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Change multiple div contents on another div mouse hover without css/with an xml source file

I'm working on this site, and I need to change the contents of image_preview, title_preview, description_preview, link_preview according to what I'm hovering over (ex: mouse hover "button_a" = image1.png, iliketitle, ulikedesc, welikelink).
I've tried using css solutions like this and this, but I wasn't able to make them work like I needed.
Since the page will have many button_#'s (50-100 buttons), I think css isn't a proper choice.
So what I'm looking for is a way to do this without css, better if with an xml source file, so it'd be easier to manage the content to display for each button. I only found this talking about the xml I'd need, but I'm not sure that's exactly what I need.

Your buttons have a class (e.g. .btn) and the associated data to each button is store somewhere, let's say each button has a data-* attribute which points to the right data.
$('.btn').hover(function() {
var data = $(this).data('something');
if(data == "b1") {
//assign the values related to b1
}
else if(data == "b2") {
//assign the values related to b2
}
//and so on
}
If you have a lot of buttons like that, then the data can be a reference to an array containing the proper info.
Here's a jsfiddle DEMO.
And here's updated DEMO.
EDIT:
.hover() can take two handler which the second will handle when mouse is out of the element.
yourElement.hover(
function() {
//mouse is on the element, do stuff
},
function() {
//mouse is out, do other stuff
}
);
You can have a function to set the default values and call that in hover's second function.
jsfiddle DEMO

Change all data-theme attributes in JQM on a button click

I'd like to programmatically change ALL data-theme attributes in the whole document to "a" after I click on a button. I have divs with the data role = page, header, content, footer, dialog, selectmenu, listview. I guess these are all the selectors. Are there any possibilities to achieve that? I have a single-page-app.
What I've tried so far:
$(document).delegate('[data-role="page"]', 'pagechange', function (e) {
$.mobile.page.prototype.options.theme = "a";
});
$(document).delegate('[data-role="page"]', 'pagechange', function (e) {
$(this).removeClass('ui-body-a ui-body-b ui-body-c ui-body-d ui-body-e').addClass('ui-body-a').attr('data-theme', 'a');
});
then just
$.mobile.page.prototype.options.theme = "a";
but none of these worked for me.

You can achieve what you want by directly selecting the elements you want to change:
$("[data-theme='<old_theme_swatch>']").attr('data-theme', '<new_theme_swatch>');
Also, you might want to trigger an update event on the modified widgets to get them effectively show with the new theme style. This way, jQuery Mobile will re-enhance all the interested elements changing their associated theme ui-* class (please note that ui-body-* isn't the only class that need to be changed, eg: ui-bar-*).

Displaying and highlighting a particular line in HTML

I am trying to implement a webpage which should have expected to have the following properties.
The HTML page contains many lines of text (thousands of lines), basically a log file.
Upon a desired action, line which is related to the action should be highlighted and shown . (exactly the way that would happen if you click on corresponding source button of a logged variable in chrome inspect element.)
This seems to be very basic but I couldn't figure out how! May be I am missing some literary terms.
Thank you.

You need to do a few things:
$("li").each(function(i, element) {
var li = $(element);
if (li.text() == "Orange") {
li.addClass("selected");
// Get position of selected element relative to top of document
var position = li.offset().top;
// Get the height of the window
var windowHeight = $(window).height();
// Scroll to and center the selected element in the viewport
$("body").scrollTop(position - (windowHeight/2));
}
});
See DEMO.

There are many ways to go about this. But is there any class tags in the logged source or is just one large text block?
If there are class or id tags on the html you can use javascript or jquery to do this.
document.getElementById('myText');
or in jquery
var element = $("#myText");
//example css changes
element.css("position","center");
element.css("color","red");
Then change the css style on those html elements.

Tracking changes in web application

I have an application in which the user needs to see the changes that have been made during the latest edit.
By changes I mean, the changes made in all inputs like a textarea, dropdowns.
I am trying to implement this by showing a background image on the right top and then when the user clicks this background image, a popup is shown which shows the difference.
I am using prototype 1.7.0.
My First question would be:-
1. What would be the best approach to implement this functionality?
2. Can I put a onClick on the background image?

There some functions in the jQuery library that I believe would be helpful to you. If you are using prototype, I would guess that there is some similar functionality you may utilize.
I would suggest writing some code like this:
var $input = $('input').add('textarea').add('select');
$input.each(function() {
var id = $(this).attr('id');
var value = $(this).val();
var hiddenId = 'hidden' + id;
var newHiddenInput = $("<input type='hidden'").val(value).attr('id',hiddenId);
$(this).after(newHiddenInput);
});
The above code will create a new hidden input for each input, textarea, and select on your page. It will have the same value as the input it duplicates. It will have an id equivalent to prepending the id with the word 'hidden'.
I don't know if you can attach a click handler to a background image. If your inputs are enclosed inside a <div>, you may be able to get the result you want by attaching the click handler to your div.
In any case, you should now have the old values where you can easily compare them to the user's input so that you can prepare a summary of the difference.

Prototype gives us the Hash class which is almost perfect for this but lacks a way of calculating the difference with another hash, so let's add that...
Hash.prototype.difference = function(hash)
{
var result = this.clone();
hash.each(function(pair) {
if (result.get(pair.key) === undefined)
// exists in hash but not in this
result.set(pair.key, pair.value);
else if (result.get(pair.key) == pair.value)
// no difference so remove from result
result.unset(pair.key);
// else exists in this but not in hash
});
return result;
};
This is no way to tell if an element was clicked on just it's background image - you can find out the coordinates where it was clicked but that is not foolproof, especially since CSS3 adds complications like multiple backgrounds and transitions. It is better to have an absolutely positioned element to act as a button.
$('button-element').observe('click', function() {
var form_values = $H($('form-id').serialize(true));
if (old_values) {
var differences = old_values.difference(form_values);
if (differences.size()) {
showDiffPopup(differences);
}
}
window.old_values = form_values;
});
// preset current values in advance
window.old_values = $H($('form-id').serialize(true));
All that remains is to implement showDiffPopup to show the calculated differences.

Text captions on multiple Images with jQuery

I'm new to jQuery so please be patient. I want to create a text caption that slides down on an image when you hover over a link on the page. I can do this when there's just one image with one caption but I have several images with different captions on one page.
I would like to create one function that can handle all of these in seperate instances and not create a function for each image/textcaption. The reason being is that the images and text is dynamic and changing in quantity overtime.
Please see an example of the code below, the .portText is a class of about 7 instances, when I hover over .moreInfo the text for every image slides down. I understand why this is happening, and I think I need to use ($this) somehow, but I also think i need to connect the picture to the text differently that it's done here. Hope this makes sense. Can anyone help? Cheers!
$(function() {
$('.moreInfo').hover(
function() {
$('.portText').slideDown('slow');
},
function() {
$('.portText').slideUp('slow');
}
)
});

You can refer to the element that was hovered over using $(this).
The way I usually do this is to make portText a child of the moreInfo div:
<div class="moreInfo">
<div class="portText">
....
</div>
</div>
Then instead of just $('.portText') you can do $('.portText', this) (i.e. all portTexts that are children of the hovered element).
Edit: Another way to do it would be to use the data attribute and give each portText an ID:
<div class="moreInfo" data-id="1">....</div>
<div class="portText" id="portText-1">...</div>
Then for Javascript:
$('.moreInfo').hover(
function() {
var myId= "#portText-" + $(this).data('id');
$(myId).slideDown('slow');
},
function() {
var myId= "#portText-" + $(this).data('id');
$(myId).slideUp('slow');
}
);