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How to pass an ajax result to a Public veriable in the same class?

I have a jQuery file which also uses unserscore.js. It controls the selections of dates and different venues. For one of the pages it also controls which visuals are displayed depending on the type of venue. I can successfully, using ajax, get the type of page, but I have been unable to pass that value to a public variable in the script. It is based on which WiFi spot the data is coming from. If the data is from a local spot the page should display a d3 bubble chart. If it's from a remote spot it should display a map of the venue. Currently I have the functionality working with hard coding based on the id of the venue which is far from ideal.In order to make the decision based on which spot the venue is using I created an ajax call that gets the "spot". With console.log I can see that I am getting the correct result from the ajax call, but I'm missing something in terms of passing that information to a variable so I can use it.
This is the complete jQuery files:
define([
"ui/selects",
], function (SelectsUiClass) {
var global = this;
var MainControlsClass = function () {
// Private vars
var _this = this,
_xhr = null,
_selects = new SelectsUiClass(),
_dateRangeSelect,
_venueSelect,
_floorSelect,
_zoneSelect;
// Public vars
this.Selects = null;
this.spotName = null;
// Private Methods
var _construct = function () {
_dateRangeSelect = _selects.InitSelect('#mainControls-dateRange', _onSelectChange);
_venueSelect = _selects.InitSelect('#mainControls-venue', _onSelectChange);
_floorSelect = _selects.InitSelect('#mainControls-floor', _onSelectChange);
_zoneSelect = _selects.InitSelect('#mainControls-zone', _onSelectChange);
var value = _this.GetVenue();
_getChartDisplayDiv(value);
};
var _getChartDisplayDiv = function (venueId) {
var path = window.location.pathname,
pathArray = path.split("/"),
page = pathArray[pathArray.length - 1];
console.log('controlsjs 36, navigation page: ' , page);
console.log('controlsjs 37, venue value: ' , venueId);
_this.Load(venueId);
console.log('Controls 40, sPot Name = ', _this.spotName);
if (page === 'heatmap') {
if (venueId === 8 || venueId === 354) {
//make the bubble div visible
$("#heatmap-bubble").show();
//make the map div invisible
$("#heatmap-map").hide();
} else {
//make the map div visible
$("#heatmap-map").show();
//make the bubble div invisible
$("#heatmap-bubble").hide();
}
}
}
this.Load = function (venueId) {
console.log("Controls 66, Venue Id sent = ", venueId);
if (_xhr) {
_xhr.abort();
_xhr = null;
}
_this.SetLoading(true);
_xhr = $.ajax({
url: $("meta[name='root']").attr("content") + '/app/heatmap/spot',
type: 'POST',
headers: {
'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
},
data: {
venue_id: venueId
},
dataType: 'JSON',
async: true,
cache: false,
error: function (jqXHR, textStatus, errorThrown) {
_this.SetLoading(false);
},
success: function (response) {
_this.SetLoading(false);
console.log("Controls 90, Response of ajax call = ", response);
_this.Update(response);
}
});
};
// Public functions
this.SetLoading = function (option) {
if (_.isUndefined(option)) { option = false; }
if (this.spotName) { this.spotName.SetLoading(option); }
};
this.Update = function (data) {
if (_.isUndefined(data) || _.isNull(data)) {
console.log('Controls 106: Spot Name: ', data)
this.spotName = data;
}
};
var _getVenueData = function (venueId) {
for (var i = 0; i < venuesData.length; i++) {
if (venuesData[i].id === venueId) {
if (!_.isUndefined(venuesData[i].spot_data)) {
return venuesData[i].spot_data;
}
}
}
};
var _onVenueChange = function () {
var value = _this.GetVenue();
if (_.isNull(value)) {
return;
}
_getChartDisplayDiv(value);
//_setSelectValue(_venueSelect, value);
var venueData = _getVenueData(value);
console.log('Venue data received: ', venueData);
if (!_.isUndefined(venueData) && !_.isUndefined(venueData.floors)) {
_selects.UpdateSelect(_floorSelect, venueData.floors);
_onFloorChange();
}
};
var _onFloorChange = function () {
var value = _this.GetFloor(),
zones = [];
if (_.isNull(value)) {
return;
}
//_setSelectValue(_floorSelect, value);
if (_.isNumber(value)) {
var venueData = _getVenueData(_this.GetVenue()),
floors = venueData.floors;
for (var i = 0; i < floors.length; i++) {
if (floors[i].id === value) {
zones = floors[i].zones;
}
}
}
_selects.UpdateSelect(_zoneSelect, zones);
};
var _onZoneChange = function () {
var value = _this.GetZone();
if (_.isNull(value)) {
return;
}
//_setSelectValue(_zoneSelect, value);
};
var _onSelectChange = function (e) {
var t = $(e.target),
id = t.attr('id');
if (_venueSelect && _venueSelect.attr('id') === id) {
_onVenueChange();
} else if (_floorSelect && _floorSelect.attr('id') === id) {
_onFloorChange();
} else if (_zoneSelect && _zoneSelect.attr('id') === id) {
_onZoneChange();
}
EventDispatcher.Dispatch('Main.Controls.Change', _this, {
caller: id
});
};
// Public Methods
this.GetDateRange = function () {
return _selects.GetSelectValue(_dateRangeSelect);
};
this.GetDateRangeKey = function () {
if (_dateRangeSelect) {
var selected = _dateRangeSelect.find('option:selected');
if (selected.length) {
return selected.attr("data-key") || "";
}
}
return "";
};
this.GetVenue = function () {
return _selects.GetSelectValue(_venueSelect);
};
this.SetVenue = function (value) {
_selects.SetSelectValue(_venueSelect, value);
}
this.GetFloor = function () {
return _selects.GetSelectValue(_floorSelect);
};
this.SetFloor = function (value) {
_selects.SetSelectValue(_floorSelect, value);
}
this.GetZone = function () {
return _selects.GetSelectValue(_zoneSelect);
};
this.SetZone = function (value) {
_selects.SetSelectValue(_zoneSelect, value);
}
this.GetData = function () {
return {
dateRange: {
date: this.GetDateRange(),
key: this.GetDateRangeKey()
},
venue: this.GetVenue(),
floor: this.GetFloor(),
zone: this.GetZone()
};
};
// Init
_construct();
};
return MainControlsClass;
});
The function that determines which visual to display is close to the top: _getChartDisplayDiv:
var _getChartDisplayDiv = function (venueId) {
var path = window.location.pathname,
pathArray = path.split("/"),
page = pathArray[pathArray.length - 1];
_this.Load(venueId);
console.log('Controls 40, sPot Name = ', _this.spotName);
if (page === 'heatmap') {
if (venueId === 8 || venueId === 354) {
//make the bubble div visible
$("#heatmap-bubble").show();
//make the map div invisible
$("#heatmap-map").hide();
} else {
//make the map div visible
$("#heatmap-map").show();
//make the bubble div invisible
$("#heatmap-bubble").hide();
}
}
}
When I am able to pass the "spot" information to it or a variable that it uses, it should look like this:
var _getChartDisplayDiv = function (venueId) {
var path = window.location.pathname,
pathArray = path.split("/"),
page = pathArray[pathArray.length - 1];
_this.Load(venueId);
console.log('Controls 40, sPot Name = ', _this.spotName);
if (page === 'heatmap') {
if (_this.spotName === 'local' ) {
//make the bubble div visible
$("#heatmap-bubble").show();
//make the map div invisible
$("#heatmap-map").hide();
} else {
//make the map div visible
$("#heatmap-map").show();
//make the bubble div invisible
$("#heatmap-bubble").hide();
}
}
}
My ajax call is here:
this.Load = function (venueId) {
console.log("Controls 66, Venue Id sent = ", venueId);
if (_xhr) {
_xhr.abort();
_xhr = null;
}
_this.SetLoading(true);
_xhr = $.ajax({
url: $("meta[name='root']").attr("content") + '/app/heatmap/spot',
type: 'POST',
headers: {
'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
},
data: {
venue_id: venueId
},
dataType: 'JSON',
async: true,
cache: false,
error: function (jqXHR, textStatus, errorThrown) {
_this.SetLoading(false);
},
success: function (response) {
_this.SetLoading(false);
console.log("Controls 90, Response of ajax call = ", response);
_this.Update(response);
}
});
};
This successfully gets the right spot, but I have been unable to pass it to a variable I can use. I think I am getting mixed up between private and public variables. I tried to use the 'this.Update' function to pass the setting to the public 'this.spotName' variable, but that comes up null. I have also tried to simply return the result of the ajax call, but I get a "not a function" error. How can I make the result of the ajax call available to my '_getChartDisplayDiv' function?

Your problem is that you are trying to read the value of _this.spotName before it is assigned. Let us walk through the steps that happen.
When you call _getChartDisplayDiv(value), the _getChartDisplayDiv function first calls _this.Load(venueId). Load, in turn, submits an ajax request with a success callback, reproduced in abbreviated form below:
this.Load = function (venueId) {
// ...
_this.SetLoading(true);
_xhr = $.ajax({
...
success: function (response) {
_this.SetLoading(false);
console.log("Controls 90, Response of ajax call = ", response);
_this.Update(response);
}
});
};
When the response arrives, the success callback will be invoked, which in turn will call _this.Update, which will set the variable you are after. The syntax you used for this purpose is correct. However!
"When the response arrives" happens to be an unpredictable event in the future. It might be after 10 milliseconds, it might take 2 seconds, or the request might time out altogether. Even 10 milliseconds is already an eternity, compared to the time it takes your browser to execute all other code in your script. You can be quite sure that by the time $.ajax returns, the success callback has not run yet.
When you pass a callback (success) to a function ($.ajax) and the callback is not run before the function returns, this is called an asynchronous callback, "async" for short. When a callback might be invoked async, it is important for the function to guarantee that it always runs async, because this type of situation needs to be handled in an entirely different way from when the callback is invoked synchronously (i.e., before the function returns). You can read more about the technicalities in this blogpost. So this is exactly what $.ajax guarantees: it will never invoke the success (or error) callback before it returns, even in the hypothetical situation that the response would arrive fast enough.
Right after $.ajax returns, your Load function returns, at which point your _getChartDisplayDiv function continues to execute. Almost immediately after that, you intend to read _this.spotName. $.ajax has already returned, so you might hope that at this point, the success callback has already been invoked.
Unfortunately for you, async callbacks are more stubborn than that. Not only does an async callback not run until the function to which you pass it returns; it does not run until any currently executing function returns. Besides $.ajax, Load needs to return, _getChartDisplayDiv needs to return, any function that was calling _getChartDisplayDiv needs to return, and so forth. The entire call stack needs to unwind. Only then (and when the response actually arrives, which is likely to be many milliseconds later) will the success callback be invoked. This game rule is called the event loop in JavaScript.
The solution is simpler than you might expect: you just need to invert the order of control. Rather than trying to force the data out of a request when you want to update the chart, you can update the chart when the response arrives, and rather than trying to update the chart directly, you can just trigger the request. Specifically in your case, you just need to make three changes:
In the places where you currently call _getChartDisplayDiv, call _this.Load instead.
Remove the line that calls _this.Load inside the _getChartDisplayDiv function.
At the end of the success handler, add a line that calls _getChartDisplayDiv.
Incidentally, using a proper application framework will make it much easier to manage this kind of thing. In your case, I recommend trying Backbone; it builds on top of Underscore and jQuery and it is unopinionated, so you can gradually adopt it without having to radically change the way you work.

I am not familiar with underscore.js. For jQuery you have two options, which you can use as an inspiration for your case. Untested code:
1. Callback function
You provide a callback function:
$('.mydiv').myPlugin({ // Pass options Object to plugin
venuId: '123',
getType: function(type) {
console.log(type); // Example accessing internal data
}
});
Your plugin code:
(function( $ ) {
$.fn.myPlugin = function(opt) {
this.filter('div').each(function() {
const settings = $.extend({
namespace: 'myPlugin',
type: 'local'
getType: function() {},
// otherSettings: 'as needed',
}, opt);
// plugin code here...
if(typeof settings.getType === 'function') {
settings.getType(settings.type);
}
});
return this;
};
}( jQuery ));
2. Plugin method
You define plugin method(s) that can be called:
$('#mydiv').myPlugin({ // Pass options Object to plugin
venuId: '123'
});
console.log($('#mydiv').myPlaugin('getType'));
Your plugin code:
(function( $ ) {
$.fn.myPlugin = function(opt) {
this.filter('div').each(function() {
const settings = $.extend({
namespace: 'myPlugin',
type: 'local',
// otherSettings: 'as needed',
}, opt);
this.getType = function() {
return settings.type;
}
let firstArg = arguments[0];
if(typeof firstArg === 'string') {
let func = this[firstArg];
if(typeof func === 'function') {
var args = [];
for(var i = 1; i < arguments.length; i++) {
args.push(arguments[i]);
}
return func.apply(this, args);
}
} else {
// plugin init code here...
}
});
return this;
};
}( jQuery ));

Vue error: In strict mode code, functions can only be declared at top level or inside a block

I'm running a Vue script with a text box and submit button, I'm calling an api to POST what I write in the textbox to the api and to return information back from the API, I'm getting this error mentioned in the title eventhough I've written the Javascript functions in vue as it should be?
With the script I'm first setting up a new XMLHttpRequest, initiating the header and api key for both GET and POST methods. I've then created 2 functions to get the data from the textbox and send them to the API, then making another button with the other function to send back the data.
I went through this approach because I kept getting a CORS issue and the API needed me to declare an access control origin header, is there anything I've done wrong with this code? Any help would be greatly appreciated
<script>
export default {
name: 'ProperForm'
}
methods: {
StartClient: function () {
this.get = function(Url, Callback){
var aHttpRequest = new XMLHttpRequest();
aHttpRequest.onreadystatechange = function() {
if (aHttpRequest.readyState == 4 && aHttpRequest.status == 200)
Callback(aHttpRequest.responseText);
}
aHttpRequest.open("GET", Url, true);
aHttpRequest.setRequestHeader("X-Api-Key", "eVnbxBPfn01kuoJIdfgi46TiYNv8AIip1r3WbjsX");
aHttpRequest.send(null);
}
this.post = function(Url, message, Callback) {
var aHttpRequest = new XMLHttpRequest();
aHttpRequest.onreadystatechange = function() {
if (aHttpRequest.readyState == 4 && aHttpRequest.status == 200)
Callback(aHttpRequest.responseText);
}
aHttpRequest.open("POST", Url, true);
aHttpRequest.setRequestHeader("x-api-key", "eVnbxBPfn01kuoJIdfgi46TiYNv8AIip1r3WbjsX");
aHttpRequest.send(message);
}
}
var client = new StartClient();
submitData: function () {
document.getElementById('inputBox').disabled = true;
var targetInputButton = document.getElementById("inputBox").value;
var message = '{"targetInputButton":"' + targetInputButton + '"}';
client.post('https://le75bkfcmg.execute-api.eu-west-2.amazonaws.com/dev/start-trace', message, function(response) {
document.getElementById('jobId').innerHTML = response;
});
}
sendBackData: function () {
var jobId = document.getElementById("jobId").innerHTML;
var message = '{"jobId":"' + jobId + '"}';
client.post('https://le75bkfcmg.execute-api.eu-west-2.amazonaws.com/dev/check-trace', message, function(response) {
document.getElementById('report').innerHTML = response;
});
}
}
</script>
New way I wrote var client:
StartClient: function () {
var client
},

You need put your methods object inside export and split the methods to comma
<script>
export default {
name: 'name',
methods:{
foo(){
},
bar(){
}
}
}
UPD: var client = new StartClient();
defined outside the method

When to call $scope.apply() for webservice callbacks

I am currently developing an Angular JS project where in I call a webservice and then in the success callback update a textbox value based on the result.
Now, my webservice gets called a bit late and the success callback takes some time. In the success callback I have updated a textbox value as well as hidden a loading progress dialog.
However the progress dialog is never hidden and textbox is not updated if I don't use $scope.apply().
If the use the same, it gets applied. What is the purpose of $scope.apply().
What are the best practices of using it. Can it be used in situations like mine. I have also tried using $timeout . Even that works but I don't think its a preferred approach.
Here is my code
//the service implementation
app.service('registerService', function ($http, APP_CONFIG, $q, spinnerService) {
this.callService = function (request) {
spinnerService.show('mySpinner')
var deferred = $q.defer();
$http({
method: 'POST',
url: APP_CONFIG.baseUrl + '/register',
data: request
}).success(function (data) {
deferred.resolve(data);
}).error(function () {
deferred.reject('There was an error while making request');
});
return deferred.promise;
};
});
//calling the service from inside the controller
registerService.callService(JSON.stringify(requestData)).then(function (data) {
$scope.$apply(function () {
spinnerService.hide('mySpinner');//hide loading..this works!
});
spinnerService.hide('mySpinner');//hide loading ..this does not if I remove $scope.apply()
}, function () {
//unable to fetch NLS resource
spinnerService.hide('mySpinner');//hide loading
});
}
//spinner service implemtation
app.factory('spinnerService', function () {
var cache = {};
return {
// A private function intended for spinner directives to register themselves with the service.
_register: function (spinnerScope) {
// If no id is passed in, throw an exception.
if (!spinnerScope.id) {
throw new Error("A spinner must have an ID to register with the spinner service.");
}
// Add our spinner directive's scope to the cache.
cache[spinnerScope.id] = spinnerScope;
},
// A private function exposed just in case the user really needs to manually unregister a spinner.
_unregister: function (spinnerId) {
delete cache[spinnerId];
},
// A private function that will remove an entire spinner group if needed.
_unregisterGroup: function (group) {
for (var spinnerId in cache) {
if (cache.hasOwnProperty(spinnerId)) {
if (cache[spinnerId].group === group) {
delete cache[spinnerId];
}
}
}
},
// A private function that will clear out all spinners from the cache.
_unregisterAll: function () {
for (var spinnerId in cache) {
if (cache.hasOwnProperty(pinnerId)) {
delete cache[spinnerId];
}
}
},
// Show the specified spinner.
// If loadingText is specified, replace the loadingText specified on the directive as we show the spinner.
show: function (spinnerId, loadingText) {
$("body").find("#loading").addClass("mydiv");
if (cache.hasOwnProperty(spinnerId)) {
var spinnerScope = cache[spinnerId];
spinnerScope.showSpinner = true;
if (loadingText !== undefined) {
spinnerScope.loadingText = loadingText;
}
}
},
// Hide the specified spinner.
// If doneText is specified, replace the doneText specified on the directive as we hide the spinner.
hide: function (spinnerId, doneText) {
if (cache.hasOwnProperty(spinnerId)) {
var spinnerScope = cache[spinnerId];
$("body").find("#loading").removeClass("mydiv");
spinnerScope.showSpinner = false;
if (doneText !== undefined) {
spinnerScope.doneText = doneText;
}
}
}
};
});

AngularJS Server Side Pagination - Recursively call API

I'm trying to call an API that takes parameters start and count, like this:
function handleSuccess() {
if (!!response.data) {
return (response.data);
} else {
return q.reject(response.data);
}
}
function handleError() {
// do some handling
}
function getData(url, sortBy) {
var count = 10;
var start = 1;
var request = http({
cache: true,
method: "GET",
url: url,
params: {
sortBy: sortBy,
sortOrder: "ASC",
count: count, // e.g. 10
start: start // e.g. 1
}
});
return (request.then(handleSuccess, handleError));
}
The JSON response from the API could contain a "next" link that would give me the URL to call to get the next set of data if there exists more...this is how the pagination works.
What's the best way to do this and concatenate all the data returned into one JSON response?

Assuming some part of the data response is an array, then simply use normal array concat() to combine it with previous pages of data in your handleSuccess() callback.

I've found that a service-oriented way is most useful when trying to get paged data from the same endpoint as it is easy to share services and objects between controllers and directives.
First, I would set up the service layer of your application so that all objects being requested have common, generic methods like so (I highly recommend you use ngResource or RESTAngular or something like that):
angular.module('myModule')
.factory('ApiObject', function($http, $q) {
ApiObject = function ApiObject(attributes) {
angular.extend(this, attributes);
};
ApiObject.query = function(url, parameters) {
var deferred = $q.defer();
$http.get(url, {params: parameters}).then(function(data) {
var results = [];
angular.forEach(data, function(apiObject) {
results.push(new ApiObject(apiObject));
});
deferred.resolve(results);
}, function(error) {
// Do error stuff
deferred.reject(error);
});
return deferred.promise;
};
return ApiObject;
});
Then set up a service to manage your paging data that accepts your generic services as well as parameters and configuration options. Also allow for events to be triggered within the service (see trigger and on methods) so that you know when new results are fetched. I've also written in a way for the results to be automatically concatenated onto the current result set:
angular.module('myModule')
.factory('SearchService', function() {
SearchService = function SearchService(service, params, config) {
this.searchParams = params || {};
this.config = config || {};
this.service = service;
this.results = [];
this.listeners = {};
};
SearchService.prototype.fetch = function(params) {
var _this = this;
this.service.query().then(function(results) {
if(_this.config.concatResults) {
_this.results = _this.results.concat(results);
// You probably should make sure results are unique at this point as that is a common problem with paging a changing API
} else {
_this.results = results;
}
_this.trigger('searchSuccess', _this.results);
});
};
SearchService.prototype.on = function(event, listener) {
(this.listeners[event] = (this.listeners[event] || [])).push(listener);
};
SearchService.prototype.trigger = function(event, payload) {
angular.forEach(this.listeners[event], function(listener) {
listener(payload);
});
};
SearchService.prototype.isLastPage = function() {
//logic here to determine last page
};
SearchService.prototype.nextPage = function() {
if(this.isLastPage()) {
return;
}
if(this.searchParams.page) {
this.searchParams.page++;
} else {
this.searchParams.page = 2;
}
this.fetch();
};
// Write more methods for previousPage, lastPage, firstPage, goToPage... etc.
return SearchService;
});
Then in your controller, you're going to want to instantiate the search service with some default parameters and configuration and then fetch the first page:
angular.module('myModule')
.controller('MyCtrl', function($scope, ApiObject, SearchService) {
$scope.searchService = new SearchService(ApiObject, {page: 1}, {concatResults: true});
$scope.searchService.on('searchSuccess', function(results) {
// Do something with results if you wish, but they'll already be stored in $scope.searchService
});
// Get the first page of data
$scope.searchService.fetch();
});
This is obviously a rough cut with a lot of room for improvement, but I hope this will be a good jumping off point to get you pointed in some sort of angular-style direction. In my experience, this is the best way to abstract out paging logic from the data/request layer in your services.

_underscore templating - loading templates from external files

I've seen a few long winded answers to how to load templates for rendering in respect of the _underscore templates utility and the like. What I've got below works:
$.ajax({
url: 'template.tmp',
type: 'get',
success: function(data) {
$('html').append(data);
}
});
The code sits after jquery is loaded but before any scripts using the templates. Would this be ok or is there a reason why it wouldn't be a good idea to load templates like this? The templates.tmp file has templates within
<script type="text/template" id="tmpId"></script>
tags. They seem to get loaded into the DOM pretty much instantly. I'm prepared to be criticised for this implementation, but I'd just like to know why. The only thing I can think of is perhaps some processing if "error:" gets called instead of "success:". Thx.

I decided to produce my own OO based solution. This is the constructor:
var TemplateLoader = function(templatePath) {
this.template = templatePath;
this.loaded = false;
this.error = false;
}
And these are the methods:
TemplateLoader.prototype.setReady = function (state) {
this.loaded = state;
}
TemplateLoader.prototype.setError = function (state) {
this.error = state;
}
TemplateLoader.prototype.isReady = function () {
return this.loaded;
}
TemplateLoader.prototype.isError = function () {
return this.error;
}
TemplateLoader.prototype.loadTemplate = function() {
templateLoader = this;
$.ajax({
url: this.template,
type: 'get',
success: function(data) {
$('html').append(data);
templateLoader.setReady(true);
},
error: function() {
templateLoader.setError(true);
}
});
}
And this is how to use it:
templateLoader = new TemplateLoader('template.tmpl');
templateLoader.loadTemplate();
And to check the template has loaded:
templateLoader.isReady() //true for loaded
templateLoader.isError() //true for error loading template, eg. template doesn't exist
Again, I'd appreciate any feedback on issues anyone could see with this code. How about checking for the DOM object appended to the HTML. Worthwhile?