We Keep Coding

Load div based on url or ID

I want a certain feature div container-new to load on certain pages only. My theory is to run a if statement on load to say if page url equals /A2017.html or /A2018.html or /A2017.html load <div id="conrainer_new"></div> else don't load.
Is this achievable with JS or jQuery.
I have tried this but div still loads on all urls. im sure there is a better more robust solution to this. also I need to be a able to include multiple urls in the rule.
if (window.location.search..search(/A2017.html))
document.getElementById('conrainer_new').display = 'block'

You can try a similar approach but with using indexOf instead. If the string for the page name is found, indexOf will return the position instead of -1 so the condition will be true.
if (window.location.href.indexOf('/A2017.html') != -1) {
document.getElementById('container_new').display = 'block'
}

As you have multiple values to check for in the URL you can use a regular expression:
if (window.location.match(/\/A2017.html|\/A2018.html/i)
document.getElementById('conrainer_new').display = 'block'
Also note that if there will never be a querystring on the URL you can add $ to the regex to ensure that the match is only at the end of the URL string, eg /\/A2017.html$|\/A2018.html$/i

Link to a modal window from URL

Title says it all, I would like to trigger a jQuery event that opens a unique model window depending on which URL is used. I've looked at a few solutions and all of them seem to require bootstrap which I am not using or simply don't seem to work for me.
I think i understand the logic, I'm just not sure how to actually code it and would be grateful for some help. Here is my thinking:
[STEP 1]
On page load, check the URL.
If the the url is normal e.g. "www.domain.com/example", don't do anything.
If the url has a substring on the end e.g. "www.domain.com/example/#red", "www.domain.com/example/#green", or "www.domain.com/example/#blue" etc., set that substring to a variable. In this case the variable would equal either red, green, or blue.
[STEP 2]
Insert the variable where the line of code says [color] and execute.
$("document").ready(function() {
$(".details, #[color]details").trigger('click');
});

use with window.location.hash. its will get the hash value form url with# .so no need to add # in the dom
$("document").ready(function() {
if(window.location.hash.trim().match(/(\w+)/)){
$(".details,"+window.location.hash+"details").trigger('click');
}
});

You can use document.referrer to get the Page URL.
Store it in a variable to fetch the last segment or the URL using substr().
Then check it in conditional operator if the last part is your desired text, add it to your class and trigger.
I ll paste my code which I used on the next page to trigger tab change for some requirement. I hope this will work for you too, hopefully. Thank you.
$(document).ready(function () {
var referrer = document.referrer; // Get the Url of the previous page
var lastPathSegment = referrer.substr(referrer.lastIndexOf('/') + 1); // extracts the last part e.g. the page name
if(lastPathSegment == "invoices.php"){
customer_detail_content();
$('a[href="#tab_6_2"]').trigger('click');
}

Use URL Parameter to call a line of text using JS?

I'm hoping to call a line of text by using a simple URL parameter. Say I had an ordered list in javascript and on load of url example.com/?i=14 would get the 14th line in my list and place it where desired.
How can I achieve this?

I'm not sure what you mean by "call a line of text," but maybe you could do this:
var url = window.location.href;
var queryPos = url.indexOf('i=');
var param = url.substr(queryPos + 'i='.length);
Now param will contain the value of the parameter and you could use it to fetch whatever.
But since you're trying to access a value from a URL with JavaScript, it might be better to make use of # as explained here: How do I get the value after hash (#) from a URL using jquery (there are non-jquery answers as well)

Hopefully this is what you need.
To place an array element where you need it on document load
<div id="placeHere"></div>
In JS
document.body.onload = function(){
document.getElementById('placeHere').innerHTML = array[14];
}
jQuery
$(document).ready(function(){
$('#placeHere').html(array[14]);
})

Javascript & HTML Getting the Current URL

Can anyone help me. I don't use Client-side Javascript often with HTML.
I would like to grab the current url (but only a specific directory) and place the results between a link.
So if the url is /fare/pass/index.html
I want the HTML to be pass

This is a quick and dirty way to do that:
//splits the document.location.href property into an array
var loc_array=document.location.href.split('/');
//have firebug? try a console.log(loc_array);
//this selects the next-to-last member of the array.
var directory=loc[loc.length-2]

url = window.location.href // Not particularly necessary, but may help your readability
url.match('/fare/(.*)/index.html')[1] // would return "pass"

There may be an easier answer, but the simplest thing I can think of is just to get the current URL with window.location and use some type of parsing to get which directory you are looking for.
Then, you can dynamically append the HTML to your page.

This may get you started:
var linkElement = document.getElementById("whatever");
linkElement.innerHTML = document.URL.replace(/^(?:https?:\/\/.*?)?\/.*?\/(.*?)\/.*?$/i,"$1");

Why does my if condition prevent either clause from executing?

I'm trying to re-write the URLs of a set of links that I select using a jQuery class selector. However, I only wish to re-write the links that don't already have a href attribute specified, so I put in an if/else construct to check for this... However, it's not working. It does work without the if else statement so I'm pretty sure that is where I screwed up. I'm new to both JavaScript and jQuery so sorry if my question is elementary and/or overly obvious.
var url = window.location;
var barTwitter = $("a.shareTwitter").attr('href');
if (barTwitter).val() == "null") {
$("a.barTwitter").attr('href','http://www.twitter.com/home?status='+ url +'');
} else {
$("a.barTwitter").attr('href',barTwitter);
}

if (barTwitter).val() == "null") {
This is syntactically invalid (count the parentheses!). You rather want to do:
if (barTwitter.val() == "null") {
Further, the val() function only works on input elements which are wrapped by jQuery, not on element attribute values which are at end just normal variables. You rather want to compare normal variables against the literal null:
if (barTwitter == null) {

There are actually a few problems with your code... BalusC correctly describes the first one - syntax errors in your if condition - but you should probably consider some of the rest...
I'll start with your code corrected according to BalusC's answer, with comments added to describe what's happening:
var url = window.location; // obtain the URL of the current document
// select the href attribute of the first <a> element with a shareTwitter class
var barTwitter = $("a.shareTwitter").attr('href');
if (barTwitter == null) { // if that attribute was not specified,
// set the attribute of every matching element to a combination of a fixed URL
// and the window location
$("a.barTwitter").attr('href','http://www.twitter.com/home?status='+ url +'');
} else {
// set the attribute of every matching element to that of the first
// matching element
$("a.barTwitter").attr('href',barTwitter);
}
Other issues with your code
Ok... now the problems:
jQuery matches sets - a single selector can potentially match multiple elements. So if there are multiple links on the page with the shareTwitter class, you'll be pulling the href attribute for the first one, but changing all of them. That's probably not what you want, although if there is only a single link with that class then you don't care.
In the else clause, you're not actually modifying the href at all... Unless you have multiple matching links, in which case you'll change all of them such that they have the href of the first one. Again, probably not what you want, although irrelevant if there is only one link... So, in the best-case scenario, the else clause is pointless and could be omitted.
You can actually omit the if/else construct entirely: jQuery allows you to test for the existence of attributes in the selector itself!
You're including the URL of the current page in the querystring of your new, custom URL - however, you're not properly escaping that URL... This could cause problems, as full URLs generally contain characters that are not strictly valid as part of URL querystrings.
Notes on working with JavaScript
A quick aside: if you plan on doing any development using JavaScript, you should obtain some tools. At minimum, install Firebug and familiarize yourself with the use of that and JSLint. The former will inform you of errors when the browser fails to parse or execute your code (in addition to many, many other useful debugging and development tasks), and the latter will check your code for syntax and common style errors: in this case, both tools would have quickly informed you of the initial problems with your code. Instructing you in the proper use of these tools is beyond the scope of this answer, but trust me - you owe it to yourself to take at least a few hours to read up on and play with them.
Toward safer code
Ok, back to the task at hand... Here's how I would re-write your code:
var url = window.location; // obtain the URL of the current document
// escape URL for use in a querystring
url = encodeURIComponent(url);
// select all <a> elements with a shareTwitter class and no href attribute
var twitterLinks = $("a.shareTwitter:not([href])");
// update each selected link with a new, custom link
twitterLinks.attr('href', 'http://www.twitter.com/home?status='+ url +'');
Note that even though this new code accomplishes the same task, it does so while avoiding several potential problems and remaining concise. This is the beauty of jQuery...

firs of all your syntax is screwed up: if (barTwitter).val() == "null") should be if (barTwitter.val() == "null") or if ((barTwitter).val() == "null")
Secondly barTwitter is either going to be a string or null so you cant call val which is a jQuery Object method specific to input elements.
Lastly you probably dont want to compare to null because it possible the value will be an empty string. Thus its better to use length property or some other method. A sample with lenght is below.. but im not sure what attr returns if if ther eis no value... check the docs.
var url = window.location;
var barTwitter = $("a.shareTwitter").attr('href');
if (barTwitter.length < 1) {
$("a.barTwitter").attr('href','http://www.twitter.com/home?status='+ url +'');
} else {
$("a.barTwitter").attr('href',barTwitter);
}