Develop Reference

What is Javascript equivalent for this jQuery code

I am working on a project and not allowed to use jQuery. I am looking for equivalent plain Javascript code for below jquery:
$('img[alt="Apple Store Logo"]').parent().removeAttr("target");
I found below information :
jQuery Javascript
parent() : .parentElement
removeAttr() : removeAttribute()
Couldn't find how to construct above selector.

You can use querySelectorAll() to get NodeList that match the specified selector. Then implement forEach() to iterate over all the elements to remove the attribute from the element's parent node with
parentNode and removeAttribute().
Try the following:
document.querySelectorAll('img[alt="Apple Store Logo"]').forEach(function(el){
el.parentNode.removeAttribute("target");
});
Some older browser does not supprot forEach() on a NodeList . Use Array.prototype.slice.call() in that situation to implement forEach():
var images = Array.prototype.slice.call(document.querySelectorAll(selector));
images.forEach(function(el){
el.parentNode.removeAttribute("target");
});

The first part of your call is a simple DOM query retrieving all <img> elements with an alt attribute matching "Apple Store Logo".
$('img[alt="Apple Store Logo"]')
This can be done in vanilla JS easily enough:
document.querySelectorAll('img[alt="Apple Store Logo"]')
However,document.querySelectorAll returns a NodeList, not an Array. We can convert the NodeList to an Array by calling Array.prototype.slice on it:
Array.prototype.slice.call(document.querySelectorAll('img[alt="Apple Store Logo"]'))
My knowledge of jQuery is poor, but I believe the remaining methods are called iteratively against the elements returned in the query result. Therefore, assuming the intent is to get a reference to the img element's parent element, and remove its target attribute, the whole code block could be translated to:
Array.prototype.slice.call(document.querySelectorAll('img[alt="Apple Store Logo"]')).forEach(function (img) {
img.parentNode.removeAttribute('target');
});

How to get all possible valid attributes on a DOM element [duplicate]

This question already has answers here:
How to list all element attributes in JS?
(3 answers)
Closed 5 years ago.
Please note that .attributes only gets the current attributes, which is not what this question is about.
I want a way to get all the attributes of a DOM element. Not just the ones that are on it now, but the ones that are possible in the future too.
The specific use case is to find the potential attributes in an SVGElement that aren't in an HTMLElement - there's a list on MDN (SVG Attribute reference), but, for obvious reasons, hardcoding is not a good idea.
My initial thought was to iterate through the prototype chain of an instance of each and compare the two lists (with basic filtering for event handlers), but this doesn't actually give the potential svg attributes.
EDIT
IMPORTANT NOTE - pasting your answer code into the console on this page and using document.body as a target should show a list of over 50 attributes, including things like contentEditable, contextMenu, dir, style, etc.
This also needs to work cross-browser.

Could something like this be what you're looking for?
It looks like a DOM element object stores empty keys for all possible attributes. Could you loop over these keys and store them in an array, then from there use something similar to filter out inherited attributes?
HTML
<svg id="blah"></svg>
Javascript
const blah = document.getElementById('blah')
let possibleKeys = []
for (let key in blah) {
possibleKeys.push(key)
}
Here's a JSBin example ... it looks like it produces a list of all possible attributes but it would need some filtering.
See also this thread.
How to list all element attributes in JS?

Any one of these should work because they return a live HTMLCollection.
var svgElement = window.document.getElementsByClassName("someSvgClass")[0];
//assume someSvgClass is on svg element.
//var svgElement = window.document.getElementsByTagName("svg")[0];
//var svgElement = window.document.getElementsByName("mySvg")[0];
//assume svg has this name.
var svgAttributes = svgElement.attributes;
for(let i=0; i<svgAttributes.length; i++) {
console.log(svgAttributes[i]);
}
See the below documentation from MDN on getElementsByTagName()
The Element.getElementsByTagName() method returns a live
HTMLCollection of elements with the given tag name. The subtree
underneath the specified element is searched, excluding the element
itself. The returned list is live, meaning that it updates itself with
the DOM tree automatically. Consequently, there is no need to call
several times Element.getElementsByTagName() with the same element and
arguments.
The documentation for getElementsByName , and getElementsByClassName say the same thing; a live node list is returned. If you'd like to try it, I created a fiddle here.
You'll see that svgAttributes list is automatically updated upon clicking "Add Attribute" without re-executing any of those functions.

There is no API for that and I don't think a workaround is possible because when you change an attribute on a current DOM node, the browser is responsible for re-rendering and updating the webpage in a low-level way that is not exposed to the JavaScript context.
Also, keep in mind that any correctly formatted attribute is actually valid in the context of a DOM tree, even though it might not trigger any change at the rendering level or in the way the browser renders the page. Especially the data-* attributes.
There might be some vendor-specific API but that wouldn't be useful if you want cross-browser compatibility.
You need to hardcode it, sadly. Given that you specifically want the SVGElement attributes, maybe you can scrape the W3's SVG standard document to automatically create the list?
Edit: I made a snippet to easily scrape the values from the standard:
const uniq = arr => Array.from(new Set(arr))
const nameElements = document.querySelectorAll('table[summary="Alphabetic list of attributes"] .attr-name')
const arrNameElements = Array.prototype.slice.call(nameElements)
const svgAttributes = uniq(arrNameElements.map(el => el.innerText.replace(/\‘|\’/g, '')))
Just execute it on the svg attributes page, by opening the dev console on the page and pasting in this code :)
Edit 2: I forgot the presentation attributes. I'll let you figure that one out ;)

Changing inner text value of tab through javascript

I'm learning Javascript right now, and attempting to change the text title of a particular tab. It's actually part of a larger Shiny dashboard project, but I want to add some custom functionality to a few tabs. Below are the tabs in question:
Simple enough. I first access my tabs in my Javascript file:
var tabScrub2 = $(document).find('[data-value="scrubTab2"]');
console.log(tabScrub2);
When I use Firefox's developer console, I see that the tab is an object:
Moreover, it looks like I need to change the innerText property of 0, whatever this is, since that corresponds to the title of my tab (the innerText of 1 corresponds to the text inside scrubTab2). However, I'm not familiar with the actual object type being returned here:
Simply put, how the heck do I access and manipulate properties from this? And am I actually accessing an array? When I type in
var scrub2 = tabScrub2["1"];
console.log(scrub2);
I get an HTML element. I'm seen the a element in CSS and jQuery, but am not super familiar with how to manipulate its properties programmatically? How do I go about accessing and manipulating the innerText properties of this via Javascript? For instance, how would I hide scrubTab2, or change its title to something else?

The first object you're seeing is jQuery's wrapper around the real DOM elements. It's not an actual array, but it does contain all of the elements that matched your query under zero-indexed properties (e.g. "0" and "1") which allows you to access to them via an array-like API (e.g. tabScrub[1]).
Your method of grabbing a node using tabScrub2["1"] is correct (see this question in the jQuery FAQ). It's more likely to see that done with a numeric key though (i.e. tabScrub[1]) because that matches the way you would access an element in a normal array.
As far as manipulating properties of the DOM node, the DOM's API is notoriously inconsistent and quirky (hence the need for things like jQuery in the first place). However, for your use case you can just assign a string to the innerText property directly (e.g. tagScrub2[1].innerText = "Tab title"). MDN is a great resource if you're looking for reference material on other parts of the DOM.
A side note: if you're looking for a specific element you should use a query that will only match that element. It's generally a bad sign if you're grabbing extra elements and then accessing the element you want at a key other than 0. If you're doing this then your code depends on other (potentially unrelated) nodes in the DOM existing before your node, and if/when you change those nodes your original code will break.

Just use jQuery eq method to get the relevant object index from the array.
For an example
//Query and get first element.
var tabScrub2 = $(document).find('[data-value="scrubTab2"]:eq(0)');
//Hide
tabScrub2.hide();
//Change title
tabScrub2.attr("title", "New Title Text");
Lean more about jQuery eq here.
https://api.jquery.com/eq/
Since you use jquery selectors tabScrub2[0] returns the native DOM element instead of another jQuery object. Therefore the hide function won't work in that object since the native DOM element doesn't implement such type of functionality for an element. That's why you have to use jQuery pseudo selector as above. Because hide will only work with a jQuery object.

Convert jquery function to javascript GSAP

I am doing some experimentation with GSAP library and i found one pen by Jonathan
http://codepen.io/jonathan/pen/qxsfc
which is pretty much i needed. i forked that pen and made my own and now i am trying to convert the same in vanilla js but the first step it self is not working.
i have converted the anonymous function to a named one and called on window.onload and its working. but now i have to replace all the $ calls of jquery selector to native selectors and its not working
the moment i change
var animContainer = $('.animContainer'),
to var animContainer = document.querySelector('.animContainer'),
my pen is
`http://codepen.io/osricmacon/pen/HAnrt`
any more suggestion on how to go about converting jquery to vanilla js

querySelector stops at the first element it finds, and returns a reference to that one element (or null if it doesn't find it). A closer analogue to jQuery's $() is querySelectorAll, which looks for all matching elements and returns a NodeList (which will be empty if none were found).
Separately from that, the key thing about jQuery is that it's set-based, whereas the DOM API is not. That's probably going to be the biggest thing for you to deal with when converting the one to the other.
For example, in jQuery, this sets the HTML of all div elements to "hey":
$("div").html("hey");
The equivalent using the DOM API might look like this:
var list = document.querySelectorAll("div"); // Or .getElementsByTagName
var i;
for (i = 0; i < list.length; ++i) {
list[i].innerHTML = "hey";
}
A common approach to making that less verbose is to reuse Array's forEach function (which is ES5, but can be shimmed for older browsers), like this:
// You'd probably do this once and reuse it
var forEach = Array.prototype.forEach;
// Where you want to use it:
forEach.call(document.querySelectorAll("div"), function(div) {
div.innerHTML = "hey";
});
Or, of course, to have a toolbelt of utility functions that do that under the covers. Which is, of course, exactly what jQuery is.
Finally, in many cases jQuery reuses the same functions as both setters and getters. The html function, for instance, sets the HTML of the elements in the jQuery set when you give it an argument, but gets the HTML of the first element of the set if you don't:
$("div").html("hey"); // Sets the HTML of all divs
console.log($("div").html()); // Gets the HTML of the *first* div
Note the assymetry: Setting applies to all elements in the set, but getting applies only to the first element in the set (ignoring any others). This is true of all of the functions that do dual duty (html, css, val, attr, prop, ...).

Can JQuery and Javascript be mixed together?

I am wondering if I could use query and javascript together so I could select an element by class with the javascript and then use javascript to work on that element. Sorry if that didn't make sense. Here is an example:
$('.nav_flag').src = "images/flags/"+userCountryLower+".gif";
Would that work, if not how do I get an element by class using regular javascript. Thanks!
EDIT:I know JQUERY is JavaScript but I was wondering if I could mix jquery selectors and javascript 'controller'-for a loss of a better word

To answer your question as asked, there are several ways to take a jQuery object, i.e., what is returned by $('some selector'), and get a reference to the underlying DOM element(s).
You can access the individual DOM elements like array elements:
// update the src of the first matching element:
$(".nav_flag")[0].src = "images/flags/"+userCountryLower+".gif";
// if you're going to access more than one you should cache the jQuery object in
// a variable, not keep selecting the same thing via the $() function:
var navFlgEls = $(".nav_flag");
for (var i = 0; i < navFlgEls.length; i++) { ... }
But you wouldn't manually loop through the elements when you can use jQuery's .each() method, noting that within the callback function you provide this will be set to the current DOM element:
$(".nav_flag").each(function() {
this.src = "images/flags/"+userCountryLower+".gif";
});
However, jQuery provides a way to set attributes with one line of code:
$(".nav_flag").attr("src", "images/flags/"+userCountryLower+".gif");
To answer the second part of your question, doing the same thing without jQuery, you can use .getElementsByClassname() or .querySelectorAll() if you don't care about supporting older browsers.

jQuery IS Javascript. You can mix and match them together. But you better know what you're doing.
In this case, you probably want to use .attr function to set value of attribute.

Use .attr() in jQuery, rather than mix the two here.
$('.nav_flag').attr('src', "images/flags/"+userCountryLower+".gif");
In many instances, it is fine to mix jQuery with plain JavaScript, but if you have already included the jQuery library, you might as well make use of it. Unless, that is, you have an operation which in jQuery would be more computationally expensive than the same operation in plain JavaScript.

You can do it with jQuery too:
$('.nav_flag').attr("src", "images/flags/"+userCountryLower+".gif");

keep in mind that jQuery is simply a library built upon javascript.
for any jQuery object, selecting its elements by subscription will return the corresponding dom element.
e.g.
$('#foo')[0] // is equivalent to document.getElementById('foo');

You need to add an index to the jQuery object to get the native Javascript object. Change:
$('.nav_flag').src = "images/flags/"+userCountryLower+".gif";
To:
$('.nav_flag')[0].src = "images/flags/"+userCountryLower+".gif";
To get elements by class name in Javascript you can use:
document.getElementsByClassName( 'nav_flag' )[0].src = "images/flags/"+userCountryLower+".gif";

To answer your question, you could use .toArray() to convert the jQuery object into an array of standard DOM elements. Then either get the first element or loop through the array to set all the elements with the class.
However, you could do this easier with pure jquery with attr or prop depending on the version:
$('.nav_flag').attr("src", "images/flags/"+userCountryLower+".gif");
Or use pure javascript:
if (navFlagElements = document.getElementsByClassName("nav_flag") && navFlagElements.length > 0) {
navFlagElements[0].src = "images/flags/"+userCountryLower+".gif"
}