官术网_书友最值得收藏!

The read command

When the read command is used, we want to call notes.getNote, passing in title. Now, title will get passed in and parsed using yargs, which means that we can use argv.title to fetch it. And that's all we have to do when it comes to calling the function:

console.log('Starting app.js');

const fs = require('fs');
const _ = require('lodash');
const yargs = require('yargs');

const notes = require('./notes.js');

const argv = yargs.argv;
var command = process.argv[2];
console.log('Command:', command);
console.log('Yargs', argv);

if (command === 'add') {
notes.addNote(argv.title, argv.body);
} else if (command === 'list') {
notes.getAll();
} else if (command === 'read') {
notes.getNote(argv.title);
} else if (command === 'remove') {
console.log('Removing note');
} else {
console.log('Command not recognized');
}

The next step is to define getNote, because currently it doesn't exist. Over in notes.js, right below the getAll variable, we can make a variable called getNote, which will be a function. We'll use the arrow function, and it will take an argument; it will take the note title. The getNote function takes the title, then it returns the body for that note:

var getNote = (title) => {

};

Inside getNote, we can use console.log to print something like Getting note, followed by the title of the note you will fetch, which will be the second argument to console.log:

var getNote = (title) => {
console.log('Getting note', title);
};

This is the first command, and we can now test it before we go on to the second one, which is remove.

Over in Terminal, we can use node app.js to run the file. We'll be using the new read command, passing in a title flag. I'll use a different syntax, where title gets set equal to the value outside of quotes. I'll use something like accounts:

node app.js read --title accounts

This accounts value will read the accounts note in the future, and it will print it to the screen, as shown here:

As you can see in the preceding code output, we get an error, which we'll debug now.

主站蜘蛛池模板: 阳春市| 五大连池市| 龙南县| 大方县| 商河县| 易门县| 保亭| 鞍山市| 新郑市| 丰宁| 承德市| 杭锦旗| 阿拉善左旗| 乐昌市| 灵川县| 区。| 安阳市| 柘荣县| 新沂市| 青冈县| 怀来县| 泽库县| 平塘县| 九寨沟县| 中山市| 娱乐| 剑川县| 舟山市| 托克托县| 肥城市| 平罗县| 乐都县| 利川市| 定西市| 奉新县| 大同市| 琼结县| 鄂尔多斯市| 桂林市| 林甸县| 镇安县|