I am using fastapi for the first time in a project.
I receive information from an html form and return a HTMLResponse object to indicate that the program is running in the background (thanks to the BackgroundTask object). Is there a way to return another HTML file and to make my browser switch to that once the background task is over?
Sorry if I use the wrong terminology, but I am no expert.
Cheers
So what you need to do here is implement websockets. After your task is finished you can have to send a message on the websockets intimidating that the task has finished.
Think of it like a notification service.
You can find some documentation here
You will have to connect to the websocket from your frontend as well.
Do you research on this, I'm sure you will find a lot of documentation and articles on this idea.
Related
I've been working on the React Native platform this last couple of months and I need to implement a solid way to handle my API calls. At the moment I'm using redux to manage satate changes. Obviously the requestes must have a couple of retries if there is no network available, refresh oAuth tokens, etc.
Three solutions have ocurred to me:
Implement a "manager" class and handle all the logic in there. I like this one but I don't know if is possible to connect a non-component to redux since they dont have state.
Implement a couple of redux actions(request, onResponse, onError...) which should do the trick.
Create separated redux actions with their own fetchs to every call instead of having a centralized component.
What solution should I implement?
Another problem I've faced is that if a Network Error happens the promise is resolved even if I call the request again and I'm no longer able to make the behavior programmed in the caller method. Any workarounds?
Thank you for your time.
Redux has two powerful libraries that are designed to work with async API calls. These allow you to handle retries, errors, and slow API calls in the background of your app, simply by listening for a specific action.
Redux-thunk or Redux-saga are what you are probably going to want to use, so that you do not have to do all of the work of managing how components deal with API calls. Strongly recommend you check these out - there are quite a few tutorials out there that describe how to use these modules. Doing this by hand is not a good best practice IMO.
For api handling. you can have one single file which will have all function (export) and other settings needed so that you just have to import required methods.
You can use starter kit for react-native for basic structure for example: https://github.com/futurice/pepperoni-app-kit
it provides most of the things that we need for fresh project setup.
Follow the pattern mentioned in the below tutorial(youtube link below)
https://www.youtube.com/watch?v=9mlwjZL3Fmw
Everyone uses this pattern for API calls when following redux in react-native.
The tutorial is really good,its a great video.
I've joined a project that uses Jax-RS (and originally there was quite a bit of Spring-based Controller code in there too, but all URL handlers use Jax-RS now). Now we want to be able to fill in a queue of tasks that should be run with a small delay between each of them. The delay can be specified in ms. I've avoided Thread.sleep, as I've heard you should not manage threads manually in Java EE. Before I came in there was already a busy wait loop implemented.
I would like to switch this to an asynchronous background task. I could of course let the client poll the server with the given delay, and just have an AsyncResponse that can be resumed. But can the same AsyncResponse be resumed/suspended multiple times? The resource does have state, so it would be possible to drop the asynchrony completely and just do client polling to handle all of it.
A lot of example code for showing off asynchronous tasks use Thread.sleep. How bad is it to do this in a background task on an ExecutorService or something similar?
The point of the delay is to simulate human interaction, and post a long list of JMS messages to a queue but ensure that two listeners don't pick up and handle messages that depend on one another.
Is it easier/better to handle this on the client side rather than the server side? Writing some JavaScript that handles all the polling would be quite simple, so if this seems like a bad idea for handling on the server side, it's not that big a deal.
The tool is only going to be used by a single user, as it's a developer testing tool. Therefore we went for solving this on the client side, pushing the messages onto the queue through AJAX calls. This works fine for our purposes, but if anyone has a solution that might help someone else. Feel free to drop a new answer.
For manually testing an HTTP client in my application, I'd like to use a tool which starts an HTTP server my application can connect to and that lets me respond to request from my application manually. I'm basically looking for a tool with a GUI that lists all incoming requests and allows me to select a status code and type a response message. I've already tested the functionality with unit tests but I also want to verify it manually with no mocking etc.
Sounds simple but I didn't find such a tool. I've found some that can be scripted but no interactive one. Do you know one?
This can probably be written relatively easily by creating the Swing GUI dialog popup inside the servlet servicing methods. Have never seen Tomcat running this way but probably it would. Only, mind the server time out. It may be not long enough for you to make an input and require to be configured, also on the client side. Also, parallel calls will make multiple popups that may be difficult to respond but probably this is a single client app.
As a simplest solution, server GUI can be simply disposed after call and newly created as the next call arrives. This will make eveything indepenent on how servlet container is managing the servlets (does it stays, is it destroyed, maybe class is unloaded, who knows). Advanced solution could include the "server servlet" that would interact through its own JSP page but then it may be complex to update it when the new call arrives (unless maybe refresh periodically).
I have a process which I will be invoking manually for the first time in prod environment. Thing is, the process stops when the server is down or if the server is stopped. In this scenario, I will not be able to invoke the process manually everytime since it will be in production environment and not feasible also. So i need to know how can i invoke a process automatically once the server is up?
Heard that one way is to write a custom component to start the process using livecycle implementation class.
Please let me know how to go about it?
Any help regarding this is much appreciated!
Thanks
There are at least two ways you can do this.
First is the custom component route. You invoke the process on component life-cycle start to ensure that the invocation happens every time your component is deployed.
Second is the servlet route. You invoke the process on the initialisation of the servlet making sure that the server started.
The servlet implementation is a better fit for purpose, the only downside is, you need to package and deploy it separately as it won't be a part of the LCAs.
You can find the code samples on how to invoke LC processes using APIs on adobe docs. You can use Java API, WS API or Rest, whichever you are more comfortable with.
http://help.adobe.com/en_US/livecycle/9.0/programLC/help/index.htm
I am creating a node.js module which communicates with a program through XML-RPC. The API for this program changed recently after a certain version. For this reason, when a client is created (createClient) I want to ask the program its version (through XML-RPC) and base my API definitions on that.
The problem with this is that, because I do the above asynchronously, there exists a possibility that the work has not finished before the client is actually used. In other words:
var client = program.createClient();
client.doSomething();
doSomething() will fail because the API definitions have not been set, I imagine because HTTP XML-RPC response has not returned from the program.
What are some ways to remedy this? I want to be able to have a variable named client and work with that, as later I will be calling methods on it to get information (which will be returned via a callback).
Set it up this way:
program.createClient(function (client) {
client.doSomething()
})
Any time there is IO, it must be async. Another approach to this would be with a promise/future/coroutine type thing, but imo, just learning to love the callback is best :)