At my new job I'm forced to use Adobe AEM and everything that comes with it.
But because everything is new to me and to my team, we are having some major dificulties understanding what are the best practices and what's the correct "code workflow". I've read everything that I could, but something's messing with my head and I just can't figure it out alone.
My question is:
When I don't want to work with the JCR tree, and I just want to make a component for a specific user (not a real CMS component, I guess), I can't understand how I'm able to reload my component information (based on some Model).
So... imagine I have an authenticated user that has N Cars.
And I've developed a component that shows the information of one of those Cars. The selected Car can change and I want to update the component with the selected Car information.
By default, when the page loads, the Car number 1 is loaded.
First question: How should this first Car be loaded?
My first try on this one was to backup my component with a WCMUse extension, and on the activate() method I would set my default Car properties.
But this seems odd to me, because I don't know how I connect this class to my Spring Controller...
I've read that ResourceModel can be used for this, but that it would map its properties to a Car JCR node that I don't have.
Second Question: Imagine that the first Car is correctly loaded and I call a method on my Spring Controller to update it.
What needs to be done to reflect this change on the Car information component?
So, to finish, I guess my main 2 problems are: What should be the model for the Sightly component, and how does the component refresh with the updated information.
Thanks a lot.
Welcome to AEM world silva, sad to listen that you are forced to work in AEM.
Though it might appear difficult initially , a developer worth his salt can gain enough expertise to work with AEM in around 6 months. For a Java developer it is difficult to relate things.
Coming back to your problem: If I understood you well you don't want to store you data in JCR and you want to hit your Spring controller to fetch the data.
Answer to First question: Ideally in AEM the data resides in JCR, it may be a User node and then Car0,Car1... CarN child nodes, here all car details are stored on car node as properties. It is all about how you want to structure your content.
If you plan not to store data in JCR you can create a OSGI service which can get the data from your spring controller and pass on to the sightly component.
Answer to Second question you can pass a parameter to your sightly component and get the relevant view of carN, Checkout Passing parameters to sightly .
You also can create href's which will load the same page and pass on some request parameter which you can read in your WCMUse (WCMUsePojo in AEM 6.2) extension activate method.
Keep learning keep helping, Cheers!
Related
I am new to Xamarin. I have done a couple of smaller projects (2-3 pages, one table). I have a new project that is a great candidate for a shell app. It will have 20 pages, will consume data from a transactional database (cloud hosted) but also have an offline datastore (SQLite). Right now, I just want to get the local version up and running. The template for Shell App generates an IDataService and a MockDataStore. That is a great place to start - but how do I have more than one table? I am a little confused how I would use that. What I would love to see is a template generated shell app that just adds another table (and corresponding list,detail views along with view models. For example, the simple "todo" sample but add a contact table to assign todo tasks to would be perfect. Thanks in advance for your help.
I hope this helps others new to Xamarin. When starting a new project and choosing anything other than the "blank template", the template generates a model (Item) and a services folder containing an Interface (IDataStore) and a MockDataStore. Being new to XAML in general, I spent a lot of time working on getting the UI to look like what I wanted it, learning about Shell navigation and similar topics. Finally it was time to include the data part of my project. Where I got stuck was trying to make sense of the boilerplate code. My understanding of DependencyService was for platform specific code (e.g. Android, iOS) and NOT data service dependency. Further, the templated code is a typed interface (IDataStore). The solution was fundamental - all that interface does is insure CRUD operations are available in whatever you use in a datastore. For me, simply changing IDataStore to not be typed as an Item, solved everything. It allowed me to keep the database layer abstracted away. In my little project, I completed my "MockDataStore" adding additional CRUD operations until I was ready for my real data operations. NOTE: if you generate the WEB API project from the template, it will make more sense - you can flip between your MockDataStore and actual data store.
Lets try this explanation again...
I'm new to polymer (and getting back into web dev after a relatively long absence), and I'm wondering what the recommended approach might be to more closely manage object state while employing 2 way databinding. I am currently consuming rest API (json) objects. My question is if polymer keeps a copy of the original object before initiating updates to the bound object's properties/attributes...so one might be able to easily undo the changes? While allowing 2 way databinding to work its magic is often desired, there are cases where I'd like to prevent / delay changes to the object / DOM until the user approves the changes (say via the paper-dialog component for instance). I suppose one could make a temporary copy of the object and bind fields to that version, and then only persist the changes back to the source object upon user approval. In any case, I'd be interested to hear thoughts and see an example or two of recommended approaches (especially if I am off-track with my ideas!)
I suppose one could make a temporary copy of the object and bind
fields to that version, and then only persist the changes back to the
source object upon user approval
This.
Consider that view-models are essentially different from pure data-models (sometimes called business-data). Frequently, the differences are irrelevant and one can use them interchangeably. However, be aware of scenarios where the view-model is distinct (uncommitted user edits are a good example).
The notion of a field editor that requires approval from the user is purely UI/View oriented. Whatever data is managed in that modality is purely in the domain of the view, and fetches/commits to the business-data should be discrete.
I am designing a system that uses asp.net webapi to serve data that is used by a number of jquery grid controls. The grids call back for the data after the page has loaded. I have a User table and a Project table. In between these is a Membership table that stores the many to many relationships.
User
userID
Username
Email
Project
projectID
name
code
Membership
membershipID
projectID
userID
My question is what is best way to describe this data and relationships as a webapi?
I have the following routes
GET: user // gets all users
GET: user/{id} // gets a single user
GET: project
GET: project/{id}
I think one way to do it would be to have:
GET: user/{id}/projects // gets all the projects for a given user
GET: project/{id}/users // gets all the users for a given project
I'm not sure what the configuration of the routes and the controllers should look like for this, or even if this is the correct way to do it.
Modern standard for that is a very simple approach called REST Just read carefully and implement it.
Like Ph0en1x said, REST is the new trend for web services. It looks like you're on the right track already with some of your proposed routes. I've been doing some REST design at my job and here are some things to think about:
Be consistent with your routes. You're already doing that, but watch out for when/if another developer starts writing routes. A user wants consistent routes for using your API.
Keep it simple. A major goal should be discoverability. What I mean is that if I'm a regular user of your system, and I know there are users and projects and maybe another entity called "goal" ... I want to guess at /goal and get a list of goals. That makes a user very happy. The less they have to reference the documentation, the better.
Avoid appending a ton of junk to the query string. We suffer from this currently at my job. Once the API gets some traction, users might want more fine grained control. Be careful not to turn the URL into something messy. Something like /user?sort=asc&limit=5&filter=...&projectid=...
Keep the URL nice and simple. Again I love this in a well design API. I can easily remember something like http://api.twitter.com. Something like http://www.mylongdomainnamethatishardtospell.com/api/v1/api/user_entity/user ... is much harder to remember and is frustrating.
Just because a REST API is on the web doesn't mean it's all that different than a normal method in client side only code. I've read arguments that any method should have no more than 3 parameters. This idea is similar to (3). If you find yourself wanting to expand, consider adding more methods/routes, not more parameters.
I know what I want in a REST API these days and that is intuition, discoverability, simplicity and to avoid having to constantly dig through complex documentation.
Most MVC tutorials I've been reading seem to create 4 View objects for each Model. For example, if my Model is "Foo", there seem to be 4 .cshtml files: Foo/Create, Foo/Delete, Foo/Details, and Foo/Edit. Using the VisualStudio "scaffolding" helper does this as well.
Is this really considered MVC best-practice? It just feels wrong to have 4 classes that are 80-90% identical to each other. When I add a new field to Foo, I need to edit all 4 .cshtml files. This sort of dual-maintenance (quad-maintenance?) just makes my OO skin crawl.
Please tell me: is there an expected/accepted best-practice which handles this differently? Or, if this really IS accepted best-practice, tell me why the quad-maintance shouldn't make me squirm.
I'm a reasonably skilled veteran of ASP.NET / c# / OO Design, but pretty new to MVC; so apologies if this is a noob question. Thanks in advance for your help!
Edit: thanks for all the replies! I marked the most thorough one as the answer, but upvoted all that were helpful.
You'll probably need between two and four different views:
List (for viewing many things)
View (for viewing a single thing. Might not be necessary, if it's OK to use Edit as View, or if List has room to show all properties)
Create
Edit (can be the same as create, if you code cleverly)
Thus, if your model doesn't have too many properties to show them all in a table, and if you're OK with not having a static, non-editable view for just examining, you can get well away with just List and Edit, and scrap the other two.
However, this doesn't solve your problem of double (or triple) maintenance if you update your model. There's other magic for that ;)
In ASP.NET MVC 3, there are extensions on HtmlHelper that let you do Html.DisplayForModel() and Html.EditorForModel(). These use predefined templates to nest themselves into your object and draw up display/edit fields for all public properites. If you pass DisplayForModel an IEnumerable<Foo>, it will create a table with column headers that are the property names of Foo (using the DisplayName attribute information if you supplied it) and where each row represent one Foo instance. If you give EditorForModel a Foo, it will create a <label> and an <input> for each public property on Foo.
All of the templates used by these powerful extension methods can be replaced by you, if you're not happy with the defaults. This can be done either on the level of Foo, in which case you'd be back in your double-maintenance scenario, or on lower levels (such as string or DateTime) to affect all editor/display fields generated with the templates.
For more information on exactly how this works, google "ASP.NET MVC 3 editor templates" and read a couple of tutorials. They'll explain the details much better than I could.
The views that ASP.NET MVC create for you don't necessarily need to be the views that you use in production. I found those just to be handy while developing quick prototypes or to test the database CRUD operations. Feel free to create whatever view(s) you would like to handle the operations.
I would generally just have 1 or 2 views to handle the basic operations and not use the built in views that are generated. For example, 1 view for adding, editing, or details and 1 view to show a list of objects.
It all depends on your application.
If you have a single item, you don't need a List view. If you can't edit it, then you don't need an edit view. Create and Edit can often be the same view, unless there are special things you need to do in one, but not the other.
In other words, use as many views as you need. There's no hard and fast rule here. The scaffolding is just there to help you on your way. Many kinds of apps will work just fine using the scaffolding, and won't require advanced HTML or Javascript.
Why would you want multiple views? Well, let's take the display and edit functions. You could create one view, in which you use if statements to determine the edit mode of the view, however this will complicated the view logic and views should be as simple as possible.
The reason to create seperate views is that its easier to maintain than one gigantic view with tons of conditional logic in it.
You can use exactly the same view when you are performing [HttpGet]. Given that you pass a proper ViewModel to this view, it will populate with appropriate data every time whether you are loading create, update, or delete Action.
The problem becomes apparent when you try to post that data to a specific Action.
Naturally View should have only one form, which will be used for posting data. When you declare this form, you specify which exactly Action to use for Post.
Having 3 different Submit buttons in that form will not make a difference since all of them will post the same form to the same Action.
You could do some javascript tweaking on OnClick event for these buttons to change Action to which data is posted, but this definitively would not be best practice.
Buttom line: having 4 different views for each of the CRUD actions is the best practice for MVC.
I tend to create the following for an object's CRUD ops:
index
_form (partial)
new
update
delete
view
As the same form is shared between new and update, there is very little difference between the two. It really depends on how much you want the variation to be, honestly.
As for delete, this is optional. I like to have a view in case javascript is disabled.
edit:
You mention view models and the guy above posted a long, convoluted (no offense) VM code sample.
Personally, I hate classes written to basically mirror domain objects and are only used to "move" data. I hate VMs. I hate DTOs. I hate everything that makes me have to write more code than is necessary.
I guess I've drank the coolaid of other frameworks (rails, sinatra, node.js) to the point where I can't stomach the idea of tossing DRY to the wind.
I personally say skip um.
Edit2 I forgot list..
I have a Drupal 6 website with about 20 pages. Inside every page, I need to create a lot of widgets with information either stored inside the database or from external web services. Most of the time, a "view" (from the view module) is just not enough to solve the requirement.
Up until now, any time I need such a widget, I create a new module which implements hook_block. Then, I drag and drop this new module inside the panel I want. I will need to create about 20 modules. This works pretty good. However, I'm not sure if this is the correct-drupal-strategy and I would love to receive some feedback from experienced Drupal developers.
A module can expose as many blocks as you want (in theory, admin/build/blocks will teach you otherwise ;)).
Have a look at the documentation of hook_block(), you just need to extend yours to return multiple block infos and then decided which one to show based on the $delta.
So you don't need 20 separate modules, maybe 2-3 and group the blocks somehow together because just a single module might be hard to maintain. The thing is that every single module makes your site a tiny bit slower (at least one more file to load, module_implements() needs to loop over every module for every hook and so on).
Without more information , it's hard to give any better advice. Maybe you could expose your data to views, or write a views plugin to display it in the way you want it, or...
Although Berdir's answer is pretty good, I'm impressed there's no link to any documentation in it. hook_block is meant for several blocks, and they can share functions that build their content. The API page is good, the example it gives defines two blocks at once.
You should notice each defined block has a delta (a key in the $blocks array). You can have dynamic deltas and use values in it to fetch data (passing a nid or uid and getting related content, for example).