How can I link a JavaScript variable to a HTML value? - javascript

I need to link an item in a table to a Javascript variable, but it won't link. I think there will be further problems changing the value.
I am running on Atom Editor, with the script package installed, although I could copy the script into Notepad++ or Brackets if needed.
</tr>
<td>Abena</td>
<td>Natale</td>
<td id = "Abena_Natale">11782</td>
<td>No.1</td>
<td>Monarch of Boars</td>
</tr>
<script>
var Abena_Natale = ""
</script>
I expected to get a variable that would change the value in the Abena_Natale element when the Javascript stated. Instead, it just stays the same.

There was an error in your HTML.
From there we need to write the selector to get the element.
And then grab the content inside the node.
Update to support editing.
var Abena_Natale = "";
var abenaElement;
document.addEventListener('DOMContentLoaded', function() {
abenaElement = document.querySelector('#Abena_Natale');
Abena_Natale = abenaElement.innerHTML;
console.log(Abena_Natale);
// Update the value
abenaElement.innerHTML = "Testing";
});
<table>
<tr>
<td>Abena</td>
<td>Natale</td>
<td id="Abena_Natale">11782</td>
<td>No.1</td>
<td>Monarch of Boars</td>
</tr>
</table>

That's not how you access the Document Object Model (DOM) with JS. You need to grab the element using one from a number of methods, and then amend the data.
1) Make sure your table row elements are opened and closed correctly.
2) Use either document.getElementById('Abena_Natale'), or document.querySelector('#Abena_Natale') to grab the element.
3) Set the textContent of the element. value is generally used for input elements.
const aN = document.getElementById('Abena_Natale');
aN.textContent = 'This has been changed';
<table>
<tr>
<td>Abena</td>
<td>Natale</td>
<td id="Abena_Natale">11782</td>
<td>No.1</td>
<td>Monarch of Boars</td>
</tr>
</table>

Related

Find and change element's textContent without breaking DOM events

I need to find an element and replace the .textContent of it within a constantly changing table. I'm fairly new to coding, but I've come across an issue when trying to replace certain elements' .textContent.
I have a table on my website that shuffles the values upon every new session. I would like to have certain values within that table to be replaced.
<table class = "tb">
<tr>
<td>Element 1</td>
<td>Element 2</td>
<td>Element 3</td>
</tr>
</table>
And upon each new session, the order of each element is changed.
I want to first find "Element 2" and change it to "Element 2.1", but I cannot do it with my current script because it just changes the 2nd row of the table rather than what I am looking for. So upon reshuffling, it might change Element 1 to the replacement value instead.
I have a very simple script to swap out elements.
const Tableswap = () => {
const findele = document.querySelectorAll(".tb")[1];
if (findele === null){
return;
};
findele.textContent = "Element 2.1";
};
I've tried the following to find the particular element that I am looking for, but I am not sure where to go from here:
//find the required element
function contains(selector, text) {
var elements = document.querySelectorAll(selector);
return Array.prototype.filter.call(elements, function(element){
return RegExp(text).test(element.textContent);
});
}
const finder = contains('.tb', "Element 2");
if (finder === null){
return;
};
finder.tb.textContent = "Element 2.1";
I am honestly not sure if I even went in the right direction with all of this, and I am a complete newbie when it comes to all of this, I've basically been scavenging bits of code from everywhere and trying to understand what I'm doing along the way. I would prefer everything to be in JS, as I have absolutely no experience with JQuery and have no clue what it even is.
Here's what you were trying to achieve through the second script.
I tried to keep it close to your orginal code to make it easier for you to comprehend.
The script should be deferred if loaded externally to prevent it from executing before the DOM has finished loading.
<!DOCTYPE html>
<html>
<body>
<table class="tb">
<tr>
<td>Element 1</td>
<td>Element 2</td>
<td>Element 3</td>
</tr>
</table>
<script> //defer if loading via src, keep it at the end otherwise
function findAndReplace(selector, find, replace) {
let elements = document.querySelectorAll(selector);
return Array.prototype.filter.call(elements, function (element) {
if (RegExp(find).test(element.textContent))
element.textContent = replace;
});
}
findAndReplace(".tb td", "Element 2", "Element 2.1");
</script>
</body>
</html>
In your HTML, change it to <td id="myID">, and then you can use document.getElementById(myID).innerHTML = "Element 2.1".

Function named "open" loads a new page - trying to change iframe src with inline JS

I wrote a simple function for change the src attribute of an iframe, and this is the code:
function open(dat) {
document.getElementById('frame1').src = dat;
}
I call the function in this way:
<table id="maintab1" align="center" border="0" style="width:95%">
<tr>
<td width="50%" onclick="open('/timetrials/european/mushroom.php');"> text </td>
<td width="50%" onclick="open('/timetrials/european/flower.php');" > text </td>
</tr>
</table>
Of course the iframe has the id 'frame1' as you can see: <iframe id="frame1" src="/timetrials/european/mushroom.php" >You browser does not support iframes.</iframe>. The page is correctly loaded on the iframe at first.
When I click on a <td>, instead of changing the src of my iframe, I see a new blank page loading forever without getting a result.
Do you know why?
Once again, the evils of inline js are clear! This is because there's a property of window called open and when you use onlick="open()" you're calling the wrong open()! Don't use inline js!
Read some of these results: Why is inline JS bad?
A simple solution to your whole problem is just to use links targeting the iframe like this:
Change iframe path!
<iframe name="myiframe"></iframe>
Improving your current code:
Live demo here (click).
Markup:
<table id="maintab1" >
<tr>
<td width="50%" data-open="/timetrials/european/mushroom.php');">Mushroom</td>
<td width="50%" data-open="/timetrials/european/flower.php');" >Flower</td>
</tr>
</table>
JavaScript:
//get element references
var tds = document.querySelectorAll('#maintab1 td');
//loop each element
for (var i=0; i<tds.length; ++i) {
//register click function
tds[i].addEventListener('click', myClickFunc);
}
function myClickFunc(event) {
var link = this.getAttribute('data-open');
openIframe(link);
}
//also note that camelCase naming is standard
function openIframe(link) {
console.log(link);
}
There are a lot of ways that this could be done, but the key is just getting your element references with javascript and attaching the click function there. Select them however you want to - id, class, selector, or you could even create the element itself with javascript! Rather than storing the data on the element as in my example, you could store them in an array in javascript and then pull them out for each element in the loop (first element will get first link from the array, etc).
I have solved my question by changing the name of my function. The name function open(dat) causes a conflict with the window.open
function open_iframe(dat) {
document.getElementById('frame1').src = dat;
}
This is the new code I wrote and it is fine now.

Inserting a numeric value to cell with Javascript

My professor has a unique task that prevents us from using any JQuery or basically anything that isn't Javascript or HTML/CSS.
I have to, on a mouse click, update the value within a cell with some numeric value. I am new to Javascript and basically here is what I am working with.
<table id="score">
<tr>
<td> One's </td>
<td class="scoring" id="ones" onClick="inputScore()"> </td>
</tr>
</table>
What I want to do is click the cell with id=ones and insert a value of 50 with the function inputScore(). What is the best way to approach this using only Javascript? Thanks in advance.
Edit: Code ported from comments:
<script>
function inputScore() {
var x = 50;
document.getElementById("ones") = x;
}
</script>
You have correctly targeted the element with getElementById(), but you need to set its innerHTML property to modify the cell's contents.
function inputScore() {
var x = 50;
document.getElementById("ones").innerHTML = x;
}
You were very nearly there. In this case you could also use .innerText since you are not adding any additional HTML markup, only the number 50.
If you want, you might consider modifying this function to accept the new value as a parameter:
function inputScore(value) {
// Set the contents to value
document.getElementById("ones").innerHTML = parseInt(value, 10);
}
// Called as
inputScore(50)
As you learn, it is recommended to use the MDN documentation as your point of reference. Here is the documentation on .innerHTML.

JS. How to replace html element with another element/text, represented in string?

I have a problem with replacing html elements.
For example, here is a table:
<table>
<tr>
<td id="idTABLE">0</td>
<td>END</td>
</tr>
</table>
(it can be div, span, anything)
And string in JavaScript:
var str = '<td>1</td><td>2</td>';
(It can be anything, 123 text, <span>123 element</span> 456 or <tr><td>123</td> or anything)
How can I replace element idTABLE with str?
So:
<table>
<tr>
<td id="idTABLE">0</td>
<td>END</td>
</tr>
</table>
Becomes:
<table>
<tr>
<td>1</td>
<td>2</td>
<td>END</td>
</tr>
</table>
<!-- str = '<td>1</td><td>2</td>'; -->
<table>
<tr>
123 text
<td>END</td>
</tr>
</table>
<!-- str = '123 text' -->
<table>
<tr>
<td>123</td>
<td>END</td>
</tr>
</table>
<!-- str = '<td>123</td>' -->
I tried createElement, replaceChild, cloneNode, but with no result at all =(
As the Jquery replaceWith() code was too bulky, tricky and complicated, here's my own solution. =)
The best way is to use outerHTML property, but it is not crossbrowsered yet, so I did some trick, weird enough, but simple.
Here is the code
var str = 'item to replace'; //it can be anything
var Obj = document.getElementById('TargetObject'); //any element to be fully replaced
if(Obj.outerHTML) { //if outerHTML is supported
Obj.outerHTML=str; ///it's simple replacement of whole element with contents of str var
}
else { //if outerHTML is not supported, there is a weird but crossbrowsered trick
var tmpObj=document.createElement("div");
tmpObj.innerHTML='<!--THIS DATA SHOULD BE REPLACED-->';
ObjParent=Obj.parentNode; //Okey, element should be parented
ObjParent.replaceChild(tmpObj,Obj); //here we placing our temporary data instead of our target, so we can find it then and replace it into whatever we want to replace to
ObjParent.innerHTML=ObjParent.innerHTML.replace('<div><!--THIS DATA SHOULD BE REPLACED--></div>',str);
}
That's all
Because you are talking about your replacement being anything, and also replacing in the middle of an element's children, it becomes more tricky than just inserting a singular element, or directly removing and appending:
function replaceTargetWith( targetID, html ){
/// find our target
var i, tmp, elm, last, target = document.getElementById(targetID);
/// create a temporary div or tr (to support tds)
tmp = document.createElement(html.indexOf('<td')!=-1?'tr':'div'));
/// fill that div with our html, this generates our children
tmp.innerHTML = html;
/// step through the temporary div's children and insertBefore our target
i = tmp.childNodes.length;
/// the insertBefore method was more complicated than I first thought so I
/// have improved it. Have to be careful when dealing with child lists as
/// they are counted as live lists and so will update as and when you make
/// changes. This is why it is best to work backwards when moving children
/// around, and why I'm assigning the elements I'm working with to `elm`
/// and `last`
last = target;
while(i--){
target.parentNode.insertBefore((elm = tmp.childNodes[i]), last);
last = elm;
}
/// remove the target.
target.parentNode.removeChild(target);
}
example usage:
replaceTargetWith( 'idTABLE', 'I <b>can</b> be <div>anything</div>' );
demo:
http://jsfiddle.net/97H5Y/1/
By using the .innerHTML of our temporary div this will generate the TextNodes and Elements we need to insert without any hard work. But rather than insert the temporary div itself -- this would give us mark up that we don't want -- we can just scan and insert it's children.
...either that or look to using jQuery and it's replaceWith method.
jQuery('#idTABLE').replaceWith('<blink>Why this tag??</blink>');
update 2012/11/15
As a response to EL 2002's comment above:
It not always possible. For example, when createElement('div') and set its innerHTML as <td>123</td>, this div becomes <div>123</div> (js throws away inappropriate td tag)
The above problem obviously negates my solution as well - I have updated my code above accordingly (at least for the td issue). However for certain HTML this will occur no matter what you do. All user agents interpret HTML via their own parsing rules, but nearly all of them will attempt to auto-correct bad HTML. The only way to achieve exactly what you are talking about (in some of your examples) is to take the HTML out of the DOM entirely, and manipulate it as a string. This will be the only way to achieve a markup string with the following (jQuery will not get around this issue either):
<table><tr>123 text<td>END</td></tr></table>
If you then take this string an inject it into the DOM, depending on the browser you will get the following:
123 text<table><tr><td>END</td></tr></table>
<table><tr><td>END</td></tr></table>
The only question that remains is why you would want to achieve broken HTML in the first place? :)
Using jQuery you can do this:
var str = '<td>1</td><td>2</td>';
$('#__TABLE__').replaceWith(str);
http://jsfiddle.net/hZBeW/4/
Or in pure javascript:
var str = '<td>1</td><td>2</td>';
var tdElement = document.getElementById('__TABLE__');
var trElement = tdElement.parentNode;
trElement.removeChild(tdElement);
trElement.innerHTML = str + trElement.innerHTML;
http://jsfiddle.net/hZBeW/1/
You would first remove the table, then add the new replacement to the table's parent object.
Look up removeChild and appendChild
http://javascript.about.com/library/bldom09.htm
https://developer.mozilla.org/en-US/docs/DOM/Node.appendChild
Edit:
jQuery .append allows sting-html without removing tags: http://api.jquery.com/append/
Your input in this case is too ambiguous. Your code will have to know if it should just insert the text as-is or parse out some HTML tags (or otherwise wind up with bad HTML). This is unneeded complexity that you can avoid by adjusting the input you provide.
If the garbled input is unavoidable, then without some sophisticated parsing (preferably in a separate function), you could end up with some bad HTML (like you do in your second example... which is Bad, right?).
I'm guessing you want a function to insert columns into a 1-row table. In this case, your contents should be passed in as an array (without table, tr, td tags). Each array element will be one column.
HTML
<table id="__TABLE__"><tr><td></td></tr></table>
JS
using jQuery for brevity...
function insert_columns (columns)
{
var $row = $('<tr></tr>');
for (var i = 0; i < columns.length; i++)
$row.append('<td>'+columns[i]+'</td>');
$('#__TABLE__').empty(); // remove everything inside
$('#__TABLE__').append($row);
}
So then...
insert_columns(['hello', 'there', 'world']);
Result
<table id="__TABLE__"><tr><td>hello</td><td>there</td><td>world</td></tr></table>
If you need to actually replace the td you are selecting from the DOM, then you need to first go to the parentNode, then replace the contents replace the innerHTML with a new html string representing what you want. The trick is converting the first-table-cell to a string so you can then use it in a string replace method.
I added a fiddle example: http://jsfiddle.net/vzUF4/
<table><tr><td id="first-table-cell">0</td><td>END</td></tr></table>
<script>
var firstTableCell = document.getElementById('first-table-cell');
var tableRow = firstTableCell.parentNode;
// Create a separate node used to convert node into string.
var renderingNode = document.createElement('tr');
renderingNode.appendChild(firstTableCell.cloneNode(true));
// Do a simple string replace on the html
var stringVersionOfFirstTableCell = renderingNode.innerHTML;
tableRow.innerHTML = tableRow.innerHTML.replace(stringVersionOfFirstTableCell,
'<td>0</td><td>1</td>');
</script>
A lot of the complexity here is that you are mixing DOM methods with string methods.
If DOM methods work for your application, it would be much bette to use those.
You can also do this with pure DOM methods (document.createElement, removeChild, appendChild), but it takes more lines of code and your question explicitly said you wanted to use a string.
use the attribute "innerHTML"
somehow select the table:
var a = document.getElementById('table, div, whatever node, id')
a.innerHTML = your_text

How to change the value of id or name?

Example:
<table id ='table'>
<tr>
<td>1</td>
<td><select id='old' name='old'></select></td>
<td><select id='old2' name='old2'></select></td>
<td><div id='old3' name='old3'></div></td>
</tr>
</table>
How to change the value of id or name from select id ='old' to select id ='new' (for example) after deleting rows in javascript?
I have been trying all the methods like trying getElementById('old') = 'new' but not work, used replaceChild also not work (or maybe I put the wrong code, no idea).
Do you have other alternatives? (No JQuery, please).
Thanks.
You can use the setAttribute method to accomplish this
document.getElementById("old").setAttribute("id","new");
document.getElementById("new").setAttribute("name","new");
var sel = document.getElementById("old"); //Reference the element
sel.id = "new"; //set the id
try this :
document.getElementById("old").name = 'NewName';
alert(document.getElementById("old").name);
document.getElementById("old").id = 'Newid';
alert(document.getElementById("Newid").id);
its work for me.
I feel there is something inelegant going on here; if you told us more we'd be able to say the "right way" to do it. If you nevertheless have a very good reason to do what you're doing, merely call this snippet of code you have made all your changes. It will update all the elements in your rows to have the correct numbering.
var formElements = document.getElementById('table').getElementsByClassName('toUpdate');
for (var i=0; i<formElements.length; i++) {
var e = formElements[i];
e.id = 'new'+i;
}
There are quite a few variations on this if you didn't want to add a class="toUpdate ..." to each one. For example you were using regular form elements, you could iterate over the <form>'s elements. Or you could iterate through all the elements and pattern-match on the names or ids. Or if you are algorithmically generating this with javascript you could add each element to an array at the same time you add it to the DOM, for later use (like this update).

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