Shorten Form Element References?
Dec 5, 2010is there a way to shorten something like:document.scoresheet["HomeTotalHCaps"].valueto a simple short name like var1.value ?
View 8 Repliesis there a way to shorten something like:document.scoresheet["HomeTotalHCaps"].valueto a simple short name like var1.value ?
View 8 RepliesI've spent several days trying to work this out. Maybe I'm just
searching for the wrong keywords/phrases.
I have some code that looks like:
[-- snippet starts --]
Console = new Object();
Console.init = function() {
this.STDIN = document.getElementById('console0_stdin');
this.STDOUT = document.getElementById('console0_stdout');
// set styles on the element references, eg:
this.STDIN.style.width = ļ`%'
this.STDOUT.style.width = ļ`%'
}
Console.focus = function() {
this.STDIN.focus();
}
Console.writeln = function(buffer) {
this.STDOUT.value += "
" + buffer;
}
[-- snippet ends --]
I'm not sure why, but the Console.focus() and Console.writeln() methods
just don't seem to be able to use the DOM references stored in
Console.STDIN and Console.STDOUT. Everything's fine in the
constructor, but other methods can't seem to use them.
I have in javascript a text say I am an idiot
I want to do it. "I am...." and on mouseover it shows up I am an idiot.
How can I do it?
Is it possible to make a loop out of this:
Code:
function tArea0(){
document.getElementById('txtarea_0').value = "";[code].....
I tried using the "For Loop" function to accomplish this but I couldn't get it to work. show me an easier way to shorten this code up
Code:
function normal()
{
var welcomelink = document.getElementById("welcomelink");[code].....
I did try to recode everything so that the link/content and sublink/content would follow a numerical sequence...e.g. link1/content1, link2/content2, link3/content3, sublink1/subcontent1, sublink2/subcontent2, sublink3/subcontent3...etc. and then use the for...loop function but again it failed on me.
I'm still learning this scripting thing. Is there any way to shorten this lengthy code. I know there is, just not sure what i'm looking for?
PA1_10ST
PA11_20ST
PA21_30ST[code].....
How can I shorten the output of the title in this JS code?
<script language="" type="text/javascript">
<!--
for (x = 0; x < 3; x++)[code].....
I need to shorten the "+threads[x].title+" sometimes the titles created by users are too long and is messed up the page display
I have a page with a lot of data validation on it (for a form). But the validation is not actually executed until the user hits Submit. The page loads really slow. Is there a way to control how a page loads so that, as I suspect, the validation Javascript loads after the form actually displays? I want the user to see the page/form displayed as quickly as possible while I recognize that the the page load may not be complete because its still loading the validation routines. What I can do to speed it up?
View 3 Replies View RelatedIs it true that Javascript has no clone() method, to pass an object by copy of value instead of reference?
If I have an object and want to make an array out of all of its instance variables, I can loop through it and pass its values to a new array, and the class instances will be passed by copy and not by reference?
Example 9.3: References Themselves Are Passed by Value
// This is another version of the add_to_totals() function. It doesn't
// work, through, because instead of changing the array itself, it
tries to
// change the reference to the array.
function add_to_totals2(totals, x)
{
newtotals = new Array(3);
newtotals[0] = totals[0] + x;
newtotals[1] = totals[1] + x;
newtotals[2] = totals[2] + x;
totals = newtotals; // this line has no effect outside of the
function.
}
Note that this rule applies not only to pass-by-reference, but also copy-by-reference. You can modify an object through a copy of a reference, but changing the copied reference itself does not affect the object nor the original reference to the object. This is a more intuitive and less confusing case, so we don't illustrate it with an example.
I'm currently engaged on a dissertation which is
investigating AJAX technologies and I was
wondering if anyone had any references that might
shed light on the subject?
I will of course carry out a literature review but
in the mean-time has anyone any (preferably print
based) sources of data on AJAX?
I am a bit new to JavaScript objects, I have the following object:
LinkTest=function() {
// init
}
LinkTest.prototype.eventHandler=function(){
// the call below fails, as 'this' refers to the link that
// generated the event, and not the instance of LinkTest object
this.doSomething();
}
LinkTest.prototype.register=function(link){
link.onclick = this.eventHandler;
}
LinkTest.prototype.doSomething=function() {
// do something!
}
So basically when you register a link, the onclick event handler gets a reference to LinkTest's eventHandler function. Now when the user clicks on the link, the 'this' refers to the link... how do I reference the instance of LinkTest object from within the eventHandler function?
I discover a strange bug in Konqueror 3.1.1.
I design a javascript application which acts in one file called
example.html. At the beggining of this js i write:
if (document.images)
{
folderopen= new Image(16,16);
folderopen.src="http://www.sergioamo.8m.com/buttons/folder_open.png";
folderclose= new Image(16,16);
folderclose.src="http://www.sergioamo.8m.com/buttons/folder_close.png";
}
functions....
....
...
..
and my javascript works perfect.
If i write:
if (document.images)
{
folderopen= new Image(16,16);
folderopen.src="./buttons/folder_open.png";
folderclose= new Image(16,16);
folderclose.src="./buttons/folder_close.png";
}
functions...
....
...
..
my javascript does not work properly. Does anyone knows if is imposible
to use relative references with konqueror 3.1.1 or which is the problem?
Apparently, there is a page with multiple frames, where one of the
frames is a "hidden" frame, and is there just to contain one or more
"fields" that are referenced from other frames.
Supposedly, if a user "sits" somewhere in this set of pages for
several minutes and then tries to do something, the page redisplays,
but an inter-frame reference (to the "hidden" frame) fails with some
sort of a "No permission" error. If the user navigates through the
site with no real delay, they don't see this problem. This is the
situation I need to understand.
I'm assuming that the "No permission" error occurs when a frame that
was obtained from domain "foo" tries to reference a frame that was
obtained from domain "bar" (I'm not sure of the correct terms in the
context of JavaScript). Under normal operation, all of the frame
contents are obtained from the same domain (I believe).
My theory is (without much information yet) that there must be a
proxy/cache server in between. When the user navigates through the
site with no delays, all of the frames are obtained from the same
server (either the cache server or the target server, I don't know
which). However, when the user "sits" for a while, I'm guessing that
the cache server hits a content timeout, and a redisplay of the page
causes one frame to be obtained from the target server, and one from
the cache server.
Does this seem like a reasonable explanation for what we might be
seeing? What are useful strategies for fixing a problem like this?
I am trying to make a function that checks/unchecks a checkbox when a specific <td> is clicked. I need to use this same function for several checkboxes in the page so I want to just pass it the name of the checkbox I want to affect as a variable and use it in the object reference lines. BUT, this doesn't work. I can pass the variable to the function as I've used alert(variable) to test this. But it doesn't work when I put it in a line like this "document.forms[0].variable.checked=true;". Code:
View 4 Replies View RelatedTHE QUESTION: How do I get a reference to my Object when processing an
event handler bound to an html element ?
CONTEXT:
Sorry if it is a bit long.
I am developing a JS calendar tool. One of the requirements is that the
calendar will need to display a varying number of months (1..3)
depending on the calling page. Imagine 1, 2 or 3 calendar pages side by
side as required.
I have built a grid object that will contain one month's dates with the
day names at the top. The calendar object inherits the grid object as an
array of "calendar pages" - one grid per month and the calendar provides
the content for each grid. I will use the grid object for another
completely different object later and so I want to use good OOP
encapsulation. The grid is a table generated on the fly and is "dumb" as
far as what it is used for.
I have attached an onlick event to each cell of the grid. Using OOP
priciples I want the calling program (the calendar object in this case)
to provide a function to handle the click and the grid object will
provide to the calendar the row and column of that cell as well as the
grid number (so the calendar can work out which date was clicked since
it knows what the data means and the grid doesnt). Code:
I'm working on a project that I want the user to be able to change the color theme of the site. For some reason if I go over about 20 themes or css references it breaks the site. Any idea why this is? if so, how can I get it to accept say 50 themes?
View 2 Replies View RelatedI have some confusion about the scripts below:
1) is getRule a local variable or global variable, as it has no var keyword, yet it is an inner function of Validation? So without var, I think global, but being an inner function, I think local. So I'm not sure which.
2) In this line of code: var rule = $.Validation.getRule(types[type]), getRule returns rules, which is just a local variable in Validation. I always see that you return functions, but how does returning a local variable that's just an object literal and not a function be able to return true or false? Now the value of rules is an object literal, and this object returns true or false. So we are basically allowed to use return keyword with local variables that are object literals and not functions?
3) In this line, is foo(age) being called, or is it just being assigned to bar OR is it being called and THEN assigned to bar: var bar = foo(age);
4) Now for the most confusing: age is obviously an object reference as opposed to a literal in the example. Does that make a difference in regards to closures?
Note that I read a number of books, including JavaScript Programmer Reference and Object Oriented JavaScript and jQuery cookbook, which compare primitives vs reference types and how primitive types store directly in memory whereas reference tpyes reference memory, so if one reference changes, they all change where primitive remains ingrained. But when assigning a function as a reference like this, how does that affect the object "age" when passed into bar?
Code:
(function($) {
/*Validation Singleton*/
var Validation = function() {
var rules = {
email : {
check: function(value) {
if(value)
return testPattern(value,".+@.+..+");
return true;
}, .....
$.Validation = new Validation();
})(jQuery);
Code:
function foo(x) {
var tmp = 3;
return function (y) {
alert(x + y + tmp);
x.memb = x.memb ? x.memb + 1 : 1;
alert(x.memb);
}}
var age = new Number(2);
var bar = foo(age); // bar is now a closure referencing age.
bar(10);
My site's working perfectly in the other browsers, and when I delete line 28 (see below) it works in IE but not exactly how I want. Is there a way to retain two jquery references on a single page in IE?
This is the head section of my code:
Is it possible to test whether two objects are equal using the data they contain inside and not comparing their pointers with ==?
Well actually of course there is but...
Is there a way to do it without actually looping through the object, instead maybe something that came with JS? (something like a .equals() method from other programming languages.)
I'm having some problems understanding the append() function. What I'd like to do is select an element using it's ID and add a row to the table with a HTML form element. The table is dynamically generated using a Django template ( form.as_table() ) so I'm not able to alter the original HTML markup too much.
If I had a table like this...
I have created a form with malsup's Form Plugin wherein it submits on change of the inputs. I have set up my jQuery script to index drop down menus and visible inputs, and uses that index to determine whether keydown of tab should move focus to the next element or the first element, and likewise with shift+tab keydown. However, instead of moving focus to the first element from the last element on tab keydown like I would like it to, it moves focus to the second element. How can I change it to cycle focus to the actual first and last elements? Here is a live link to my form: [URL]. Here is my script:
$(document).ready(function() {
var options = {
target: '#c_main',
success: setFocus
[Code]....
I am confused about the true difference between the two below examples.
first example:
// Demonstrating a problem with closures and loops
var myArray = [āAppleā, āCarā, āTreeā, āCastleā];
var closureArray = new Array();
[code]....
Here we iterate through the length of myArray, assigning the current index of myArray to theItem variable. We declare closureArray 4 times as an anonymous function. The anonymous function in turn declares the predefined write() function, which is passed parameters. Since write() is in closureArray() a closure is created??? During each iteration, theItem is reassigned its value. The four closures reference this value. Since they reference this same value and since this value is reassigned ultimately to the value of the fourth index position, tHe time we execute closureArray later on, all four closures output the same string. This is because all four closures are within the same scope "the same environment" and therefore are referencing the same local variable, which has changed.
I have a couple of problems with this example:
1) I thought a closure is a function that is returned - the inner function is not returned above.
2) theItem is not even a local variable of the parent function (closureArray) - I thought in order for a closure to work, the inner function only accesses the local variables of the outer function, but in this case the local variable is defined OUTSIDE of the parent function.
3) the "the four closures are sharing the same environment." The thing is even in the second example, they are sharing the same environment.
Second example:
// A correct use of closures within loops
var myArray = [āAppleā, āCarā, āTreeā, āCastleā];
var closureArray = new Array();
[code]....
Here we iterate over the length of myArray (4 times), assigning the index of myArray to theItem variable. We also return a function reference to the closureArray during each iteration (closureArray[i]), where i is index number so we assign 4 functon references. So when we iterate through myArray, we immediatelly call the writeItem() fucntion passing an argument of theItem at its current value. This returns a child anonymous function and when that child function is called, it will execute a block that calls the predefined write() method. We assign that returned anonymous function to the variable closureArray. Hence, closureArray holds a reference to that anonymous function. So closureArray during each iteration holds a reference to the anonymous function and we later call closureArray, which in turn calls the anonymous function, therefore calling the predefined write() function to output the local variable of the parent function. This outputs each distinct index of myArray.
This is because since we created the closure, when we call writeItem, passing theItem argument, since theItem is a local variable of the parent function of the closure, it is never destroyed when we later call closureArray (the reference to the child anonymous function)? Yet weren't we using a closure in the first example as well? So whey wasn't those variables preserved?
I don't think it has anything to do with assigning a returned anonymous function to closureArray. Even though an anonymous function creates a new memory position in the javascript engine, therefore not overwriting the other function references we create during the iteration, it's still referring to a local variable declared outside the reference. So if it's about the closure retaining value of parent's local variable even after exiting the parent function allowing for the current indexes to be preserved, then why did the closure in the first example fail to retain each index?
I have a javascript here for adding my div element to my registration form,Adding the div element is easy, but it shows on the bottom of my form. I cant make it as the first child element of my form...This is my code
var _form = document.getElementById('registration_form');
var errorDiv = document.createElement('div');
errorDiv.setAttribute('class', 'confBox');
[code]....
I tried jQuery('#calculateform').children('input, select, textarea').each(function(key){ alert(key + ': ' + jQuery(this).val()); but it goes only 2time throw (for each button it has)and it SOULD list all elemts (including hidden fields). I need each element with name and value.
View 3 Replies View RelatedHow does one cause a form element to appear ONLY if a certain form selection is made before it?
That is for example say there is a form element of type Radio called "format" so only if they select format value = normal then the form input fields called URL and Name are to appear as the next choices otherwise form input field Group and checklist Places are to appear as the next choices.
I'm working on a script that will produce multiple dynamic forms based on the results of an ajax request. The ajax request does a db query that will return 0 to x number of rows. For each row, a new serialized form is created. Since the forms do not exist at page load, I'm having problems getting the value of the form elements so that I can run other functions on them (update inputs and selects). I've stripped down everything so that I can show a basic example. In the example, how would I get the value of "#orderID"? The body contains a div (previousList) that has a list of items that when clicked will trigger the ajax query. It also has a div (line details) that will hold all of the forms that are generated.
<div id="lineDetails">
check it out </div>
<div id="previousFrm" class="ui-widget-header ui-state-highlight ui-corner-all">
<h3>Previous Returns/Cancels</h3>
<div id="previousList">
<ul class="previous" id="returnList">
<li id="1000997" class="names">1000997: 101853</li>
<li id="1000995" class="names">1000995: 101853</li> .....
But callingconsole.log("order line value is " + $("#orderID").val());
results in 'undefined'.