How to reference an array in a function argument - javascript

I have a series of arrays that contain words I want to use as text in various HTML divs (there are about 35 of these, I included only a few for brevity).
var bodyplan = ['Anguilliform', 'Compressiform', 'Depressiform', 'Filiform', 'Fusiform', 'Globiform', 'Sagittiform', 'Taeniform'];
var mouthposition = ["Inferior", "Jawless", "Subterminal", "Superior", "Terminal"];
var barbels = ['1', '2', '4 or more'];
var caudalshape = ['Continuous', 'Emarginate', 'Forked', 'Lunate', 'Rounded', 'Truncate'];
I have a switch function that is supposed to change the text based on user selections:
switch(n){
case 1:
changelabels(bodyplan, 8);
break;
case 2:
changelabels(mouthposition, 5);
break;
case 3:
changelabels(barbels, 3);
break;
case 4:
changelabels(caudalshape, 6);
break;
case 5:
changelabels(dorsalspines, 8);
break;
default:
alert("handquestsel error")}};
Finally, I have the function which I would like to make the changes (except it doesn't):
function changelabels(opt1,opt2){
var i = opt2;
var im = opt2 - 1;
var c = 1;
var index = 0;
while (i>=c){
var oldlbl = document.getElementById("rb" + c + "lbl");
var newlbla = opt1.slice(im,i);
var newlblb = opt1.toString();
oldlbl.innerHTML = newlblb;
c = c + 1
index = index + 1
}};
I know the code for my function is just plain wrong at this point, but I have altered it so many times that I'm not sure what's going on anymore. At one point I did have the function able to change the text, but it did so incorrectly (it parsed the name of the array, not extracted a value from the array as I wished). Please help. I know I am overlooking some fundamental concepts here, but am not sure which ones. I've lost count of the hours I've spent trying to figure this out. It's seems like it should be so simple, yet in all my chaotic attempts to make it work, I have yet to stumble on an answer.
EDIT: I want my switch statement to call the function and pass to the function, the appropriate array from which to pull the labels from. The purpose of the app is to help a user learn to identify fish. When the user makes selections on the page, a series of pictures will be shown for various character states with an accompanying label describing the state. For example, when the user selects Mouth Position a series of divs will show the different mouth positions that fish have and have a label below the picture to tell the user what that certain character state is called. I can get the pictures to change just fine, but I am having a hell of a time with the labels.

Why not just something along the lines of:
document.getElementById("bodyplan_label").innerHTML = bodyplan[bodyplan_index];
You seem trying to put everything in really abstract data structures, I see no reason to. Just keep it simple.
Also bodyplan has only 8 elements, so bodyplan[8] will give you an out of bounds exception because arrays start at 0 as is common in all modern programming languages.

If I'm reading your requirement and code correctly, in your switch statement you are passing both a reference to the appropriate array and that array's expected length - you don't need the second parameter because all JavaScript arrays have a .length property.
You don't want to use .slice() to get the individual values out of the array, because that returns a new array copied out of the original - just use arrayVariable[index] to get the individual item at index.
So, putting that together try something like this (with your existing array definitions):
switch(n){
case 1:
changelabels(bodyplan);
break;
case 2:
changelabels(mouthposition);
// etc.
}
function changelabels(data) {
var i,
lbl;
for (i = 0; i < data.length; i++) {
lbl = document.getElementById("rb" + (i+1) + "lbl");
lbl.innerHTML = data[i];
}
}
Notice how much simpler that is than your code? I'm assuming here the elements you are updating have an id in the format "rb1lbl", "rb2lbl", etc, with numbering starting at 1: I'm getting those ids using (i+1) because JavaScript array indexes start at zero. Note also that you don't even need the lbl variable: you could just say document.getElementById("rb" + (i+1) + "lbl").innerHTML = data[i] - however I've left it in so that we have something to expand on below...
Within your function you seem to be changing the labels on a set of elements (radio button labels?), one per value in the array, but you stop when you run out of array items which means any leftover elements will still hold the values from the previous selection (e.g., if the previous selection was "bodyplan" with 8 options and you change to "mouthposition" with only 5 - you probably should hide the 3 leftover elements that would otherwise continue to display the last few "bodyplan" items. One way to do that is instead of setting your loop up based on the array length you could loop over the elements, and if the current element has an index beyond the end of the array hide it, something like this:
function changelabels(data) {
var i,
lbl,
elementCount = 20; // or whatever your element count is
for (i = 0; i < elementCount; i++) {
lbl = document.getElementById("rb" + (i+1) + "lbl");
if (i < data.length) {
lbl.innerHTML = data[i];
lbl.style.display = "";
} else {
lbl.innerHTML = "";
lbl.style.display = "none";
}
}
}
If these elements are labels for radio buttons (just a guess based on the ids) then you'd also want to hide or show the corresponding radio buttons, but I hope you can figure out how to add a couple of lines to the above to do that.
(As mentioned above, be careful about having element ids count up from 1 when the array indexes start at 0.)
If the above doesn't work please post (at least some of) the relevant HTML - obviously I've just had to guess at what it might be like.

SOLUTION: Changed the scope of the array variables to local by moving them into the function where they are used, instead of having them as global variables at the top of the page. I don't understand as I was following every rule of variable declaration. But for some unknown reason, global variables in javascript are abhorrent.
Solution Edit: Found an error in declaring my global variables. This may have been the source of my problem of why I could not access them. But it is a non-issue at this point since I corrected my code.

I don't understand what your trying to achieve exactly with your code. But to pass a variable (in this case an array) by reference you just have to add "&" before the variable.
function the_name(&$var_by_ref, $var_by_value) {
// Here if you modify $var_by_ref this will change the variable passed to the function.
}
More: http://php.net/manual/en/language.references.pass.php
Hope that helps.

Related

keeping localStorage objects that iterate whilst using clear() within the same function

I'm trying to clear all local storage when the user either completes the game loop or starts a new game, but also keep some values.
I can do this already with my sound values for volume:
// inside a conditional statement that fires when the user chooses to start a new game.
if (newGameBool === '1') {
var tst = myAu;
//myAu is the stored value that the user sets as sound using a range type input
localStorage.clear();
localStorage.setItem("Au", tst);//A newly cleared localStorage just got a new value, and it's the same as it was before.
UI.myLoad();//reload the function that uses LS to do things.
}
How do I do this for key's that have an iterating number attached to them?
Here is how I save them:
var i = +v + +1;
localStorage.setItem("v", i);
var vv = localStorage.getItem("v");
localStorage.setItem("LdrBrd_" + vv, JSON.stringify(LdrBrd));//saves all data with the iterating key name.
Calling them the way i did the sound function:
var gv = v + 1;//v calls the value from LS and adjusted for off-by-one error. gv is a local variable.
if (newGameBool === '1') {
var ldd, vg;
for (var ii = 0; ii < gv; ii++) {
var ld = localStorage.getItem("LdrBrd_" + ii);
if (ld != null) {
//these are the values that i want to pass beyond the clear point
ldd = JSON.parse(ld);//JSON string of data saved
vg = ii;//how many of them.
}
}
localStorage.clear();
for (var xx = 0; xx < vg; xx++) {
var nld = localStorage.getItem("LdrBrd_" + xx);
if (nld != null) {
localStorage.setItem("LdrBrd_" + ii, JSON.stringify(ldd));
}
}
localStorage.setItem("v", vg);
UI.myLoad();
}
I have been using console.log() in various spots to see what is going on. I comment-out the clear function just to see if the values were wrong and they don't save all all. I tried to make a fiddle, but the local storage wasn't working at all there. In visual studio, it works fine but the script to this file is almost 2000 lines long, so i tried to dress it up the best i knew how.
Thanks in advance for any help or guidance.
I was stuck on this for a few days, but i think i found something that will work, so i'll answer my own question in case there is value in posterity.
locatStorage.clear();
/* ^LS clear() function is above all new setItem codes, some variables are declared globally and some are declared at the top of the functional scope or as param^ */
var itemClass = document.querySelectorAll(".itemClass");//the strings are here
if (itemClass) {//make sure some exist
for (var p = 0; p < itemClass.length; p++) {//count them
mdd = JSON.parse(itemClass[p].innerText);//parse the data for saving
localStorage.setItem("v", v);//this is the LS item that saves the amount of items i have, it's declared at the top of the functions timeline.
localStorage.setItem("LdrBrd_" + p, JSON.stringify(mdd));//this setItem function will repeat and increment with 'p' and assign the right string back to the key name it had before.
}
}
The key is to keep the strings physically attached to an element, then call the class name. The i ran a loop counting them. 'mdd' will spit back each item i want. So then all that is left to do is re-set the item back to it's original status.
This has allowed me to create a way for my users to collect trophies and keep them even after clearing the localStorage when the he/she decides to start a new game.
I use CSS to hide the text from the string.
color:transparent;
In my gameLoop, i have a function that will read the saved strings and show them as cards just below the hidden strings.
Since you want to keep some values I recommend one of two things:
Don't call localStorage.clear() and instead only wipe out the values that you want using localStorage.removeItem('itemName'). Since you said the item names have a numeric component, maybe you can do this in a loop to reduce code.
Pull item(s) that you want saved first and restore them after calling clear(). This option is best if there are way more items that you want removed rather than saved (see below)
function mostlyClear() {
var saveMe = {};
saveMe['value1'] = localStorage.getItem('value1');
saveMe['anotherValue'] = localStorage.getItem('anotherValue');
localStorage.clear();
for(var prop in saveMe) {
if(!saveMe.hasOwnProperty(prop)) continue;
localStorage.setItem(prop, saveMe[prop]);
}
}

Storing data with nested .each() function causes to replicate values

I've modified a survey-multi-choice plugin from JsPsych, in order to get responses in the form of checkboxes, instead of radio-buttons, since I need to present an image to the user, followed by 4 alternatives, like this:
Where A, B, C and D are also images, with their respective checkbox below each one. This structure must be presented more than once, like this:
So in this example, the expected output would be:
{"Q0":["Option A","Option B"]} //this is the first "question" displayed
{"Q1":["Option B","Option C"]} //second one
{"Q2":["Option B","Option D"]} //third one
But instead I get the first answer replicated for the rest of the questions:
{"Q0":["Option A","Option B"]} //this is the first "question" displayed
{"Q1":["Option A","Option B"]} //second one
{"Q2":["Option A","Option B"]} //third one
My code is provided below:
$("div." + plugin_id_name + "-question").each(function(index) {
var id = "Q" + index;
var val = [];
var a = $(".jspsych-survey-multi-choicemrbeta-option");
$("input:checkbox:checked").each(function(){
val.push($(this).attr("value"));
});
var obje = {};
obje[id] = val;
$.extend(question_data, obje);
});
I've tried tracking down the values generated on each step by printing them on console, so I'm guessing the problem is how I'm implementing those nested loops, thus the name of this question.
I've tried different approaches when implementing this loop, without better results:
for (var j = 0; j < trial.options[index].length; j++) {
if ($('jspsych-survey-multi-choicemrbeta-response-' + j).is(':checked')) {
val.push($(this).attr("value"));
}
}
A working example of my full code can be found here, for you to test it (look for the jspsych-survey-multi-choicemrbeta.js file, from line #141). CSS isn't included so it'll look slightly different.
Please note that the output of this code is a CSV file, and the full set of responses is given on a single cell, since all those questions belongs to the same JsPsych "trial".
Thanks for your help.
The inner loop iterates over all checkboxes, not only the ones belonging to the question.
Assuming the checkboxes are descendants of the div for the associated question, you should change the inner loop from this:
$("input:checkbox:checked").each( ...
to this:
$(this).find("input:checkbox:checked").each( ...

Better way of splitting and assigning many values in Javascript?

I have a for loop that cycles through the number of elements that the user has created. There are a lot of available settings in this plugin, and each element can receive it's specific settings.
User settings are entered in the following format: speed_x: "1000,500 > 1000,200 > 0,0"
This controls the speed_x in/out for 3 separate elements. The > divides by object and the commas separate the in/out.
So I can grab specific object speed_x values, I've split speed_x into speed_x_set (splitting by >) resulting in:
1 1000,500
2 1000,200
3 0,0`
3 Inside the loop, I grab the value by index (since it's the object #) and split it by comma (to get speed_x_in and speed_x_out.)
for(var i=0; i<OS.numberofobjects; ++i){
OS.speed_x_on_set[i]=speed_x_set[i].split(",")[0],
OS.speed_x_off_set[i]=speed_x_set[i].split(",")[1],
...
};
Everything is assigned by object and by setting in/out correctly into the master OS settings object. T*he problem is I have many, many settings which need to be split in this fashion...* for example: delay_x_set, speed_y_set, opacity_set, etc. Their names are all based on the default setting name, with "_set" added as shown above. Hopefully this provides enough information. Thanks!
I would avoid to access to the same item twice and perform the same split twice for each iteration. So, you could have something like:
for (var i = 0, item; item = speed_x_set[i++];) {
var values = item.split(",");
OS.speed_x_on_set.push(values[0]);
OS.speed_x_off_set.push(values[1]);
}
Notice that in JavaScript 1.7 (Firefox) you can simply have:
for (var i = 0, item; item = speed_x_set[i++];) {
var [on, off] = item.split(",");
OS.speed_x_on_set.push(on);
OS.speed_x_off_set.push(off);
}
And hopefully in the next version of ECMAScript as well.
It's called "destructuring assignment".
I would say to cache the split result
for(var objindex=0; objindex<OS.numberofobjects; ++objindex){
var splits = speed_x_set[objindex].split(","); //Cache the split so its does not need to be done twice
OS.speed_x_on_set[objindex] = splits[0];
OS.speed_x_off_set[objindex] = splits[1];
...
};
What you're looking for is called parallel assignment, but unfortunately, JavaScript doesn't have it.
In ruby, however, it is common to see similar patterns:
first, second = "first second".split
As others have noted, the obvious way would be to cache split results and assign them separately. Sorry for not answering your question directly.

Password Strength Meter

I'm trying to create my own JS Password Strength Meter.
It was working before but i didn't like how it worked so I tried using
{score +=10;}
Instead of just:
score++
This is my code:
http://jsfiddle.net/RSq4L/
Best Regards,
Shawn,
Hope someone can help
Multiple issues:
Your passwordStrength() function was not defined in the global scope in the jsFiddle so it wasn't getting called. This is probably an artifact of how you set up the jsFiddle, perhaps not an issue in your real code.
The method of getting the appropriate ratingMsg will not work because you don't have array values for every possible score so many scores will generate an "undefined" ratingMsg.
Your CSS classes are also sparse so there are many score values that they will not match for either and no appropriate CSS class/style will be in effect. If you want a specific class for each rating value, then perhaps you should put the classname in the ratings array so it can be fetched from there along with the ratingsMsg.
For the first issue, in your jsFiddle, you also have to make sure the password processing function is defined in the global scope. The way your jsFiddle is set up, it is not (it's in the onload handler). You can fix this in the jsFiddle by just setting the first drop-down in the upper left to "no wrap (head)".
For the second issue, you are using:
ratingMsg[score]
but, your array is a sparse array not guaranteed to have an entry for most possible scores. You simply can't do it that way because many elements you access will have undefined values which won't give you a meaningful message. For example, if score was 15, you would be accessing ratingMsg[15], but there is no value in that space in the array so you won't get a meaningful rating message.
The solution is to find a different way to select the right message. The simplest way would just be an if/else if/else if statement that would check which range the score is in and set the appropriate msg. There are more elegant table driven ways, but all will involve searching through a data structure to find which two values the current score is between and using that msg.
If you look at this jsFiddle http://jsfiddle.net/jfriend00/dA7XC/, you'll see that your code is getting called, but it only hits values in the array sometimes.
And, here's a rewritten algorithm that finds the appropriate msg no matter what the score show in this fiddle: http://jsfiddle.net/jfriend00/jYcBT/.
It uses a data structure like this:
var ratingMsg = [
0, "Unclassified",
10, "Weak",
20, "Fair",
50, "Better",
60, "Medium",
70, "Good",
90, "Strong"
];
and a for loop like this to get the appropraite ratingMsg:
for (var i = ratingMsg.length - 2 ; i >= 0; i-=2) {
if (score >= ratingMsg[i]) {
msg = ratingMsg[i+1];
break;
}
}
Here you go: http://jsfiddle.net/RSq4L/11/
The first problem is that in your fiddle you have the onLoad option set, so your passwordStrength function is not actually being declared in the global scope. It is being declared inside of the onLoad block that jsFiddle wraps your code with. This causes the page to error out when the keypress handler tries to invoke the function.
You can fix this problem in several different ways:
By explicitly declaring the function as global as per my example above.
By choosing one of jsFiddle's "no wrap" options instead of onLoad.
By dynamically binding your event-handler instead of setting it through the element's onkeydown attribute in the markup.
The second problem is how you are keying your score messages. You have:
var ratingMsg = new Array(0);
ratingMsg[0] = "Unclassified";
ratingMsg[10] = "Weak";
ratingMsg[30] = "Fair";
ratingMsg[50] = "Better";
ratingMsg[60] = "Medium";
ratingMsg[70] = "Good";
ratingMsg[90] = "Strong";
...and you lookup the message by doing ratingMsg[score]. This will only work if the score exactly matches one of your indices. And based upon your math this will not always be the case.
I would suggest doing something like:
ratingMsg = {};
ratingMsg[0] = "Unclassified";
ratingMsg[10] = "Weak";
ratingMsg[30] = "Fair";
ratingMsg[50] = "Better";
ratingMsg[60] = "Medium";
ratingMsg[70] = "Good";
ratingMsg[90] = "Strong";
function closestRating(score) {
var bestKey = 0;
var bestMatch = 100;
for (var key in ratingMsg) {
if (key <= score && score - key < bestMatch) {
bestMatch = score - key;
bestKey = key;
}
}
return ratingMsg[bestKey];
}
On an unrelated note, are you sure you want to be using onkeydown? I think onkeyup would work better.
Your fiddler script had several errors. Here's the corrected one: new script.
You were missing a semicolon here: document.getElementById("passwordDescription").innerHTML = "" + ratingMsg[score] + ""
You forgot to escape '^' on your regular expression
I just wrote this for it:
Jquery Plugin for password strength forcing

Removing items from data bound array

How do I remove an items from a data bound array? My code follows.
for(var i = 0; i < listBox.selectedIndices.length; i++) {
var toRemove = listFiles.selectedIndices[i];
dataArray.splice(toRemove, 1);
}
Thanks in advance!
Edit Here is my swf. The Add Photos works except when you remove items.
http://www.3rdshooter.com/Content/Flash/PhotoUploader.html
Add 3 photos different.
Remove 2nd photo.
Add a different photo.
SWF adds the 2nd photo to the end.
Any ideas on why it would be doing this?
Edit 2 Here is my code
private function OnSelectFileRefList(e:Event):void
{
Alert.show('addstart:' + arrayQueue.length);
for each (var f:FileReference in fileRefList.fileList)
{
var lid:ListItemData = new ListItemData();
lid.fileRef = f;
arrayQueue[arrayQueue.length]=lid;
}
Alert.show('addcomplete:' + arrayQueue.length);
listFiles.executeBindings();
Alert.show(ListItemData(arrayQueue[arrayQueue.length-1]).fileRef.name);
PushStatus('Added ' + fileRefList.fileList.length.toString() + ' photo(s) to queue!');
fileRefList.fileList.length = 0;
buttonUpload.enabled = (arrayQueue.length > 0);
}
private function OnButtonRemoveClicked(e:Event):void
{
for(var i:Number = 0; i < listFiles.selectedIndices.length; i++) {
var toRemove:Number = listFiles.selectedIndices[i];
//Alert.show(toRemove.toString());
arrayQueue.splice(toRemove, 1);
}
listFiles.executeBindings();
Alert.show('removecomplete:' + arrayQueue.length);
PushStatus('Removed photos from queue.');
buttonRemove.enabled = (listFiles.selectedItems.length > 0);
buttonUpload.enabled = (arrayQueue.length > 0);
}
It would definitely be helpful to know two things:
Which version of ActionScript are you targeting?
Judging from the behavior of your application, the error isn't occurring when the user removes an item from the list of files to upload. Looks more like an issue with your logic when a user adds a new item to the list. Any chance you could post that code as well?
UPDATE:
Instead of: arrayQueue[arrayQueue.length]=lid
Try: arrayQueue.push(lid)
That will add a new item to the end of the array and push the item in to that spot.
UPDATE 2:
Ok, did a little more digging. Turns out that the fileList doesn't get cleared every time the dialog is opened (if you're not creating a new instance of the FileReferenceList each time the user selects new files). You need to call splice() on the fileList after you add each file to your Array.
Try something like this in your AddFile() method...
for(var j:int=0; j < fileRefList.fileList.length; j++)
{
arrayQueue.push(fileRefList.fileList[j]);
fileRefList.fileList.splice(j, 1);
}
That will keep the fileList up to date rather than holding on to previous selections.
I see one issue. The selected indices are no longer valid once you have spliced out the first element from the array. But that should only be a problem when removing multiple items at once.
I think we need to see more code about how you are handling the upload before we can figure out what is going on. It looks to me like you are holding a reference to the removed FileReference or something. The described problem is occurring when you upload a new file, not when you remove the selected one.
Do you mean to use listBox and listFiles to refer to the same thing?
I'm stepping out on a limb here, because I don't have a ton of experience with JavaScript, but I'd do this the same way that I'd do it in C, C++, or Java: By copying the remaining array elements down into their new locations.
Assuming that listFiles.selectedIndices is sorted (and its contents are valid indices for dataArray), the code would be something like the following:
(WARNING: untested code follows.)
// Don't bother copying any elements below the first selected element.
var writeIndex = listFiles.selectedIndices[0];
var readIndex = listFiles.selectedIndices[0] + 1;
var selectionIndex = 1;
while(writeIndex < (dataArray.length - listFiles.selectedIndices.length)) {
if (selectionIndex < listFiles.selectedIndices.length) {
// If the read pointer is currently at a selected element,
// then bump it up until it's past selected range.
while(selectionIndex < listFiles.selectedIndices.length &&
readIndex == listFiles.selectedIndices[selectionIndex]) {
selectionIndex++;
readIndex++;
}
}
dataArray[writeIndex++] = dataArray[readIndex++];
}
// Remove the tail of the dataArray
if (writeIndex < dataArray.length) {
dataArray.splice(writeIndex, dataArray.length - writeIndex);
}
EDIT 2009/04/04: Your Remove algorithm still suffers from the flaw that as you remove items in listFiles.selectedIndices, you break the correspondence between the indices in arrayQueue and those in listFiles.selectedIndices.
To see this, try adding 3 files, then doing "Select All" and then hit Remove. It will start by removing the 1st file in the list (index 0). Now what had been the 2nd and 3rd files in the list are at indices 0 and 1. The next value taken from listFiles.selectedIndices is 1 -- but now, what had been the 3rd file is at index 1. So the former File #3 gets spliced out of the array, leaving the former 2nd file un-removed and at index 0. (Using more files, you'll see that this implementation only removes every other file in the array.)
This is why my JavaScript code (above) uses a readIndex and a writeIndex to copy the entries in the array, skipping the readIndex over the indices that are to be deleted. This algorithm avoids the problem of losing correspondence between the array indices. (It does need to be coded carefully to guard against various edge conditions.) I tried some JavaScript code similar to what I wrote above; it worked for me.
I suspect that the problem in your original test case (removing the 2nd file, then adding another) is analogous. Since you've only shown part of your code, I can't tell whether the array indices and the data in listFiles.selectedIndices, arrayQueue, and fileRefList.fileList are always going to match up appropriately. (But I suspect that the problem is that they don't.)
BTW, even if you fix the problem with using splice() by adjusting the array index values appropriately, it's still an O(N2) algorithm in the general case. The array copy algorithm is O(N).
I'd really need to see the whole class to provide a difinitive answer, but I would write a method to handle removing multiple objects from the dataProvider and perhaps assigning a new array as the dataProvider for the list instead of toying with binding and using the same list for the duration. Like I said, this is probably inefficient, and would require a look at the context of the question, but that is what I would do 9unless you have a big need for binding in this circumstance)
/**
* Returns a new Array with the selected objects removed
*/
private function removeSelected(selectedItems:Array):Array
{
var returnArray:Array = []
for each(var object:Object in this.arrayQueue)
{
if( selectedItems.indexOf(object)==-1 )
returnArray.push( object )
}
return returnArray;
}
You might be interested in this blog entry about the fact that robust iterators are missing in the Java language.
The programming language, you mentioned Javascript, is not the issue, it's the concept of robust iterators that I wanted to point out (the paper actually is about C++ as the programming language).
The [research document]() about providing robust iterators for the ET++ C++ framework may still e helpful in solving your problem. I am sure the document can provide you with the necessary ideas how to approach your problem.

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