I am trying to parse a string of xml and I getting an error
[Error: Invalid character entity
Line: 0
Column: 837
Char: ]
Does xml not like brackets? Do I need to replace all the brackets with something like \\]. Thanks
Ok, the invalid character was the dash and an &. I fixed it by doing the following:
xml = data.testSteps.replace(/[\n\r]/g, '\\n')
.replace(/&/g,"&")
.replace(/-/g,"-");
Thanks
Using a node domparser will get around having to do a string replace on every character that is not easily parsed as a string. This is especially useful if you have a large amount of XML to parse that may have different characters.
I would recommend xmldom as I have used it successfully with xml2js
The combined usage looks like the following:
var parseString = require('xml2js').parseString;
var DOMParser = require('xmldom').DOMParser;
var xmlString = "<test>some stuff </test>";
var xmlStringSerialized = new DOMParser().parseFromString(xmlString, "text/xml");
parseString(xmlStringSerialized, function (err, result) {
if (err) {
//did not work
} else {
//worked! use JSON.stringify()
var allDone = JSON.stringify(result);
}
});
Related
I'm trying to write a node script that identifies unused translation strings in my React project.
First, I want to get a list of all the translations that are used. To do this, I am getting a list of each JS file in my /src/components folder and then reading the file.
My translation strings look like this: t('some.translation.key'), so basically, I want to identify each instance of t('...') using RegEx and then get the key in between those parentheses (i.e. "some.translation.key"). From there, I should be able to compare the keys to the ones in my translation JSON file and remove the ones that aren't being used.
unused.js
const path = require('path');
const fs = require('fs');
let files = [];
// https://stackoverflow.com/a/63111390/2262604
function getFiles(dir) {
fs.readdirSync(dir).forEach(file => {
const absolute = path.join(dir, file);
if (fs.statSync(absolute).isDirectory()) {
getFiles(absolute);
} else {
if (absolute.includes('.js')) {
files.push(absolute);
}
}
});
return files;
}
function getTranslations() {
const pathComponents = path.join(__dirname, '../../src/components');
// get all js files in components directory
const files = getFiles(pathComponents);
const translationKeys = [];
// for each js file
for(let i = 0; i < files.length; i++) {
// read contents of file
const contents = fs.readFileSync(files[i]).toString();
// search contents for all instances of t('...')
// and get the key between the parentheses
}
}
getTranslations();
How can I use RegEx to find all instances of t('...') in contents and then extract the ... string between the parentheses?
Yes, you could use a regular expression:
for (const [, str] of contents.matchAll(/\bt\(['"](.*?)['"]\)/g)) {
console.log('t called with string argument:', str)
}
However, with regular expressions the problem will be that they don't understand the code and would cause trouble with matching strings that contain ( ) or \' themselves, have issues with concatenated strings or extra whitespace, etc., and you'd then also get the contents literally, including possible escape sequences.
A more robust way would be to create an AST (abstract syntax tree) from the code and look for calls to t in it.
A popular AST parser would be acorn. There is also the supplementary module acorn-walk that helps walking through the whole syntax tree without building your own recursive algorithm.
import acorn from 'acorn'
import walk from 'acorn-walk'
// Example
const contents = "function a () { if (123) { t('hello') } return t('world') }"
// The arguments to acorn.parse would have to be adjusted based
// on what kind of syntax your files can use.
const result = acorn.parse(contents, {ecmaVersion: 2020})
walk.full(result, node => {
if (node.type === 'CallExpression' && node.callee.type === 'Identifier' && node.callee.name === 't') {
if (node.arguments.length === 1 && node.arguments[0].type === 'Literal' && typeof node.arguments[0].value === 'string') {
// This is for the case `t` is called with a single string
// literal as argument.
console.log('t called with string argument:', node.arguments[0].value)
} else {
// In case you have things like template literals as well,
// or multiple arguments, you'd need to handle them here too.
console.log('t called with unknown arguments:', node.arguments)
}
}
})
// Will output:
// t called with string argument: hello
// t called with string argument: world
I'm trying to escape quotes in txt file using node.js and regex.
My code looks like this:
const fs = require("fs");
const utf8 = require("utf8");
var dirname = ".\\f\\";
const regex = new RegExp(`(?<=".*)"(?=.*"$)`, "gm");
fs.readFile(dirname + "test.txt", (error, data) => {
if (error) {
throw error;
}
var d = data.toString();
d = utf8.encode(d)
console.log(`File: ${typeof d}`); //string
// d = `Another string\n"Test "here"."\n"Another "here"."\n"And last one here."`;
console.log(`Text: ${typeof d}`); //string
var re = d.replace(regex, '\\"');
console.log(`Result:\n${re}`);
/* Another string
"Test \"here\"."
"Another \"here\"."
"And last one here."
*/
});
The problem is:
When I remove comment from the line, everything works fine. But if i read the text from the file it doesn't want to work.
Thanks for any comments on this.
Well.. turns out the problem was in file encoding. The file was encoded in UTF-16, not in UTF-8. Node.js wasn't giving me any signs of wrong encoding, so well, nice.
I am getting the following error while reading the json file using Node.js. I am explaining my code below.
SyntaxError: Unexpected token # in JSON at position 0
at JSON.parse (<anonymous>)
My json file is given below.
test.json:
#PATH:/test/
#DEVICES:div1
#TYPE:p1
{
name:'Raj',
address: {
city:'bbsr'
}
}
This json file has some # included strings . Here I need to remove those # included string from this file. I am explaining my code below.
fs.readdirSync(`${process.env['root_dir']}/uploads/${fileNameSplit[0]}`).forEach(f => {
console.log('files', f);
let rawdata = fs.readFileSync(`${process.env['root_dir']}/uploads/${fileNameSplit[0]}/${f}`);
let parseData = JSON.parse(rawdata);
console.log(parseData);
});
Here I am trying to read the code first but getting the above error. My need is to remove those # included lines from the json file and then read all the data and convert the removed lines to object like const obj ={PATH:'/test/',DEVICES:'div1',TYPE:p1}. Here I am using node.js fs module to achive this.
As you said, you need to remove those # lines from the JSON file. You need to code this yourself. To help with that, read the file into a string and not a Buffer by providing a charset to readFileSync.
const text = fs.readFileSync(path, 'utf8');
console.log(text);
const arr = raw.split("\n");
const noComments = arr.filter(x => x[0] !== "#"));
const filtered = noComments.join("\n");
const data = JSON.parse(filtered);
console.log(data);
I am creating an application with Node.js and I am trying to read a file called "datalog.txt." I use the "append" function to write to the file:
//Appends buffer data to a given file
function append(filename, buffer) {
let fd = fs.openSync(filename, 'a+');
fs.writeSync(fd, str2ab(buffer));
fs.closeSync(fd);
}
//Converts string to buffer
function str2ab(str) {
var buf = new ArrayBuffer(str.length*2); // 2 bytes for each char
var bufView = new Uint16Array(buf);
for (var i=0, strLen=str.length; i < strLen; i++) {
bufView[i] = str.charCodeAt(i);
}
return buf;
}
append("datalog.txt","12345");
This seems to work great. However, now I want to use fs.readFileSync to read from the file. I tried using this:
const data = fs.readFileSync('datalog.txt', 'utf16le');
I changed the encoding parameter to all of the encoding types listed in the Node documentation, but all of them resulted in this error:
TypeError: Argument at index 2 is invalid: Invalid encoding
All I want to be able to do is be able to read the data from "datalog.txt." Any help would be greatly appreciated!
NOTE: Once I can read the data of the file, I want to be able to get a list of all the lines of the file.
Encoding and type are an object:
const data = fs.readFileSync('datalog.txt', {encoding:'utf16le'});
Okay, after a few hours of troubleshooting a looking at the docs I figured out a way to do this.
try {
// get metadata on the file (we need the file size)
let fileData = fs.statSync("datalog.txt");
// create ArrayBuffer to hold the file contents
let dataBuffer = new ArrayBuffer(fileData["size"]);
// read the contents of the file into the ArrayBuffer
fs.readSync(fs.openSync("datalog.txt", 'r'), dataBuffer, 0, fileData["size"], 0);
// convert the ArrayBuffer into a string
let data = String.fromCharCode.apply(null, new Uint16Array(dataBuffer));
// split the contents into lines
let dataLines = data.split(/\r?\n/);
// print out each line
dataLines.forEach((line) => {
console.log(line);
});
} catch (err) {
console.error(err);
}
Hope it helps someone else with the same problem!
This works for me:
index.js
const fs = require('fs');
// Write
fs.writeFileSync('./customfile.txt', 'Content_For_Writing');
// Read
const file_content = fs.readFileSync('./customfile.txt', {encoding:'utf8'}).toString();
console.log(file_content);
node index.js
Output:
Content_For_Writing
Process finished with exit code 0
I would like add string on the top of my js file. Actuly, it's on the end :
var file = './public/js/app.bundleES6.js',
string = '// My string';
fs.appendFileSync(file, string);
Do you have idea for add my string on the first line ?
Thank you !
I think there is no built-in way to insert at the beginning of the file in Node.js.
But you can use readFileSync and writeFile methods of fs to resolve this issue
It will append string at top of the file
Try this
Method#1
var fs = require('fs');
var data = fs.readFileSync('./example.js').toString().split("\n");
data.splice(0, 0, "Append the string whatever you want at top" );
var text = data.join("\n");
fs.writeFile('./example.js', text, function (err) {
if (err) return err;
});
Method#2
If you are relying on to use third party module then you can use prepend module to add the string at the top as suggested by #robertklep.
var prepend = require('prepend');
prepend(FileName, 'String to be appended', function(error) {
if (error)
console.error(error.message);
});