I have a React Native app that may connect to different API endpoints. Some users may need to change API endpoint on the run time, without restarting the app. All the API requests are bound to sagas, and the root saga looks like
export default function* rootSaga() {
yield [
takeLatest([
ONE_REQUEST,
ANOTHER_REQUEST,
// a bunch of sagas that are responsible for API querying
], api); // <- here, api is global.
];
}
so it can run along with the newly instantiated Redux store:
import rootSaga from './sagas';
const sagaMiddleware = createSagaMiddleware();
const store = createStore(rootReducer, applyMiddleware(sagaMiddleware));
// other stuff, and finally
sagaMiddleware.run(rootSaga).done.catch(console.error);
The problem is, once executed, the Store, let alone sagas, can never be updated.
I tried to pass api to root saga as the first argument:
export default function* rootSaga(baseUrl = DEFAULT_API_URL) {
const api = create({
baseUrl,
// other stuff that is required by apisauce
});
yield [
takeLatest([
ONE_REQUEST,
ANOTHER_REQUEST,
// a bunch of sagas that are responsible for API querying
], api); // <- here, api is instantiated per every yield* of rootSaga.
];
}
I tried to refer to the generator itself from within a function executed per a certain action type:
yield [
takeLatest([
ONE_REQUEST,
ANOTHER_REQUEST,
// a bunch of sagas that are responsible for API querying
], api); // <- here, api is instantiated per every yield* of rootSaga.
takeEvery([
REPLACE_API // <- the action I would dispatch to replace API endpoint
], ({endpoint}) => {
yield cancel(rootSaga);
yield* rootSaga(endpoint); // <- the new API endpoint
});
];
But it didn't work. I also tried a bunch of other tactics, but none really worked either. And I looked up the docs for something similar to Redux's replaceReducer, but there's nothing like this for redux-saga, which makes me feel that it can be done using only proper sequence yielded by root saga generator.
So, is there a general approach to this problem? Is it possible to re-instantiate root saga on the run time?
It seems that you can add the endpoint URL to the state tree and manage updating the URL based on a typical redux-saga flow. Then, when you dispatch your REQUEST actions, just read the current end point URL from the state tree and attach that as a payload to the REQUEST action. Then, in your api saga, use that URL payload.
Related
I'm relatively new to puppeteer and I'm trying to understand the patterns that can be used to build more complex apis with it. I am building a cli where I am running a WebGL app in puppeteer which i call various functions in, and with my current implementation i have to copy and paste a lot of setup code.
Usually, in every cli command i have to setup pupeteer, setup the app and get access to its api object, and then run an arbitrary command on that api, and get the data back in node.
It looks something like this.
const {page, browser} = await createBrowser() // Here i setup the browser and add some script tags.
let data;
page.exposeFunction('extractData', (data) => {
data = data;
})
await page.evaluate(async (input) => {
// Setup work
const requestEvent = new CustomEvent('requestAppApi', {
api: undefined;
})
window.dispatchEvent(requestEvent);
const api = requestEvent.detail.api;
// Then i call some arbitrary function, that will
always return some data that gets extracted by the exposed function.
const data = api.arbitraryFunction(input);
window.extractData(data)
}, input)
What i would like is to wrap all of the setup code in a function, so that i could call it and just specify what to do with the api object once i have it.
My initial idea was to have a function that will take a callback that has this api object as a parameter.
const { page, browser } = wait createBrowser();
page.exposeFunction(async (input) =>
setupApiObject(((api) =>
api.callSomeFunction(input)
), input)
However, this does not work. I understand that puppeteer requires any communication between the node context and the browser to be serialised as json, and obviously a function cant be. Whats tripping me up is that I'm not actually wanting to call these methods in the node context, just have a way to reuse them. The actual data transfer is already handled by page.exposeFunction.
How would a more experienced puppeteer dev accomplish this?
I'll answer my own question here, since i managed to figure out a way to do it. Basically, you can use page.evaluate to create a function on the window object that can later be reused.
So i did something like
await page.evaluate(() => {
window.useApiObject = function(callback: (api) => void){
// Perform setup code
callback()
}
})
Meaning that later on i could use that method in the browser context and avoid redoing the setup code.
page.evaluate(() => {
window.useApiObject((api) => {
api.someMethod()
})
})
I am dealing with creating AWS API Gateway. I am trying to create CloudWatch Log group and name it API-Gateway-Execution-Logs_${restApiId}/${stageName}. I have no problem in Rest API creation.
My issue is in converting restApi.id which is of type pulumi.Outout to string.
I have tried these 2 versions which are proposed in their PR#2496
const restApiId = apiGatewayToSqsQueueRestApi.id.apply((v) => `${v}`);
const restApiId = pulumi.interpolate `${apiGatewayToSqsQueueRestApi.id}`
here is the code where it is used
const cloudWatchLogGroup = new aws.cloudwatch.LogGroup(
`API-Gateway-Execution-Logs_${restApiId}/${stageName}`,
{},
);
stageName is just a string.
I have also tried to apply again like
const restApiIdStrign = restApiId.apply((v) => v);
I always got this error from pulumi up
aws:cloudwatch:LogGroup API-Gateway-Execution-Logs_Calling [toString] on an [Output<T>] is not supported.
Please help me convert Output to string
#Cameron answered the naming question, I want to answer your question in the title.
It's not possible to convert an Output<string> to string, or any Output<T> to T.
Output<T> is a container for a future value T which may not be resolved even after the program execution is over. Maybe, your restApiId is generated by AWS at deployment time, so if you run your program in preview, there's no value for restApiId.
Output<T> is like a Promise<T> which will be eventually resolved, potentially after some resources are created in the cloud.
Therefore, the only operations with Output<T> are:
Convert it to another Output<U> with apply(f), where f: T -> U
Assign it to an Input<T> to pass it to another resource constructor
Export it from the stack
Any value manipulation has to happen within an apply call.
So long as the Output is resolvable while the Pulumi script is still running, you can use an approach like the below:
import {Output} from "#pulumi/pulumi";
import * as fs from "fs";
// create a GCP registry
const registry = new gcp.container.Registry("my-registry");
const registryUrl = registry.id.apply(_=>gcp.container.getRegistryRepository().then(reg=>reg.repositoryUrl));
// create a GCP storage bucket
const bucket = new gcp.storage.Bucket("my-bucket");
const bucketURL = bucket.url;
function GetValue<T>(output: Output<T>) {
return new Promise<T>((resolve, reject)=>{
output.apply(value=>{
resolve(value);
});
});
}
(async()=>{
fs.writeFileSync("./PulumiOutput_Public.json", JSON.stringify({
registryURL: await GetValue(registryUrl),
bucketURL: await GetValue(bucketURL),
}, null, "\t"));
})();
To clarify, this approach only works when you're doing an actual deployment (ie. pulumi up), not merely a preview. (as explained here)
That's good enough for my use-case though, as I just want a way to store the registry-url and such after each deployment, for other scripts in my project to know where to find the latest version.
Short Answer
You can specify the physical name of your LogGroup by specifying the name input and you can construct this from the API Gateway id output using pulumi.interpolate. You must use a static string as the first argument to your resource. I would recommend using the same name you're providing to your API Gateway resource as the name for your Log Group. Here's an example:
const apiGatewayToSqsQueueRestApi = new aws.apigateway.RestApi("API-Gateway-Execution");
const cloudWatchLogGroup = new aws.cloudwatch.LogGroup(
"API-Gateway-Execution", // this is the logical name and must be a static string
{
name: pulumi.interpolate`API-Gateway-Execution-Logs_${apiGatewayToSqsQueueRestApi.id}/${stageName}` // this the physical name and can be constructed from other resource outputs
},
);
Longer Answer
The first argument to every resource type in Pulumi is the logical name and is used for Pulumi to track the resource internally from one deployment to the next. By default, Pulumi auto-names the physical resources from this logical name. You can override this behavior by specifying your own physical name, typically via a name input to the resource. More information on resource names and auto-naming is here.
The specific issue here is that logical names cannot be constructed from other resource outputs. They must be static strings. Resource inputs (such as name) can be constructed from other resource outputs.
Encountered a similar issue recently. Adding this for anyone that comes looking.
For pulumi python, some policies requires the input to be stringified json. Say you're writing an sqs queue and a dlq for it, you may initially write something like this:
import pulumi_aws
dlq = aws.sqs.Queue()
queue = pulumi_aws.sqs.Queue(
redrive_policy=json.dumps({
"deadLetterTargetArn": dlq.arn,
"maxReceiveCount": "3"
})
)
The issue we see here is that the json lib errors out stating type Output cannot be parsed. When you print() dlq.arn, you'd see a memory address for it like <pulumi.output.Output object at 0x10e074b80>
In order to work around this, we have to leverage the Outputs lib and write a callback function
import pulumi_aws
def render_redrive_policy(arn):
return json.dumps({
"deadLetterTargetArn": arn,
"maxReceiveCount": "3"
})
dlq = pulumi_aws.sqs.Queue()
queue = pulumi_aws.sqs.Queue(
redrive_policy=Output.all(arn=dlq.arn).apply(
lambda args: render_redrive_policy(args["arn"])
)
)
I am writing a private plugin for nodebb (open forum software). In the nodebb's webserver.js file there is a line that seems to be hogging all incoming json data.
app.use(bodyParser.json(jsonOpts));
I am trying to convert all incoming json data for one of my end-points into raw data. However the challenge is I cannot remove or modify the line above.
The following code works ONLY if I temporarily remove the line above.
var rawBodySaver = function (req, res, buf, encoding) {
if (buf && buf.length) {
req.rawBody = buf.toString(encoding || 'utf8');
}
}
app.use(bodyParser.json({ verify: rawBodySaver }));
However as soon as I put the app.use(bodyParser.json(jsonOpts)); middleware back into the webserver.js file it stops working. So it seems like body-parser only processes the first parser that matches the incoming data type and then skips all the rest?
How can I get around that? I could not find any information in their official documentation.
Any help is greatly appreciated.
** Update **
The problem I am trying to solve is to correctly handle an incoming stripe webhook event. In the official stripe documentation they suggested I do the following:
// Match the raw body to content type application/json
app.post('/webhook', bodyParser.raw({type: 'application/json'}),
(request, response) => {
const sig = request.headers['stripe-signature'];
let event;
try {
event = stripe.webhooks.constructEvent(request.body, sig,
endpointSecret);
} catch (err) {
return response.status(400).send(Webhook Error:
${err.message});
}
Both methods, the original at the top of this post and the official stripe recommended way, construct the stripe event correctly but only if I remove the middleware in webserver. So my understanding now is that you cannot have multiple middleware to handle the same incoming data. I don't have much wiggle room when it comes to the first middleware except for being able to modify the argument (jsonOpts) that is being passed to it and comes from a .json file. I tried adding a verify field but I couldn't figure out how to add a function as its value. I hope this makes sense and sorry for not stating what problem I am trying to solve initially.
The only solution I can find without modifying the NodeBB code is to insert your middleware in a convenient hook (that will be later than you want) and then hack into the layer list in the app router to move that middleware earlier in the app layer list to get it in front of the things you want to be in front of.
This is a hack so if Express changes their internal implementation at some future time, then this could break. But, if they ever changed this part of the implementation, it would likely only be in a major revision (as in Express 4 ==> Express 5) and you could just adapt the code to fit the new scheme or perhaps NodeBB will have given you an appropriate hook by then.
The basic concept is as follows:
Get the router you need to modify. It appears it's the app router you want for NodeBB.
Insert your middleware/route as you normally would to allow Express to do all the normal setup for your middleware/route and insert it in the internal Layer list in the app router.
Then, reach into the list, take it off the end of the list (where it was just added) and insert it earlier in the list.
Figure out where to put it earlier in the list. You probably don't want it at the very start of the list because that would put it after some helpful system middleware that makes things like query parameter parsing work. So, the code looks for the first middleware that has a name we don't recognize from the built-in names we know and insert it right after that.
Here's the code for a function to insert your middleware.
function getAppRouter(app) {
// History:
// Express 4.x throws when accessing app.router and the router is on app._router
// But, the router is lazy initialized with app.lazyrouter()
// Express 5.x again supports app.router
// And, it handles the lazy construction of the router for you
let router;
try {
router = app.router; // Works for Express 5.x, Express 4.x will throw when accessing
} catch(e) {}
if (!router) {
// Express 4.x
if (typeof app.lazyrouter === "function") {
// make sure router has been created
app.lazyrouter();
}
router = app._router;
}
if (!router) {
throw new Error("Couldn't find app router");
}
return router;
}
// insert a method on the app router near the front of the list
function insertAppMethod(app, method, path, fn) {
let router = getAppRouter(app);
let stack = router.stack;
// allow function to be called with no path
// as insertAppMethod(app, metod, fn);
if (typeof path === "function") {
fn = path;
path = null;
}
// add the handler to the end of the list
if (path) {
app[method](path, fn);
} else {
app[method](fn);
}
// now remove it from the stack
let layerObj = stack.pop();
// now insert it near the front of the stack,
// but after a couple pre-built middleware's installed by Express itself
let skips = new Set(["query", "expressInit"]);
for (let i = 0; i < stack.length; i++) {
if (!skips.has(stack[i].name)) {
// insert it here before this item
stack.splice(i, 0, layerObj);
break;
}
}
}
You would then use this to insert your method like this from any NodeBB hook that provides you the app object sometime during startup. It will create your /webhook route handler and then insert it earlier in the layer list (before the other body-parser middleware).
let rawMiddleware = bodyParser.raw({type: 'application/json'});
insertAppMethod(app, 'post', '/webhook', (request, response, next) => {
rawMiddleware(request, response, (err) => {
if (err) {
next(err);
return;
}
const sig = request.headers['stripe-signature'];
let event;
try {
event = stripe.webhooks.constructEvent(request.body, sig, endpointSecret);
// you need to either call next() or send a response here
} catch (err) {
return response.status(400).send(`Webhook Error: ${err.message}`);
}
});
});
The bodyParser.json() middleware does the following:
Check the response type of an incoming request to see if it is application/json.
If it is that type, then read the body from the incoming stream to get all the data from the stream.
When it has all the data from the stream, parse it as JSON and put the result into req.body so follow-on request handlers can access the already-read and already-parsed data there.
Because it reads the data from the stream, there is no longer any more data in the stream. Unless it saves the raw data somewhere (I haven't looked to see if it does), then the original RAW data is gone - it's been read from the stream already. This is why you can't have multiple different middleware all trying to process the same request body. Whichever one goes first reads the data from the incoming stream and then the original data is no longer there in the stream.
To help you find a solution, we need to know what end-problem you're really trying to solve? You will not be able to have two middlewares both looking for the same content-type and both reading the request body. You could replace bodyParser.json() that does both what it does now and does something else for your purpose in the same middleware, but not in separate middleware.
I'm new at emberjs and I'm starting to learn how it works,
what is the difference when specifying the json on routes or on models
model: function() {
var url = 'https://api.github.com/repos/emberjs/ember.js/pulls';
return Ember.$.getJSON(url).then(function(data) {
return data.splice(0, 4);
});
},
this is how i call the json on routes , now my problem , what is the use of this function
export default DS.RESTAdapter.extend({});
The DS.RESTAdapter is part of ember-data. You can use ember-data to load your json from a rest api. It is how ever very opinionated about said api. I don't believe it will work out of the box with the github api you are calling.
If I were you I'd focus on getting to grips with emberjs and when you feel you're getting comfortable with it you can expand your focus to include ember-data.
I'm using Ember-Data 1.0.0.Beta-9 and Ember 1.7 to consume a REST API via DreamFactory's REST Platform. (http://www.dreamfactory.com).
I've had to extend the RESTAdapter in order to use DF and I've been able to implement GET and POST requests with no problems. I am now trying to implement model.save() (PUT) requests and am having a serious hiccup.
Calling model.save() sends the PUT request with the correct data to my API endpoint and I get a 200 OK response with a JSON response of { "id": "1" } which is what is supposed to happen. However when I try to access the updated record all of the properties are empty except for ID and the record on the server is not updated. I can take the same JSON string passed in the request, paste it into the DreamFactory Swagger API Docs and it works no problem - response is good and the record is updated on the DB.
I've created a JSBin to show all of the code at http://emberjs.jsbin.com/nagoga/1/edit
Unfortunately I can't have a live example as the servers in question are locked down to only accept requests from our company's public IP range.
DreamFactory provides a live demo of the API in question at
https://dsp-sandman1.cloud.dreamfactory.com/swagger/#!/db/replaceRecordsByIds
OK in the end I discovered that you can customize the DreamFactory response by adding a ?fields=* param to the end of the PUT request. I monkey-patched that into my updateRecord method using the following:
updateRecord: function(store, type, record) {
var data = {};
var serializer = store.serializerFor(type.typeKey);
serializer.serializeIntoHash(data, type, record);
var adapter = this;
return new Ember.RSVP.Promise(function(resolve, reject) {
// hack to make DSP send back the full object
adapter.ajax(adapter.buildURL(type.typeKey) + '?fields=*', "PUT", { data: data }).then(function(json){
// if the request is a success we'll return the same data we passed in
resolve(json);
}, function(reason){
reject(reason.responseJSON);
});
});
}
And poof we haz updates!
DreamFactory has support for tacking several params onto the end of the requests to fully customize the response - at some point I will look to implement this correctly but for the time being I can move forward with my project. Yay!
EmberData is interpreting the response from the server as an empty object with an id of "1" an no other properties in it. You need to return the entire new object back from the server with the changes reflected.