Writing a web chat application with Vue:
Introduction: Vue.js is a
progressive framework for building user interfaces. It is one of the most
popular JavaScript frameworks to build user interfaces from the ground up in an
incremental manner. The core library is a view-only framework and as such can
be linked into web pages directly from a content data network. For example, if
we want to build a webchat application, the following article
will help us get started.
Description: A sample web
page to be written in Vue could start with just the template, style, and script
as shown in reference 1. All of this can be on the same web page but Vue
provides excellent integration with many other frameworks so it is easy to package
code in single file components that end with the .vue extension. These
can then be combined into the main page with the help of component declaration
and use. Each view file allows specifying a template, script, and style snippet.
A vue instance
consists of a root Vue instance and includes a tree of nested, reusable
components when the application is well-organized. The instance created with a
dictionary for data and methods which tells Vue’s reactivity system how to
respond when the data changes from the user interface. There is a freezing method
available that can prevent the existing properties from being changed but for
the most part, a vue instance responds to the user’s directives.
The state can be maintained
to avoid re-rendering. This requires the use of a keep-alive directive
surrounding the component Together with data, methods, and state, the vue instance
can be successfully tested in all three forms: unit-testing, component testing
and end-to-end testing.
When we build a web-chat system, we simply
define the template to comprise the component items we want to show. For
example, a
webchat system will be created with the help of vue-quick-chat. The look and feel of the web
chat can be customized using the participants, messages, onType,
onMessageSubmit, chatTitle, placeholder, colors, borderStyle, hideCloseButton
and icon sizes. The onType and onMessageSubmit attributes allow the user
experience to be customized and connected with any backend APIs.
The data and
method handlers can be integrated with any backend system that parses the
content of the messages. There is only one requestor and one responder, in this
example, but the webchat user interface control can is independent of the
backend system that behaves as the responder. It can even allow passive
forwarding of messages between a group chat simply by making calls to a backend
system. If the backend system is to be avoided to make the calls, the nodeJs
can forward the message from one member to the other members of the group chat.
Conclusion: The framework
provides incrementally adoptable components that can be mixed and matched to
create a view and complex controls, logic, and workflow can be broken down and
packaged into granular and reusable components.
#codingexercises
find the largest square embeddable in a bar chart
import java.util.*;
class Solution {
public int solution(int[] A) {
int max = Integer.MIN_VALUE;
for (int i = 0; i < A.length; i++) {
for (int j = 0; j < A[i]; j++){
int side = 1;
for (int k = i + 1; k < A.length && k - i + 1 <= j + 1 && A[k] >= j+1; k++) {
side = k - i + 1;
}
if (side > max) {
max = side;
}
}
}
return max;
}
}
