HttpContext
Http context stores arbitrary user defined values and ensures type safety without
actually knowing the types. It is backed by a Map and guarantees that keys do not clash.
class HttpContext {
set<T>(token: HttpContextToken<T>, value: T): HttpContext
get<T>(token: HttpContextToken<T>): T
delete(token: HttpContextToken<unknown>): HttpContext
has(token: HttpContextToken<unknown>): boolean
keys(): IterableIterator<HttpContextToken<unknown>>
}
Description
This context is mutable and is shared between cloned requests unless explicitly specified.
Further information is available in the Usage Notes...
Methods
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Store a value in the context. If a value is already present it will be overwritten. |
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Parameters
Returns
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Retrieve the value associated with the given token. |
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Parameters
Returns
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Delete the value associated with the given token. |
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Parameters
Returns
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Checks for existence of a given token. |
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Parameters
Returns
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ParametersThere are no parameters. Returns
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Usage notes
Usage Example
// inside cache.interceptors.ts
export const IS_CACHE_ENABLED = new HttpContextToken<boolean>(() => false);
export class CacheInterceptor implements HttpInterceptor {
intercept(req: HttpRequest<any>, delegate: HttpHandler): Observable<HttpEvent<any>> {
if (req.context.get(IS_CACHE_ENABLED) === true) {
return ...;
}
return delegate.handle(req);
}
}
// inside a service
this.httpClient.get('/api/weather', {
context: new HttpContext().set(IS_CACHE_ENABLED, true)
}).subscribe(...);