Re: [Engine-devel] Introducing generics to UiCommon

From: "Vojtech Szocs" <vszocs(a)redhat.com&gt; To: "Tomas Jelinek" <tjelinek(a)redhat.com&gt; Cc: "engine-devel" <engine-devel(a)ovirt.org&gt;, "Daniel Erez" <derez(a)redhat.com&gt;, "Gilad Chaplik" <gchaplik(a)redhat.com&gt;, "Tal Nisan" <tnisan(a)redhat.com&gt;, "Alona Kaplan" <alkaplan(a)redhat.com&gt; 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

- any other change necessary? (aside from modifying specific model classes such as DataCenterModel)

[*] IIUC for each editor widget we need: the widget itself, editor, renderer/parser (potential reuse)

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

[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)

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(a)redhat.com&gt; > To: "engine-devel" <engine-devel(a)ovirt.org&gt; > Cc: "Vojtech Szocs" <vszocs(a)redhat.com&gt;, "Daniel Erez" <derez(a)redhat.com&gt;, > "Gilad Chaplik" <gchaplik(a)redhat.com&gt;, > "Tal Nisan" <tnisan(a)redhat.com&gt;, "Alona Kaplan" <alkaplan(a)redhat.com&gt; > 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(a)redhat.com&gt; > > To: "engine-devel" <engine-devel(a)ovirt.org&gt; > > 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(a)ovirt.org > > http://lists.ovirt.org/mailman/listinfo/engine-devel > > >