Dependency Injection in Views #946
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| A Simple Example | ||
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| With the above warning in mind, you can inject a service into a view using the ``@inject`` directive, as shown below: |
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I'd like to see some more descriptive text on the syntax of @inject. It's effectively a property definition, where the first parameter is the type of the property and the second parameter is the property name. @using statements apply when specifying the property type. The property will then get populated from DI.
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Not sure it's worth calling out the warning here. If you emphasize it enough in the intro it'll stand on its own.
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Remove "With the above warning in mind,"
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The code below (from the http://docs.asp.net/projects/mvc/en/latest/views/view-components.html sample), shows injecting a service into a view using the @Inject directive:
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Updated to include syntax and remove "with the above warning".
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@NTaylorMullen Please review. |
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| `View sample files <https://github.com/aspnet/Docs/tree/1.0.0-rc1/mvc/views/dependency-injection/sample>`_ | ||
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| .. warning:: When applying this functionality, ensure you maintain `separation of concerns <http://deviq.com/separation-of-concerns>`_ between your controllers and views. Most of the data your views display should be passed in from the controller. This technique is recommended only for view-specific data. |
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Ehh, not sure this warrants a warning. Weave this into the above introduction on how dependency injection can be good and bad if not used correctly.
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I'd write it as
We recommend you maintain SoC between .. Generally the data displayed in views should be passed ...
what is This technique? Write that as
Injecting a service into a view is recommended for view-specific data.
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Reworded; removed warning block.
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Hmm, after looking over the format of this article I'm not sure the format's right. It dives into the linked samples pretty extensively but I was under the assumption this would be more of a reference doc (@danroth27 please verify)? If so I'd envision the layout being:
Each showcasing how to do inject the service and the outcome but not diving too much into detail on what's going on in the sample. |
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| public List<State> ListStates() | ||
| { | ||
| // the abbreviated states of america |
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Some abbreviated states in the USA.
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@NTaylorMullen This topic wasn't intended to be an @ardalis Please do add a section about being able to override a previously injected service. For example you can override |
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Are you sure overriding works? I have this: |
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Hey @ardalis what bits are you using? I tried this locally with rc1-update1 bits and all seems well: public class FooHelper
{
public int Value { get; set; }
}
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I'm using rc1-update1 bits as well. Let me know your email and I can send you the project - it's tiny. |
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@ardalis Taylor dot Mullen at microsoft.com |
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@NTaylorMullen Thanks. Not sure how to resolve that immediately. I'll write the code I think should work and check it in and you can see if it looks good and wrap up this PR, ok? Thanks! |
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@ardalis Does it work at runtime for you? |
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@NTaylorMullen it does now that I remembered to add the helper to DI... Should be all good now. Shipit? |
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| By `Steve Smith`_ | ||
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| ASP.NET MVC 6 supports `dependency injection <https://docs.asp.net/en/latest/fundamentals/dependency-injection.html>`_ into views. This can be useful for view-specific services, such as localization or data required only for populating view elements. You should try to maintain `separation of concerns <http://deviq.com/separation-of-concerns>`_ between your controllers and views. Most of the data your views display should be passed in from the controller; injecting services into views is recommended only for view-specific data. |
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@danroth27 should we be changing names to core (instead of MVC 6)?
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Nope - not until we ship bits with the new names. See https://blogs.msdn.microsoft.com/webdev/2016/02/01/an-update-on-asp-net-core-and-net-core/
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Nuke ; injecting services into views is recommended only for view-specific data.. You already mention this in the previous bit.
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@NTaylorMullen Shouldn't we be using the latest RC2 bits at this late stage. Why have planned obsolescence? |
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@ardalis Just spin up a clean VM with the latest bits, it's the lowest friction approach to a clean environment. I do my development on a VM and have a scheduled task robocopy the code to my publishing VM every minute. |
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@Rick-Anderson RC2 bits have the core renames. If @danroth27 wants to hold off on those then RC1 bits should be fine. |
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ardalis
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Merged. |
Fixes #128