Make eventlisteners unique? - javascript

So I have a problem where the eventlisteners I setup all happen to work with the same variable.
This is how it looks like:
// Prepare tooltips
for (var i = 0; i < document.getElementsByClassName("tooltip").length; i++) {
var tooltip = document.getElementsByClassName("tooltip")[i];
var input = document.getElementsByName(tooltip.id.substr(8))[0];
var offsetTop = 0;
var tmp = input;
while (tmp != null) {
offsetTop += tmp.offsetTop;
tmp = tmp.offsetParent;
}
offsetTop -= 130;
var offsetLeft = (input.offsetParent.offsetLeft + input.scrollWidth) + 50;
tooltip.innerHTML += "<div class='corner'></div>";
tooltip.style.top = offsetTop + "px";
tooltip.style.left = offsetLeft + "px";
input.addEventListener("focus", function() { document.getElementById(tooltip.id).style.display = "block"; });
input.addEventListener("blur", function() { document.getElementById(tooltip.id).style.display = "none"; });
}
In the last two lines I set the eventlisteners.
So whenever I focus an input field, no matter which one tooltip.id is always the same.
I checked the input.id before its different in every loop.

Javascript is a funny language :)
In each loop you're declaring a function which uses a reference to the variable tooltip.
Since you use the variable many times: its value changes but the reference remains the same.
When the function executes, it uses the reference (which has the last value).
Here is the solution:
(I recommend calling the method 'document.getElementsByClassName("tooltip")' only once since it causes DOM traverse.
==== CODE STARTS HERE
var toolips = document.getElementsByClassName("tooltip");
for (var i = 0; i < toolips.length; i++)
{
var tooltip = toolips[i];
var input = document.getElementsByName(tooltip.id.substr(8))[0];
var offsetTop = 0;
var tmp = input;
while (tmp != null)
{
offsetTop += tmp.offsetTop;
tmp = tmp.offsetParent;
}
offsetTop -= 130;
var offsetLeft = (input.offsetParent.offsetLeft + input.scrollWidth) + 50;
tooltip.innerHTML += "<div class='corner'></div>";
tooltip.style.top = offsetTop + "px";
tooltip.style.left = offsetLeft + "px";
// assign tooltip id to the input
input.tooltipId = tooltip.id;
// add event listeners
input.addEventListener("focus", function() { document.getElementById(this.tooltipId ).style.display = "block"; });
input.addEventListener("blur", function() { document.getElementById(this.tooltipId).style.display = "none"; });
}
==== CODE ENDS HERE

Related

vanilla javascript: element.close() not working on element

This is a Sudoko generator I'm programming in vanilla javascript:
Fiddle with code
Nicer looking full screen fiddle
If you click on one of the fields, a popup will be shown with 3x3 fields from 1 to 9. The problem is this popup can't be closed anymore, although I'm applying the close dialog.
The code how I'm generating the Sudoku board:
// create sudoku
function tableCreate() {
var body = document.getElementsByClassName("frame")[0];
var containerDiv = body.appendChild(document.createElement('div'))
containerDiv.className = 'container';
// create single cells with numbers
function createInnnerCells(parent, xx, yy) {
for (var x = 1; x <= 3; x++) {
for (var y = 1; y <= 3; y++) {
var abc = function () {
var div = parent.appendChild(document.createElement('div'))
var X = y+yy;
var Y = x+xx;
var id = 'x' + [X] + 'y' + [Y];
var cellValue = sudoku[X][Y]['value'] || '';
div.style.background = sudoku[X][Y]['background'] || 'white'
div.className = 'cell';
div.id = id;
var popover = createDialog(id);
popover.onclick = function() {
popover.close();
};
div.onclick = function() {
popover.show();
};
div.appendChild(popover);
div.appendChild(document.createTextNode(cellValue));
};
abc();
}
}
}
// create big cells for 3x3 single cells
for (var i = 0; i <= 6; i+=3) {
for (var j = 0; j <= 6; j+=3) {
var div = containerDiv.appendChild(document.createElement('div'))
div.className = 'block';
createInnnerCells(div, i, j);
}
}
}
Note that I apply the close() function to each cell:
popover.onclick = function() {
popover.close();
};
The code how I create the popup:
// create dialog
function createDialog(position){
var dialog = document.createElement('dialog');
dialog.id ='window_'+ position;
var dialogblock = dialog.appendChild(document.createElement('div'));
dialogblock.className = 'dialogblock';
for (var z = 1; z <= 9; z++) {
var div = dialogblock.appendChild(document.createElement('div'));
div.className = 'dialogcell';
div.id = position + 'z'+ z;
div.appendChild(document.createTextNode(position));
}
dialog.onclick = function() {
dialog.close();
};
return dialog;
}
I applied the close() dialog here as well
dialog.onclick = function() {
dialog.close();
};
I don't know why show() is working, but close() not?
DOM events bubble up the DOM through its parents. In your code, the dialog is a child of div. Therefore, a click event happens on dialog and then again on div which means you're closing and then opening the dialog.
You can stop the propagation of the event by using event.stopPropagation.
You can change your code like this:
popover.onclick = function(e) {
e.stopPropagation();
popover.close();
};
and
dialog.onclick = function(e) {
e.stopPropagation();
dialog.close();
};
modified your fiddle: http://jsfiddle.net/p40oahkd/9/
There's no method close() on the element you are trying to hide. You should either do element.style.display = "none" if you need to hide. Or do the following:
dialog.addEventListener('click', function() {
this.remove();
});
Check out this edit to your fiddle.

assign parameter value of an object javascript

I have been looking at this code for a long time trying to figure this out, but I am having no luck. This issue is that I want to assign a value to the parameter boxId. When I click on a box in the webpage an alert will come up displaying that id. I have tried many things, but nothing seems to work. I'm a beginner, so I feel at this point there just must be something that I don't know how to do.
constructor function:
function Box (boxId, name, color, number, coordinates) {
this.boxId = boxId;
this.name = name;
this.color = color;
this.number = number;
this.coordinates = coordinates;
}
global variables:
var boxes = [];
var counter = 0;
var boxId = 0;
init function:
window.onload = init;
function init() {
var generateButton = document.getElementById("generateButton");
generateButton.onclick = getBoxValues;
var clearButton = document.getElementById("clearButton");
clearButton.onclick = clear;
}
function to get values and create new boxes:
function getBoxValues() {
var nameInput = document.getElementById("name");
var name = nameInput.value;
var numbersArray = dataForm.elements.amount;
for (var i = 0; i < numbersArray.length; i++) {
if (numbersArray[i].checked) {
number = numbersArray[i].value;
}
}
var colorSelect = document.getElementById("color");
var colorOption = colorSelect.options[colorSelect.selectedIndex];
var color = colorOption.value;
if (name == null || name == "") {
alert("Please enter a name for your box");
return;
}
else {
var newbox = new Box(boxId, name, color, number, "coordinates");
boxes.push(newbox);
counter++;
var boxId = counter;
}
addBox(newbox);
var data = document.getElementById("dataForm");
data.reset();
}
function that adds boxes to the page:
function addBox(newbox) {
for (var i = 0; i < newbox.number; i++) {
var scene = document.getElementById("scene");
var div = document.createElement("div");
div.className += " " + "box";
div.innerHTML += newbox.name;
div.style.backgroundColor = newbox.color;
var x = Math.floor(Math.random() * (scene.offsetWidth-101));
var y = Math.floor(Math.random() * (scene.offsetHeight-101));
div.style.left = x + "px";
div.style.top = y + "px";
scene.appendChild(div);
div.onclick = display;
}
}
function to display alert when box is clicked:
function display(e) {
var a = e.target;
alert(a.counter);
}
function to clear boxes:
function clear() {
var elems = document.getElementsByClassName("box");
for ( k = elems.length - 1; k >= 0; k--) {
var parent = elems[k].parentNode;
parent.removeChild(elems[k]);
}
}
All of the other functions work just fine. I keep running into the id showing up as "undefined" when I click it, or the counter displaying "0" in the console log, for everything I've tried.
You can do it like this.
First, in addBox() embed boxId as an tag's attribute like this:
div.setAttribute('data-boxId', newbox.boxId);
Then in display() you can retrieve it back:
alert(e.target.getAttribute('data-boxId'));
Please tell if you do not prefer this approach and I will post an alternative (closure things).
Edit: Add jsfiddle example http://jsfiddle.net/runtarm/8FJpU/
One more try. Perhaps if you change:
var boxId = counter;
to
boxId = counter;
It will then use the boxId from the outer scope instead of the one defined in the function getBoxValues()

how to use an event object to dispaly information about a DOM element

I want to be able to click on a box (the boxes are created through code, and receive values from a form) in the webpage and display information about the box. I am working on a display() function that uses an event object and an alert to display information about the box. So far, I've had multiple odd failures in my attempt to do this, which leads me to believe that I'm not accessing object attributes correctly. I'm a beginner, so this could be really obvious, but thanks for the help.
constructor function:
function Box (counter, name, color, number, coordinates) {
this.counter = counter;
this.name = name;
this.color = color;
this.number = number;
this.coordinates = coordinates;
}
Global variables:
var boxes = [];
var counter = 0;
Init function:
function init() {
var generateButton = document.getElementById("generateButton");
generateButton.onclick = getBoxValues;
var clearButton = document.getElementById("clearButton");
clearButton.onclick = clear;
}
Function that gets values from the form:
function getBoxValues() {
var nameInput = document.getElementById("name");
var name = nameInput.value;
var numbersArray = dataForm.elements.amount;
for (var i = 0; i < numbersArray.length; i++) {
if (numbersArray[i].checked) {
number = numbersArray[i].value;
}
}
var colorSelect = document.getElementById("color");
var colorOption = colorSelect.options[colorSelect.selectedIndex];
var color = colorOption.value;
if (name == null || name == "") {
alert("Please enter a name for your box");
return;
} else {
var newbox = new Box(counter, name, color, number, "coordinates");
boxes.push(newbox);
counter++;
/*for(m = 0; m < boxes.length; m++) {
counter.newbox = boxes[m];
}*/
}
addBox(newbox);
var data = document.getElementById("dataForm");
data.reset();
}
function that assigns attributes to the boxes:
function addBox(newbox) {
for (var i = 0; i < newbox.number; i++) {
var scene = document.getElementById("scene");
var div = document.createElement("div");
div.className += " " + "box";
div.innerHTML += newbox.name;
div.style.backgroundColor = newbox.color;
var x = Math.floor(Math.random() * (scene.offsetWidth-101));
var y = Math.floor(Math.random() * (scene.offsetHeight-101));
div.style.left = x + "px";
div.style.top = y + "px";
scene.appendChild(div);
div.onclick = display;
//console.log(newbox);
//shows all of the property values of newbox in the console
//console.log(div); shows that it is an object in the console
//console.log(div.hasAttribute(number)); says false
}
}
display function:
function display(e) {
// alert(e.target); says its an html object
//alert(e.target.className); works - says "box"
//alert(e.target.hasAttribute(name)); says false
}
I've included some of the things i've found in comments.
The event object only gives you the name not a reference to the element. So... a couple of things.
First if you want to be browser agnostic you want something like (e.srcElement is for IE):
var x = e.target||e.srcElement;
Then get a reference to the element and do what you want:
var refToElement = document.getElementById(x.id);

Javascript function not recognizing id in getElementById

I am adding a row to a table, and attached an ondblclick event to the cells. The function addrow is working fine, and the dblclick is taking me to seltogg, with the correct parameters. However, the var selbutton = document.getElementById in seltogg is returning a null. When I call seltogg with a dblclick on the original table in the document, it runs fine. All the parameters "selna" have alphabetic values, with no spaces, special characters, etc. Can someone tell me why seltogg is unable to correctly perform the document.getElementById when I pass the id from addrow; also how to fix the problem.
function addrow(jtop, sel4list, ron4list) {
var tablex = document.getElementById('thetable');
var initcount = document.getElementById('numrows').value;
var sel4arr = sel4list.split(",");
var idcount = parseInt(initcount) + 1;
var rowx = tablex.insertRow(1);
var jtop1 = jtop - 1;
for (j = 0; j <= jtop1; j++) {
var cellx = rowx.insertCell(j);
cellx.style.border = "1px solid blue";
var inputx = document.createElement("input");
inputx.type = "text";
inputx.ondblclick = (function() {
var curj = j;
var selna = sel4arr[curj + 2];
var cellj = parseInt(curj) + 3;
inputx.id = "cell_" + idcount + "_" + cellj;
var b = "cell_" + idcount + "_" + cellj;
return function() {
seltogg(selna, b);
}
})();
cellx.appendChild(inputx);
} //end j loop
var rowCount = tablex.rows.length;
document.getElementById('numrows').value = rowCount - 1; //dont count header
} //end function addrow
function seltogg(selna, cellid) {
if (selna == "none") {
return;
}
document.getElementById('x').value = cellid; //setting up for the next function
var selbutton = document.getElementById(selna); //*****this is returning null
if (selbutton.style.display != 'none') { //if it's on
selbutton.style.display = 'none';
} //turn it off
else { //if it's off
selbutton.style.display = '';
} //turn it on
} //end of function seltogg
You try, writing this sentence:
document.getElementById("numrows").value on document.getElementById('numrows').value
This is my part the my code:
contapara=(parseInt(contapara)+1);
document.getElementById("sorpara").innerHTML+="<li id=\"inputp"+contapara+"_id\" class=\"ui-state-default\"><span class=\"ui-icon ui-icon-arrowthick-2-n-s\"></span>"+$('#inputp'+contapara+'_id').val()+"</li>";
Look you have to use this " y not '.
TRY!!!!

GridView Freeze Header

I am using this tutorial to freeze the header of the GridView. I did everything as explained in the tutorial but I got the following error in IE9 and I don't know why.
Error:
Line: 182
Error: Unable to get value of the property 'offsetWidth': object is
null or undefined
I defined the GridView in the Javascript code as show below:
<script type = "text/javascript">
var GridId = "<%=GridView1 %>";
var ScrollHeight = 300;
window.onload = function () {
var grid = document.getElementById(GridId);
var gridWidth = grid.offsetWidth;
var gridHeight = grid.offsetHeight;
var headerCellWidths = new Array();
for (var i = 0; i < grid.getElementsByTagName("TH").length; i++) {
headerCellWidths[i] = grid.getElementsByTagName("TH")[i].offsetWidth;
}
grid.parentNode.appendChild(document.createElement("div"));
var parentDiv = grid.parentNode;
var table = document.createElement("table");
for (i = 0; i < grid.attributes.length; i++) {
if (grid.attributes[i].specified && grid.attributes[i].name != "id") {
table.setAttribute(grid.attributes[i].name, grid.attributes[i].value);
}
}
table.style.cssText = grid.style.cssText;
table.style.width = gridWidth + "px";
table.appendChild(document.createElement("tbody"));
table.getElementsByTagName("tbody")[0].appendChild(grid.getElementsByTagName("TR")[0]);
var cells = table.getElementsByTagName("TH");
var gridRow = grid.getElementsByTagName("TR")[0];
for (var i = 0; i < cells.length; i++) {
var width;
if (headerCellWidths[i] > gridRow.getElementsByTagName("TD")[i].offsetWidth) {
width = headerCellWidths[i];
}
else {
width = gridRow.getElementsByTagName("TD")[i].offsetWidth;
}
cells[i].style.width = parseInt(width - 3) + "px";
gridRow.getElementsByTagName("TD")[i].style.width = parseInt(width - 3) + "px";
}
parentDiv.removeChild(grid);
var dummyHeader = document.createElement("div");
dummyHeader.appendChild(table);
parentDiv.appendChild(dummyHeader);
var scrollableDiv = document.createElement("div");
if(parseInt(gridHeight) > ScrollHeight){
gridWidth = parseInt(gridWidth) + 17;
}
scrollableDiv.style.cssText = "overflow:auto;height:" + ScrollHeight + "px;width:" + gridWidth + "px";
scrollableDiv.appendChild(grid);
parentDiv.appendChild(scrollableDiv);
}
</script>
So how I fix this problem?
You have written code incorrectly
Instead of
var GridId = "<%=GridView1 %>";
Change to
var GridId = "<%=GridView1.ClientID %>"; //<= Check this
When ASP.Net controls are rendered their Id gets mangled and to get the mangled on client side the notation is as shown above.
Hope this solves your problem.

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