21 lines
1022 B
Markdown
21 lines
1022 B
Markdown
@name No Provider Found
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@category runtime
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@videoUrl https://www.youtube.com/embed/lAlOryf1-WU
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@shortDescription No provider for {token} found!
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@description
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You see this error when you try to inject a service but have not declared a corresponding provider. A provider is a mapping that supplies a value that you can inject into the constructor of a class in your application.
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Read more on providers in our [Dependency Injection guide](guide/dependency-injection).
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@debugging
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Work backwards from the object where the error states that a [provider](guide/architecture-services) is missing: `No provider for ${this}!`. This is commonly thrown in [services](tutorial/toh-pt4), which require non-existing providers.
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To fix the error ensure that your service is registered in the list of providers of an `NgModule` or has the `@Injectable` decorator with a `providedIn` property at top.
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The most common solution is to add a provider in `@Injectable` using `providedIn`:
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```typescript
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@Injectable({ providedIn: 'app' })
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```
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