69 lines
2.0 KiB
Markdown
69 lines
2.0 KiB
Markdown
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---
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title: "MVC1004: Rename model bound parameter"
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description: "Learn about analysis rule MVC1004: Rename model bound parameter"
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author: pranavkm
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monikerRange: '>= aspnetcore-3.1'
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ms.author: riande
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ms.date: 10/22/2021
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no-loc: [Home, Privacy, Kestrel, appsettings.json, "ASP.NET Core Identity", cookie, Cookie, Blazor, "Blazor Server", "Blazor WebAssembly", "Identity", "Let's Encrypt", Razor, SignalR]
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uid: diagnostics/mvc1004
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---
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# MVC1004: Rename model bound parameter
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| | Value |
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| **Rule ID** |MVC1004|
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| **Fix is breaking or non-breaking** |Breaking|
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## Cause
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A model bound parameter has the same name as one of its properties.
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### Rule description
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Model binding a complex parameter with a property that has the same name may result in unexpected binding behavior. Consider renaming the parameter, or using a binding attribute to specify a different name.
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Consider the following code:
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```csharp
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public class HomeController : Controller
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{
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public IActionResult Get(SearchModel search)
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{
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...
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}
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}
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public class SearcModel
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{
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public string Search { get; set; }
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}
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```
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In this model, the parameter and its property are both named `Search`, which results in model binding attempting to bind the property as `search.Search`. Naming a parameter and its property the same prevents binding to a value without a prefix such as a query that looks like `?search=MySearchTerm`.
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## How to fix violations
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* Rename the parameter if its prefix is not used during binding:
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```csharp
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public IActionResult Get(SearchModel model)
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{
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...
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}
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```
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Renaming a parameter on a public type could be considered a breaking change since it changes a library's public API surface.
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* If this is problematic, consider using a model binding attribute such as `Bind` to specify the model binding prefix:
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```csharp
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public IActionResult Get([Bind(Prefix = "")] SearchModel search)
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{
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...
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}
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```
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## When to suppress warnings
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Warnings can be suppressed if you intend to use the parameter name as a prefix during model binding.
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