Reading all files in a directory - javascript

here is the code snippet of what I am working with right now...
/*
Module: inputReader.js, directoryScanner.js (included)
Description: Basic file reader returns string of contents of a file from a set file name
Needs to be done: Add key listener to allow for a dynamic file name
*/
// Declare node.js module dependencies from API
var fs = require('fs'),
wrench = require('wrench'),
util = require('util')
// Define module to be exported as a function(s)
module.exports = {
dirRead: function() {
var rootfolder = './node_modules';
var filteredfiles = [];
var files = [];
var fileextension = '.html';
files = wrench.readdirSyncRecursive(rootfolder)
for (var i = 0; i<files.length; i++) {
if (files[i].indexOf(fileextension) != -1) {
filteredfiles.push(files[i]);
}
}
return filteredfiles;
},
fileRead: function() {
// Call synchronous fileSystem function readFileSync on file name
for(i = 0; i<filteredfiles.length; i++) {
var temp = fs.readFileSync(filteredfiles[i].toString(), 'utf8')
return temp
}
}
};
I am exporting a module of 2 different functions; the first (readDir) that reads a directory and its' subdirectories for a list of files and the second (readFile) which relies on the first (reads the list of files from the first function and actually goes through each file).
The problem is when I try to call that look of filteredfiles in the 2nd function, readFile, I get an error saying filteredfiles is undefined.
I am not sure how to fix this, may someone help me please? (My guess is a scope problem)...
res.send(reader.dirRead()) and then, res.send(reader.fileRead(reader.dirRead()))

filteredfiles is declared locally in dirRead function (so it is not visible for fileRead function). You must declare it in some higher scope, or pass it as a fileRead parameter.

Related

How to loop through the folder with files?

How can I loop through the folder that has subfolder and retrieve all files with extension '.element.ts' ?
const fs = require('fs');
const filesDir = fs.readdirSync('packages/web-components/src');
// the json result that will be generated
let content = [];
files.forEach(file => {
if (fileName === '???')
content.push(file);
});
const fs=require('fs');
function getAllFiles (dir, allFilesList = []){
const files = fs.readdirSync(dir);
files.map(file => {
const name = dir + '/' + file;
if (fs.statSync(name).isDirectory()) { // check if subdirectory is present
getAllFiles(name, allFilesList); // do recursive execution for subdirectory
} else {
allFilesList.push(name); // push filename into the array
}
})
return allFilesList;
}
const allFiles = getAllFiles('./testfolder');
const fileEndsWith = allFiles.filter(file => file.endsWith('.element.ts'))
console.log(fileEndsWith);
Easy way: use glob package.
const glob = require("glob");
const pattern = "packages/web-components/src/*.element.ts"
const elementTsFilenames = glob.sync(pattern);
Manual way:
const dir = "packages/web-components/src";
const extension = ".element.ts";
const elementTsFilenames = fs.readdirSync(dir).filter(fn => fn.endsWith(extension));
This is easy enough that the manual way is as easy or easier; if you have more complex requirements (e.g. recursively searching subdirectories), a library approach is nice.
I'll show you how to recursively get all the files in a directory (even those located in a subdirectory).
To do this, we need to create a recursive function that can call itself when dealing with sub-directories. And we also need the function to go through each of the sub-directories and add any new files it encounters. Then we also need to check if the filename contains a specific string. When the function is finished , it should return an array with all the files it encountered.
Here's what the recursive function looks like:
const fs = require("fs")
const path = require("path")
const getAllFiles = function(dirPath, extension, arrayOfFiles) {
files = fs.readdirSync(dirPath);
arrayOfFiles = arrayOfFiles || [];
files.forEach(function(file) {
if (fs.statSync(dirPath + "/" + file).isDirectory()) {
arrayOfFiles = getAllFiles(dirPath + "/" + file, arrayOfFiles);
} else if (file.endsWith(extension)){
arrayOfFiles.push(path.join(__dirname, dirPath, "/", file));
}
});
return arrayOfFiles;
}
First, we require() the Node.js path module. Since this is
included with Node.js, you don't need to install anything for it to
work. This module will help us easily create full file paths for our
files.
The getAllFiles variable holds the recursive function that will go
through each subdirectory and return an array of filenames. It takes a
directory file path, a specified character and an optional arrayOfFiles as arguments.
Inside the getAllFiles function, we first use the readdirSync()
function to get all of the files and directories inside the given
dirPath supplied to the function.
Then, we create an arrayOfFiles that will hold all the filenames
that will be returned when the function is done running.
Next, we loop over each item (file or directory) found by the
readdirSync() function. If the item is a directory, we have the
function recursively call itself to get all of the files and
sub-directories inside the given directory.
And if the item is a file, we simply append the file path to the
arrayOfFiles array. (When the end of the file name is confirmed to
contain characters)
When the forEach loop has finished, we return the arrayOfFiles
array.
Here is how you use the function in your code:
const result = getAllFiles("packages/web-components/src", ".element.ts");
I don't think you need an npm package for this: It's not too hard to walk the file system using an async iterator and filter the results based on something like a regular expression.
Another bonus of an async technique is that it doesn't block your thread while it iterates the files (other work can be done in between each result while it's searching), especially if you have a lot of sub-directories/files to search through.
If you want to reduce your project's dependencies, you can do something like this:
example.mjs:
import * as path from 'node:path';
import {readdir} from 'node:fs/promises';
/** Search all subdirectories, yielding matching file entries */
export async function* findFiles (dir, regexpFilter) {
for (const entry of await readdir(dir, {withFileTypes: true})) {
const fPath = path.resolve(dir, entry.name);
if (entry.isDirectory()) {
yield* findFiles(fPath, regexpFilter);
continue;
}
if (regexpFilter && !regexpFilter.test(entry.name)) continue;
yield Object.assign(entry, {path: fPath});
}
}
async function main () {
const dir = 'packages/web-components/src';
// Regular expression which means: ends with '.element.ts'
const filter = /\.element\.ts$/;
for await (const entry of findFiles(dir, filter)) {
// ^^^^^^
// If you don't include a filter argument, then all files will be iterated
console.log(entry.name); // just the file name
console.log(entry.path); // the full file path
}
}
main();

how to export a function from one file to another node.js?

I have some function that needs to be accessed from another file. But for some reason I can't do it.
creatureScreenfunction (dir, jsonFile, pathToFile){
let Mode = require('stat-mode');
let temp;
fs.readdir(dir, function(err, items)
.............................................
}
Here's what I tried
exports.creatureScreen = creatureScreen();
in second file
const index = require("../index.js");
What you did here exports.creatureScreen = creatureScreen(); is named export. While importing it in some other file you need to do const {creatureScreen} = require("../index.js");.

javascript read .ini file

I tried searching . How do i do it? I'm create html and i want to read .ini file by javascript on the client Not in the server.
I copy code from javascript parser for a string which contains .ini data
error Uncaught ReferenceError: require is not defined var fs = require('fs')
function parseINIString() {
var fs = require('fs')
var data = fs.readFileSync('C:\\test.ini', 'utf8');
var regex = {
section: /^\s*\[\s*([^\]]*)\s*\]\s*$/,
param: /^\s*([\w\.\-\_]+)\s*=\s*(.*?)\s*$/,
comment: /^\s*;.*$/
};
var value = {};
var lines = data.split(/\r\n|\r|\n/);
var section = null;
alert(lines);
for (x = 0; x < lines.length; x++) {
if (regex.comment.test(lines[x])) {
return;
} else if (regex.param.test(lines[x])) {
var match = lines[x].match(regex.param);
if (section) {
value[section][match[1]] = match[2];
} else {
value[match[1]] = match[2];
}
} else if (regex.section.test(lines[x])) {
var match = lines[x].match(regex.section);
value[match[1]] = {};
section = match[1];
} else if (lines.length == 0 && section) {//changed line to lines to fix bug.
section = null;
};
}
return value;
}
Let's say the javascript running in a browser is so called 'client script'. There are lots of limitation while writing client script, one of them is that it's not allowed to visit the user file on disk. This is to prevent any injected hacker script from reading private data. And the explicit error you see is about the new key word 'require' which is well known as 'commonjs' module which is introduced by Nodejs usually. The 'fs' is one of the internal module of Nodejs as well.
So if you still consist using client script to get the job done, you have to rewrite the script, not 'require' the 'fs' module. And use the file reader to get the content of a file object, which is generated by a file input usually.
A detailed introduction about how to read local files.

how to get pdf context into html?

for several days now I'm learning html, CSS and now javascript. What I need is a way to get the informations of an pdf document into my html webpage.
I tried several things now and couldnt find the correct answer or informations I need. So here come an use case:
get an .pdf document into a folder
get the information of all .pdf documents of the target folder (with the exact same formatting)
convert those information into html context
get this html context to show on the webpage (images and text)
1 is trivial, I can just drag and drop my documents
2 I'm thinking about something like an array, which then calls the folder to get data into it.
For this I found:
'use strict';
function getFiles(dir) {
fileList = [];
var files = fs.readdirSync(dir);
for (var i in files) {
if (!files.hasOwnProperty(i)) continue;
var name = dir + '/' + files[i];
if (!fs.statSync(name).isDirectory()) {
fileList.push(name);
}
}
return fileList;
}
console.log(getFiles('pathtodirectory'));
Here I'm always getting a reference error, no matter what the path, well I can use only a local path on my pc for now. I'm not 100% sure what everything does, but I think I got it good so far. This function just gets me a list of the documents to work with.
3 That's even more tricky for me now, but I think if I get the data to work with, I may be able to work something out.
4 I think I can do it with a little research
I am happy for any tips or solutions, as I said I'm quite new to all of this :)
regards,
Pascal
'use strict';
function getFiles(dir) {
fileList = []; // <- This becomes a global variable
Should be:
'use strict';
function getFiles(dir) {
var fileList = []; // <- Now it's local to this scope
Because creating implicit global variables are not allowed in strict mode.
Also the getDirSync return an array, so you should treat it as such:
function getFiles(dir) {
fileList = [];
var files = fs.readdirSync(dir);
for (var i = 0; i < files.length; i++) {
var name = dir + '/' + files[i];
if (!fs.statSync(name).isDirectory()) {
fileList.push(name);
}
}
return fileList;
}
Or with .reduce:
function getFiles(dir) {
return fs.readdirSync(dir).reduce(function(arr, file) {
var name = dir + '/' + file;
if (!fs.statSync(name).isDirectory()) {
arr.push(name);
}
return arr;
}, []);
}

Accessing typescript file variable values using gulp

I have several typescript files, some of them export a const named APIS.
I'm trying to access those exports (I want to concatenated all of them to a single file), but it doesn't seem to work. I'm obviously doing something wrong, but I'm not sure what.
For example, I have a folder named services, with 2 files: service1.ts, service2.ts.
service1.ts:
...
export const APIS = [ { "field1" : "blabla" } ];
service2.ts: does not contain the APIS var.
This is my gulpfile.js:
var gulp = require('gulp');
var concat = require('gulp-concat');
var map = require('gulp-map');
gulp.task('default', function() {
return gulp.src('.../services/*.ts')
.pipe(map(function(file) {
return file.APIS;
}))
.pipe(concat('all.js'))
.pipe(gulp.dest('./test/'));
});
When I run this task, I get nothing. When I added console.log(file.APIS); to the map function, I get undefined for all the values (although it is defined in service1.ts!).
This is following to: Extracting typescript exports to json file using gulp
EDIT: OK, so I tried saving the exports in a .js file instead of a .ts file, and now I can access those vars using require:
gulp.task('default', function() {
return gulp.src('./**/*.service.export.js')
.pipe(map(function(file) {
var fileObj = require(file.path);
...
}))
Now if I try console.log(fileObj.APIS); I get the correct values. What I'm still confused about is how I can pass these value on, and create a single file out of all these vars. Is it possible to push them into an array?
This will not work as you think it would work. Gulp itself knows nothing about typescript files, that file is a vinyl-file and has no knowledge about the typescript code within its content.
Edit
Based on your example, you can do something like this:
var gulp = require('gulp');
var concat = require('gulp-concat');
var map = require('gulp-map');
var fs = require('fs');
gulp.task('test', function ()
{
var allConstants = [];
var stream = gulp.src('./**/*.service.export.js')
.pipe(map(function(file)
{
var obj = require(file.path);
if (obj.APIS != null)
allConstants = allConstants.concat(obj.APIS);
return file;
}));
stream.on("end", function (cb)
{
// Do your own formatting here
var content = allConstants.map(function (constants)
{
return Object.keys(constants).reduce(function (aggregatedString, key)
{
return aggregatedString + key + " : " + constants[key];
}, "");
}).join(", ");
fs.writeFile('filename.txt', content, cb);
});
return stream;
});
Suggestion
If you want to collect multiple variables into a single file i.e. a common variables file I suggest gulp-replace.
Steps
Create a file, require it and use tags within that file to place your variables.
Advice
If you are already using services don't create an array. Instead create an object (JSON) where every property is a constant. i.e.
var constants = {
const_1: 0,
const_2: 1,
const_3: 2,
}

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