How to fix jslint warning Don't make functions within a loop - node.js

Getting this warning on the following code:
workflow.removeZSets = function(fn) {
var processed = 0;
for (var c = 1; c < 10; c++) {
workflow.removeZSet(c, function() {
processed++;
if (processed === 9) {
return fn(null, "finished removing");
}
});
}
}
workflow.removeZSet = function(precision, fn) {
rc.zrem("userloc:" + precision, function() {
return fn(null, 'done');
});
});
}
Does anyone have a suggestion how to accomplish this without triggering the warning?
I have some ideas like using the async library to run them all in parallel but this is a fairly common thing I do throughout this code base so interested in feedback on the best way.

The error is because you have define a function within your for loop.
You could try something like this, defining the function outside of the loop:
workflow.removeZSets = function(fn) {
var processed = 0;
function removeZ(c) {
workflow.removeZSet(c, function(err) {
processed++;
if (processed === 9) {
return fn(null, "finished removing");
}
});
}
for (var c = 1; c < 10; c++) {
removeZ(c);
}
}
Using a library like async to do the looping would help clean up your code, it would allow you to avoid checking if all the items have processed (processed ===9) because it is handled by async.

Related

getFileAsync causing Excel to crash

I'm building an office-js add-in for Excel. I need to upload the current workbook to a back end server. I've implemented an example from the Micrsoft Documentation, which seems to work fine the first time I call it, but on subsequent calls, it causes Excel to crash. I'm using Excel 365 version 1812 (build 11126.20132)
Here is the link to the example in the MS docs:
https://learn.microsoft.com/en-us/javascript/api/office/office.document
There are many examples on this page, to find the one I'm working from search for "The following example gets the document in Office Open XML" I've included the example below for ease of reference.
The code just get's the current file and dumps the characters to the console's log. It works fine the first but crashes Excel the second time--after it has shown the length of FileContent.
export function getDocumentAsCompressed() {
Office.context.document.getFileAsync(Office.FileType.Compressed, { sliceSize: 65536 /*64 KB*/ },
function (result) {
if (result.status == "succeeded") {
// If the getFileAsync call succeeded, then
// result.value will return a valid File Object.
var myFile = result.value;
var sliceCount = myFile.sliceCount;
var slicesReceived = 0, gotAllSlices = true, docdataSlices = [];
console.log("File size:" + myFile.size + " #Slices: " + sliceCount);
// Get the file slices.
getSliceAsync(myFile, 0, sliceCount, gotAllSlices, docdataSlices, slicesReceived);
}else {
console.log("Error:", result.error.message);
}
});
}
function getSliceAsync(file, nextSlice, sliceCount, gotAllSlices, docdataSlices, slicesReceived) {
file.getSliceAsync(nextSlice, function (sliceResult) {
if (sliceResult.status == "succeeded") {
if (!gotAllSlices) { // Failed to get all slices, no need to continue.
return;
}
// Got one slice, store it in a temporary array.
// (Or you can do something else, such as
// send it to a third-party server.)
// console.log("file part",sliceResult.value.data)
docdataSlices[sliceResult.value.index] = sliceResult.value.data;
if (++slicesReceived == sliceCount) {
// All slices have been received.
file.closeAsync();
onGotAllSlices(docdataSlices);
}
else {
getSliceAsync(file, ++nextSlice, sliceCount, gotAllSlices, docdataSlices, slicesReceived);
}
}
else {
gotAllSlices = false;
file.closeAsync();
console.log("getSliceAsync Error:", sliceResult.error.message);
}
});
}
function onGotAllSlices(docdataSlices) {
var docdata = [];
for (var i = 0; i < docdataSlices.length; i++) {
docdata = docdata.concat(docdataSlices[i]);
}
var fileContent = new String();
for (var j = 0; j < docdata.length; j++) {
fileContent += String.fromCharCode(docdata[j]);
}
console.log("fileContent.length",fileContent.length)
// Now all the file content is stored in 'fileContent' variable,
// you can do something with it, such as print, fax...
}
Here is the result
File size:21489 #Slices: 1
fileContent.length 21489
Original example from Microsoft documentation (https://learn.microsoft.com/en-us/javascript/api/office/office.document)
// The following example gets the document in Office Open XML ("compressed") format in 65536 bytes (64 KB) slices.
// Note: The implementation of app.showNotification in this example is from the Visual Studio template for Office Add-ins.
function getDocumentAsCompressed() {
Office.context.document.getFileAsync(Office.FileType.Compressed, { sliceSize: 65536 /*64 KB*/ },
function (result) {
if (result.status == "succeeded") {
// If the getFileAsync call succeeded, then
// result.value will return a valid File Object.
var myFile = result.value;
var sliceCount = myFile.sliceCount;
var slicesReceived = 0, gotAllSlices = true, docdataSlices = [];
app.showNotification("File size:" + myFile.size + " #Slices: " + sliceCount);
// Get the file slices.
getSliceAsync(myFile, 0, sliceCount, gotAllSlices, docdataSlices, slicesReceived);
}
else {
app.showNotification("Error:", result.error.message);
}
});
}
function getSliceAsync(file, nextSlice, sliceCount, gotAllSlices, docdataSlices, slicesReceived) {
file.getSliceAsync(nextSlice, function (sliceResult) {
if (sliceResult.status == "succeeded") {
if (!gotAllSlices) { // Failed to get all slices, no need to continue.
return;
}
// Got one slice, store it in a temporary array.
// (Or you can do something else, such as
// send it to a third-party server.)
docdataSlices[sliceResult.value.index] = sliceResult.value.data;
if (++slicesReceived == sliceCount) {
// All slices have been received.
file.closeAsync();
onGotAllSlices(docdataSlices);
}
else {
getSliceAsync(file, ++nextSlice, sliceCount, gotAllSlices, docdataSlices, slicesReceived);
}
}
else {
gotAllSlices = false;
file.closeAsync();
app.showNotification("getSliceAsync Error:", sliceResult.error.message);
}
});
}
function onGotAllSlices(docdataSlices) {
var docdata = [];
for (var i = 0; i < docdataSlices.length; i++) {
docdata = docdata.concat(docdataSlices[i]);
}
var fileContent = new String();
for (var j = 0; j < docdata.length; j++) {
fileContent += String.fromCharCode(docdata[j]);
}
// Now all the file content is stored in 'fileContent' variable,
// you can do something with it, such as print, fax...
}
// The following example gets the document in PDF format.
Office.context.document.getFileAsync(Office.FileType.Pdf,
function(result) {
if (result.status == "succeeded") {
var myFile = result.value;
var sliceCount = myFile.sliceCount;
app.showNotification("File size:" + myFile.size + " #Slices: " + sliceCount);
// Now, you can call getSliceAsync to download the files,
// as described in the previous code segment (compressed format).
myFile.closeAsync();
}
else {
app.showNotification("Error:", result.error.message);
}
}
);
Since you're using Excel, have you tried the CreateWorkbork API? Might be a good workaround if the Document API has a bug, like Xuanzhou indicated earlier.
Here's a CreateDocument snippet that you can load into Script Lab. It shows how to create a Workbook copy based on an existing file.
Hope all that is helpful.
We already have a fix for it now. But the fix still need some time to go to production. Please try it several days later and let me know if the issue still exists. Thanks.

Create mongoose plugin with typescript

I have found on the internet this interesting article about plugins in mongoose. From that site I got this code:
function HidePlugin(schema) {
var toHide = [];
schema.eachPath(function(pathname, schemaType) {
if (schemaType.options && schemaType.options.hide) {
toHide.push(pathname);
}
});
schema.options.toObject = schema.options.toObject || {};
schema.options.toObject.transform = function(doc, ret) {
// Loop over all fields to hide
toHide.forEach(function(pathname) {
// Break the path up by dots to find the actual
// object to delete
var sp = pathname.split('.');
var obj = ret;
for (var i = 0; i < sp.length - 1; ++i) {
if (!obj) {
return;
}
obj = obj[sp[i]];
}
// Delete the actual field
delete obj[sp[sp.length - 1]];
});
return ret;
};
}
The problem is that I use typescript together with node.js. The typescript compiler gives me errors because there are no explicit types. In fact, I do not know exactly what type I have to attribute to the variables in the code

Node acting synchronously, waiting for the loop to finish

I have encounted a few issues in the project I am doing since node is async, but now I have a for loop and I do something after the loop ends or breaks, and it seems to be working synchronously and I want to know why.
I have this code:
var newItem = true;
for (var i = 0; i < cart.length; i++) {
if (cart[i].title == slug) {
cart[i].qty++;
newItem = false;
break;
}
}
if (newItem) {
cart.push({
title: slug
});
}
And all this works as expected! the newItem variable always has the correct value.
How come newitem is not always true?
I never have more than 3 items in the cart array, is this why? Would it behave differently if I had a 1000 items?
The code you have provide is running synchronously, if you want to test whether it works in an asynchronous condition try running this code
var newItem = true;
for (var i = 0; i < cart.length; i++) {
setTimeout(function(){
if (cart[i].title == slug) {
cart[i].qty++;
newItem = false;
break;
}
}, 1000);
}
if (newItem) {
cart.push({
title: slug
}
}

execute variable number of mongo queries in node, return single result

Ooof. Ever have one of those days where you know you're close, but you just can't quite get it?
I am writing a hangman puzzle solver. This is running in a service written with node/hapi backended with mongo db.
So I have a function:
solvePuzzle(puzzle, alreadyCalled);
The args are the puzzle itself, with solved letters as literals, and unsolved as ?s, like so:
?O?N? ?O ?H? ?TO??
and alreadyCalled being simply a list of letters called but incorrect. After some mucking about, a RegEx is created for each word, which is then sent to a function that queries a wordlist stored in mongo for matches.
Everything is functioning as it should, and if I create a dummy wordlist as a simple array, everything works fine and I get a list of matches.
The return format is an array of objects like so: (I use array indices to preserve word order when displaying possible solutions)
matches[0][?O?N?] = ['GOING', 'DOING', 'BOING'];
So on to the actual PROBLEM. I split the whole puzzle into words, and run a for loop over them, calling the function which performs the mongo query for each one. Problem is, that function call seems to be returning before the query has actually run. The console logs interspersed throughout seem to bear this theory out.
I tried having the query function return a promise, but that has only served to muddy the waters further. I feel like I'm close but yeah - I dunno. Here was my original non-promise code:
function solvePuzzle(puzzle, called) {
// first build the exclusion match pattern
//console.log('solvePuzzle: building match pattern');
var x = buildMatchPattern(puzzle, called);
// split the puzzle into words
//console.log('solvePuzzle: tokenizing puzzle');
var words = tokenize(puzzle.toUpperCase());
//console.log('solvePuzzle:', words);
var results = [];
for(var i = 0; i < words.length; i++) {
console.log('solvePuzzle: matching ' + words[i]);
results[i] = {};
results[i][words[i]] = matchWord(words[i], x);
}
console.log('solvePuzzle: matches: ', results);
return results;
}
function matchWord(word, exclude) {
var pattern = '^';
var letters = word.toUpperCase().split('');
var matches = new Array();
var query = {};
//console.log('matchWord:', letters);
for(var i = 0; i < letters.length; i++) {
if(letters[i] !== '?') {
pattern += letters[i];
}
else {
pattern += exclude;
}
}
pattern += '$';
var re = new RegExp(pattern);
//console.log('matchWord:', re);
query.word = {"$regex" : re, "$options": "i"};
//console.log("matchWord query:", JSON.stringify(query));
db.wordlist.find(query, function (err, words) {
if(err) {
console.error('error:', err);
}
for(let i = 0; i < words.length; i++) {
if(words[i] !== null) {
console.log('loop:', words[i].word);
matches.push(words[i].word);
}
}
console.log('matchWord:', matches.length);
if(matches.length < 1) {
console.log('matchWord: found no matches');
matches.push('No Matches Found');
}
return matches;
});
}
So my console output was basically:
solvePuzzle: matching ?O?N?
solvePuzzle: matches: [] <---- problem
loop: 'going'
loop: 'doing'
etc etc.
.
.
matchWord: 5 (number of matches found);
So as you can see, the call to matchWord is returning before the actual query is running. So I have never done a hapi service backed by mongo. How can I structure this code so it loops over all the words, queries mongo for each one, and returns a single array as result?
TIA.
In node, database calls are asynchronous so you can't use return like this.
You need to use Promise (native in node.js)
this code should work :
function solvePuzzle(puzzle, called) {
var results = [];
// first build the exclusion match pattern
var x = buildMatchPattern(puzzle, called);
// split the puzzle into words
var words = tokenize(puzzle.toUpperCase());
// an array to store the words index
var indexes = Array.apply(null, {
length: words.length
}).map(Number.call, Number); // looks like [1, 2, 3, 4, ...]
// create a Promise for each word in words
var promises = indexes.map(function(index) {
return new Promise(function(resolve, reject) {
console.log('solvePuzzle: matching ' + words[index]);
results[index] = {};
var pattern = '^';
var letters = words[index].toUpperCase().split('');
var matches = new Array();
var query = {};
for (var i = 0; i < letters.length; i++) {
if (letters[i] !== '?') {
pattern += letters[i];
} else {
pattern += exclude;
}
}
pattern += '$';
var re = new RegExp(pattern);
query.word = {
"$regex": re,
"$options": "i"
};
db.wordlist.find(query, function(err, wordsRes) {
if (err) {
console.error('error:', err);
reject(err); // if request failed, promise doesn't resolve
}
for (let i = 0; i < wordsRes.length; i++) {
if (wordsRes[i] !== null) {
console.log('loop:', wordsRes[i].word);
matches.push(wordsRes[i].word);
}
}
console.log('matchWord:', matches.length);
if (matches.length < 1) {
console.log('matchWord: found no matches');
matches.push('No Matches Found');
}
results[index][words[index]] = matches;
resolve(); // request successfull
});
});
});
// when all promise has resolved, then return the results
Promise.all(promises).then(function() {
console.log('solvePuzzle: matches: ', results);
return results;
});
}

How to get an object that was changed in angularjs?

I use this function to watch an array of objects for changes:
$scope.$watch('Data', function (newVal) { /*...*/ }, true);
How can I get an object in which property has been changed so that I can push it in an array?
For example:
var myApp = angular.module("myApp", []);
myApp.factory("Data", function(){
var Data = [{id:1, property: "Random"}, {id:2, property: "Random again"}];
return Data;
});
var myBigArray = [];
function tableCtrl($scope, Data){
$scope.TheData = Data;
$scope.$watch("TheData", function() {
//Here an object should be pushed
myBigArray.push(">>Object in which property has been changed <<<");
}, true);
}
I don't see a way currently in Angular to get the changed object... I suspect you might need to traverse the new array and try to find the differences with the old array...
Edit: Note that this solution turns out to be a bad practice as it is adding a lot of watchers, which is something you do not want because it has a performance penalty.
=======
I eventually came up with this solution:
items.query(function (result) {
_(result).each(function (item, i) {
$scope.items.push(item);
$scope.$watch('items[' + i + ']' , function(){
console.log(item); // This is the item that changed.
}, true);
});
});
There is still no option like this for $watch, but you can use jQuery plugin for that, http://archive.plugins.jquery.com/project/jquery-diff
I implemented undo/redo with AngularJS using $watch, mb this can help
//History Manager Factory
.factory('HistoryManager', function () {
return function(scope) {
this.container = Array();
this.index = -1;
this.lock = false;
//Insert new step into array of steps
this.pushDo = function() {
//we make sure that we have real changes by converting to json,
//and getting rid of all hash changes
if(this.container.length == 0 || (angular.toJson(scope.widgetSlider) != angular.toJson(this.container[this.index][0]))) {
//check if current change didn't came from "undo" change'
if(this.lock) {
return;
}
//Cutting array, from current index, because of new change added
if(this.index < this.container.length-1) {
this.container = this.container.slice(0, this.index+1);
}
var currentStepSlider = angular.copy(scope.widgetSlider);
var selectedWidgetIndex = scope.widgetSlider.widgets.indexOf(scope.widgetCurrent);
//Initialising index, because of new "Do" added
this.index = this.container.length;
this.container.push([currentStepSlider, selectedWidgetIndex]);
if (this.onDo) {
this.onDo();
}
}
}
//Upon undo returns previous do
this.undo = function() {
this.lock = true;
if(this.index>0){
this.index--;
scope.widgetSlider = angular.copy(this.container[this.index][0]);
var selectedWidgetIndex = this.container[this.index][1];
scope.widgetCurrent = scope.widgetSlider.widgets[selectedWidgetIndex];
}
this.lock = false;
}
//Upon redo returns next do
this.redo = function() {
if(this.index < this.container.length-1) {
this.index++;
scope.widgetSlider = angular.copy(this.container[this.index][0]);
var selectedWidgetIndex = this.container[this.index][1];
scope.widgetCurrent = scope.widgetSlider.widgets[selectedWidgetIndex];
}
}
}
})
;

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