I am familiar with invoking lambda from another lambda and also to pass param to handler function based on which it calls different methods from a service(Same as stated here AWS Lambda - Invoke a method of another lambda function), But when there is a case to expose all the methods of a service its quite tedious to add multiple condition in the handler function.
So my question is Is there any dynamic way we can expose all the methods of the service using single lambda handler function, or may be any other efficient way. My main motive is to expose whole method in a service using lambda handler so that I don't have to add different conditions and another lambda can invoke it method name without any conditional parameter.
Sample code here
export const handler = async function(params: params,
context: Context,
callback: Callback) {
if(params.type === 'type1'){
const results = await testService.testmethod1(params.value);
context.succeed(results);
}
else if(params.type === 'type2'){
const results = await testService.testmethod2(params.value);
context.succeed(results);
} and so on...
};
So Is there any way we can expose all methods of testService(above we have exposed to methods testmethod1 and testmethode, there can be other methods as well) without all these conditional statements?
Related
I have an API that has different methods - (GET, POST, DELETE) Is there a way to make one LAMBDA function work with all of these methods or does each method have its own LAMBDA function?
I mean I have parts in the code that each part is supposed to work in calling a different method.
and what if i have a few resources?
client = boto3.resource('dynamodb')
table = client.Table('papi.table')
def lambda_handler(event, context):
//for GET METHOD
tab= table.scan()
item = tab['Items']
for id in item:
print(id)
// for POST
response = table.put_item(
Item={
'id':"1"
}
)
return response
and so..
You can get the httpMethod parameter from the event, see Documentation for the API gateway response to the Lambda.
I need to register a object to the service container.
I tried with the following code but I get
Error Call to undefined method ::process()
$o = $this->instance(Service::class, Mockery::mock(Service::class, function ($mock) {
$mock->shouldReceive('process')->once()->andReturn(10);
}));
$this->app->instance(Service::class, $o);
dd((new Service())->process());
Firstly for mocking an object, this should suffice. The middle step is not required.
$this->instance(Service::class, Mockery::mock(Service::class, function ($mock) {
$mock->shouldReceive('process')->once()->andReturn(10);
}));
For your mock to load, you have to get it out through the container, you have recently bound it with the container. There are many ways of doing this, $this->app->instance(), app(), resolve() etc.
dd($this->app->instance(Service::class)->process());
I have an Api Gateway GET method called /tasks/{tasktype}
It's pointed to a Lambda function with the X-Amz-Invocation-Type set to 'Event'
Then in my Lambda I have this
public void FunctionHandler(Object input, ILambdaContext context)
{
LambdaLogger.Log($"GOT: {input.ToString()}");
}
This all works fine, except input is null.
Is there any way I can pass through and access the value of {tasktype} from the Api Gateway?
Thanks
You need to pass them in using either a mapping template or check the box for "Use Lambda Proxy integration".
Mapping Template reference:
https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-mapping-template-reference.html
Proxy Integration reference:
https://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-lambda-proxy-integrations.html
I'm new to NGXS and I'm trying to fully understand the docs so I can start using it knowing what I'm doing.
There is one thing I don't understand in this code snippet from here.
export class ZooState {
constructor(private animalService: AnimalService) {}
#Action(FeedAnimals)
feedAnimals(ctx: StateContext<ZooStateModel>, action: FeedAnimals) {
return this.animalService.feed(action.animalsToFeed).pipe(tap((animalsToFeedResult) => {
const state = ctx.getState();
ctx.setState({
...state,
feedAnimals: [
...state.feedAnimals,
animalsToFeedResult,
]
});
}));
}
}
Just below this code, it says:
You might notice I returned the Observable and just did a tap. If we
return the Observable, the framework will automatically subscribe to
it for us, so we don't have to deal with that ourselves. Additionally,
if we want the stores dispatch function to be able to complete only
once the operation is completed, we need to return that so it knows
that.
The framework will subscribe to this.animalService.feed, but why?
The action, FeedAnimals, uses the injected service, AnimalService to feed the animals passed in the action's payload. Presumably the service is operates asynchronously and returns an Observable. The value of that Observable is accessed via the tap function and is used to update the ZooState state context based on completing successfully.
In order to use NGXS specifically and Angular in general, you really have to understand RxJS... here's my goto doc page for it
$http service in angular is singleton, and my previous experience with xhr/ ajax request shown to have clash when two request share the same xhr object. Should it not a problem with angular ? if yes how angular handles such situation ?
I think you're misunderstanding the fact that the $http service is a singleton to mean that all requests somehow will share the same XHR object. They don't.
The $http service itself is a singleton, but that doesn't mean that the requests share the same XHR object.
Anytime you call an $http service method (for example, $http#get), it initializes a new asynchronous request... However, it doesn't initialize a new $http object.
Take a look at some of Addy Osmani's sample code for the singleton pattern:
return {
getInstance: function () {
if ( !instance ) {
instance = init();
}
return instance;
}
};
The singleton pattern simply ensures that a new instance of the $http service itself doesn't get initiliazed over and over again... But it doesn't mean there is just one XHR object.
The pseudo-code for the $http service would look something like this:
var $httpProvider = (function() {
var somePrivateConfig = "something important";
var service = {
request: function() {
// make an HTTP request with an XHR object
}
};
return {
init: function() {
// this is the important part that makes sure its a singleton
window.$http = window.$http || service;
}
};
})();
/**
* Something like this would be called whenever you
* inject the $http service as a dependency...
* However, since it could be passed into multiple things all in the same runtime,
* like controllers, directives, etc., we only need to initialize it ONE time
*/
$httpProvider.init();
/**
* Now let's pretend we're inside, say, a controller.
*
* This method can safely be called many times,
* but the method is always being called from the same singleton object
*/
$http.request();
Also, you'll notice that there's a local variable somePrivateConfig within the $httpProvider IIFE. If we were to re-initialize a new $http every time its injected to a component (whether that's a controller, directive, or whatever), a new private variable would be created, but we always want to be referencing that same value throughout the lifecycle of the $http object, so that we can guarantee that all those components are always referencing the same information.
But this has nothing to do with the XHR object itself. I may have misused some of the terminology above and misrepresented where and how providers themselves within the context of AngularJS are initialized into singleton objects, but the principle of the singleton pattern still stands in that it simply means the async request wrapper "class" (which is the $http service) is a singleton, but the XHR isn't.
$http requests are async and return a promise with methods success() and error(). Below more information ($q service, which is an implementation of promises by Angularjs):
"A service that helps you run functions asynchronously, and use their return values (or exceptions) when they are done processing"
Read here:
https://docs.angularjs.org/api/ng/service/$http
https://docs.angularjs.org/api/ng/service/$q