How to render a Log / text file in node js through url? - node.js

I am trying to view the log File in the browser on hitting a particular url. I have the log file in my local (/logsFolder/app.log)
I tried the following codes:
Code: 1
var app = express();
var path = require('path');
var logFile = require('/logs/app');
app.use('/logs',logFile);
It threw error like
Error: Cannot find module '/logs/app'
Code :2
const app = express();
const path = require('path');
const router = express.Router();
router.get('/logFile', function(req, res){
console.log("inside logt :");
res.render('./logs/app.log');
});
can anyone Please help me to resolve.

Your log is static text file, not a javascript, nor json file, that why you can't require it. (code 1)
You are not using template engine either, that's why your code 2 didn't work, It cannot be render by itself.
You can use the built in express middleware for static files.
Try this:
app.use(express.static('logsFolder'))
Now you can access all the content of logsFolder by requesting the file name. For example: http://your-url/app.log
Or try your code 2 with res.sendFile instead of res.render

Related

Nodjs swagger auto gen integration

I need to develop an API using NodeJS and also need to develop documentation for API also. I integrated with swagger auto-gen for swagger.json creation. But the swagger.json not generating properly if I used routes.js as below
var express = require('express');
module.exports = function(app) {
var userController = require('../controller/userController');
var apiRouter = express.Router();
var routerV1 = express.Router();
var routerV2 = express.Router();
app.use('/admin', apiRouter);
apiRouter.use("/v1", routerV1);
apiRouter.use("/v2", routerV2);
routerV1.route('/users').get(userController.getUsersV1);
routerV2.route('/users').get(userController.getUsersV2);
}
and also mapped these routes.js in swagger.js
Please suggest the best way to generate swagger.js
Do we need to create routes file for all controller?
Version 2 of swagger-autogen added this feature. Previous versions don't recognize routes. In your case, the best way to generate the file swagger.js is:
file: swagger.js
const swaggerAutogen = require('swagger-autogen')();
const outputFile = './swagger_output.json';
const endpointsFiles = ['./routes.js']; // root file where the route starts.
swaggerAutogen(outputFile, endpointsFiles).then(() => {
require('./index.js'); // Your project's root file
})
Update your module to the latest version.
And run your project with: node swagger.js
And about the routes file for all controller, you don't need to implement it for each one, but it also depends on the structure of your code. If you have a root route file like the example, this is enough for all sub-routes to be scanned. I hope it helps you. Take a look at this example if you need to:
swagger-autogen using router

Do not see the reason I am getting a NOENT returned when I can see the file at the exact spot I am calling for it to be

I know this is very similar to other questions that have been asked on the same error. In the case I have seen though, the file name had been left off of the url. In my case (as far as I know) the url is specified as it should be and I can see the file on my localhost using other tools.
I have a need in a node.js app to perform I/O on json files without the benefit of using express routing. This is an API that has only one route (processor.js). It is accessed by a menu selection on the GUI by selecting 'Process'. From that point on everything happens within that route including multiple GETs/PUTs to json (for ids to data and then using the ids to get the data) and the building of SQL rows for populating SQL-Server Tables from the parsed json data. That, at least is the concept I am testing now. It is the hand I have been dealt, so I don't have other options.
I am using fs-extra rather than request or axios etc., because they all seem to expect express routes to accomplish the I/O. I appear to be able to directly read and write the json using fs-extra. I am using sequelize (or will be) for the SQL side.
That's the background.
Here is my processor.js (I am merely validating that I can in fact get idsList returned to me at this point):
'use strict';
// node_modules
const express = require('express');
const router = express.Router();
const fse = require('fs-extra')
// local modules
const idsList = require('../functions/getIds');
router.get('/', (req, res) => {
console.log(idsList);
});
module.exports = router;
Here is my getIds function:
'use strict';
// library modules
const express = require('express');
const router = express.Router();
const fse = require('fs-extra');
const uri = require('../uri');
// initialize general variables
let baseURL = `http://localhost:5000${uri}/`;
let idsID = 'ids.json';
const getIds = async () => {
let url = `${baseURL}${idsID}`;
try {
const idsList = await fse.readJson(url);
console.log('fse.readJson',idsList);
} catch (err) {
console.error(err);
}
}
module.exports = getIds();
And, here is my error, output to the console (it didn't format very well):
Listening on port 5000...
{ [Error: ENOENT: no such file or directory, open
'http://localhost:5000/Users/doug5solas/sandbox/libertyMutual/playground/api/ids.json']
errno: -2,
code: 'ENOENT',
syscall: 'open',
path:
'http://localhost:5000/Users/doug5solas/sandbox/libertyMutual/playground/api/ids.json' }
What am I missing?
You can use fs-extra to manipulate files and directories in your local file system only.
If you want to read files hosted on other machine over http, try using an http client like: axios.
I moved away from fs-extra to fs.readFileSync and solved the problem. It is not my preference. But it does work and the file is small, and only once.

Node.js and Express.JS 4 are not loading linked files when using sendFile method

Using Express.js 4, when I try to use sendFile in order to serve a page that has additional links to javascript files or images, the browser does not load those other assets. If I access the page using a URL it works fine, it is just when I try loading the page with the sendFile method that is the problem.
For example, here is what my code looks like:
var express = require('express');
var app = express();
app.use(express.static('client'));
var path = require('path');
app.get('/game/:gameid', function (req,res) {
var gameID = req.params.gameid;
if (checkGameExists(gameID)) {
res.sendFile(path.resolve(__dirname + '/client/chessBoard.html'));
}
I have tried a bunch of variations like:
res.sendFile(path.resolve(__dirname + '/client/chessBoard.html'));
res.sendFile(__dirname + "/chessBoard.html");`
res.sendFile("chessBoard.html", {root: __dirname + "/client/"});
I have read the Express4 API documentation on sendFile (http://expressjs.com/4x/api.html#res.sendFile), but I am not sure what I am doing wrong.
I am new to Node.js & Express.js so any help would be appreciated!
You can do something like:
app.use('/assets',express.static(path.join(__dirname,'public/assets')));
and also to make it more specific
app.use('/stylesheets',express.static(path.join(__dirname,'public/javascripts/stylesheets')));
Now put your files in the public/assets folder and let's say your HTML file name is index.html.
In the index.html you can link files as src="/assets/js/abc.js".
For more reference you can look into my demo here.
I hope this helps.

NodeJS exports not defined in external JS file

I am calling a function from an external JS file in my routes file. So, I am trying to export a function from my externalFile.js file. However, when I run the node server, it throws Uncaught ReferenceError: exports is not defined . externalFile.js is in public/javascripts/ and the route files is in routes/.
External file (externalFile.js):
exports.capsolvingComplete = function (stdout){
//Received, display text and hide the spinner, put check in place.
$('#capsolv-complete').css("display", "block")
$('#capsolv-output').text(stdout);
}
Route file:
var express = require('express');
var router = express.Router();
var script = require('../public/javascripts/externalFile.js')
/* GET home page. */
router.get('/', function(req, res) {
res.render('index', { title: 'CapSolv' });
});
router.post('/file-upload', function(req, res){
script.capsolvingComplete("HI");
res.end("success");
})
module.exports = router;
Thank you for your help! Bit of a node noob here.
Looking at your example, mscdex is right. Anything you require in Node is designed to run on the server, and doesn't have access to the browser's DOM.
I would recommend building a REST API that accepts the file upload, stores it, and returns a JSON object containing metadata: i.e. where the file was stored, size, etc., and let your client deal with that.

java.lang.NoClassDefFoundError at runtime when using express framework and node.js

I am trying to write a sample code to create an instance of a java class and then invoke a method using that instance. I am using node-java module to do this. The code compiles without any error. However when I hit the URL which actually hits the same code then I get the class not found exception.
I have verified that the jar and it is there in the same directory as index.js and the jar also contains the class file (Application.class) for which the instance is being created.
My index.js file
var java = require("java");
java.classpath.push("demo.jar");
var express = require('express');
var router = express.Router();
var Application = java.import('Application');
/* GET home page. */
router.get('/', function(req, res) {
var application = new Application();
var resp = application.getResponse();
res.render('index', { title: resp });
});
module.exports = router;
Sorry for my english. I had the same problem. Look [https://github.com/joeferner/node-java/issues/147]
my code:
`var java = require("java");
var path=require("path");
var fs=require("fs");
console.log("ruta in directory",path.join(__dirname));
console.log("exist file:",fs.existsSync(path.resolve(__dirname,"./lib-java/lib-tgd.jar")));
java.classpath.push("commons-lang3-3.1.jar");
java.classpath.push("commons-io.jar");
java.classpath.push(path.resolve(__dirname,"./lib-java/lib-tgd.jar"));
java.classpath.push(path.resolve(__dirname,"./lib-java/jackson-annotations- 2.5.1.jar"));
java.classpath.push(path.resolve(__dirname,"./lib-java/jackson-core-2.5.1.jar"));
java.classpath.push(path.resolve(__dirname,"./lib-java/jackson-databind-2.5.1.jar"));`
with path.resolve solves the problem of the file path

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