material-table 2.0-SNAPSHOT in my project

[kevzlou7979]

@youncta-dev I think it's not the navigation side bar as it's not reattaching on your demo, the only thing that is reattaching is your content.

[youncta-dev]

As an info for you, I can state that the problem disappears if I use the following instead of SNAPSHOT:

    <parent>
        <artifactId>gwt-material-parent</artifactId>
        <groupId>com.github.gwtmaterialdesign</groupId>
        <version>2.0-20170421.032733-302</version>
    </parent>

        <dependency>
            <groupId>com.github.gwtmaterialdesign</groupId>
            <artifactId>gwt-material</artifactId>
            <version>2.0-20170421.032828-298</version>
        </dependency>
        <dependency>
            <groupId>com.github.gwtmaterialdesign</groupId>
            <artifactId>gwt-material-themes</artifactId>
            <version>2.0-20170427.080029-20</version>
        </dependency>
        <dependency>
            <groupId>com.github.gwtmaterialdesign</groupId>
            <artifactId>gwt-material-addins</artifactId>
            <version>2.0-20170424.095630-196</version>
        </dependency>

        <dependency>
            <groupId>com.github.gwtmaterialdesign</groupId>
            <artifactId>gwt-material-table</artifactId>
            <version>2.0-20170502.071319-13</version>
        </dependency>

[brkuntmz]

With the new version, don't know why, some components started to act weirdly. For example, I was having the similar type of exception during the attachment and detachment of components, and in my case, the problematic component was MaterialWindow.

So, I did a workaround solution as the following:

if(somewindow.isAttached()){
    RootPanel.get().remove(somewindow);
}
RootPanel.get().add(somewindow);

Inside the view constructor, I simply removed the component from the RootPanel if it's attached (because the error was saying "cannot add another parent while the old one is there")and added again to bypass the error. However, the workaround solution is for sure not elegant although it does the trick.

So, you should find the right component for you which causes the problem. At least until a fix is released.

[matam]

I'm also had problem with MaterialWindow https://github.com/GwtMaterialDesign/gwt-material-addins/issues/229, but now this error not exist and i closed this issue.

[kevzlou7979]

Ok I confirmed that I can reproduce this issue on Demo snapshot Window page.

[kevzlou7979]

Fixed via GwtMaterialDesign/gwt-material-addins@94db449