I'm trying to target a child of a specific waypoint element, the following is my code but it gives an error:
this.element.find is not a function
var paralaxInView = new Waypoint.Inview({
element: $('.paralax')[0],
enter: function(direction) {
var tis = this.element;
console.log(tis)
this.element.find(".txt-block").addClass("in-view");
}
});
The 'element' property is a DOM element, or the actual container being watched as a Waypoint. So targeting 'this.element' would return the following HTML:
<div class="paralax">
<div class="txt-block"></div>
</div>
In order to use the element as a jQuery selector, you'll need give it an ID attribute in the HTML and target it with that. Like so:
$(this.element.id)
Here's an updated version of your code:
var paralaxInView = new Waypoint.Inview({
element: $('.paralax')[0],
enter: function(direction) {
$(this.element.id).find('.txt-block').addClass('in-view');
}
});
See a working JSFiddle here.
Reference: A little more info on the 'this' keyword is towards the bottom of the Waypoints Getting Started page.
Related
I am not allowed to answer questions yet, but I feel that since this issue has taken me some days to resolve, I should post the solution the only way I can - as a question.
If you have a better solution then please include that in your reply.
Until an element is rendered it is not in the DOM so if you add an event listener to the element in your code you will get an error (element value null).
But you can add a listener to the root element, which is always there. WHen the event is triggered you can then retrieve the className and ID of the element involved in your event-handler.
Code:
var rootElement = document.getElementById('root');
console.log(rootElement);
rootElement.addEventListener('click', rootElementClicked);
console.log('event listener added to root element');
function rootElementClicked(event) {
event.preventDefault();
const { name, value } = event.target;
console.log("Root element clicked with [" + event.target.className, event.target.id);
}
/code
So, the event-listener is app-wide, so a click anywhere will call the event-handler function. Then in the code for that function, the element class and ID will tell you what was clicked.
Note the event.preventDefault(); line - it prevents a refresh of the web page, otherwise the target class & ID are returned as "undefined"
In React you shouldn't need to addEventListener manually since you can use onClick. However if you would like to manually attach click handler on an HTML element in React you can use React Ref. If you pass a ref object to React with <div ref={myRef} /> React will set its .current property to the corresponding DOM node whenever that node changes.
Example: https://codesandbox.io/s/react-hooks-useref-xfvlb
const App = () => {
const elementRef = useRef();
useEffect(() => {
elementRef.current.addEventListener('click', handleOnClick);
},[elementRef])
const handleOnClick = () => {
alert("click")
}
return (
<div className="App">
<div ref={elementRef}>
click on me
</div>
</div>
);
}
I've followed a tutorial to create a Website Menu, this involves JQuery to provide some transitions.
I've got it working as intended, but to prove I understand this new code and framework, and also, to follow development guidelines, I want to move to the Menu code to a plug-in.
Working (not-plug-in) version:
This appears in the .ascx, along with a UL tag, ID = MainMenu
<script type="text/javascript">
NavBarMenu();
</script>
In another file, NavBar.js, the following code is used to associate some JQuery events:
function NavBarMenu() {
$(function() {
var $menu = $('#MainMenu');
var $menu_items = $menu.children('li');
...
Not working version:
Now the plug-in code is created, the NavBarMenu function is called like this from the .ascx:
<script type="text/javascript">
$("#MainMenu").NavBarMenu();
</script>
In NavBar.js I now have:
(function($) {
$.fn.NavBarMenu = function() {
var $menu_items = this.children('li');
However, the $menu_items variable is unpopulated?
Shouldn't this (2nd example) be equivalent to $('#MainMenu') (1st example)
I followed this example, where a JQuery selector is switched for the this pointer. http://learn.jquery.com/plugins/basic-plugin-creation/
Thanks in advance :D
There must be other factor affecting my implementation, I will revisit it.
I have created 2 JSFiddle pages, as part of my investigation and it has proved that the JQuery Selector can be swapped for the this pointer in a plug-in.
Fiddle detailing 1st example: http://jsfiddle.net/rL7zpr15/1/
$('input[type=button]').click( function() {
$( "div" ).css( "background", "green" );
});
Is equivalent to
Fiddle detailing 2nd example: http://jsfiddle.net/hds7advx/
$.fn.greenify = function() {
this.css( "background", "green" );
};
$('input[type=button]').click( function() {
$( "div" ).greenify();
});
I have a container div which includes lots of element divs all of which have a unique ID. I then make an ajax call to get more elements and append these to the DOM.
This works using the function below but I need to check that what I append doesn't already exist in the DOM. I've been looking into using each() and possibly remove() or detach() in order to do this, but I am not sure of jQuery syntax and really need some assistance.
function loadMoreItems(url) {
$.get(url, null, function(data) {
var container = $(data).find('#container');
var newItemsHTML = "";
/*-- not sure what to do in between
container.find('.element').remove();
container.each('.element').detach();
--*/
newItemsHTML = $(container).html();
var $newItems = $(newItemsHTML);
$container.isotope('insert', $newItems, true);
}, 'html');
}
<div class="element" id="id_172977"></div>
Assuming all of appended divs has class element you can do
$(".element").each(function() {
container.find("#" + this.id).remove();
});
Demo
I am calling a function on onselect event of a kendo auto complete. I want to get reference to the element on which kendo auto complete property is applied. I have 4 auto complete with same data source. I want to show a loading image on this elements when search is in progress. How do i get the reference to this elements ? How do I know, from which auto complete element onSelect is called? Please help me
$("#pmt_apply_order1").kendoAutoComplete({
select: onSelect,
});
$("#pmt_apply_order2").kendoAutoComplete({
select: onSelect,
});
function onSelect(e) {
// I want reference to $("#pmt_apply_order1") when selects from $("#pmt_apply_order1")
}
You can get the reference of the parent element using this.element inside the onSelect event .
To see get the id of the parent auto complete element, u need to use this.element.attr("id").
You can see a full demo here: http://jsfiddle.net/FVQkG/
function onSelect(e) {
alert("id of parent auto complete: " + this.element.attr("id"));
var dataItem = this.dataItem(e.item.index());
}
I'm making a project where a whole div with buttons is being inserted dynamically when user click a button, and inside that div there's a button, which when the user click on it, it does something else, like alerting something for example.
The problem is when i press on that button in the dynamically added div, nothing happens. The event doesn't fire at all.
I tried to add that div inside the HTML and try again, the event worked. So i guess it's because the div is dynamically added.
The added div has a class mainTaskWrapper, and the button has a class checkButton.
The event is attached using .on() at the end of script.js file below.
Here's my code :
helper_main_task.js : (that's the object that adds the div, you don't have to read it, as i think it's all about that div being dynamically added, but i'll put it in case you needed to)
var MainUtil = {
tasksArr : [],
catArr : ["all"],
add : function(){
var MTLabel = $("#mainTaskInput").val(), //task label
MTCategory = $("#mainCatInput").val(), //task category
MTPriority = $("#prioritySlider").slider("value"), //task priority
MTContents = $('<div class="wholeTask">\
<div class="mainTaskWrapper clearfix">\
<div class="mainMarker"></div>\
<label class="mainTaskLabel"></label>\
<div class="holder"></div>\
<div class="subTrigger"></div>\
<div class="checkButton"></div>\
<div class="optTrigger"></div>\
<div class="addSubButton"></div>\
<div class="mainOptions">\
<ul>\
<li id="mainInfo">Details</li>\
<li id="mainEdit">Edit</li>\
<li id="mainDelete">Delete</li>\
</ul>\
</div>\
</div>\
</div>');
this.tasksArr.push(MTLabel);
//setting label
MTContents.find(".mainTaskLabel").text(MTLabel);
//setting category
if(MTCategory == ""){
MTCategory = "uncategorized";
}
MTContents.attr('data-cat', MTCategory);
if(this.catArr.indexOf(MTCategory) == -1){
this.catArr.push(MTCategory);
$("#categories ul").append("<li>" + MTCategory +"</li>");
}
$("#mainCatInput").autocomplete("option", "source",this.catArr);
//setting priority marker color
if(MTPriority == 2){
MTContents.find(".mainMarker").css("background-color", "red");
} else if(MTPriority == 1){
MTContents.find(".mainMarker").css("background-color", "black");
} else if(MTPriority == 0){
MTContents.find(".mainMarker").css("background-color", "blue");
}
MTContents.hide();
$("#tasksWrapper").prepend(MTContents);
MTContents.slideDown(100);
$("#tasksWrapper").sortable({
axis: "y",
scroll: "true",
scrollSpeed : 10,
scrollSensitivity: 10,
handle: $(".holder")
});
}
};
script.js : (the file where the .on() function resides at the bottom)
$(function(){
$("#addMain, #mainCatInput").on('click keypress', function(evt){
if(evt.type == "click" || evt.type =="keypress"){
if((evt.type =="click" && evt.target.id == "addMain") ||
(evt.which == 13 && evt.target.id=="mainCatInput")){
MainUtil.add();
}
}
});
//Here's the event i'm talking about :
$("div.mainTaskWrapper").on('click', '.checkButton' , function(){
alert("test text");
});
});
It does not look like div.mainTaskWrapper exist.
From the documentation (yes, it is actually bold):
Event handlers are bound only to the currently selected elements; they must exist on the page at the time your code makes the call to .on(). To ensure the elements are present and can be selected, perform event binding inside a document ready handler for elements that are in the HTML markup on the page.
[...]
By picking an element that is guaranteed to be present at the time the delegated event handler is attached, you can use delegated events to avoid the need to frequently attach and remove event handlers.
You might want to bind it to #tasksWrapper instead:
$("#tasksWrapper").on('click', '.checkButton' , function(){
alert("test text");
});
You need to specify a selector with on (as a parameter) to make it behave like the old delegate method. If you don't do that, the event will only be linked to the elements that currenly match div.mainTaskWrapper (which do not exists yet). You need to either re-assign the event after you added the new elements, or add the event to an element that already exists, like #tasksWrapper or the document itself.
See 'Direct and delegate events' on this page.
I know this is an old post but might be useful for anyone else who comes across...
You could try:
jQuery('body')on.('DOMNodeInserted', '#yourdynamicallyaddeddiv', function () {
//Your button click event
});
Here's a quick example - https://jsfiddle.net/8b0e2auu/