Develop Reference

matrix-js-sdk setup and configuration

I am having some issues trying to connect to a matrix server using the matrix-js-sdk in a react app.
I have provided a simple code example below, and made sure that credentials are valid (login works) and that the environment variable containing the URL for the matrix client is set. I have signed into element in a browser and created two rooms for testing purposes, and was expecting these two rooms would be returned from matrixClient.getRooms(). However, this simply returns an empty array. With some further testing it seems like the asynchronous functions provided for fetching room, member and group ID's only, works as expected.
According to https://matrix.org/docs/guides/usage-of-the-matrix-js-sd these should be valid steps for setting up the matrix-js-sdk, however the sync is never executed either.
const matrixClient = sdk.createClient(
process.env.REACT_APP_MATRIX_CLIENT_URL!
);
await matrixClient.long("m.login.password", credentials);
matrixClient.once('sync', () => {
debugger; // Never hit
}
for (const room of matrixClient.getRooms()) {
debugger; // Never hit
}
I did manage to use the roomId's returned from await matrixClient.roomInitialSync(roomId, limit, callback), however this lead me to another issue where I can't figure out how to decrypt messages, as the events containing the messages sent in the room seems to be of type 'm.room.encrypted' instead of 'm.room.message'.
Does anyone have any good examples of working implementations for the matrix-js-sdk, or any other good resources for properly understanding how to put this all together? I need to be able to load rooms, persons, messages etc. and display these respectively in a ReactJS application.

It turns out I simply forgot to run startClient on the matrix client, resulting in it not fetching any data.

Send String to Node.js

I'm trying create a simple UI here on my iOS app to test a thing or two out but I'm having some issues here. My app is set up with a UITextField and UIButton. I'm trying to replace a string on my .js file which is saved on my virtual server. In my .js file I have below:
// Prepare a new notification
var notification = new apn.Notification();
// Display the following message (the actual notification text, supports emoji)
notification.alert = 'Hi James';
I basically would like to replace "Hi James" with whatever I typed in the UITextField in my Swift 3 project but not too sure where to start. This would be my first time sending data to .js file so anything would help. I'm thinking so far that it'd be something along the lines to below. Node.js would be similar to Javascript since it's cross platform.
func sendSomething(stringToSend : String) {
appController?.evaluateInJavaScriptContext({ (context) -> Void in
//Get a reference to the "myJSFunction" method that you've implemented in JavaScript
let myJSFunction = evaluation.objectForKeyedSubscript("myJSFunction")
//Call your JavaScript method with an array of arguments
myJSFunction.callWithArguments([stringToSend]) }, completion: { (evaluated) -> Void in
print("we have completed: \(evaluated)")
})
}
Found that on a relevant StackOverflow post so I feel like I'm getting close. Any assistant would be appreciated in advanced. Have a good one!

I recommend using the Node HTTP or ExpressJS server reading the POST fields and posting a document from your iOS app with the desired field
See
https://nodejs.org/en/docs/guides/anatomy-of-an-http-transaction/

Filter Active Users based on page title- Google Analytics

I need to show active visitors on my website based on Page title.
Example : If the user is Contact Us page, then onlycount of active visitors on 'Contact us' page is to be shown instead of entire site.
I am following Embed API Third Party Visualizations
I tried the following code but it is not working
var activeUsers = new gapi.analytics.ext.ActiveUsers({
container: 'active-users-container',
pollingInterval: 5,
query: {
filters:'ga:pageTitle==Contact'
}
});
Please help me to resolve this issue.

As I mentioned in the Github issue opened about this same question, what you're asking to do is not possible with the current ActiveUsers Embed API component (it's just for demo purposes, it's not intended to be a full-featured Real Time query component).
However, this component could easily be modified to support your use case. You'd just have to update the lines that make the API request to add your query parameters.
Here is the relevant line of code that makes the request:
gapi.client.analytics.data.realtime
.get({ids: options.ids, metrics: 'rt:activeUsers'})
.then(function(response) {
// ... do something with the response
});
To add your filter, you'd just have to change that line to something like this:
gapi.client.analytics.data.realtime
.get({
ids: options.ids,
metrics: 'rt:activeUsers',
filters: 'ga:pageTitle==Contact'
})
.then(function(response) {
// ... do something with the response
});
Of course, you'd probably rather refactor the component to accept an options object (as you show in your question), so you don't have to hard code your query, but I'll leave it up to you to make that code change.
To point you in the right direction, you should read the Embed API guide: Creating Custom Components. You'll probably also need to reference the Shared Component Reference to see the methods all components can call.

I tried this Show active visitors after filtering
it worked.

creating a configuration page and passing variables to a simply.js app

i developed a simply.js app that fetches bus arrival time from a webservice, problem is that as of now it work only for one stop.
i want to create a configuration page with a multiselect where i could choose multiple stops , sending them to the pebble as an array and at the press of up/down buttons i want to cycle the array to show different bus stops.
Im not good in C, i prefere javascript thats because i used simply.js.
id like to know and learn how to do it, because i think online there isnt much documentation and examples.

Found a similar question/ issue at simply.js github page https://github.com/Meiguro/simplyjs/issues/11. The code example below comes from Meiguros first answer. The code sends the user to your configuration website, which you should configure to send json back.
You can probably copy the code example for enabling the configuration window and paste it in the begining of your main pebble app.js file. Do not forget to add "capabilities": [ "configurable" ], in your appinfo.json file. If you are using cloudpebble you should go to the settings page of your app and make sure the configurable box is checked.
var initialized = false;
Pebble.addEventListener("ready", function() {
console.log("ready called!");
initialized = true;
});
Pebble.addEventListener("showConfiguration", function() {
console.log("showing configuration");
//change this url to yours
Pebble.openURL('http://assets.getpebble.com.s3-website-us-east-1.amazonaws.com/pebble-js/configurable.html');
});
Pebble.addEventListener("webviewclosed", function(e) {
console.log("configuration closed");
// webview closed
var options = JSON.parse(decodeURIComponent(e.response));
console.log("Options = " + JSON.stringify(options));
});
(https:// github.com/pebble-hacks/js-configure-demo/blob/master/src/js/pebble-js-app.js - remove space after https://)
To then push the settings back to the pebble i think you need to add
Pebble.sendAppMessage(options);
just before
console.log("configuration closed");
// webview closed
I found this out at the last post on this pebble forum thread http://forums.getpebble.com/discussion/12854/appmessage-inbox-handlers-not-getting-triggered-by-javascript-configuration-data
You can aslo find a configuration website example named configurable.html in the same git as the code example at https:// github.com/pebble-hacks/js-configure-demo remove space after https://
Hope this helps a bit on the way to achieving your goal

So the configuration page is a web page, and you can host it and provide your URL as mentioned by Ankan above.
Like this:
Pebble.openURL('http://assets.getpebble.com.s3-website-us-east-1.amazonaws.com/pebble-js/configurable.html');
Lets say you decide to take the name and age of the user in the configuration page, you would have two text fields for them to enter their information, then you would have a submit button. For the submit button write a javascript function which uses jQuery to take the values of the text fields onclick, then save those values to a variable, and use JSON to send them to the phone. Here is an example of a fully created configuration web page: https://github.com/pebble-hacks/js-configure-demo
Enjoy.

How do I catch an invalid API key for google maps

I have this code:
<script src="http://maps.google.com/maps?file=api&v=2&sensor=false&key=babab" type='text/javascript'></script>
If the key is invalid then it pops up an alert, but I want to perform some action in this case. I'm not sure how to hook into it though. Any ideas?

Google does not offer an external method of checking the Google Maps API key. Hence you cannot query some service with e.g. "Is this code valid abcde1234" and get a TRUE/FALSE response.
There is a discussion on how the Maps API key is generated. But I suggest you look at a post from Mike Williams about the GValidateKey function. This is the function actually doing the magic validation - what it exactly does, like creating a hash from your Google account / domain - we don't know.
I see two solutions for your problem of checking whether the API key provided is correct:
Overwrite the incoming alert with some custom code (check for the content of the alert, or check if an alert occurs withing X seconds after page load)
Somehow get the GValidateKey function to validate your key beforehand. Maybe you can call it before referencing the API Javascript? Sounds kind of hackish to me...
The problem you will likely have is that you don't know what Google actually checks. The referrer, the referring site, the host - many possibilities (it is not the IP address of the server, but the name plus some additional information).

I just ran across the need to perform an action if an invalid API key was used. Google's documentation states:
If you want to programmatically detect an authentication failure (for example to automatically send an beacon) you can prepare a callback function. If the following global function is defined it will be called when the authentication fails.
This was all I needed to do:
function gm_authFailure() { // Perform action(s) }

For modern browsers (IE9+ and others) you may use DOMNodeRemoved event. You just need to add event handler to the element that you pass to the map constructor:
var map = new google.maps.Map(element, myOptions);
element.addEventListener("DOMNodeRemoved", function(e){
if (e.target === element){
//your code here
element.removeEventListener("DOMNodeRemoved", mapWasRemovedHandler, true);
}
}, false);