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React .trim() is not a function

My application has a landing page with two components in two separate tabs.
The code from the first component that is causing the crash looks like this:
for (let key in linegraphdata) {
linegraphdata[key].price = Number(
linegraphdata[key].price.trim().slice(1)
);
linegraphdata[key].month = parseDate(linegraphdata[key].month);
}
When I load into my application initially it doesn't crash, loads the data from the first tab fine. I'll click into the second tab and when I eventually click back the whole application crashes and the log gives me this error:
Uncaught TypeError: linegraphdata[key].price.trim is not a function
It must have something to do with how React handles refreshing components once already rendered, could anyone help me figure it out please :)

You're setting what was a string to a number, and numbers don't have the trim() method on them. That's why it works the first time (when it's a string) and not the second time around:
array[key] = Number(array[key].trim());
So that code must be executing more than once.

linegraphdata[key].price is either null or not a string.
If there is a value, you can try using linegraphdata[key].price.toString().trim().slice(1)
You can check that price is a string with this ternary. If it's not a string it will set the value to -1
linegraphdata[key].price = Number(
typeof linegraphdata[key].price == 'string' ? linegraphdata[key].price.trim().slice(1) : -1
);

Print JavaScript condition used in Shiny conditionalPanel

I'm creating a conditionalPanel in a Shiny app. I'm attempting to debug the JavaScript condition, but without inspecting it, I'm just guessing random JavaScript bits. Is there a way to inspect the condition directly?
selectizeInput('groups','Groups:',
choices = list('Choice1' = 'choice1','Choice2' = 'choice2'),
multiple = TRUE,selected = NULL
)
conditionalPanel(
print("input.groups.indexOf('choice2') >= 0"), # desired output
condition = "input.groups.indexOf('choice2') >= 0",
selectInput("statusfilter", "StatusFilter",
list("NewChoice1" = "nc1","NewChoice2" = "nc2"))
)
The above code (generalized from my production code) is showing the conditionalPanel at start up before I even click a choice. Once I do, it will disappear until I choose 'choice2'. If I could inspect the condition, I could fix this quickly.

After commenting our the print statement so that the code runs, if you open your javascript console, you'll see an error:
Error parsing expression: input.groups.indexOf('choice2') >= 0
This suggests your JS code breaks. This is because input.groups is null , and doing .indexOf on a null value causes an error.
So what you want in the condition is:
condition = "input.groups !== null && input.groups.indexOf('choice2') >= 0"

Foundation.MediaQuery.current in a loop (first iteration always shows nothing, next are always correct)

I use Foundation.MediaQuery.current to determine current breakpoint. Every time I call console.log(Foundation.MediaQuery.current) for the first time (n=0) I get nothing.
For all next calls (n>0) I always get correct breakpoint, let's say large.
This is my function:
_calculateLimit = function () {
var postsInjectedCount = container.find('.post-appended').length;
console.log(Foundation.MediaQuery.current);
if (Foundation.MediaQuery.current === 'large') { // gives nothing on first iteration :/
return postsInjectedCount % 3 !== 0 ? 2 : 3;
}
return postsInjectedCount % 2 !== 0 ? 1 : 2;
},
Below picture shows a screen from my Chrome Dev Tools.
Helpful info 1: There is no difference in terms of business logic between first call and next calls.
Helpful info 2: I use Foundation For Sites ~6.2.1
What am I doing wrong?

It looks like you are running the code before Foundation has initialized. It is a good practice to put the init code at the top of JavaScript file.

You will see it better if put the console.log at the end of the function. So try it and just tell the results.
It will clarify where the error is.

Unchecking and simulating a click on checkboxes in Javascript

I am admittedly a super newbie to programming in general. I am trying to design a quick piece of javascript to inject on a website for a class that will both uncheck and simulate a click on a series of checkboxes. This is nothing malicious, the web form we use to download data for use in this class presents way more variables than necessary, and it would be a lot more convenient if we could 'uncheck' all and only check the ones we want. However, simply unchecking the boxes via javascript injection doesn't yield the desired result. A mouse click must be simulated on each box. I have been trying to use the .click() function to no avail. Any help is greatly appreciated. My code below fails with an error of:
"TypeError: Cannot read property 'click' of null"
CODE:
var getInputs = document.getElementsByTagName("input");
for (var i = 0, max = getInputs.length; i < max; i++){
if (getInputs[i].type === 'checkbox')
getInputs[i].checked = false;
document.getElementById('shr_SUBJECT=VC' + i).click();
}
--------EDIT#1--------------
FYI, this is the website that I am trying to use this on:
http://factfinder2.census.gov/faces/nav/jsf/pages/searchresults.xhtml
if you search for and open up any of these tables they are huge. It would be awesome if I could easily pare down the variables by 'unchecking' and 'clicking' them all at once via javascript.
The code at the bottom ALMOST works.
The problem I am running into now is that it throws an error after the first or second run through the for loop:
"TypeError: document.getElementById(...) is null"
I understand that this is because the value it's trying to find doesn't exist? Sometimes on these tables the checkboxes are greyed out/don't exist or are otherwise 'unclickable'. My theory as to why I am getting this error is because in the table/form the 'available' ID's will start around:
shr_SUBJECT=VC03 or sh_SUBJECT=VC04
and it may then skip to:
shr_SUBJECT=VC06 then skip to shr_SUBJECT=VC09 and so on...
So if the for loop hits an ID that isn't available such as 05 or 07, it returns a null error :(
I did some reading and learned that javascript is able to 'catch' errors that are 'thrown' at it? My question now is that I'm wondering if there is an easy way to simply iterate to the next ID in line if this error is thrown.
Again, any and all help is appreciated, you guys are awesome.
OLD DRAFT OF SCRIPT
var getInputs = document.getElementsByTagName("input");
for (var i = 3, max = getInputs.length; i < max; i++){
if (getInputs[i].type === 'checkbox' && i < 10){
var count = i;
var endid = count.toString();
var begid = "shr_SUBJECT=VC0";
var fullid = begid.concat(endid);
document.getElementById(fullid).click();
}
else if(getInputs[i].type === 'checkbox' && i >= 10){
var count = i ;
var endid = count.toString();
var begid = "shr_SUBJECT=VC";
var fullid = begid.concat(endid);
document.getElementById(fullid).click();
}
}
--------EDIT#2----------
An example of a table that I am trying to manipulate can be found at this URL:
http://factfinder2.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=ACS_12_5YR_DP02&prodType=table#
If you click on the 'Modify Table' button, you are able to select/deselect specific variables via the checkboxes. If you right-click on a couple of 'active' checkboxes and inspect the elements, and it looks something like this:
<input id="shr_SUBJECT=VC03" checked="" alt="hide SUBJECT=VC03" name="" value="" onclick="javascript:hiderow('SUBJECT=VC03');" type="checkbox">
<input id="shr_SUBJECT=VC25" checked="" alt="hide SUBJECT=VC25" name="" value="" onclick="javascript:hiderow('SUBJECT=VC25');" type="checkbox">
Thank you so much #Jonathan Steinbeck for the tip about the ternary operator, it really cleaned up my code.
The script works properly, but the problem I am running into now is that it doesn't iterate enough times after the try, catch statement. If there is a gap in the id #'s; say it jumps from shr_SUBJECT=VC19 to shr_SUBJECT=VC=24 the script will stop running. Is there a way to make it keep retrying the try/catch until it gets a valid ID # or one that exists/is an active checkbox?
CURRENT DRAFT OF SCRIPT :
var getInputs = document.getElementsByTagName("input");
for (var i = 3, max = getInputs.length; i < max; i += 1) {
try {
if (getInputs[i].type === 'checkbox'){
document.getElementById("shr_SUBJECT=VC" + (i < 10 ? "0" : "") + i).click();
}
}
catch (err) {
i+=1;
if (getInputs[i].type === 'checkbox'){
if (getInputs[i].type === 'checkbox'){
document.getElementById("shr_SUBJECT=VC" + (i < 10 ? "0" : "") + i).click();
}
}
}
}

When you call document.getElementById() with a non-existing ID, null is returned. Therefore this error means that you're trying to call the .click() method on null, which can't work.
So you should check what the correct ID naming scheme for the elements you want is. Maybe the elements' count starts with 1 instead of 0?
Also, the .click() doesn't work for all elements like you would expect as far as I know. So depending on the kind of element you are trying to retrieve you might have to create and dispatch your own event as suggested by RobG's comment.
EDIT in response to your recent edit:
You can wrap code that throws errors in a try-catch like this:
for (var i = 3, max = getInputs.length; i < max; i += 1) {
try {
document.getElementById("the_ID").click();
}
catch (error) {
console.error(error);
// continue stops the current execution of the loop body and continues
// with the next iteration step
continue;
}
// any code here will only be executed if there's not been an error thrown
// in the try block because of the continue in the catch block
}
Also, what are you doing with the 'i' variable? It doesn't make sense to assign it to so many variables. This does the same:
document.getElementById("shr_SUBJECT=VC" + (i < 10 ? "0" : "") + i).click();
The ... ? ... : ... is an operator (called the 'ternary operator') that works like this: evaluate the expression before the "?" - if it results in a truthy value, the expression between "?" and ":" is evaluated and becomes the result of using the operator; if the condition results to false, the part after the ":" is evaluated as the value of the operator instead. So while "if" is a statement in JavaScript (and statements usually don't result in a value), the ternary operator can be used as an expression because it results in a value.
By concatenating a string with something else, you are forcing the 'something else' to be converted to string. So an expression like this will usually result in a string:
"" + someNonStringVar
Also, it doesn't make sense to define variables in a loop body in JavaScript. JavaScript variables have function scope, not block scope. What this means is that any variables defined in the loop body exist inside the whole function as well. Therefore it is recommended to write all of the "var"s at the top of your function to make it clear what their scope is. This behaviour of JavaScript is called 'hoisting', by the way.
I've furthermore taken a look at the URL you've given in your recent edit but I fail to find the kind of naming scheme for IDs you describe. In which table did you find those?
Edit in response to your second edit:
You shouldn't mess with the 'i' variable inside the body of a for loop. It makes your code much harder to reason about and is probably not what you want to do anyway. You don't need to handle the next step of the iteration in the catch block. The 'i' variable is incremented even if there's an error during fetching the element from the DOM. That's why you use catch in the first place.

What's wrong with my logic? (JS string Length)

A couple days ago, on a site that I'm the only author on, I added this code to a script:
if (PowerArray[0][0].length < 1);
{
return false;
}
and everything worked fine. When PowerArray[0][0] was "70", the script ran. When PowerArray was empty, the script didn't run past the above quoted line.
This is no longer true. For the life of me, I can't figure it out. I tested with variants of the code, like below:
if (PowerArray[0][0].length < 1);
{
alert(PowerArray[0][0].length);
return false;
}
and set PowerArray[0][0] = "70". When I run the code, I get an alert with "2" in the text. This is the only place that I have an alert in the script. What's going on here, and how do I fix it?
Note: The expected behavior is, of course, no alert, because "70" has a length of 2, and shouldn't trigger the truth of the if.
Edit: 1) Yes, the False in the first block was a typo. It's been corrected. 2) The expected behavior was for it to stop processing if (and only if) PowerArray[0][0].length was 0. 3) I had previously initialized PowerArray as an empty array, and then copied an array (which had the potential to be empty) into it.

You should remove semicolon from if statement, it terminates your statement there.
And yes, when your PowerArray is empty,
PowerArray[0][0] will throw an undefined error,
So should put a null check for that as well.

when PowerArray is empty PowerArray[0] gives undefined then you will get an error for PowerArray[0][0] saying TypeError: Cannot read property '0' of undefined that is why the script is nor running after that line
if (PowerArray && PowerArray[0] && PowerArray[0][0] && PowerArray[0][0].length < 1)
{
return false;
}

I think the semicolon after the if is the issue.
I would also check if PowerArray is a valid 2D array implementation.
Check this link for ideas How can I create a two dimensional array in JavaScript?
Start by changing it to this if (PowerArray[0][0].length < 1)

try this
if (PowerArray[0]) {
if (PowerArray[0][0].length < 1) {
return False;
}
}