Routine analysis of the amazing node.js reading notes_node.js

This week’s nodejs learning content is about the use of several dependent packages, and I have gone through all the examples in the book. This article uses routine as a clue to review the work of the week.

1.connect

This routine mainly uses the connect dependency package. connect provides a middleware function (composed of functions that interact with request and response objects). The book also introduces other built-in middleware in connect, which play a role in organizing code to complete web functions.

2.session

Use connect for user sessions and basic login to the system. The functions of checking login, displaying forms, user matching, and processing logout are implemented through middleware. Demonstrates the power and organization of middleware.

3.express-tweet

In this chapter, we learned to use the express package, which is based on connect. The programming is still simple, but in different versions of np, the function names will have some changes. For example, express.createServer() became express() after 3.0. The biggest benefit of using express is that it is simple and flexible. However, tweets cannot be accessed, and when it was rewritten as Weibo, Weibo's API access was too complicated, so the program actually failed to run successfully.

4.echo

These two routines use the WebSocket package. The function of echo is mainly to record the time of message transmission. The way to play with Websocket is to use ws to listen (on) an event and process it in the callback function. In the html file, js is also used to interact with the message.

5.cursors

In this example, we learned about broadcasting. This function is handled by a broadcast function written by ourselves. When ensuring whether the cursor element exists, it is done through DOM ID lookup.

6.chat

This chapter can be said to be the highlight of this book, because the Socket.IO package was developed by the author. It differs from WS in that its message passing is based on transport and not entirely WS. In this routine, the chat function is first implemented, and then the radio song (DJ) function is implemented. No major problems were encountered during the process. A process is socket.emit an event, and the socket at the other end listens to the event and processes it.

7. Summary

The efficiency this week is quite good, and the problems encountered are still placed on evernote. The problem that has arisen before is the difference between localhost and 127.0.0.1. This week, I learned a function while debugging js, which allows js to dump an object like php. Post it now and share it below.

Copy code The code is as follows:

function dump(arr,level) {
var dumped_text = "";
If(!level) level = 0;
     
//The padding given at the beginning of the line.
var level_padding = "";
for(var j=0;j      
If(typeof(arr) == 'object') { //Array/Hashes/Objects
for(var item in arr) {
            var value = arr[item];
                                                                       If(typeof(value) == 'object') { //If it is an array,
                     dumped_text = level_padding "'" item "' ...n";
                      dumped_text = dump(value,level 1);
                } else {
dumped_text = level_padding "'" item "' => "" value ""n";
            }
         }
} else { //Stings/Chars/Numbers etc.
           dumped_text = "===>" arr "<===(" typeof(arr) ")";
}
Return dumped_text;
}

I will start learning mongoDB next week. My node learning is mainly improved by

learning routines and reading the source code API. After all, the advantage of node is the large number of npcs on the Internet.