Hi all I have this working method to call an array of functions at recurring intervals.
Here you can see the object with the methods to add/remove functions in the array and the functions to start/stop the calling interval. (You have to focus only to the start method but I put them all for clarification)
function updateEngine() {
var _callRecurringFunctions = null,
_functionsToCall = [],
_functionIds = [],
_functionApps = [];
updateEngine.prototype.addFunction = function (appCode, funcId, func) {
if ($.isFunction(func) &&
$.inArray('_' + appCode + '_' + funcId, _functionIds) == -1) {
_functionApps.push(appCode);
_functionIds.push('_' + appCode + '_' + funcId);
_functionsToCall.push(func);
}
}
updateEngine.prototype.removeFunction = function (appCode, funcId) {
if (funcId == null) { // remove all functions relative to an app
for (var x = 0; x < _functionApps.length; x++) {
if (_functionApps[x] == appCode) {
_functionApps.splice(x, 1);
_functionIds.splice(x, 1);
_functionsToCall.splice(x, 1);
}
}
}
else { // remove the single app function
var pos = $.inArray('_' + appCode + '_' + funcId, _functionIds);
if (pos >= 0) {
_functionApps.splice(pos, 1);
_functionIds.splice(pos, 1);
_functionsToCall.splice(pos, 1);
}
}
}
updateEngine.prototype.start = function () {
_callRecurringFunctions = setInterval(function () {
for (var x = 0; x < _functionsToCall.length; x++) {
var frame = null;
// id == -1: local function
// id == 0: function defined in home iframe
// id > 0: function defined in an app iframe
if (_functionApps[x] >= 0)
frame = _portalContent.find("iframe[id='" + _functionApps[x] + "']");
if (frame != null && frame.get(0) != null) {
var iframeContent = frame.get(0).contentWindow || frame.get(0).contentDocument;
_functionsToCall[x].apply(iframeContent);
}
else
_functionsToCall[x]();
}
}, _updateFrequence); // tick every 5 seconds
}
updateEngine.prototype.stop = function () {
clearInterval(_callRecurringFunctions);
_callRecurringFunctions = null;
_functionApps = [];
_functionIds = [];
_functionsToCall = [];
}
}
I want to convert the start method using setTimeout instead of setInterval and I wrote something like this:
updateEngine.prototype.start = function () {
function doLoop() {
$.when.apply($, _functionsToCall)
.done(function() {
setTimeout(doLoop, _updateFrequence);
});
}
setTimeout(doLoop, _updateFrequence);
}
How can I change the context of the array functions _functionsToCall like I do in the previous method to pass the iframe context to each function?
I've resolved my problem in another way...
Now I have an array of functions that return a promise each;
Those functions can be declared inside differents iframes;
I increase a counter when each promise is resolved, and when all promises are resolved I can start again with another loop.
Obviously on each iteration the array can contains a different number of functions.
I'd like to know if there is a better way to do this task or if there are some issues with my code.
Thank you all.
updateEngine.prototype.start = function () {
function doLoop() {
var count = 0,
functionsCount = _functionsToCall.length
for (var x = 0; x < functionsCount; x++) {
var frame = null;
// id == -1: local function
// id >= 0: function defined in iframe
if (_functionApps[x] >= 0)
frame = _portalContent.find("iframe[id='" + _functionApps[0] + "']");
if (frame != null && frame.get(0) != null) {
var iframeContent = frame.get(0).contentWindow || frame.get(0).contentDocument;
$.when.apply(iframeContent, _functionsToCall[x]())
.done(function () {
count++;
})
.fail(function () {
count++;
console.log("err")
})
.always(function () {
if (count == functionsCount)
setTimeout(doLoop, _updateFrequence)
})
}
else
$.when(_functionsToCall[x]())
.done(function () {
count++;
})
.fail(function () {
count++;
console.log("err")
})
.always(function () {
if (count == functionsCount)
setTimeout(doLoop, _updateFrequence)
})
}
}
setTimeout(doLoop, _updateFrequence)
}
Related
I have a counter which is local to the scope of a parent function and being passed across multiple child functions and is incremented across multiple instances. I am having trouble maintaining the count
I have tried the following
var maxLimit = 150;
async function incrementCounter(counter) {
counter++;
console.log(counter);
return counter;
}
async function processRights() {
var counter = 0,
end = false;
var queryInput = [0, 1, 1, 0, 1];
for (var i = 0; i < queryInput.length; i++) {
var element = queryInput[i];
var thOutput = await processTitle(counter, element, 'th');
if (!thOutput) {
end = true;
return;
}
var nthOutput = await processTitle(counter, element, 'nth');
if (!nthOutput) {
end = true;
return;
};
}
if (!queryInput || !queryInput.length) {
end = true;
}
return;
}
async function processTitle(counter, element, type) {
var output = await callFunc(counter, element, type);
if (!output) {
return false;
}
return output;
}
async function callFunc(counter, element) {
var responses = [];
var counterValue1 = await incrementCounter(counter);
if (counterValue1 >= maxLimit) {
return false;
}
await callAnotherFunc();
if (1) {
var qryArr = [0, 1, 1, 0, 1];
for (let i = 0; i < qryArr.length; i++) {
var counterValue2 = await incrementCounter(counterValue1);
console.log("counterValue2 -- " + counterValue2);
if (counterValue2 >= maxLimit) {
return false;
}
await callAnotherFunc();
}
return responses;
}
}
async callAnotherFunc(){
return true;
}
processRights();
I would like the increment the counter and check against the maximum limit each time the callAnotherFunc function is called. I am a novice to JS. Pl help!
If the counter can be really a global variable, you can declare it side by side with the maxLimit variable, something like this:
var overallCounter = 0;
var maxLimit = 150;
...
async callAnotherFunc(){
return overallCounter++ <= maxLimit;
}
From the question and the code I think this is what you want to achieve, right?
I have a MultiSelectDropDown, that is, several RadComboBox controls are used in a combined way. For example, I can have a dropdown for regions, another for depots and another for user. The idea is to change the content of lower levels dynamically whenever items are selected or unselected on a higher level. The problem is that in the case when many items are selected, this becomes brutally slow due to some Telerik functions, but I do not understand why. This is a chunk from the client-side of the MultiSelectDropDown prototype:
changeLowerLevels: function (valueIndex, values, value) {
if (!this.canChange) return;
//Get selected values from combobox
var combo = $find(this.ddlIDs[valueIndex - 1]);
var cbItems = combo.get_checkedItems();
var selectedItems = [];
var change = null;
var counter = 0;
if (cbItems.length) this.filterString = "";
for (var i = 0; i < cbItems.length; i++) {
counter++;
if (this.filterString == "") this.filterString = cbItems[i].get_text();
selectedItems.push(cbItems[i].get_value());
}
if (counter > 1) this.filterString += " with " + (counter - 1) + " other" + ((counter > 2) ? "s" : "");
if (JSON.stringify(selectedItems) === JSON.stringify(this.selectedItems[valueIndex - 1]) || selectedItems == [])
return;
this.selectedItems[valueIndex - 1] = selectedItems;
var controlObject = this;
var combo = $find(this.ddlIDs[valueIndex]);
var comboItems = combo.get_items();
if(!this.disabled) combo.enable();
combo.clearItems();
if (valueIndex == 1) this.twoLevelCache = values;
var val = values;
//break if all items are found
var nrOfSelectedItems = this.selectedItems[valueIndex - 1].length;
var nrOfFoundItems = 0;
var index = 0;
var indexes = [];
var found = false;
while (nrOfFoundItems < nrOfSelectedItems && val[index] !== undefined) {
found = (this.selectedItems[valueIndex - 1].indexOf(val[index].Value) != -1);
if (!(found))
index++;
else {
indexes.push(index)
nrOfFoundItems++;
index++;
}
}
//separators from valuesIndex - 1 level
var controlObject = this;
for (var i = 0; i < indexes.length; i++) {
var separator = new Telerik.Web.UI.RadComboBoxItem();
separator.set_text("<span><a class=\"checkAll tt-multi-uncheck-icon\" index=\"" + index + "\">U</a>" + $find(this.ddlIDs[valueIndex - 1]).findItemByValue(val[indexes[i]].Value).get_text() + "</span>");
separator.set_value("");
separator.set_isSeparator(true);
comboItems.add(separator);
this.twoLevelCache.push(val[indexes[i]].Levels);
//valuesIndex level
var valuesArray = val;
var comboItem = new Telerik.Web.UI.RadComboBoxItem();
for (var depot in valuesArray[indexes[i]].Levels) {
comboItem = new Telerik.Web.UI.RadComboBoxItem();
comboItem.set_text(valuesArray[indexes[i]].Levels[depot].Name);
comboItem.set_value(valuesArray[indexes[i]].Levels[depot].Value);
comboItems.add(comboItem);
comboItem = null;
}
$('#' + this.ddlIDs[valueIndex] + '_DropDown a.checkAll').unbind().on("click", function () {
checkAllLowerItems(this, controlObject.ddlIDs[valueIndex]);
});
}
combo.set_emptyMessage(this.allText);
//$("#" + this.ddlIDs[valueIndex]).html(returnValue);
if (this.ddlIDs.length > valueIndex + 1) {
var paramToPass = (((val == undefined) || (val[index] === undefined)) ? ("") : (val[index]));
if (this.allText.length > 0)
this.changeLowerLevels(valueIndex + 1, paramToPass, "");
else {
if (paramToPass !== "")
paramToPass = paramToPass.Levels;
if ((val[index] == undefined) || (val[index].Levels[0] === undefined) || (val[index].Levels[0].Value === "")) {
this.changeLowerLevels(valueIndex + 1, paramToPass, "");
}
else {
this.changeLowerLevels(valueIndex + 1, paramToPass, val[index].Levels[0].Value);
}
}
}
else {
if (this.allText.length > 0)
this.selectedItems[valueIndex] = "";
else
if ((val[index] == undefined) || (val[index].Levels[0] === undefined) || (val[index].Levels[0].Value === "")) {
this.selectedItems[valueIndex] = "";
}
else {
this.selectedItems[valueIndex] = val[index].Levels[0].Value;
}
}
this.setText();
}
combo.clearItems() is extremeley slow. I have take a look on how it is implemented:
function (){var f=this._parent._getControl();?if(f._checkBoxes){f._checkedIndicesJson="[]";?f._checkedIndices=[];?var g=f.get_items();?for(var d=0,e=g.get_count();?d<e;?d++){var c=f.get_items().getItem(d);?c.set_checked(false);?}f.updateClientState();?}a.RadComboBoxItemCollection.callBaseMethod(this,"clear");?}
How can I make sure that this Javascript function speeds up?
I have finally solved the problem by rewriting Telerik client-side functionalities. It was a long and difficult debugging, but it yielded a large performance boost in the most difficult circumstances. From ~30 000 milliseconds, to ~300. Let's see the parts of the optimization:
The actual rewrite
/* Overriding Telerik functions Start */
var overridenTelerikControls = false;
function overrideTelerikFunctionalities() {
if (!overridenTelerikControls) {
overridenTelerikControls = true;
Telerik.Web.UI.RadComboBox.prototype.clearItems = function (isMultiSelectDropDown) {
this.get_items().clear(isMultiSelectDropDown);
this._itemData = null;
};
Telerik.Web.UI.RadComboBoxItemCollection.prototype.clear = function (isMultiSelectDropDown){
var f=this._parent._getControl();
if(f._checkBoxes){
f._checkedIndicesJson="[]";
f._checkedIndices=[];
var g = f.get_items();
for(var d=0,e=g.get_count();d<e;d++){
var c=f.get_items().getItem(d);
c.set_checked(false, isMultiSelectDropDown);
}
if (isMultiSelectDropDown) {
f._updateComboBoxText();
if (f._checkAllCheckBoxElement != null) {
f._updateCheckAllState();
}
}
f.updateClientState();
}
Telerik.Web.UI.RadComboBoxItemCollection.callBaseMethod(this, "clear");
};
Telerik.Web.UI.RadComboBoxItem.prototype.set_checked = function (d, isMultiSelectDropDown){
if(!this.get_enabled()){
return;
}
this._setChecked(d);
var c=this.get_comboBox();
if(c){
if(d){
c._registerCheckedIndex(this.get_index());
}else{
c._unregisterCheckedIndex(this.get_index());
}
if (!isMultiSelectDropDown) {
c._updateComboBoxText();
}
if((!isMultiSelectDropDown) && (c._checkAllCheckBoxElement!=null)){
c._updateCheckAllState();
}
}
};
}
}
/* Overriding Telerik functions End*/
My approach was to keep the old way of their working by default, but if an isMultiSelectDropDown parameter is passed, then work in the optimized manners. So we have a switch materialized as a parameter and we can turn it on/off. The main difference was that the old way was to change the label text showing the selected elements each time a checkbox is checked/unchecked. The main improvement was to do this change after all the checkboxes were checked/unchecked. This extremely simple idea was the driving force behind the boost of performance.
Actual usage
overrideTelerikFunctionalities();
combo.clearItems(true);
This was the functionalities were overriden if they were not already and the parameter was true, therefore the new approach was chosen.
Test, test, test
I am working on a project that needs an excel like calculation engine in the browser. But, it doesn't need the grid UI.
Currently, I am able to do it by hiding the 'div' element of Handsontable. But, it isn't elegant. It is also a bit slow.
Is there a client side spreadsheet calculation library in javascript that does something like this?
x = [ [1, 2, "=A1+B1"],
[2, "=SUM(A1,A2"),3] ];
y = CalculateJS(x);
##############
y: [[1, 2, 3],
[2,3,3]]
I'm not aware of any (although I haven't really looked), but if you wish to implement your own, you could do something along these lines (heavily unoptimized, no error checking):
functions = {
SUM: function(args) {
var result = 0;
for (var i = 0; i < args.length; i++) {
result += parseInt(args[i]);
}
return result;
}
};
function get_cell(position) {
// This function returns the value of a cell at `position`
}
function parse_cell(position) {
cell = get_cell(position);
if (cell.length < 1 || cell[0] !== '=')
return cell;
return parse_token(cell.slice(1));
}
function parse_token(tok) {
tok = tok.trim();
if (tok.indexOf("(") < 0)
return parse_cell(tok);
var name = tok.slice(0, tok.indexOf("("));
if (!(name in functions)) {
return 0; // something better than this?
}
var arguments_tok = tok.slice(tok.indexOf("(") + 1);
var arguments = [];
while (true) {
var arg_end = arguments_tok.indexOf(",");
if (arg_end < 0) {
arg_end = arguments_tok.lastIndexOf(")");
if (arg_end < 0)
break;
}
if (arguments_tok.indexOf("(") >= 0 && (arguments_tok.indexOf("(") < arg_end)) {
var paren_amt = 1;
arg_end = arguments_tok.indexOf("(") + 1;
var end_tok = arguments_tok.slice(arguments_tok.indexOf("(") + 1);
while (true) {
if (paren_amt < 1) {
var last_index = end_tok.indexOf(",");
if (last_index < 0)
last_index = end_tok.indexOf(")");
arg_end += last_index;
end_tok = end_tok.slice(last_index);
break;
}
if (end_tok.indexOf("(") > 0 && (end_tok.indexOf("(") < end_tok.indexOf(")"))) {
paren_amt++;
arg_end += end_tok.indexOf("(") + 1;
end_tok = end_tok.slice(end_tok.indexOf("(") + 1);
} else {
arg_end += end_tok.indexOf(")") + 1;
end_tok = end_tok.slice(end_tok.indexOf(")") + 1);
paren_amt--;
}
}
}
arguments.push(parse_token(arguments_tok.slice(0, arg_end)));
arguments_tok = arguments_tok.slice(arg_end + 1);
}
return functions[name](arguments);
}
Hopefully this will give you a starting point!
To test in your browser, set get_cell to function get_cell(x) {return x;}, and then run parse_cell("=SUM(5,SUM(1,7,SUM(8,111)),7,8)"). It should result in 147 :)
I managed to do this using bacon.js. It accounts for cell interdependencies. As of now, it calculates values for javascript formula instead of excel formula by using an eval function. To make it work for excel formulae, all one has to do is replace eval with Handsontable's ruleJS library. I couldn't find a URI for that library... hence eval.
https://jsfiddle.net/sandeep_muthangi/3src81n3/56/
var mx = [[1, 2, "A1+A2"],
[2, "A2", "A3"]];
var output_reference_bus = {};
var re = /\$?[A-N]{1,2}\$?[1-9]{1,4}/ig
var alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".split('');
function convertToCellRef(rows, cols) {
var alphabet_index = rows+1,
abet = "";
while (alphabet_index>0) {
abet = alphabet[alphabet_index%alphabet.length-1]+abet;
alphabet_index = Math.floor(alphabet_index/alphabet.length);
}
return abet+(cols+1).toString();
}
function getAllReferences(value) {
if (typeof value != "string")
return null;
var references = value.match(re)
if (references.length == 0)
return null;
return references;
}
function replaceReferences(equation, args) {
var index = 0;
return equation.replace(re, function(match, x, string) {
return args[index++];
});
}
//Assign an output bus to each cell
mx.forEach(function(row, row_index) {
row.forEach(function(cell, cell_index) {
output_reference_bus[convertToCellRef(row_index, cell_index)] = Bacon.Bus();
})
})
//assign input buses based on cell references... and calculate the result when there is a value on all input buses
mx.forEach(function(row, row_index) {
row.forEach(function(cell, cell_index) {
if ((all_refs = getAllReferences(cell)) != null) {
var result = Bacon.combineAsArray(output_reference_bus[all_refs[0]]);
for (i=1; i<all_refs.length; i++) {
result = Bacon.combineAsArray(result, output_reference_bus[all_refs[i]]);
}
result = result.map(function(data) {
return eval(replaceReferences(cell, data));
})
result.onValue(function(data) {
console.log(convertToCellRef(row_index, cell_index), data);
output_reference_bus[convertToCellRef(row_index, cell_index)].push(data);
});
}
else {
if (typeof cell != "string")
output_reference_bus[convertToCellRef(row_index, cell_index)].push(cell);
else
output_reference_bus[convertToCellRef(row_index, cell_index)].push(eval(cell));
}
})
})
output_reference_bus["A2"].push(20);
output_reference_bus["A1"].push(1);
output_reference_bus["A1"].push(50);
I'm making a simple twitter app to work on my javascript.
The code below is supposed to identify every tweets location and count the number of tweets per location.
However, it doesn't increment, it just creates a new array.
What is wrong with my code? How can I make it better?
Thank you
var Twitter = require('node-twitter'),
twit = {},
loc = [];
twit.count = 0;
var twitterStreamClient = new Twitter.StreamClient(
//credentials
);
twitterStreamClient.on('close', function () {
console.log('Connection closed.');
});
twitterStreamClient.on('end', function () {
console.log('End of Line.');
});
twitterStreamClient.on('error', function (error) {
console.log('Error: ' + (error.code ? error.code + ' ' + error.message : error.message));
});
twitterStreamClient.on('tweet', function (tweet) {
if (loc.indexOf(tweet.user.location) === -1) {
loc.push({"location": tweet.user.location, "locCount": 1});
} else {
loc.loation.locCount = loc.loation.locCount + 1;
}
console.log(loc);
});
var search = twitterStreamClient.start(['snow']);
You need to rewrite on tweet callback:
var index = loc.reduce(function(acc, current, curIndex) {
return current.location == tweet.user.location ? curIndex : acc;
}, -1);
if (index === -1) {
loc.push({"location": tweet.user.location, "locCount": 1});
} else {
loc[index].locCount++;
}
Array.indexOf is not matching as you think it is. You're creating a new object and pushing it into the array, and regardless of whether its properties match a different object perfectly, it will not be === equal. Instead, you have to find it manually:
var foundLoc;
for (var i = 0; i < loc.length; i++) {
if (loc[i].location.x === location.x)
foundLoc = loc[i];
break;
}
}
if (!foundLoc) {
loc.push({location: location, count: 0});
} else {
foundLoc.count++
}
I have this code and i can add or edit the object if exists, but the "for" finish before the function onsuccess is called, then the index "for" is bad.
How to pass the index onSuccess?
Help!!!
var active = dataBase.result;
var data = "";
var object = "";
var index = null;
var request;
$(".layers").promise().done(function () {
var elements = document.getElementsByClassName('layers');
for (var i = 0; typeof (elements[i]) != 'undefined'; i++) {
if (elements[i].getAttribute("src").split("/")[4] !== "alpha.png") {
data = active.transaction([elements[i].getAttribute("src").split("/")[3]], "readwrite");
object = data.objectStore(elements[i].getAttribute("src").split("/")[3]);
index = object.index("by_Name");
request = index.get(String(elements[i].getAttribute("src").split("/")[4] + "/" + elements[i].getAttribute("src").split("/")[6]));
request.onsuccess = function (e) {
var result = e.target.result;
if (result === undefined) {
var resultPut = object.put({
Name: String(elements[i].getAttribute("src").split("/")[4] + "/" + elements[i].getAttribute("src").split("/")[6]),
Count: 1,
Type: String(elements[i].getAttribute("src").split("/")[4])
});
resultPut.onerror = function (e) {
alert(resultPut.error.name + '\n\n' + resultPut.error.message);
};
} else {
result.Count++;
var requestUpdate = object.put(result);
requestUpdate.onerror = function (event) {
alert(requestUpdate.error.name + '\n\n' + requestUpdate.error.message);
};
}
}(event);
}
}
alert("Finish");
})
The thing is that, by the time the for has ended, the transactions with the object store are not. What you could try is to encapsulate the index like this:
for(var i = 0; i < elements.length; i++) {
(function(myElement) {
if (myElement.getAttribute("src").split("/")[4] !== "alpha.png") {
...
}
})(elements[i]);
}