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Get request not logging anything

This is my code:
$.get("http://www.roblox.com/catalog/", function(onWebsite) {
console.log($(onWebsite).find('.name.notranslate')[0].attr("href"));
});
Whenever I run it, it does not log anything to the console, all it says is: "Object {readyState: 1}". However, if I remove the .attr("href"), it works. Is there something wrong with my syntax?

Since .attr() is a jQuery function you need to use it with jQuery object.
Use
$(onWebsite).find('.name.notranslate').attr("href")
As per your current code $(onWebsite).find('.name.notranslate')[0] will return you underlying DOM element which doesn't have .attr() method.
You can use href property or Element.getAttribute() method
$(onWebsite).find('.name.notranslate')[0].href
OR
$(onWebsite).find('.name.notranslate')[0].getAttribute('href')

Maybe try:
$.get("http://www.roblox.com/catalog/", function(onWebsite) {
console.log(onWebsite.find('.name.notranslate')[0].attr("href"));
});
onWebsite must not be wrapped with the jQuery selector as its a return from a function.

Lets try this approach:
var a;
$.get("http://www.roblox.com/catalog/", function(onWebsite) {
a = $(onWebsite).find('.name.notranslate')[0];
console.log(a);
});
You will get
<a class="name notranslate" href="/Headless-Horseman-item?id=134082613" title="Headless Horseman">Headless Horseman</a>
So var a is the HTML Tag with href attribute. HTML tags doesn't have jQuery methods - only jQuery objects selected from DOM or "wrapped/selected HTML"
Here you can:
reference .href to get href
wrap a in jQuery to get: $(a).attr('href')
So end code would be (variant 1 is better):
var a;
$.get("http://www.roblox.com/catalog/", function(onWebsite) {
a = $(onWebsite).find('.name.notranslate')[0].href
console.log(a);
});
or without creation of temp variable
$.get("http://www.roblox.com/catalog/", function(onWebsite) {
console.log($(onWebsite).find('.name.notranslate')[0].href);
});

Passing a function with parameter to event handler

Let's say I have the following code:
$('#from').focus(listExpand(1));
$('#to').focus(listExpand(3));
It's not working as I expected. I think that it works wrong due to the fact that I'm passing a function result but not the function itself.
So the right syntax would be:
$('#from').focus(listExpand); // no brackets and no parameters
But in this case I can not pass any parameters to a function :(
How can I implement the subject?

Wrap the call to listExpand in a separate function definition:
$('#from').focus(function(){ listExpand(1); });
$('#to').focus(function(){ listExpand(3); })

below will work. use this.
$('#from').focus(function() {listExpand(1) });
$('#to').focus(function(){listExpand(3);})
I found other cool way also that #sudher mentioned. You can check it working in http://jsfiddle.net/kvHDA/
Sample Code
$('#from').focus({x: 1},myfunc);
function myfunc( e){
alert(e.data.x);
}

If a data argument is provided to .on() and is not null or undefined,
it is passed to the handler in the event.data property each time
an event is triggered.
$('#from').on("focus" , {id:1} , listExpand);
$('#to').on("focus" , {id:3} , listExpand);
function listExpand(event){
console.log(event.data.id);
}

Getting 'this' object in javascript without using the word 'this'

What I am trying to do is getting the same result as clicking on this following submit button.
<input id="submit_http:" class="add_submit" type="button" onclick="return dex.forms.form_ajax_submit(this,function(res) { alert('posting failed'); },function(res) { alert('posting success'); });" value="Next" name="submit_http:">
I was trying to do it like that:
$('.NextButton').click(function () {
dex.forms.form_ajax_submit(document.getElementsByName('submit_http:'),
function(res) {
alert('posting failed');
},
function(res) {
alert('posting success');
});
});
But looks like document.getElementsByName is not returning the same result
as the submit button 'this'
How can I solve this issue?

The only actual mistake you made was using the function document.getElementsByName, because it returns an array of elements (as indicated by the plural). What you need is a single element.
Either access the first element of the array by using:
document.getElementsByName('submit_http:')[0]
or use the already recommended and more precise function:
document.getElementById('submit_http:')

document.getElementsByName('submit_http:') will return an array of elements that have that name. If you want to get your submit button, you want to use document.getElementsByName('submit_http:')[0].

While Anthony Grist is correct, in your case, since you already have an id for your input, you could do document.getElementById('submit_http:') (which returns a single element).

generally, we use a "self" variable for this. Before the submit, do that :
var self = this;
then use "self" into your callback

How to add functions to some jQuery objects, but not others?

Let's say I have a <ul> list:
<ul class="products">
...
</ul>
I want to select it with jQuery, then add some functions to that object. For example, I'd like to add an addProduct(productData) function and a deleteProduct(productId) function. However, I'd like the functions to only be added to the object that's returned by the selector. So for example, something like this:
var productList = $.extend($('ul.products'), {
addProduct: function(productData) {
// add a new li item
},
deleteProduct: function(productId) {
// delete li with id
}
});
How would I do this using jQuery? The key point here is that I only want to add the functions to an instance returned by a jQuery selector. In other words, I don't want to modify jQuery's prototype or create a plugin, since those will make the functions available across everything, whereas I only want to add the functions to one specific instance.

If you only want the addProduct and deleteProduct methods to feature on that single jQuery object, then what you've got will work fine; but you'll have to keep a reference to that jQuery object/ only use it once, to preserve the existance of the addProduct and deleteProduct methods.
However, these addProduct and deleteProduct methods are unique to that particular jQuery object; the methods won't exist on any other jQuery objects you create;
var productList = $.extend($('ul.products'), {
addProduct: function(productData) {
// add a new li item
},
deleteProduct: function(productId) {
// delete li with id
}
});
// Using this particular jQuery object (productList) will work fine.
productList.addProduct();
productList.removeProduct();
// However, addProduct() does not exist on new jQuery objects, even if they use
// the same selector.
$('ul.products').addProduct(); // error; [object Object] has no method 'addProduct'
The best way do to this would be to go-back-to-basics and define separate addProduct and deleteProduct functions, which accept a jQuery object. If you wanted to restrict these functions to they only worked on the ul.products selector, you could do;
function addProduct(obj) {
obj = obj.filter('ul.products');
// do something with `obj` (its a jQuery object)
}
This approach would be recommended as it keeps the jQuery.fn API consistent; otherwise you'd be adding addProduct and removeProduct to some jQuery.fn instances but not others, or making their usage redundant in others. With this approach however addProduct and removeProduct are always there, but don't get in anyones way if they don't want to use them.
Historical Notes
This answer was originally written in November 2011, when jQuery 1.7 was released. Since then the API has changed considerably. The answer above is relevant to the current 2.0.0 version of jQuery.
Prior to 1.9, a little used method called jQuery.sub used to exist, which is related to what you're trying to do (but won't help you unless you change your approach). This creates a new jQuery constructor, so you could do;
var newjQuery = jQuery.sub();
newjQuery.fn.addProduct = function () {
// blah blah
};
newjQuery.fn.deleteProduct = function () {
// blah blah
};
var foo = newjQuery('ul.products');
foo.deleteProduct();
foo.addProduct();
var bar = jQuery('ul.products');
bar.deleteProduct(); // error
bar.addProduct(); // error
Be careful though, the $ method alias would reference the old jQuery object, rather than the newjQuery instance.
jQuery.sub was removed from jQuery in 1.9. It is now available as a plugin.

You can make your own jQuery methods as follows:
$.fn.addProduct = function(){
var myObject = $(this);
// do something
}
// Call it like:
$("ul.products").addProduct();
This is a bit tricky though because you are making methods that are very specific to lists. So, to be sure you should at least add some checking on the object's type and handle the code correctly if the current object is, let's say an input element.
An alternative is to make a normal Javascript method that receives the list as a parameter. That way you can make a more list specific method.

I think you want to add a function to that DOM Object.
$(function(){
// [0] gets the first object in array, which is your selected element, you can also use .get(0) in jQuery
$("#test")[0].addProduct = function(info){
alert("ID: " + this.id + " - Param: " + info);
};
$("#test")[0].addProduct("productid");
});
Above script wil alert "ID: test - Param: productid"
A live example: http://jsfiddle.net/jJ65A/1/
Or normal javascript
$(function(){
document.getElementById("test").addProduct = function(info){
alert(info);
};
});

I think may be just using delegate in jQuery:
$(".parentclass").delegate("childclass","eventname",function(){});

Unable to re-define a function in my javascript object

I have an object defined using literal notation as follows (example code used). This is in an external script file.
if (RF == null) var RF = {};
RF.Example= {
onDoSomething: function () { alert('Original Definition');} ,
method1 : function(){ RF.Example.onDoSomething(); }
}
In my .aspx page I have the following ..
$(document).ready(function () {
RF.Example.onDoSomething = function(){ alert('New Definition'); };
RF.Example.method1();
});
When the page loads the document.ready is called but the alert('Original Definition'); is only ever shown. Can someone point me in the right direction. I basically want to redefine the onDoSomething function. Thanks, Ben.
Edit
Thanks for the comments, I can see that is working. Would it matter that method1 is actually calling another method that takes the onDoSomething() function as a callback parameter? e.g.
method1 : function(){
RF.Example2.callbackFunction(function() {RF.Example.onDoSomething();});
}

Your code as quoted should work (and does: http://jsbin.com/uguva4), so something other than what's in your question is causing this behavior. For instance, if you're using any kind of JavaScript compiler (like Closure) or minifier or something, the names may be being changed, which case you're adding a new onDoSomething when the old one has been renamed. Alternately, perhaps the alert is being triggered by something else, not what you think is triggering it. Or something else may have grabbed a reference to the old onDoSomething (elsewhere in the external script, perhaps) and be using it directly, like this: http://jsbin.com/uguva4/2.

Thanks for the response .. in the end the answer was unrelated to the code posted. Cheers for verifying I wasn't going bonkers.