We Keep Coding

How to use RiveScript in Node.js to reply with a Facebook Messenger bot

Currently, I keep receiving Promise, and the error User localuser was in an empty topic named 'random'.
My code is structured like this
const bot = new RiveScript();
bot.loadDirectory("./brain");
bot.sortReplies();
Below is in a function
// blah
if (text === 'blah') {
return {
attachment: blah()
};
}
// No command is correct
return {
text: getReply(text)
};
function getReply(msg) {
const reply = bot.reply("localuser", msg);
return reply;
}
I've been trying everything, but I still need help getting a result where the text goes into the function and returns a reply from the RiveScript. I also ran debug, so the RiveScript files are definitely being read. I also tried using async functions and await for getReply but it doesn't work either.

I'm not overly familiar with RiveScript, however checking their GitHub, loadDirectory is an asynchronous function which would show as Promise<Pending> until the Promise has resolved (or is rejected).
You need to wait for the Promise to resolve before moving on in your code. Read up on asynchronous javascript or node, because there is a lot to learn! https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Asynchronous is a good start!
To start you off with your example:
const bot = new RiveScript();
bot.loadDirectory("./brain").then((response) => {
//Once loadDirectory is complete then do this...
bot.sortReplies();
});
then() will wait until the Promise has resolved before executing bot.sortReplies().
Note that .reply() also returns a Promise according to the ReadMe (https://github.com/aichaos/rivescript-js). So:
//bot.reply is asynchronous to you need to await the Promise to resolve before returning.
async function getReply(msg) {
return await bot.reply("localuser", msg);
}
Hopefully this gives you something to play with!

Waiting for another async function to finish before running

I have two functions that I want to run one after the other finishes. I'm using webdriver.IO so I need to wait for one function to log into the page, and then I want another function to run.
Other questions here on SOF are telling me to use a promise, however I need to use a promise, however when I wrap my functions in a promise I get the error SyntaxError: await is only valid in async function.
I have a login function
const Login = async () => {
const browser = await remote({
capabilities: {
browserName: 'chrome'
}
})
const userName = await browser.$('#username')
const password = await browser.$('#password')
await userName.setValue(process.env.NAMEUSERNAME)
await password.setValue(process.env.PASSWORD)
const loginButton = await browser.$('button[type="submit"]')
await loginButton.click()
}
Once this completes and the page loads I want to run another function.
I have gotten this to work with a setTimeout however I don't want to just have a chain of setTimeout in my application

It's hard to give you precise code without seeing where this is called from: but presuming it's inside some other function, you just have to mark that one async and use await inside it:
async theOuterFunction() {
await Login();
doTheOtherThing();
}
(If doTheOtherThing also returns a promise you could await that too - and would need to if you want to run other code inside theOuterFunction after that. But there's no need if it's the last statement inside the function.)

Module-scope variable refuses to be overwritten by an async function. Why?

The module-scope variable "output" refuses to be overwritten by the async function "retrieveTextWrapper", and I cannot figure out why. My objective is to output the text on StackOverFlow's homepage. retrieveTextWrapper successfully scrapes this information, but I can't seem to assign this content to the output variable. What am I doing wrong? How can I print the scraped information from the main() function?
Note: I am using electron version 3.0.4 because bypassing CORS is less of a pain on that version.
const {BrowserWindow, app} = require('electron')
output = "this should be overwritten by the retrieveTextWrapper method"
async function main(){
navigate();
win.openDevTools();
await win.webContents.once('dom-ready',retrieveTextWrapper);
console.log(output);
//prints "this should be overwritten by the retrieveTextWrapper method"
}
function navigate() {
win = new BrowserWindow({width:900,height:900});
win.loadURL(`https://stackoverflow.com/`);
}
function retrieveText(){
return `document.querySelector("*").innerText`;
}
async function retrieveTextWrapper(){
output = await win.webContents.executeJavaScript(retrieveText().replace("*", "#content"));
}
app.on('ready',main)

win.webContents.once() does not return a promise (since interfaces generally don't accept both callbacks and return a promise at the same time).
Therefore await doesn't wait for the asynchronous operation to complete. Therefore, you're looking at output before its value has been reassigned. await only does something useful when you await a promise that is connected to the asynchronous operation you're trying to wait for.
To confirm this timing issue, add a unique console.log() statement before and after the await win.webContents.once('dom-ready',retrieveTextWrapper); and inside of retrieveTextWrapper and then you can see the sequencing of these log messages.
Yep, everything changes as it should within retrieveTextWrapper function. And your explanation makes a lot of sense. However, is it possible to wait for the callback to finish (using some other syntax aside from await)? That way, I can use the updated value for other operations in the main function?
You have a couple options.
You could "promisify" win.webContents.once() so you could then use await with it.
You could put the callback inline and put the rest of your code in main inside that callback (a classic way of dealing with asynchronous operations).
Here's an example of promisifying win.webContents.once():
function waitForDomReady() {
return new Promise((resolve, reject) => {
// may want to check if document already has dom-ready and resolve immediately
win.webContents.once('dom-ready', resolve);
});
}
And, you could then use it like this:
async function main(){
navigate();
win.openDevTools();
await waitForDomReady();
await retrieveTextWrapper();
console.log(output);
}
This assumes that the code in retrieveTextWrapper that calls win.webContents.executeJavaScript() does actually return a promise when it's done. If not, you have to promisify that too.

Unexpected Promise in React Native

I am new to React Native and coding in general. I paid for some code on upwork and am having a hard time integrating it in my program.
async pullBatch(since){
let param = {
userScreenName: '?screen_name=google',
count: "&count=5",
retweets: "&include_rts=false",
replies: "&exclude_replies=false",
trim: "&trim_user=true",
since: "&max_id=" + since
};
let twitterRest = new TwitterRest(); //create a new instance of TwitterRest Class
let batch = await twitterRest.pullTweets(param); //pull the Google TimeLine
return batch;
}
pullTimeline(){
let timeLine = []
for(i = 0; i <= 2; i++){
let currentBatch = this.pullBatch("1098740934588751900")
console.log(currentBatch);
timeLine = timeLine.concat(currentBatch);
}
console.log(timeLine);
// timeLine = currentBatch
return(timeLine)
}
I believe that when running pullTimeLine() the program is returning an array of three promises. (I have also run the code with "await" before pullBatch(), but it is erroring out telling me await is a reserved word) This means I am making two mistakes:
I am not correctly understanding promises in JS or how they are resolved.
I am incorrectly concatenating the arrays.
I am constantly trying to learn, so while I greatly appreciate suggestions for code fixes, I also really would appreciate if you'd teach me about where my lapses in understanding lies.
Thank you

Let's break it down. You seem to understand that pullBatch is an async function, and so calling it will return a promise create by the twitterRest interaction.
The problem is that your call to pullBatch inside your for loop will not resolve these promise (which seems to be what you want to do). The easiest way is to use await for currentBatch, but as you tried, you got the reserved error. Basically you just need to also make pullTimeline async like this:
async pullTimeline(){
...
Just realise that once you do this, pullTimeline is now an async function that will also return a promise. So to use this function you need to either use .then(), for example:
pullTimeline().then(timeLine => {
// do something with your timeline here
})
Or if you are using it within another async function, you can use await.
const timeLine = await pullTimeline() // must be inside async function
Basically at some point in your calling chain, you will have to resolve a promise using .then(), or disregard the top level promise by making a top level async function. For example:
async useTimeline() {
const timeLine = await pullTimeline()
// do something with your timeline
}
// call the function above, and just disregard its promise
useTimeLine()
Just don't forget to handle errors somewhere. Either use a .catch() on your top level promise, or use try / catch around any of your await calls.

Sleep function for React-Native?

So I'm trying to fetch all 'places' given some location in React Native via the Google Places API. The problem is that after making the first call to the API, Google only returns 20 entries, and then returns a next_page_token, to be appended to the same API call url. So, I make another request to get the next 20 locations right after, but there is a small delay (1-3 seconds) until the token actually becomes valid, so my request errors.
I tried doing:
this.setTimeout(() => {this.setState({timePassed: true})}, 3000);
But it's completely ignored by the app...any suggestions?
Update
I do this in my componentWillMount function (after defining the variables of course), and call the setTimeout right after this line.
axios.get(baseUrl)
.then((response) => {
this.setState({places: response.data.results, nextPageToken: response.data.next_page_token });
});

What I understood is that you are trying to make a fetch based on the result of another fetch. So, your solution is to use a TimeOut to guess when the request will finish and then do another request, right ?
If yes, maybe this isn't the best solution to your problem. But the following code is how I do to use timeouts:
// Without "this"
setTimeout(someMethod,
2000
)
The approach I would take is to wait until the fetch finishes, then I would use the callback to the same fetch again with different parameters, in your case, the nextPageToken. I do this using the ES7 async & await syntax.
// Remember to add some stop condition on this recursive method.
async fetchData(nextPageToken){
try {
var result = await fetch(URL)
// Do whatever you want with this result, including getting the next token or updating the UI (via setting the State)
fetchData(result.nextPageToken)
} catch(e){
// Show an error message
}
}
If I misunderstood something or you have any questions, feel free to ask!
I hope it helps.

try this it worked for me:
async componentDidMount() {
const data = await this.performTimeConsumingTask();
if (data !== null) {
// alert('Moved to next Screen here');
this.props.navigator.push({
screen:"Project1.AuthScreen"})
}
}
performTimeConsumingTask = async() => {
return new Promise((resolve) =>
setTimeout(
() => { resolve('result') },
3000
)
);
}