[Engine-devel] Introducing generics to UiCommon
Tomas Jelinek
tjelinek at redhat.com
Fri Oct 11 08:56:03 UTC 2013
----- Original Message -----
> From: "Vojtech Szocs" <vszocs at redhat.com>
> To: "Tomas Jelinek" <tjelinek at redhat.com>
> Cc: "engine-devel" <engine-devel at ovirt.org>, "Daniel Erez" <derez at redhat.com>, "Gilad Chaplik" <gchaplik at redhat.com>,
> "Tal Nisan" <tnisan at redhat.com>, "Alona Kaplan" <alkaplan at redhat.com>
> Sent: Monday, October 7, 2013 12:17:30 PM
> Subject: Re: [Engine-devel] Introducing generics to UiCommon
>
> Hi Tomas,
>
> I missed the original mail and just reviewed both patches (+1 from my side).
>
> I think introducing generics to UiCommon is a step in the right direction; as
> you wrote, using non-generic types (i.e. List instead of List<ElementType>)
> leads to hidden expectations and type casts that make code harder to read
> and maintain (and also impacts GwtCommon/WebAdmin/UserPortal code that needs
> to adapt to such code).
>
> Do we have some general plan to cover UiCommon as a whole?
> - patch [1] modifies EntityModel/ListModel, what about other base models?
> (i.e. SearchableListModel)
> - patch [1] adds String version of EntityModelTextBox, what about other
> editor widgets? [*]
> according to your original mail, these are: EntityModelLabel,
> EntityModelTextAreaLabel, EntityModelPasswordBox, EntityModelTextArea,
> ListModelSuggestBox
yes, this should be the widgets which needs to be done
> - any other change necessary? (aside from modifying specific model classes
> such as DataCenterModel)
I would say nothing else.
> [*] IIUC for each editor widget we need: the widget itself, editor,
> renderer/parser (potential reuse)
yep
>
> What about following approach (just a suggestion):
>
> [separate patch - rebased on patch 1]
> - make remaining base models generic too (i.e. SearchableListModel)
> - add remaining GUI infra to bind to generic models, i.e. editor widgets and
> related stuff
well, my idea was to do the infrastructure as needed while refactoring the specific models.
But ok, I can prepare this infrastructure patch first.
>
> [separate patch per specific main tab model]
> - make main tab model use generics (including any dialog models referenced
> from this code)
> - make related sub tab models use generics (including any dialog models
> referenced from this code)
yes, sounds reasonable.
>
> Having said that, I value your effort to improve existing code. This is not
> an easy task, it will take more patches but I think it's worth it.
>
> Thanks!
> Vojtech
>
>
> ----- Original Message -----
> > From: "Tomas Jelinek" <tjelinek at redhat.com>
> > To: "engine-devel" <engine-devel at ovirt.org>
> > Cc: "Vojtech Szocs" <vszocs at redhat.com>, "Daniel Erez" <derez at redhat.com>,
> > "Gilad Chaplik" <gchaplik at redhat.com>,
> > "Tal Nisan" <tnisan at redhat.com>, "Alona Kaplan" <alkaplan at redhat.com>
> > Sent: Friday, September 27, 2013 1:32:14 PM
> > Subject: Re: [Engine-devel] Introducing generics to UiCommon
> >
> > Hey all,
> >
> > some time ago I have created a patch which introduces generics to UiCommon
> > [1] and one which uses it
> > in DataCenterModel [2]. Today I have changed a bit the generic version of
> > the
> > EntityModelTextBox to
> > be truly generic (since it can edit also e.g. integers) and than a simple
> > subclass StringEntityModelTextBox
> > which provides the String renderer/parser to simplify the usage. All the
> > other details are available in the previous
> > mail.
> >
> > What do you think about it?
> >
> > Tomas
> >
> > [1]: http://gerrit.ovirt.org/#/c/17604/
> > [2]: http://gerrit.ovirt.org/#/c/17605/
> >
> > ----- Original Message -----
> > > From: "Tomas Jelinek" <tjelinek at redhat.com>
> > > To: "engine-devel" <engine-devel at ovirt.org>
> > > Sent: Monday, August 5, 2013 9:41:29 AM
> > > Subject: [Engine-devel] Introducing generics to UiCommon
> > >
> > > Hey all,
> > >
> > > as we have passed the oVirt feature freeze I would like to celebrate it
> > > with
> > > a little bit of cleanup :)
> > >
> > > A good candidate for this is to introduce generics into uicommonweb
> > > project.
> > > The fact that it is not generic
> > > brings quite some hidden expectations into our code, makes it unreadable
> > > and
> > > error prone.
> > >
> > > Also, the gwt-common and both webadmin and userportal are mostly prepared
> > > to
> > > be generic but because the uicommonweb is not, we have code like:
> > >
> > > new ListModelListBoxEditor<Object>(new NullSafeRenderer<Object>() {
> > > @Override
> > > public String renderNullSafe(Object object)
> > > return ((Version) object).getValue();
> > > }
> > > });
> > >
> > > which is quite ugly and error prone.
> > >
> > > So I have prepared two patches, one [1] which introduces the generic
> > > infrastructure (and prepares one widget for it, more about this below)
> > > and
> > > one [2] which uses it and refactors the DataCenterModel
> > > to use it (I have chosen this model because it is big enough to show how
> > > to
> > > do it and what the benefits are but small enough to be quickly
> > > review-able).
> > >
> > > The infrastructure change:
> > > - changes the ListModel and EntityModel to be genreic
> > > - adjusts the UiCommonEditorDriverGenerator to work with generics (e.g.
> > > to
> > > make it aware that ListModel<String> is indeed a ListModel, same for
> > > EntityModel)
> > > - created a String version of EntityModelTextBox
> > >
> > > The reason why the String EntityModelTextBox had to be created is that
> > > the
> > > EntityModelTextBox is an EditorWidget<Object, ...> so it can work only
> > > with
> > > EntityModel<Object>. I saw 2 ways how to make this work with
> > > EntityModel<String>:
> > > 1: Create a String version of this editor inside the .generic
> > > sub-package,
> > > incrementally replace the usage of the non-generic EntityModelTextBox and
> > > when the non-generic will be completely replaced, delete it and move the
> > > generic one
> > > out from the generic sub-package
> > >
> > > 2: Change the EditorWidget<Object, ...> to EditorWidget<T, ...> and
> > > replace
> > > each usage of the "EntityModelTextBox someWidget" by
> > > "EntityModelTextBox<Object> someWidget" and than incrementally replace
> > > the
> > > <Object> to <String> as the
> > > underlying models will be refactored. After the last one will be
> > > refactored, change the EditorWidget<T, ...> to EditorWidget<String,
> > > ...>
> > > and replace all "EntityModelTextBox<Object> someWidget" by
> > > "EntityModelTextBox someWidget"
> > >
> > > I have chosen the first option because:
> > > - much less classes touched at once (e.g. much more safe)
> > > - the EntityModelTextBox<T> invites to use something like
> > > EntityModelTextBox<VM> which is not correct and fails on class cast
> > > exceptions
> > >
> > > But at the same time I see the disadvantages of this approach (mostly
> > > that
> > > we
> > > have two versions of the same class). Please note that far not all the
> > > widgets will need two versions, only the ones editing only Strings which
> > > are declared as EditorWidget<Object> which are:
> > > - EntityModelLabel
> > > - EntityModelTextAreaLabel (used only in couple of places - can be
> > > refactored
> > > together without the need to have two versions)
> > > - EntityModelTextBox (already in the [1])
> > > - EntityModelPasswordBox
> > > - EntityModelTextArea
> > > - ListModelSuggestBox (used only in couple of places - can be refactored
> > > together without the need to have two versions)
> > >
> > > The rest of the widgets should be already prepared to be used in generic
> > > environment.
> > >
> > > Please let me know what do you think about it,
> > >
> > > have a nice day,
> > > Tomas
> > >
> > > [1]: http://gerrit.ovirt.org/#/c/17604/
> > > [2]: http://gerrit.ovirt.org/#/c/17605/
> > >
> > > _______________________________________________
> > > Engine-devel mailing list
> > > Engine-devel at ovirt.org
> > > http://lists.ovirt.org/mailman/listinfo/engine-devel
> > >
> >
>
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