I have an upload function like this :
app.post("/upload", function (req, res) {
let base64 = req.body.image.replace(/^data:image\/png;base64,/, "");
binaryData = Buffer.from(base64, "base64").toString("binary");
fs.writeFile(
"./pictures/" + Date.now() + ".png",
binaryData,
"binary",
function (err) {
if (err) {
console.log(err);
}
}
);
fs.writeFile(
"./thumbnails/" + Date.now() + ".png",
binaryData,
"binary",
function (err) {
if (err) {
console.log(err);
}
}
);
The first part saves image into "pictures" folder.
That works ok, nothing to do here.
The second parts saves the same image into "thumbnails" folder.
What I need to do is to resize the image before its saved, to have only resized images in that folder.
You can try with Sharp library: https://sharp.pixelplumbing.com/api-resize
app.post("/upload", function (req, res) {
let base64 = req.body.image.replace(/^data:image\/png;base64,/, "");
binaryData = Buffer.from(base64, "base64").toString("binary");
fs.writeFile(
"./pictures/" + Date.now() + ".png",
binaryData,
"binary",
function (err) {
if (err) {
console.log(err);
}
}
);
sharp(binaryData)
.resize({ width: 100 })
.toBuffer()
.then(data => {
// 100 pixels wide, auto-scaled height
fs.writeFile(
"./thumbnails/" + Date.now() + ".png",
data,
"binary",
function (err) {
if (err) {
console.log(err);
}
}
)
})
})
How to fix this error message?
[xhr.js?b50d:178 POST http://localhost:3000/editor/add net::ERR_CONNECTION_RESET][1]
It works and append data, but I get this error message...
My API looks like this:
app.js
app.post('/editor/add', function (req, res) {
let articleData;
let textData;
let article = {
title: req.body.title,
content: req.body.content
}
fs.readFile(urlPath, 'utf8', (err, data) => {
if (err) {
console.log('readfile => ' + err);
} else {
articleData = JSON.parse(data);
articleData[article.title] = article.content;
textData = JSON.stringify(articleData, null, 2);
fs.writeFile(urlPath, textData, 'utf8', (err) => {
if (err) {
console.log('write file => ' + err);
} else {
console.log('Finished writing');
}
});
}
});
});
And my Axios POST method looks like this.
editor.vue
submitEditor: function() {
var self = this;
self.$axios({
headers: {
"Content-Type": "application/json"
},
method: "post",
url: "http://localhost:3000/editor/add",
data: {
title: "test5",
content: self.html
}
})
.then(res => {
console.log(res);
})
.catch(error => {
if (!error.response) {
// network error
this.errorStatus = "Error: Network Error";
} else {
this.errorStatus = error.response.data.message;
}
});
}
I use Vue/cli, I separate my client code and my server code. They are on a separate folder. I put Vue/cli in my client folder, and express.js in my server folder.
Thank you in advance!
Try sending a response from your route:
fs.writeFile(urlPath, textData, 'utf8', (err) => {
if (err) {
console.log('write file => ' + err);
} else {
console.log('Finished writing');
res.json({ msg: 'success' }); // send the client something
}
});
I am trying learn nodejs and stumble upon this error
TypeError: callback is not a function
when I am trying to call the server using this command.
curl http://localhost:8090/albums.json
and here is the code for my server.js
var http = require('http'),
fs = require('fs');
function load_album(album_name, callback) {
fs.readdir("albums/", +album_name, (err, files) => {
if (err) {
if (err.code == "ENOENT") {
callback(make_error("no_such_album", "That album doesn't exist"));
} else {
callback(make_error("can't load album", "The server is broken"));
}
} else {
//callback(null, files);
var only_files = [];
var path = 'albums/${album_name}/';
var iterator = (index) => {
if (index == files.length) {
var obj = {
short_name: album_name,
photos: only_files
};
callback(null, obj);
return;
}
fs.stat(path + files[index], (err, stats) => {
if (!err && stats.isFile()) {
only_files.push(files[index]);
}
iterator(index + 1);
});
};
iterator(0);
}
});
}
function handle_incoming_request(req, res) {
console.log("incoming request: " + req.method + " " + req.url);
if (req.url == '/albums.json') {
load_album((err, albums) => {
if (err) {
res.writeHead(500, {
"Content-Type": "application/json "
});
res.end(JSON.stringify({
code: "cant_load_albums",
message: err.message
}));
} else {
var output = {
error: null,
data: {
albums: albums
}
};
res.writeHead(200, {
"Content-Type": "application/json"
});
res.end(JSON.stringify(output) + "\n");
}
});
} else if (req.url.substr(0, 7) == '/albums' && req.url.substr(req.url.length - 5) == '.json') {
//user is requesting contents of album
load_album(req.url.substr(7, req.url.length - 12), (err, photos) => {
if (err) {
res.writeHead(500, {
"Content-type": "application/json"
});
res.end(JSON.stringify(err));
} else {
var output = {
error: null,
data: {
photos: photos
}
};
res.writeHead(200, {
"Content-Type": application / json
});
res.end(JSON.stringify(output) + "\n");
}
});
} else {
res.writeHead(404, {
"Content-type": "application/json"
});
res.end(JSON.stringify({
code: "no_such_page",
message: "No such page"
}));
}
}
var s = http.createServer(handle_incoming_request);
s.listen(8090);
can you tell me what's wrong with my code that I got an error telling me callback isn't a function?
thanks though
for more formatted code then you can go here https://jsfiddle.net/02dbx6m9/
var http = require('http'),
fs = require('fs');
function load_album(album_name, callback) {
fs.readdir("albums/", +album_name, (err, files) => {
if (err) {
if (err.code == "ENOENT") {
callback(make_error("no_such_album", "That album doesn't exist"));
} else {
callback(make_error("can't load album", "The server is broken"));
}
} else {
//callback(null, files);
var only_files = [];
var path = 'albums/${album_name}/';
var iterator = (index) => {
if (index == files.length) {
var obj = {
short_name: album_name,
photos: only_files
};
callback(null, obj);
return;
}
fs.stat(path + files[index], (err, stats) => {
if (!err && stats.isFile()) {
only_files.push(files[index]);
}
iterator(index + 1);
});
};
iterator(0);
}
});
}
function handle_incoming_request(req, res) {
console.log("incoming request: " + req.method + " " + req.url);
if (req.url == '/albums.json') {
load_album("ALBUM NAME", (err, albums) => {
if (err) {
res.writeHead(500, {
"Content-Type": "application/json "
});
res.end(JSON.stringify({
code: "cant_load_albums",
message: err.message
}));
} else {
var output = {
error: null,
data: {
albums: albums
}
};
res.writeHead(200, {
"Content-Type": "application/json"
});
res.end(JSON.stringify(output) + "\n");
}
});
} else if (req.url.substr(0, 7) == '/albums' && req.url.substr(req.url.length - 5) == '.json') {
//user is requesting contents of album
load_album("Album Name", req.url.substr(7, req.url.length - 12), (err, photos) => {
if (err) {
res.writeHead(500, {
"Content-type": "application/json"
});
res.end(JSON.stringify(err));
} else {
var output = {
error: null,
data: {
photos: photos
}
};
res.writeHead(200, {
"Content-Type": application / json
});
res.end(JSON.stringify(output) + "\n");
}
});
} else {
res.writeHead(404, {
"Content-type": "application/json"
});
res.end(JSON.stringify({
code: "no_such_page",
message: "No such page"
}));
}
}
var s = http.createServer(handle_incoming_request);
s.listen(8090);
You forgot to pass album name parameter in load_album method. That's why album_name parameter is assigned the actual callback, while callback parameter remains undefined.
Here is the root cause of your issue:
load_album((err, albums) => {
// ...
});
The signature for the function requires two parameters, yet you're only passing the first one:
function load_album(album_name, callback) {}
Therein, once called, callback will be undefined, yet you're trying to treat it as a callable. Here's a more succint example of how to reproduce the error:
function foo(bar, baz) {
baz()
}
foo(() => {})
I have written a nice little error reporting middleware, that sits after all the GET and POST handling (after app.use(app.router); ). See below.
This works great for simple quick GET and POST that goes to the PostGIS database etc.
But I have one POST request that is designed to create a bunch of directories, a number of files, and then spawn 1 -> 8 child_processes tasks
childProcess.execFile(job.config.FMEPath, ["PARAMETER_FILE", job.fmeParamFile], { cwd: job.root },
All that setup does not take much time (less than a second, and it is all async (I use the async library at one point to sequence 5 steps (see below).
My issue is error handling. Right now I return a response immediately before creating all the files and doing all the steps. This means that next(err) is not working as expected. What is a good paradigm for reporting back the errors? I am using WINSTON to log errors [logger.log() ], but should I just log the errors on the server, or should I also report it to the original request. here is the current post request (and remember, I would have to keep the rest, and req and next object around for quite a while to be able to call next(err).
exports.build = function (req, res, next) {
var config = global.app.settings.config;
var jobBatch = groupJobs(req.body.FrameList);
var ticket = tools.newGuid("", true);
var fileCount = req.body.FrameList.length * nitfMultiplier;
var ts = timespan.fromSeconds(fileCount / config.TileRate);
var estimate = ts.hours + ":" + tools.pad(ts.minutes, 2) + ":" + tools.pad(ts.seconds, 2);
res.set({ 'Content-Type': 'application/json; charset=utf-8' });
res.send({ ticket: ticket, maxTiles: fileCount, timeEstimate: estimate, tileRate: config.TileRate, wwwURL: config.WWWUrl });
jobBatchRoot(req, res, jobBatch, config, ticket, next);
};
jobBatchRoot() (I will then go off and do a lot of processing, I did not include all that code.
exports.bugs = function (err, req, res, next) {
global.app.settings.stats.errors += 1;
if (err.code == undefined) {
err.code = 500;
err.message = "Server Error";
}
res.status(err.code);
logger.log('error', '%s url: %s status: %d \n', req.method, req.url, err.code, { query: req.query, body: req.body, message: err.message, stack: err.stack });
var desc = req.method + " " + req.url;
var body = util.format("%j", req.body);
var query = util.format("%j", req.query);
var stack = err.stack.split('\n');
res.format({
text: function () {
res.send(util.format("%j", { title: err.message, code: err.code, desc: desc, query: query, message: err.message, stack: err.stack, body: body}));
},
html: function () {
query = tools.pretty(req.query);
res.render('error', { title: err.message, code: err.code, desc: desc, query: query, message: err.message, stack: stack, body: body });
},
json: function () {
res.send({ title: err.message, code: err.code, desc: desc, query: query, message: err.message, stack: err.stack, body: body });
}
});
};
Perhaps I should be re-factoring this (maybe object oriented), anyway I thought I would post the full module here and all I am looking for is a few tips on structure, best practices.
var util = require('util');
var query = require("pg-query");
var timespan = require('timespan');
var _ = require('lodash');
var path = require('path');
var fs = require('fs');
var query = require("pg-query");
var async = require("async");
var childProcess = require("child_process");
var tools = require("../tools/tools");
var nitfMultiplier = 99;
var manifestVersionID = 5;
exports.setup = function (app) {
};
exports.estimate = function (req, res, next) {
var config = global.app.settings.config;
var fileCount = req.body.FrameList.length * nitfMultiplier;
var ts = timespan.fromSeconds(fileCount / config.TileRate);
var estimate = ts.hours + ":" + tools.pad(ts.minutes, 2) + ":" + tools.pad(ts.seconds, 2);
res.set({ 'Content-Type': 'application/json; charset=utf-8' });
res.send({ ticket: "Estimate", maxTiles: fileCount, timeEstimate: estimate, tileRate: config.TileRate, wwwURL: config.WWWUrl });
};
exports.build = function (req, res, next) {
var config = global.app.settings.config;
var jobBatch = groupJobs(req.body.FrameList);
var ticket = tools.newGuid("", true);
var fileCount = req.body.FrameList.length * nitfMultiplier;
var ts = timespan.fromSeconds(fileCount / config.TileRate);
var estimate = ts.hours + ":" + tools.pad(ts.minutes, 2) + ":" + tools.pad(ts.seconds, 2);
res.set({ 'Content-Type': 'application/json; charset=utf-8' });
res.send({ ticket: ticket, maxTiles: fileCount, timeEstimate: estimate, tileRate: config.TileRate, wwwURL: config.WWWUrl });
jobBatchRoot(req, res, jobBatch, config, ticket, next);
};
function groupJobs(list) {
var jobBatch = {};
_.forEach(list, function (obj) {
if (jobBatch[obj.type] == undefined) {
jobBatch[obj.type] = [];
}
jobBatch[obj.type].push(obj);
});
return jobBatch;
};
function jobBatchRoot(req, res, jobBatch, config, ticket, next) {
var batchRoot = path.join(config.JobsPath, ticket);
fs.mkdir(batchRoot, function (err) {
if (err) return next(err);
var mapInfoFile = path.join(batchRoot, "MapInfo.json");
var mapInfo = {
Date: (new Date()).toISOString(),
Version: manifestVersionID,
Zoom: req.body.Zoom,
CenterLat: req.body.CenterLat,
CenterLon: req.body.CenterLon
};
fs.writeFile(mapInfoFile, tools.pretty(mapInfo), function (err) {
if (err) return next(err);
spawnJobs(req, res, batchRoot, mapInfo, config, ticket, jobBatch, next);
});
});
};
function spawnJobs(req, res, root, mapInfo, config, ticket, jobBatch, next) {
_.forEach(jobBatch, function (files, key) {
var job = {
req: req,
res: res,
type: key,
files: files,
batchRoot: root,
mapInfo: mapInfo,
config: config,
ticket: ticket,
missingFiles: [],
run: true,
next: next
};
setup(job);
});
};
function setup(job) {
job.root = path.join(job.batchRoot, job.type);
job.fmeParamFile = path.join(job.root, "fmeParameters.txt");
job.fmeWorkSpace = path.join(job.config.LibrarianPath, "TileBuilder.fmw");
job.fmeLogFile = path.join(job.root, "jobLog.log");
job.errorLog = path.join(job.root, "errorLog.log");
job.jobFile = path.join(job.root, "jobFile.json");
job.manifestFile = path.join(job.root, "manifest.json");
async.series({
one: function (callback) {
maxZoom(job, callback);
},
two: function (callback) {
fs.mkdir(job.root, function (err) {
if (err) return job.next(err);
callback(null, "Job Root Created");
});
},
three: function (callback) {
makeParamFile(job, callback);
},
four: function (callback) {
delete job.req;
delete job.res;
fs.writeFile(job.jobFile, tools.pretty(job), function (err) {
if (err) return job.next(err);
callback(null, "Wrote Job File");
});
},
five: function (callback) {
runJob(job, callback);
},
six: function (callback) {
tileList(job, callback);
},
seven: function (callback) {
finish(job, callback);
},
},
function (err, results) {
if (err) return job.next(err);
console.log(tools.pretty(results));
});
}
function maxZoom(job, callback) {
var qString = util.format('SELECT type, "maxZoom" FROM portal.m_type WHERE type=\'%s\'', job.type);
query(qString, function (err, rows, result) {
if (err) {
var err = new Error(queryName);
err.message = err.message + " - " + qString;
err.code = 400;
return job.next(err);
}
job.maxZoom = rows[0].maxZoom - 1; // kludge for 2x1 root layer in leaflet
return callback(null, "Got MaxZoom");
});
}
function makeParamFile(job, callback) {
var text = util.format("%s\n", job.fmeWorkSpace);
text += util.format("--OutputDir %s\n", job.root);
text += util.format("--LogFile %s\n", job.fmeLogFile);
var source = "";
_.forEach(job.files, function (file) {
var path = ('development' == process.env.NODE_ENV) ? file.path.replace(job.config.SourceRootRaw, job.config.SourceRoot) : file.path;
if (fs.existsSync(path)) {
source += wrap(path, '\\"') + " ";
}
else {
job.missingFiles.push(path);
}
});
source = wrap(wrap(source, '\\"'), '"');
text += "--Sources " + source;
if (job.missingFiles.length == job.files.length) job.run = false;
fs.writeFile(job.fmeParamFile, text, function (err) {
if (err) return job.next(err);
return callback(null, "Wrote Paramaters File");
})
};
function wrap(content, edge) {
return edge+content+edge;
}
function runJob(job, callback) {
if (!job.run) return callback(null, "Skipped JOB, no files");
childProcess.execFile(job.config.FMEPath, ["PARAMETER_FILE", job.fmeParamFile], { cwd: job.root },
function (err, stdout, stderr) {
if (err) return job.next(err);
job.stdout = stdout;
job.stderr = stderr;
var bar = "\n--------------------------------------------------------------------------------------------------------\n";
var results = util.format("%s STDOUT: \n %s%s STDERR: \n %s", bar, job.stdout, bar, job.stderr);
fs.appendFile(job.fmeLogFile, results, function (err) {
return callback(err, "FME JOB " + job.type + " run completed");
});
});
}
function tileList(job, callback) {
var tiles = [];
var byteCount = 0;
fs.readdir(job.root, function (err, files) {
if (err) {
logger.log('error', 'tileList directory read: %s \n', job.root, { message: err.message, stack: err.stack });
return job.next(err);
}
async.each(files, function (file, done) {
var fileName = file.split(".");
fs.lstat(job.root + "\\" + file, function (err, stats) {
if (!err && stats.isFile() && (fileName[1] == "png")) {
tiles.push({ id: fileName[0], size: stats.size });
byteCount += stats.size;
};
done(null);
});
}, function (err) {
job.tileList = tiles;
job.byteCount = byteCount;
return callback(null, "got tile list");}
);
});
}
function finish(job, callback) {
var manifest = {
Date: (new Date()).toISOString(),
Version: manifestVersionID,
MaxZoom: job.maxZoom,
Class: "OVERLAY",
FileCount: job.tileList.length,
Size: job.byteCount / (1024 * 1024), // Mbytes
files: job.tileList
};
fs.writeFile(job.manifestFile, tools.pretty(manifest), function (err) {
if (err) {
logger.log('error', 'manifest write: %s \n', job.manifestFile, { message: err.message, stack: err.stack });
return job.next(err);
}
return callback(null, "JOB " + job.type + " completed");
});
}
I went and re-factored this. I created a module, with module.exports = function(..) {...}
and then added lots of state and methods to create a class. That contains the Job definition. So now I create the top level directories, return a response, and spawn the sub jobs. They all run async after the express response. But they should not get errors, and if they do, then I use WINSTON to log them in the server, and also return a job done information to the user when all the builds are done.