Develop Reference

Overwriting existing object properties

I am having trouble with two small blocks of code and understanding why one works and one doesn't.
I have an array of 'tasks'.
When a user updates a task, I need to update the AuditLog, to show the update.
I have two blocks of code, first one works, second one doesn't.
1st block - when I view the updated task, it shows the updated log.
2nd block - when I view the updated task, the log is not updated.
I suspect that it is something to do with the way I am referencing, assigning things.
This block correctly updates the "task" and viewing it shows the updated "audit log".
//update task with server response 'a'
this.updateTask(task).subscribe(a => {
let updatedTask = initializeTask(a);
task.auditLog = updatedTask.auditLog;
});
Then I thought I could simplify the code a bit...
but when using this block, when I view the task, it does not show the updated log.
(I should mention that printing 'intializeTask(a)' works correctly and prints the updated log values, so it's not to do with that).
//update task with server response 'a'
this.updateTask(task).subscribe(a => {
task = initializeTask(a);
});
I feel like I may be missing something fundamental in the way JavaScript references/assigns variables etc. Perhaps someone can shed some light on it.
Thanks in advance!
PS: initializeTask simply ensures that nothing is left undefined and that dates are formatted correctly:
export function initializeTask(t): Task {
t.subject = t.subject || '';
t.startTime = initDate(t.startTime);
t.state = t.state || 'Published';
t.createdBy = t.createdBy || '';
if (t.auditLog) {
t.auditLog.forEach(d => {
d.createdOn = initDate(d.createdOn);
});
}
return t;
}

Google Scripts/Basic JavaScript - Issue fixed by debugger

I'm working on a Google Scripts add on for Google Sheets, but I'm trying to get the script working before I actually set it up on the sheet. The code below works fine if I set a breakpoint somewhere in the extractNumbers function. If I just execute the code without breakpoints, I get an error:
TypeError: Cannot call method "replace" of undefined. (line 36, file "")
Here's the code:
var myVar = phoneCheck("a1","a2","o1","o2");
Logger.log(myVar);
function phoneCheck(newCell,newHome,oldCell,oldHome) {
Logger.clear();
var newCell = extractNumbers(newCell);
var oldCell = extractNumbers(oldCell);
var newHome = extractNumbers(newHome);
var oldHome = extractNumbers(oldHome);
if (newCell === oldCell) {
return newCell;
exit;
} else if (newCell === oldHome && newHome === oldCell) {
return oldCell;
exit;
}
if (newCell === '' && oldCell !== '' ) {
return oldCell;
exit;
}
if (newCell !== oldCell && newCell !== oldHome) {
return newCell;
exit;
}
return "No value found";
exit;
}
function extractNumbers(input) {
Logger.log(input);
var str = input;
return str.replace( /\D+/g, '');
}
Now I realize my if/then logic is more than a bit inelegant, but for my purposes, quick and dirty is fine. I just need it to run.
ALSO, I have read of other novice JavaScript programmers having similar issues related to the sequence of code execution. If someone would like to link to a concise source aimed at a non-advanced audience, that would be great too. Thanks!
EDIT: I put my code into a new fiddle and it works fine, but it continues to fail in Google Scripts editor unless running in debug mode with a breakpoint. The problem seems to be that the function parameters aren't available to the function unless there is a breakpoint. Anyone have access to Google Scripts that can try my updated code from https://jsfiddle.net/hrzqg64L/ ?

None of the suggestions got to the root of your problem - and neither did your answer, although you've avoided the problem by putting an enclosure around everything.
There's no AJAX, no asynchronous behavior - it's simpler than that. "Shadowing of parameters" is likewise a red herring. Bad coding practice, yes - but not a factor here.
If someone would like to link to a concise source aimed at a non-advanced audience, that would be great too.
Sorry - no such thing. I can explain what's going on, but can't guarantee it will be accessible to novices.
The exception
Let's just clarify what causes the exception, or thrown error, that you've observed.
As written, extractNumbers() will throw an exception if it has a null parameter (or any non-string parameter) passed to it. If you choose to extractNumbers() then hit "run", you'll get:
TypeError: Cannot call method "replace" of undefined. (line 36, file "")
That is telling you that on line 36, which is return str.replace( /\D+/g, '');, the variable str contains an object that is undefined (...and has no replace() method).
For bullet-proof code, you would check your parameter(s) to ensure they are valid, and handle them appropriately. Sometimes that would be with a valid default, and other times you might return an error or throw an exception that is more explicit about the parameter problems.
Running code in Google's debugger
The only way to run code in Google's Debugger is to select a function, then choose "run" or "debug". Assuming you posted all your code, you had just two functions to choose from:
phoneCheck()
extractNumbers()
Whenever Google Apps Script runs any part of a script, the entire script is loaded and scanned to find all symbols & check syntax. The scope of all symbols is noted as well, and so are any dependencies between functions and global symbols (symbols outside of any closure, or block of code).
That takes some time. To speed things up when asked to execute a specific function, the global symbols are only evaluated if they are a dependency for the requested function or the functions it may call. There is another condition that will trigger evaluation of global symbols, and that is if there is a possibility that the debugger may need to stop and display values.
When this happens, any code that is outside a closure (outside a function, for example) will be executed. This is what you observed when you set breakpoints.
Why did it work when breakpoints were set?
As explained, just having a breakpoint set triggers evaluation of global symbols.
You start this script with a few lines of code that are not in any closure:
var myVar = phoneCheck("a1","a2","o1","o2");
Logger.log(myVar);
It is that code which makes the only proper invocation of phoneCheck() with parameters. Because myVar is evaluated, phoneCheck() gets called with parameters, and in turn calls extractNumbers() with a defined parameter.
Unfortunately, because of the way the debugger works, you cannot choose to run that code yourself. You need to rely on these side-effect behaviors.
How to fix this?
Simple. Don't rely on global code to invoke functions under test. Instead, write an explicit test function, and call that.
function test_phoneCheck() {
var myVar = phoneCheck("a1","a2","o1","o2");
Logger.log(myVar);
}

Finally found the issue, but I don't fully understand it.
This question got me thinking about scope and how it might be different in the Google Script environment. I figured a simple workaround would be to enclose the entire script in its own void function, and it worked! Also, I simplified the script quite a bit with an array:
function init () {
var numberArray = ["a3", "a2", "o3", "o10"];
var myVar = phoneCheck(numberArray);
Logger.log(myVar);
function phoneCheck(myArray) {
var phoneString = '';
Logger.clear();
var arrayLength = myArray.length;
for (i = 0; i < arrayLength; i++) {
phoneString += myArray[i].replace(/\D+/g, '');
}
return phoneString;
}
}
Also, I realize the functionality of this script is different than the original, but I was really just trying to solve this problem. Now that I have, I can finish the script properly.
Thanks for all the suggestions, everyone! I learned a lot of good things, even though they turned out not to be the answer.

PyBossa loading and presenting tasks

I am trying to set up a project on CrowdCrafting.org by using the PyBOSSA framework.
I followed their tutorial for project development.
The first parts seemed very clear to me, creating the project and adding the tasks worked fine.
Then I built my own HTML webpage to present the task to the users. Now the next step would be to load the tasks from the project, present them to the users, and save their answers.
Unfortunately, I don't understand how to do this.
I will try to formulate some questions to make you understand my problem:
How can I try this out? The only way seems to be by updating the code and then running pbs update_project
Where can I find documentation for PyBossa.js? I just saw (in the tutorial and on other pages) that there are some functions like pybossa.taskLoaded(function(task, deferred){}); and pybossa.presentTask(function(task, deferred){});. But I don't know how they work and what else there is. This page looks like it would contain some documentation, but it doesn't (broken links or empty index).
How do I use the library? I want to a) load a task, b) present it to the user, c) show the user his progress, and, d) send the answer. So I think I'll have to call 4 different functions. But I don't know how.
Looking at the example project's code, I don't understand what this stuff about loading disqus is. I think disqus is a forum software, but I am not sure about that and I don't know what this has to do with my project (or theirs).
As far as I understand, the essential parts of the JS-library are:
pybossa.taskLoaded(function(task, deferred) {
if ( !$.isEmptyObject(task) ) {
deferred.resolve(task);
}
else {
deferred.resolve(task);
}
});
pybossa.presentTask(function(task, deferred) {
if ( !$.isEmptyObject(task) ) {
// choose a container within your html to load the data into (depends on your layout and on the way you created the tasks)
$("#someID").html(task.info.someName);
// by clickin "next_button" save answer and load next task
$("#next_button").click( function () {
// save answer into variable here
var answer = $("#someOtherID").val();
if (typeof answer != 'undefined') {
pybossa.saveTask(task.id, answer).done(function() {
deferred.resolve();
});
}
});
}
else {
$("#someID").html("There are no more tasks to complete. Thanks for participating in ... ");
}
});
pybossa.run('<short name>');

I will try to answer your points one by one:
You can either run pbs update project or go to the project page >
tasks > task presenter and edit the code there.
I believe this link works, and there you should find the
information you want.
So, once you've created the project and added the tasks and the
presenter (the HTML you've built) you should include the Javascript
code inside the presenter itself. You actually only need to write
those two functions: pybossa.taskLoaded(function(task,
deferred){}); and pybossa.presentTask(function(task, deferred){});
Within the first one you'll have to write what you want to happen
once the task has been loaded but before you're ready to present it
to the user (e.g. load additional data associated to the tasks,
other than the task itself, like images from external sites). Once
this is done, you must call deferred.resolve(), which is the way
to tell pybossa.js that we are done with the load of the task
(either if it has been successful or some error has happened).
After that, you must write the callback for the second one
(pybossa.presentTask) where you set up everything for your task,
like the event handlers for the button answer submission and here is
where you should put the logic of the user completing the task
itself, and where you should then call pybossa.saveTask(). Again,
you should in the end call deferred.resolve() to tell pybossa.js
that the user is done with this task and present the next one. I
would recommend you to do in inside the callback for
pybossa.saveTask(task).done(callbackFunc()), so you make sure you
go on to the next task once the current one has correctly been
saved.
You can forget about that discuss code. These are only templates
provided, in which there is included some code to allow people
comment about the tasks. For that, Disquss is used, but it is up to
you whether you want to use it or not, so you can safely remove this
code.

This object constructor is preventing my script from running

I'm working on a project (creating a browser based check list). One of my goals has been to write every piece by hand without a library like jquery or a mysql database.
Currently I'm trying to create on object for managing tasks. I'm not finished the primary function, but everything is closed, and I don't detect any errors. Furthermore, I'm haven't iterated it or called it's functions yet, so there's nothing to reference it yet. When I comment it out, the script runs normally.
I've included the xml request links up above and tested them successfully in a separate portion of the script.
I'm testing in firefox.
I'm writing this in SciTE
Here's the code:
function Task(name,node,childNode,divClass,content,onclick)
{
function retrieveTask(node,childNode)
{
var taskArray = [];
taskArray.push(xmlDoc.getElementsByTagName(name)[node].childNodes[childNode].nodeValue;)
taskArray.push(xmlDoc.getElementsByTagName(description)[node].childNodes[childNode].nodeValue;)
taskArray.push(xmlDoc.getElementsByTagName(complete)[node].childNodes[childNode].nodeValue;)
return taskArray;
}
function displayTask(name,content)
{
var task = retrieveTask(node,childNode);
var clickDiv = "";
formatDiv(name,"task",task[1],clickDiv);
task[2] === true ? formatDiv(name+1,"incompleteBox"," ",clickDiv) : formatDiv(name+1,"completeBox","O",clickDiv);
}
}
If anyone could give me some insight or tips that would be awesome. This isn't homework, it's a hobby, so it's a self teaching process.

...childNodes[childNode].nodeValue;)
should be );

Auto-load/include for JavaScript

I have file called common.js and it's included in each page of my site using <script />.
It will grow fast as my sites functionality will grow (I hope; I imagine). :)
Lets example I have a jQuery event:
$('#that').click(function() {
one_of_many_functions($(this));
}
For the moment, I have that one_of_many_functions() in common.js.
Is it somehow possible that JavaScript automatically loads file one_of_many_functions.js when such function is called, but it doesn't exist? Like auto-loader. :)
The second option I see is to do something like:
$('#that').click(function() {
include('one_of_many_functions');
one_of_many_functions($(this));
}
That not so automatically, but still - includes wanted file.
Is any of this possible? Thanks in an advice! :)

It is not possible to directly auto-load external javascripts on demand. It is, however, possible to implement a dynamic inclusion mechanism similar to the second route you mentioned.
There are some challenges though. When you "include" a new external script, you aren't going to be able to immediately use the included functionality, you'll have to wait until the script loads. This means that you'll have to fragment your code somewhat, which means that you'll have to make some decisions about what should just be included in the core vs. what can be included on demand.
You'll need to set up a central object that keeps track of which assets are already loaded. Here's a quick mockup of that:
var assets = {
assets: {},
include: function (asset_name, callback) {
if (typeof callback != 'function')
callback = function () { return false; };
if (typeof this.assets[asset_name] != 'undefined' )
return callback();
var html_doc = document.getElementsByTagName('head')[0];
var st = document.createElement('script');
st.setAttribute('language', 'javascript');
st.setAttribute('type', 'text/javascript');
st.setAttribute('src', asset_name);
st.onload = function () { assets._script_loaded(asset_name, callback); };
html_doc.appendChild(st);
},
_script_loaded: function (asset_name, callback) {
this.assets[asset_name] = true;
callback();
}
};
assets.inlude('myfile.js', function () {
/* do stuff that depends on myfile.js */
});

Sure it's possible -- but this can become painful to manage. In order to implement something like this, you're going to have to maintain an index of functions and their corresponding source file. As your project grows, this can be troublesome for a few reasons -- the 2 that stick out in my mind are:
A) You have the added responsibility of maintaining your index object/lookup mechanism so that your scripts know where to look when the function you're calling cannot be found.
B) This is one more thing that can go wrong when debugging your growing project.
I'm sure that someone else will mention this by the time I'm finished writing this, but your time would probably be better spent figuring out how to combine all of your code into a single .js file. The benefits to doing so are well-documented.

I have created something close to that a year ago. In fact, I have found this thread by search if that is something new on the field. You can see what I have created here: https://github.com/thiagomata/CanvasBox/blob/master/src/main/New.js
My project are, almost 100% OOP. So, I used this fact to focus my solution. I create this "Class" with the name "New" what is used to, first load and after instance the objects.
Here a example of someone using it:
var objSquare = New.Square(); // Square is loaded and after that instance is created
objSquare.x = objBox.width / 2;
objSquare.y = objBox.height / 2;
var objSomeExample = New.Stuff("some parameters can be sent too");
In this version I am not using some json with all js file position. The mapping is hardcore as you can see here:
New.prototype.arrMap = {
CanvasBox: "" + window.MAIN_PATH + "CanvasBox",
CanvasBoxBehavior: "" + window.MAIN_PATH + "CanvasBoxBehavior",
CanvasBoxButton: "" + window.MAIN_PATH + "CanvasBoxButton",
// (...)
};
But make this more automatic, using gulp or grunt is something what I am thinking to do, and it is not that hard.
This solution was created to be used into the project. So, the code may need some changes to be able to be used into any project. But may be a start.
Hope this helps.
As I said before, this still is a working progress. But I have created a more independent module what use gulp to keep it updated.
All the magic que be found in this links:
https://github.com/thiagomata/CanvasBox/blob/master/src/coffee/main/Instance.coffee
https://github.com/thiagomata/CanvasBox/blob/master/src/node/scripts.js
https://github.com/thiagomata/CanvasBox/blob/master/gulpfile.js
A special look should be in this lines of the Instance.coffee
###
# Create an instance of the object passing the argument
###
instaceObject = (->
ClassElement = (args) ->
window[args["0"]].apply this, args["1"]
->
ClassElement:: = (window[arguments["0"]])::
objElement = new ClassElement(arguments)
return objElement
)()
This lines allows me to initialize a instance of some object after load its file. As is used in the create method:
create:()->
#load()
return instaceObject(#packageName, arguments)