providing designtime ViewModel data for Blend and VS - mvvm

In a MVVM based application, what options do I have to provide ViewModel data at design time, so our designers can actually see something in Blend3 (and VS 2008). How are you doing this? Can I utilize mc:ignorable for this somehow?

Yes, Expression Blend can help you with this. Use the "Data" tab to create sample data that has the same shape as your production data. When you create the data source, be sure to uncheck "Enable sample data when application is running".
Sample Data http://www.smips.com/brad/stackoverflow/design-model1.jpg
After you've created your sample data, set the DataContext of your page to the sample data in the XAML. This will let the designers see the sample data when they open the page in Blend.
<navigation:Page DataContext={StaticResource MyFakeDesignData}
In the code for the Loaded handler, write code to set the DataContext to the real model. Since this code will only run when the app is running, and you've told your sample data to not be available when the app is running, this means the running app will get the real data.
private void Home_Loaded(object sender, RoutedEventArgs e)
{
DataContext = new MyRealViewModel();
}

Using VS2010 you can use Design-Time attributes (works for both SL and WPF). I usually have a mock data-source anyway so it's just a matter of:
Adding the namespace declaration
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
Adding the mock data context to window/control resources
<UserControl.Resources>
<ViewModels:MockXViewModel x:Key="DesignViewModel"/>
</UserControl.Resources>
Setting design-time data context
<Grid d:DataContext="{Binding Source={StaticResource DesignViewModel}}">
...
Works well enough.

Related

Synchronization of multiple catalogs in hybris

I need help on this issue. I am upgrading hybris to version 2105, I ran into the problem that the 'DefaultSetupSyncJobService' class has changed its methods from 'SyncItemJob' to 'SyncItemJobModel'. How could I adapt these classes so that the catalogs are correctly synchronized ?
The new implementation for synchronization is stored in CatalogSynchronizationService.synchronizeFully(source,target) for a full synchronization. There are other methods to perform partial syncs with a select subset of items aswell in that service.
Do note that this will always create new SyncItemCronJobModel objects instead of reusing an existing syncjob. Depending on what you want, you can modify the implementation somewhat to reuse the same syncjob. The code then becomes something like this:
catalogSynchronizationService.getSyncJob(source, target, null);
instead of calling createSyncItemJob(...)
The rest is the same as the original implementation. So customized implementation of synchronizeFully could look something like(Extend from DefaultCatalogSynchronizationService)
public void synchronizeFully(final CatalogVersionModel source, final CatalogVersionModel target) {
final SyncItemJobModel syncJob = getSyncJob(source, target, null);
final SyncItemCronJobModel syncCronJob = createSyncCronJob(syncJob);
cronJobService.performCronJob(syncCronJob, true);
}

v2.ODataModel: which API is more preferred? "bindElement" or "read"?

I set the view.setModel(model), get the model for the view, and request for model.read("/entitySet('10000')").
The model is then filled up with /entitySet('10000')/properties.
But it is difficult to assign them to view fields, as now in the view, <Text text="{property}"> doesn't work. It has to be <Text text="{/entitySet('10000')/property}">.
On the other hand, if I set view's context binding to "/entitySet('10000')", then <Text text="{property}"> would start working.
Which one is the preferred method? When to use .read?
I almost never use .read if I want to use the results from an OData call directly in a binding context. The only time I use .read is if I want to manipulate the results before doing anything with them.
Look at this example from the sdk for instance: https://ui5.sap.com/#/entity/sap.ui.table.Table/sample/sap.ui.table.sample.OData
Syntax on this kind of binding is similar to read but with a few differences in events, and a few different types of methods depending on what you want to bind. Binding to a view for instance uses bindElement:
this.getView().bindElement("/entitySet('1000')");
After this, fields on that particular entity can be accessed as <Text text="{property}" />.
Here's an example from one of my current apps with events and some other call parameters:
this.getView().bindElement({
path: `/Orders('${currentOrderNumber}')`,
parameters: {
expand: 'Texts'
},
events: {
dataRequested: _ => this.getView().setBusy(true),
dataReceived: data => {
if (!this.getView().getBindingContext()) {
// navigate to `Not Found` view
}
},
change: _ => this.getView().setBusy(false)
}
});
For a table, it's slightly different, since it depends on the aggregation you wish to bind, such as
oTable.bindRows({
path: "properties"
});
Which is the same as:
<Table rows="{properties}" />
It's always important to be more expressive. Use the API that is specifically designed to do that one task.
Comparing the two variants:
myModel.read(sPath) with text="{/path/property}"
myControl.bindElement(sPath) with text="{property}"
I'd be perplexed about the 1st call whereas in the 2nd call, I'd know exactly what you want to achieve (You want to bind element. Alternatively, bindObject can be also used).
The same applies to the framework. Since you're telling exactly what you want to achieve, the framework can improve its behavior based on your intent. E.g.: in (route)PatternMatched handler when the user navigates to the same page, .bindElement with the same path won't trigger another request since the model already stored the entity from the previous call. It can show the result immediately.
With .read, however, the framework doesn't know what you want to achieve, so it sends the request right away regardless of the application state.
Additionally, the 1st variant is anything but future-proof. It relies on the cached results. It's almost a side-effect that it works at all. The problem is that there is no guarantee that this behavior will continue to work in later versions. Also there won't be read method in V4 ODataModel.
TL;DR
v2.ODataModel#read
Does not create context from the response. Repeating .read("<same path>") always sends a new request.
Less expressive. Encourages app developers to work with a client-side model (e.g. JSONModel).
Application loses context awareness, increasing TCO, less future-proof.
bindElement or bindObject
Creates context from the response and stores it internally so that the same request can return the data immediately.
Clearly expresses the intent; application as well as framework can work with the existing APIs.
More future-proof: v4.ODataModel does not support manual read. Imagine you've built your applications with the v2ODataModel.read-jsonModel.setData approach, and you need to migrate to v4. Have fun. :)
I honestly think that v2.ODataModel#read should have never become a public method. I wouldn't encourage anyone to use .read except of when reading the $count value manually.
If the entity values need to be formatted, there are formatters and binding types out of the box which are also easy to extend.
If the application needs to restructure the response body, usually it's a sign of a poor design of the data model or the service not conforming to the OData spec.
I almost agree with Jorg, but not entirely:
It really depends on what are you trying to achieve. If looking to display data from backend then the easiest way to go is with this.getView().bindElement()
but if you are in need to manipulate data before displaying (like formatting text, displaying images from base64 strings, etc) OR if you would like to create new entity using some of existing data, OR update the existing data - the this.getModel(sName).read() is the way to go - as you can set read entity with all its deep entities to JSONModel in successCallback and manipulate it from the localModel.
If using localModel the dataBinding is pretty much the same in the view - except you have to additionally give model name to take data from. So for example, if in successCallback of your Model.read() you set your data to Model named "localModel":
this.getModel().read(sObjectPath, {
urlParameters: {
$expand: ""
},
success: function (oData) {
// "localModel" is name you gave in onInit function to your new JSONMOdel, when setting it to View e.g. this.getView().setModel(oJSONMOdel, "localModel")
this.getModel("localModel").setData(oData);
}
})
then in XML view you would indicate that
<Text text="{localModel>/mainPropertyName}"/>
// for displaying deep entities as List items or in Table
<List items="{localModel>/deepEntityName}">
<StandardListItem title="{localModel>propertyNamefromDeepEntity}" />
</List>
From my experience working with more complex apps that Read-Only - I always use Model.read().

SAPUI5 bindAggregation complete for a Table

I am binding an aggregation to a table . I couldn't find an event which is triggered after the binding is complete . There is "updateFinished" event for sap.m.List , which is exactly what I am looking for in a Table (and a dropodown). I thought of using attachRequestCompleted() on the model , but the model is used at other places where I do not want this event to trigger.
Is there anyway to trigger a event once the databinding is complete on a Table (and a dropdown)?
Any help is appreciated.
Thanks in advance.
update: There is "updateFinished" event for table extended from ListBase. I am still not sure how I missed it before I posted this question. But, the question is still valid for a dropdown and TableSelectDialog controls.
I also stumbled upon that problem, but in a different Context.
I have a Grid layout in which I dynamically load Panels via an oData Model.
Therefore I have entered the path in my XML Grid-View element.
<l:Grid id="grid" content="{some path...}">...</l:Grid>
Now I wanted to set the grid view busy and when the data is loaded revert this.
Therefore I use the Binding of the grid view.
In the Controllers onInit method I have added:
this._oGrid = this.getView().byId("grid");
this.getRouter().attachRouteMatched(this._onRouteMatch.bind(this));
Please note that the bind method is not available in every browser. You need to apply a polyfill. (See https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Global_Objects/Function/bind)
Also Bind has nothing to do with the binding :D
I needed to do this because the Binding is not available in the onInit function.
The _onRouteMatched function:
var oContent = this._oGrid.getBinding("content");
oContent.attachDataReceived(function(oData) {
this._oGrid.setBusy(false);
}.bind(this));
Now when the data is received the busy option is set to false.
If you want to show a 'loading' indicator for your table while the data is still loading (and thus not bound), I think the best approach is the following:
Use a dedicated JSONModel which holds only UI-specific stuff, like toggling enabled/readonly/busy/etc properties of controls.
In your case, something like:
var oUIModelData = {
tableIsBusy : false,
//etc, things like :
btnSubmitEnabled : false,
someControlVisible : true
};
var oUIModel = new sap.ui.model.json.JSONModel();
oUIModel.setData(oUIModelData);
sap.ui.getCore().setModel(oUIModel, "UIModel");
In your table definition, bind the busy property to {UIModel>/tableIsBusy} and set the table's property busyIndicatorDelay to 0 to avoid any delays
Just before you do your OData service call, set the property tableBusy to true. This will immediately show the busy overlay to your table:
sap.ui.getCore().getModel("UIModel").setProperty(tableIsBusy, true);
//here your OData read call
In your OData service's requestCompleted (and if needed, also in requestFailed) event handlers, set the busy property of the UIModel back to false:
sap.ui.getCore().getModel("UIModel").setProperty(tableIsBusy, false);
The big benefit of this approach is (IMHO) instead of relying on each control to check whether the data has been loaded, simply do it during the actual load.
And by binding these UI-related things to a (separate) model saves you from writing lots of extra code ;-)
In general you could solve the problem by using batch processing on the OData service. According to https://sapui5.netweaver.ondemand.com/docs/guide/6c47b2b39db9404582994070ec3d57a2.html:
Use OData model v2.
var oModel = new sap.ui.model.odata.v2.ODataModel(myServiceUrl);
Define a set of deferred batch groups.
oModel.setDeferredBatchGroups(["myGroupId", "myGroupId2"]);
Add the batch group information to the corresponding bindings, e.g:
{
path:"/myEntities",
parameters: {
batchGroupId: "myGroupId"
}
}
All read/query actions on bindings in a certain batch group will be held back until a .submitChanges(.) call on the batch group is made.
oModel.submitChanges({
batchGroupId: "myGroupId",
success: mySuccessHandler,
error: myErrorHandler
});
Use the success/error handlers to execute actions.
This rather generic approach gives you additional control such as trigger actions, grouping and event handling on the OData model.

How to obtain wicket URL from PageClass and PageParameters without running Wicket application (i.e. without RequestCycle)?

In my project, there are additional (non-wicket) applications, which need to know the URL representation of some domain objects (e.g. in order to write a link like http://mydomain.com/user/someUserName/ into a notification email).
Now I'd like to create a spring bean in my wicket module, exposing the URLs I need without having a running wicket context, in order to make the other application depend on the wicket module, e.g. offering a method public String getUrlForUser(User u) returning "/user/someUserName/".
I've been stalking around the web and through the wicket source for a complete workday now, and did not find a way to retrieve the URL for a given PageClass and PageParameters without a current RequestCycle.
Any ideas how I could achieve this? Actually, all the information I need is somehow stored by my WebApplication, in which I define mount points and page classes.
Update: Because the code below caused problems under certain circumstances (in our case, being executed subsequently by a quarz scheduled job), I dived a bit deeper and finally found a more light-weight solution.
Pros:
No need to construct and run an instance of the WebApplication
No need to mock a ServletContext
Works completely independent of web application container
Contra (or not, depends on how you look at it):
Need to extract the actual mounting from your WebApplication class and encapsulate it in another class, which can then be used by standalone processes. You can no longer use WebApplication's convenient mountPage() method then, but you can easily build your own convenience implementation, just have a look at the wicket sources.
(Personally, I have never been happy with all the mount configuration making up 95% of my WebApplication class, so it felt good to finally extract it somewhere else.)
I cannot post the actual code, but having a look at this piece of code will give you an idea how you should mount your pages and how to get hold of the URL afterwards:
CompoundRequestMapper rm = new CompoundRequestMapper();
// mounting the pages
rm.add(new MountedMapper("mypage",MyPage.class));
// ... mount other pages ...
// create URL from page class and parameters
Class<? extends IRequestablePage> pageClass = MyPage.class;
PageParameters pp = new PageParameters();
pp.add("param1","value1");
IRequestHandler handler = new BookmarkablePageRequestHandler(new PageProvider(MyPage.class, pp));
Url url = rm.mapHandler(handler);
Original solution below:
After deep-diving into the intestines of the wicket sources, I was able to glue together this piece of code
IRequestMapper rm = MyWebApplication.get().getRootRequestMapper();
IRequestHandler handler = new BookmarkablePageRequestHandler(new PageProvider(pageClass, parameters));
Url url = rm.mapHandler(handler);
It works without a current RequestCycle, but still needs to have MyWebApplication running.
However, from Wicket's internal test classes, I have put the following together to construct a dummy instance of MyWebApplication:
MyWebApplication dummy = new MyWebApplication();
dummy.setName("test-app");
dummy.setServletContext(new MockServletContext(dummy, ""));
ThreadContext.setApplication(dummy);
dummy.initApplication();

EF 4 Self Tracking Entities does not work as expected

I am using EF4 Self Tracking Entities (VS2010 Beta 2 CTP 2 plus new T4 generator). But when I try to update entity information it does not update to database as expected.
I setup 2 service calls. one for GetResource(int id) which return a resource object. the second call is SaveResource(Resource res); here is the code.
public Resource GetResource(int id)
{
using (var dc = new MyEntities())
{
return dc.Resources.Where(d => d.ResourceId == id).SingleOrDefault();
}
}
public void SaveResource(Resource res)
{
using (var dc = new MyEntities())
{
dc.Resources.ApplyChanges(res);
dc.SaveChanges();
// Nothing save to database.
}
}
//Windows Console Client Calls
var res = service.GetResource(1);
res.Description = "New Change"; // Not updating...
service.SaveResource(res);
// does not change anything.
It seems to me that ChangeTracker.State is always show as "Unchanged".
anything wrong in this code?
This is probably a long shot... but:
I assume your Service is actually in another Tier? If you are testing in the same tier you will have problems.
Self Tracking Entities (STEs) don't record changes until when they are connected to an ObjectContext, the idea is that if they are connected to a ObjectContext it can record changes for them and there is no point doing the same work twice.
STEs start tracking once they are deserialized on the client using WCF, i.e. once they are materialized to a tier without an ObjectContext.
If you look through the generated code you should be able to see how to turn tracking on manually too.
Hope this helps
Alex
You have to share assembly with STEs between client and service - that is the main point. Then when adding service reference make sure that "Reuse types in referenced assemblies" is checked.
The reason for this is that STEs contain logic which cannot be transfered by "Add service reference", so you have to share these types to have tracing logic on client as well.
After reading the following tip from Daniel Simmons, the STE starts tracking. Here is the link for the full article. http://msdn.microsoft.com/en-us/magazine/ee335715.aspx
Make certain to reuse the Self-Tracking Entity template’s generated entity code on your client. If you use proxy code generated by Add Service Reference in Visual Studio or some other tool, things look right for the most part, but you will discover that the entities don’t actually keep track of their changes on the client.
so in the client make sure you don't use add service reference to get the proxy instead access service through following code.
var svc = new ChannelFactory<IMyService>("BasicHttpBinding_IMyService").CreateChannel();
var res = svc.GetResource(1);
If you are using STEs without WCF you may have to call StartTracking() manually.
I had the same exact problem and found the solution.
It appears that for the self-tracking entities to automatically start tracking, you need to reference your STE project before adding the service reference.
This way Visual Studio generates some .datasource files which does the final trick.
I found the solution here:
http://blogs.u2u.be/diederik/post/2010/05/18/Self-Tracking-Entities-with-Validation-and-Tracking-State-Change-Notification.aspx
As for starting the tracking manually, it seems that you do not have these methods on the client-side.
Hope it helps...