friend-list | A non-trivial front-end programming challenge | State Container library

I have two child components updating the same state of a parent component. both the child component contains a loop and each element of the loop updates the state on click by event.

The parent Component:-

I'm developing aspnetzero application with angular but when I'm assigning value of categories property in p-dataTable I'm getting this error in browser console:

Can't bind to 'value' since it isn't a known property of 'p-dataTable'

I have three files. First file categories.component.ts

I'm trying to add AGM Angular Google Maps (https://github.com/SebastianM/angular-google-maps) to my Angular4 Project

Guide followed: https://github.com/SebastianM/angular-google-maps/blob/master/docs/getting-started.jade

The error I get when I visit the page with the agm component:

This template is on friends page init. I have tried to call button click in 2 ways button#id or just with #id but i havent been able to capture the button click. I have debugged it and it never joins onClick function. I would appreciate any help or documentation link. Thanks for your time.

I am creating chat box to my web application. When I click the float button the chat box will appear after the div container. But I want chat box fixed at the right side. I don't know where I did wrong. Here I attached some code samples.

html:

I'm experiencing crashes and I'm not too sure how to handle the situation with nested dispatchgroup inside a dispatchgroup. I know I'm doing something wrong and getting crashes and would like some help with how to handle below situation:

I am using IOS Swift and Firebase and basically grabbing relevant mutual friends by first grabbing a friendList, and then grabbing the friends of each of the friends on my friendList (as those are my mutual friends), if I have not grabbed them earlier (I use a list to track ids of friends Ive already grabbed), I send another network request to fb to grab the number of mutual friends between current user and mutual friend and check if they are relevant enough to be added.

However I have another request after that grabs school friends from firebase and I need to make sure there arent duplicate entries because there are school friends that are also mutual friends. I'm using Dispatch groups like so:

BACKBONE and Jquery

I have a piece of code:

I am in the process of creating an android application which uses Firebase. I am actually new to Firebase and I was searching on how to do the below features. I couldn't find a specific answer or the ones I found, I couldn't understand them well. If anyone can answer them, I will really appreciate it. :)

Features:

Feature 1: In my application when User A adds User B. I want the User B to get a notification, something like, "User A wants to add you as a friend." If User B confirms it then and only then should User B be added to User A's "friend-list" and vice-versa. If User B rejects, then the opposite should happen. Also, when User B removes User A from the "friend-list", both of them should be deleted from each other's "friend=list" and a notification of the said should happen.

Feature 2: I want the same to happen now but this time I want User Z to be the admin of User B and now when User A wants to add User B. The notification should go to User Z as well as User B. But rejecting it or accepting it should depend on User Z alone. So here it's between User A and User Z.

I want to know if I should use triggers in the Firebase database to achieve this or should I use the 'Security Features' of Firebase. I am sure there is a way to do this. I appreciate the help. :)