As I went trough the client channel code (inside the phoenix.js file) I saw that it uses ES6. Sample code:
let chan = socket.chan("rooms:123", {token: roomToken})
// chan.on("new_msg", msg => console.log("Got message", msg) )
// $input.onEnter( e => {
// chan.push("new_msg", {body: e.target.val})
// .receive("ok", (message) => console.log("created message", message) )
// .receive("error", (reasons) => console.log("create failed", reasons) )
// .after(10000, () => console.log("Networking issue. Still waiting...") )
this.onError( reason => {
this.socket.log("channel", `error ${this.topic}`, reason)
this.state = CHAN_STATES.errored
this.rejoinTimer.setTimeout()
})
That means that it won't run natively in IE and Safari (ate least). Shouldn't I use some kind of polyfills?
What's the best approach/polyfill?
Also, I'm under the impression that polyfills cover classes/let/...but not arrow functions/new string interpolation. Should I change those myself?
Since ES6 adds new syntax to the language, there is no way to polyfill arrow functions.
However, when creating a new application, Phoenix installs a library called Brunch which is used for combining assets. It includes a wrapper for Babel which will transpile ES6 to JavaScript that will run in the browser.
If you look at priv/static/app.js (the compiled output) instead of web/static/app.js (the source) then you will see it does not have the new ES6 syntax.
One thing you may find if you use certain functions then you may need to include babel-polyfill.js which you can read about at https://babeljs.io/docs/advanced/caveats/
This was introduced in Phoenix 0.10.0 and you can read more about it in the announcement post http://www.phoenixframework.org/v0.14.0/blog/phoenix-0100-released-with-assets-handling-generat
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()
})
})
So I'm trying to programmatically answer phone calls (on Android 10) in React Native. I tried using react-native-callkeep but it seems that I can't figure out the documentation. Here's my code using the package:
// Listening on call state changes
this.listener = EventRegister.addEventListener(
CallManager.listenerName,
type => {
switch (type) {
case CallManager.eventNames.Incoming:
self.setState({
isCurrentlyBeingCalled: true,
});
CallKeep.answerIncomingCall(); // This won't work
break;
}
},
);
The documentation tells me to pass a uuid - but what uuid??? I tried using random uuids but that doesn't work either.
Does someone maybe know another better package to simply answer phone calls in React Native?
If you look towards the lower end of the documentation, you will see the "Events" section. There you can register listeners which'll give you the callUUID so you can pass it into your method.
import RNCallKeep from 'react-native-callkeep';
RNCallKeep.addEventListener('didReceiveStartCallAction', ({ handle, callUUID, name }) => {
console.log(`Received Start Call Event - Name: ${name}, Uuid: #{callUUID}`;
RNCallKeep.answerIncomingCall(callUUID);
});
I haven't tested this, just what i compiled from the documentation, but try it out.
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.
The Aurelia fetch client docs have a basic example of getting json data:
bind() {
let client = new HttpClient();
return client.fetch('data.json')
.then(response => response.json())
.then(data => {
console.log(data[1]);
});
}
The above works fine yet the following does not:
files = [];
bind() {
let client = new HttpClient();
return client.fetch('data.json')
.then(response => response.json())
.then(files => this.files = files);
}
Gulp now complains "error TS2322: Type 'Response' is not assignable to type 'any[]'."
Even more odd is that I now get XHR 404 errors in my console. This makes no sense; the data.json file had no issue being found and fetched the first time. The only difference in the second code snippet is that instead of logging the data to the console, I'm actually trying to do something with it.
I believe your specific issue may be caused by an older version of TypeScript (2.1, the latest is 2.5). If you have an opportunity to do so, you can try updating it.
response in the statement response => is of type Response defined by Aurelia. When you are running this.files = files, it seems like TypeScript thinks that files is of type Response. You are already implicitly declaring this.files as type any[], so the assignment is not allowed.
You can get around this by setting an explicit type for files, or even just using any:
.then((files: any[]) => this.files = files);
I would try to avoid using any to get around type safety and work with the types, but the issue you're running into appears to be a bug in the version of TypeScript and/or Aurelia that you're using.
I'm using JSON.NET version 6.0.1 and here my code below
var text = await FileHelper.ReadFileAsync(folderSetting, fileName);
var items = await JsonConvert.DeserializeObjectAsync<ObservableCollection<ItemModel>>(text);
But my Visual Studio Warning
Warning 7 'Newtonsoft.Json.JsonConvert.DeserializeObjectAsync(string)' is obsolete: 'DeserializeObjectAsync is obsolete. Use the Task.Factory.StartNew method to deserialize JSON asynchronously: Task.Factory.StartNew(() => DeserializeObject(value))'
The library authors decided that it was not the responsibility of the library to provide asynchronous wrappers and marked them obsolete. (see http://blogs.msdn.com/b/pfxteam/archive/2012/03/24/10287244.aspx). In future versions these methods will be removed. You should do something like this instead:
var result = await
Task.Factory.StartNew(() => JsonConvert.DeserializeObject<MyObject>(jsonText));