Ok, I'm trying to come to grips with this nextSibling function in JS. Here's my issue within the following code...
var fromRow = document.getElementById("row_1");
while(fromRow.nodeType == 1 && fromRow.nextSibling != null)
{
var fRowId = fromRow.id;
if (!fRowId) continue;
// THIS ONLY gets done once and alerts "row_1" ONLY :(
alert(fRowId);
fromRow = fromRow.nextSibling;
}
Ok can someone please tell me what is wrong with this code? There are siblings next to this document.getElementById("row_1"); element for sure as I can see them, and they all have id attributes, so why is it not getting the id attributes of the siblings?? I don't get it.
row_1 is a TR element, and I need to get the TR elements next to it within this table, but for some reason, it only gets the 1 element that I can already get using document.getElementById, arggg.
Thanks guys :)
Try:
var fromRow = document.getElementById("row_1");
while(fromRow !== null)
{
var fRowId = fromRow.id;
if (!fRowId || fromRow.nodeType != 1) {
fromRow = fromRow.nextSibling;
continue;
}
// THIS ONLY gets done once and alerts "row_1" ONLY :(
alert(fRowId);
fromRow = fromRow.nextSibling;
}
While fromRow.nextSibling != null would halt on the second to last iteration because you already set fromRow to its nextSibling at the end. Also, you don't necessarily want to halt if the next node isn't an element, you just want to move onto the next one if possible. Finally, if you hit the continue in your original example, you'll run into an endless loop because fromRow would never change value.
Your while loop stops as soon as it encounters a node not of type 1. So if there is any whitespace between your elements the while loop will break after the first element.
What you probably want is:
while(fromRow.nextSibling != null)
{
if(fromRow.nodeType == 1) {
...
}
}
Related
I am trying to fetch data from www.matchbook.com using this script
function scrape(){
var row = document.querySelectorAll(".mb-runner")[0]; //get rows
console.log(row.textContent); //log row content
}setInterval(scrape, 1000);
This code produces inline data ArsenalArsenal1.347$2591.349$20,8171.352$4811.363$11,2331.368$11,4571.379$9,948 without delimiter. Do you know how should I separate this data?
Here I am posting screen how data looks on a web
When the contents of that cell changes to MAKE OFFER, it no longer has the mb-price__odds class, so the selector matches the next cell.
Instead of selecting by this cell's class, use the class of the container, which I don't think goes away.
Then check whether this matched anything before trying to access .textContents.
function scrape() {
var cell = document.querySelector(".mb-price:first-of-type .mb-price__odds");
if (!cell) {
console.log("Log me null please, do not skip to another cell !");
} else {
console.log(cell.textContents);
}
}
Finally I solved my problem via this javascript code:
function scrape(){
var radek = document.querySelectorAll(".mb-runner")[2];//row
var bunka = radek.querySelectorAll(".mb-price")[0]; //cell
console.log(bunka.textContent); //cell value
}setInterval(scrape, 1000); //run every second
Try this.
No need to querySelectorAll if you only need the first element
Find the parent first and look for the price only if the element exists
Put null check on the element && the text content
function scrape(){
var x = document.querySelector(".mb-price");
var y = x && x.querySelector('.mb-price__odds');
if (y && y.textContent){
console.log(y.textContent);
}
else {
console.log('No Content');
}
}
selectedContentWrap: HTML nodes.
htmlVarTag: is an string.
How do I check if the HTML element exists in the nodes?
The htmlVarTag is a string and don't understand how to convert it so it check again if there is a tag like that so that if there is I can remove it?
here is output of my nodes that is stored in selectedContentWrap
var checkingElement = $scope.checkIfHTMLinside(selectedContentWrap,htmlVarTag );
$scope.checkIfHTMLinside = function(selectedContentWrap,htmlVarTag){
var node = htmlVarTag.parentNode;
while (node != null) {
if (node == selectedContentWrap) {
return true;
}
node = node.parentNode;
}
return false;
}
Well if you could paste the content of selectedContentWrap I would be able to test this code, but I think this would work
// Code goes here
var checkIfHTMLinside = function(selectedContentWrap,htmlVarTag){
for (item of selectedContentWrap) {
if (item.nodeName.toLowerCase() == htmlVarTag.toLowerCase()){
return true;
}
}
return false;
}
Simplest is use angular.element which is a subset of jQuery compatible methods
$scope.checkIfHTMLinside = function(selectedContentWrap,htmlVarTag){
// use filter() on array and return filtered array length as boolean
return selectedContentWrap.filter(function(str){
// return length of tag collection found as boolean
return angular.element('<div>').append(str).find(htmlVarTag).length
}).length;
});
Still not 100% clear if objective is only to look for a specific tag or any tags (ie differentiate from text only)
Or as casually mentioned to actually remove the tag
If you want to remove the tag it's not clear if you simply want to unwrap it or remove it's content also ... both easily achieved using angular.element
Try using: node.innerHTML and checking against that
is it me or post a question on stackoverflow and 20min after test testing I figure it.,...
the answer is that in the selectedContentWrap I already got list of nodes, all I need to do i compare , so a simple if for loop will fit.
To compare the names I just need to use .nodeName as that works cross browser ( correct me if I am wrong)
Some dev say that "dictionary of tag names and anonymous closures instead" - but couldn't find anything. If anyone has this library could you please post it to the question?
here is my code.
var node = selectedContentWrap;
console.log('node that is selectedwrapper', selectedContentWrap)
for (var i = 0; i < selectedContentWrap.length; i++) {
console.log('tag name is ',selectedContentWrap[i].nodeName);
var temptagname = selectedContentWrap[i].nodeName; // for debugging
if(selectedContentWrap[i].nodeName == 'B' ){
console.log('contains element B');
}
}
I want to use the same .js for a bunch of html pages, but not necessarily all the ID's from this .js in every single page. Right now, if I don't use one ID; no ID's are showing at all.
var yes = 'Yes';
var no = 'No';
var available = 'Available: ';
document.getElementById("001").innerHTML=available+yes;
document.getElementById("002").innerHTML=available+no;
document.getElementById("003").innerHTML=available+yes;
A html with this works fine:
<div id="001"></div>
<div id="002"></div>
<div id="003"></div>
A html with this, not so fine:
<div id="002"></div>
<div id="003"></div>
What to do to make it run even though some ID's arn't being used?
Complete noob to this, there's probably a super simple solution to it(?) - but I can't find it. Hopefully, someone here can help me - without totally bashing me, or telling me how much of a bad praxis this is and that I should rewrite it in some mega haxxor language that I havn't even heard of :D
Thanks in advance!
While I'd question why you'd need incrementing numeric IDs like that, one solution would simply be to keep an map of IDs to values, then iterate the map checking for null.
var m = {
"001":yes,
"002":no,
"003":yes
};
for (var p in m) {
var el = document.getElementById(p);
if (el) // or if (el !== null)
el.innerHTML = available + m[p];
}
The document.getElementById() function returns null if no matching element is found. null.innerHTML is an error that stops the current script executing. So you just have to test for null:
var el = document.getElementById("001");
if (el != null) el.innerHTML = available + yes;
The null test can be simplified to:
if (el) el.innerHTML = available + yes;
If element "001" is always going to be "yes", "002" is always going to be "no" and so forth then you can do this:
var results = {"001" : yes, "002" : no, "003" : yes};
var el, k;
for (k in results) {
el = document.getElementById(k);
if (el) el.innerHTML = available + results[k];
}
wrap it with if(document.getElementById("id")!==null) ?
Just wrap the whole thing in a try statement to avoid any issues and put code afterwards into a finally statement::
try{
document.getElementById("001").innerHTML=available+yes;
document.getElementById("002").innerHTML=available+no;
document.getElementById("003").innerHTML=available+yes;
//etc
}
finally{
//any other code that there is after the id stuff
}
that'll prevent errors, so if something fails, it will still continue
I've got two problems with the following javascript and jquery code.
The jquery each loop only iterates once, it gets the first element with the right ID does what it needs to do and stops.
The second problems is that when I use the else in the code the one inside the each function, it doesn't even tries the next if, it just exits there.
I'm probably doing something fundamental wrong, but from the jquery each function and what I'd expect from an else, I don't see it.
Javascript code:
var $checkVal;
var $checkFailed;
$("#compliance").live("keypress", function (e) {
if (e.which == 10 || e.which == 13) {
var checkID = $(this).parents('td').next().attr('id');
var checkVal = $(this).val();
$('#' + checkID).each(function () {
var cellVal = $(this).text();
if (checkVal == cellVal) {
$(this).removeClass("compFail").addClass("compOk");
} else {
$(this).removeClass("compOk").addClass("compFail");
var checkFailed = True;
}
});
if (checkFailed == 'True') {
(this).addClass("compFail");
} else {
(this).addClass("compOk");
}
}
});
How could I get the each loop to iterate through all instances of each element with the id assigned to the variable checkID, and get the code to continue after the else, so it can do the last if?
An id should appear on a page only once. If you want to have multiple elements with same id, then use a class, not an id.
Your each loop iter only once because you are selecting by id thus you are selecting only one element in the page. If you change you elements to a class it should work like you expect.
This is to illustrate what I'm talking about in my comment, so that you do not remove the wrong var:
var checkVal;
var checkFailed;
$("#compliance").live("keypress", function (e) {
if (e.which == 10 || e.which == 13) {
var checkID = $(this).parents('td').next().attr('id');
//HERE is the first edit
checkVal = $(this).val();
$('#' + checkID).each(function () {
var cellVal = $(this).text();
if (checkVal == cellVal) {
$(this).removeClass("compFail").addClass("compOk");
} else {
$(this).removeClass("compOk").addClass("compFail");
//HERE is the second
checkFailed = True;
}
});
if (checkFailed == 'True') {
(this).addClass("compFail");
} else {
(this).addClass("compOk");
}
}
});
Normally, the way you have it would cause a compile-time error (in a typed language like C#) for redeclaring a variable. Here, it's not clear to me if it will be used as a local variable (ignoring your global variable) or if javascript will combine them and consider them the same. Either way, you should use it as I have shown so that your intent is more clear.
EDIT: I have removed the $ from your variables (var $checkVal) as on jsFiddle it was causing issues. SO if you do not need those $'s, then remove them. Also, note that testing on jsFiddle indicates that you do not need to change your code (other than possibly removing the $ from your declaration) as javascript appears to consider them the same variable, despite the redeclaration, which I find a bit suprising tbh.
The jquery each loop only iterates once, it gets the first element
with the right ID does what it needs to do and stops.
Yes, this is absolutely right for the code you're using:
$('#' + checkID).each(function(){};)
ID attributes are unique. There must be only one element with a given ID in the DOM. Your selector can match only one element. You are iterating over a collection containing just 1 item.
The check box's exist for each row. the table is created by PHP and I need a way to check if the check box exists. when they are created they are given the ID of checkbox_(an incrementing number).
This is what I have so far, but it does not work on checking if the element exists.
var check = true;
var todelete = "";
var counter = 0;
//check if box exisits and record id and post
while(check)
{
if ($("#Checkbox_"+counter).length > 0)
{
todelete = todelete + $("#Checkbox_"+counter).value;
counter = counter + 1;
}
else
{
check = false;
}
}
I have also tried
if ($("Checkbox_"+counter))
if (document.getElementById("tbody").value == null)
Update:
Even with the # symbol or if i do it by javascripts element ID - when I debug the DOM, it hits the while, then the if, adds the value to todelete, adds 1 to the counter, then it goes back to the while, then hits the if
Then bounces back up to the while without even going into the if or the else???
this I do not understand, then it just bounces up and down between the two lines and crash's the browser?
Update2:
I needed to .tostring() the counter when adding it to the string for an element id. problem solved
You can use
if ($("#Checkbox_"+counter).length > 0)
I'm assuming that 'Checkbox_0' is an ID, so I've added the # symbol. If it's the name of the checkbox, you can use
if ($("input[name='Checkbox_"+counter+"']").length > 0);
[edit]Also, you should check to make sure you do / don't need the capital 'C'.
You can use for "checkbox exists in this case"
if ($("#Checkbox_"+counter).length > 0) {
//checkbox exists
}
if (($("#Checkbox_"+counter).length) > 0) {
...
//Or something more generalized
jQuery.fn.exists = function(){
return jQuery(this).length>0;
}
//then, if you have valid selector
if ($("#Checkbox_"+counter).exists()){
//do something here if our selected element exists
}
// if document.getElementById(name) do not exist
// document.getElementById(name).value generate already an error
if (document.getElementById(name) != null) {
// you code if checkbox exist
}