Develop Reference

How to change case of certain letters in input?

I am very new to js/jquery (obviously) and am working on a small project that involves changing the case to toUpperCase on all letters except for "o", which will remain/change to lowercase.
I have implemented this: http://jsfiddle.net/HwTEj/
$(function() {
$('input').keyup(function() {
this.value = this.value.toUpperCase();
});
});
however I am struggling to define certain letters to remain/change to lowercase.
Any help on this would be greatly appreciated, and since I am new to posting questions to SO please let me know if there is any additional info you need to point me in the right direction.

To replace all instances you will need something like this:
this.value.toUpperCase().replace(/O/g, "o")
EDIT:
If you want to have a selection of characters that will be replaced you could do this (using o, f and h as an example here):
this.value.toUpperCase().replace(/[OFH]/g, function($1){
return $1.toLowerCase();
})

Updated fiddle
$(function() {
$('input').keyup(function() {
this.value = this.value.toUpperCase().split('O').join('o');
});
});

The other answers are good, but here's an alternative:
this.value = this.value.replace(/(o)|./ig, function(x, y) {
return y ? y.toLowerCase() : x.toUpperCase();
});
You can replace o in the pattern with a character class (e.g. [xyz]) if you need to make other characters lower case.

How to get first text node of a string while containing bold and italic tags?

String(s) is dynamic
It is originated from onclick event when user clicks anywhere in dom
if string(s)'s first part that is:
"login<b>user</b>account"
is enclosed in some element like this :
"<div>login<b>user</b>account</div>",
then I can get it with this:
alert($(s).find('*').andSelf().not('b,i').not(':empty').first().html());
// result is : login<b>user</b>account
But how can i get the same result in this condition when it is not enclosed in any element .i.e. when it is not enclosed in any element?
I tried this below code which works fine when first part do not include any <b></b> but it only gives "login" when it does include these tags.
var s = $.trim('login<b>user</b> account<tbody> <tr> <td class="translated">Lorem ipsum dummy text</td></tr><tr><td class="translated">This is a new paragraph</td></tr><tr><td class="translated"><b>Email</b></td></tr><tr><td><i>This is yet another text</i></td> </tr></tbody>');
if(s.substring(0, s.indexOf('<')) != ''){
alert(s.substring(0, s.indexOf('<')));
}
Note:
Suggest a generic solution that is not specific for this above string only. It should work for both the cases when there is bold tags and when there ain't any.

So it's just a b or a i, heh?
A recursive function is always the way to go. And this time, it's probably the best way to go.
var s = function getEm(elem) {
var ret = ''
// TextNode? Great!
if (elem.nodeType === 3) {
ret += elem.nodeValue;
}
else if (elem.nodeType === 1 &&
(elem.nodeName === 'B' || elem.nodeName === 'I')) {
// Element? And it's a B or an I? Get his kids!
ret += getEm(elem.firstChild);
}
// Ain't nobody got time fo' empty stuff.
if (elem.nextSibling) {
ret += getEm(elem.nextSibling);
}
return ret;
}(elem);
Jsfiddle demonstrating this: http://jsfiddle.net/Ralt/TZKsP/
PS: Parsing HTML with regex or custom tokenizer is bad and shouldn't be done.

You're trying to retrieve all of the text up to the first element that's not a <b> or <i>, but this text could be wrapped in an element itself. This is SUPER tricky. I feel like there's a better way to implement whatever it is you're trying to accomplish, but here's a solution that works.
function initialText(s){
var test = s.match(/(<.+?>)?.*?<(?!(b|\/|i))/);
var match = test[0];
var prefixed_element = test[1];
// if the string was prefixed with an element tag
// remove it (ie '<div> blah blah blah')
if(prefixed_element) match = match.slice(prefixed_element.length);
// remove the matching < and return the string
return match.slice(0,-1);
}
You're lucky I found this problem interesting and challenging because, again, this is ridiculous.
You're welcome ;-)

Try this:
if (s.substring(0, s.indexOf('<')) != '') {
alert(s.substring(0, s.indexOf('<tbody>')));
}

Regex to check if http or https exists in the string

So i have this code:
function validateText(str)
{
var tarea = str;
var tarea_regex = /^(http|https)/;
if(tarea_regex.test(String(tarea).toLowerCase()) == true)
{
$('#textVal').val('');
}
}
This works perfectly for this:
https://hello.com
http://hello.com
but not for:
this is a website http://hello.com asdasd asdasdas
tried doing some reading but i dont where to place * ? since they will check the expression anywhere on the string according here -> http://www.regular-expressions.info/reference.html
thank you

From the looks of it, you're just checking if http or https exists in the string. Regular expressions are a bit overkill for that purpose. Try this simple code using indexOf:
function validateText(str)
{
var tarea = str;
if (tarea.indexOf("http://") == 0 || tarea.indexOf("https://") == 0) {
// do something here
}
}

Try this:
function validateText(string) {
if(/(http(s?)):\/\//i.test(string)) {
// do something here
}
}

The ^ in the beginning matches the start of the string. Just remove it.
var tarea_regex = /^(http|https)/;
should be
var tarea_regex = /(http|https)/;

((http(s?))\://))
Plenty of ideas here : http://regexlib.com/Search.aspx?k=URL&AspxAutoDetectCookieSupport=1

Have you tried using a word break instead of the start-of-line character?
var tarea_regex = /\b(http|https)/;
It seems to do what I think you want. See here: http://jsfiddle.net/BejGd/

Convert HTML Character Entities back to regular text using javascript

the questions says it all :)
eg. we have >, we need > using only javascript
Update: It seems jquery is the easy way out. But, it would be nice to have a lightweight solution. More like a function which is capable to do this by itself.

You could do something like this:
String.prototype.decodeHTML = function() {
var map = {"gt":">" /* , … */};
return this.replace(/&(#(?:x[0-9a-f]+|\d+)|[a-z]+);?/gi, function($0, $1) {
if ($1[0] === "#") {
return String.fromCharCode($1[1].toLowerCase() === "x" ? parseInt($1.substr(2), 16) : parseInt($1.substr(1), 10));
} else {
return map.hasOwnProperty($1) ? map[$1] : $0;
}
});
};

function decodeEntities(s){
var str, temp= document.createElement('p');
temp.innerHTML= s;
str= temp.textContent || temp.innerText;
temp=null;
return str;
}
alert(decodeEntities('<'))
/* returned value: (String)
<
*/

I know there are libraries out there, but here are a couple of solutions for browsers. These work well when placing html entity data strings into human editable areas where you want the characters to be shown, such as textarea's or input[type=text].
I add this answer as I have to support older versions of IE and I feel that it wraps up a few days worth of research and testing. I hope somebody finds this useful.
First this is for more modern browsers using jQuery, Please note that this should NOT be used if you have to support versions of IE before 10 (7, 8, or 9) as it will strip out the newlines leaving you with just one long line of text.
if (!String.prototype.HTMLDecode) {
String.prototype.HTMLDecode = function () {
var str = this.toString(),
$decoderEl = $('<textarea />');
str = $decoderEl.html(str)
.text()
.replace(/<br((\/)|( \/))?>/gi, "\r\n");
$decoderEl.remove();
return str;
};
}
This next one is based on kennebec's work above, with some differences which are mostly for the sake of older IE versions. This does not require jQuery, but does still require a browser.
if (!String.prototype.HTMLDecode) {
String.prototype.HTMLDecode = function () {
var str = this.toString(),
//Create an element for decoding
decoderEl = document.createElement('p');
//Bail if empty, otherwise IE7 will return undefined when
//OR-ing the 2 empty strings from innerText and textContent
if (str.length == 0) {
return str;
}
//convert newlines to <br's> to save them
str = str.replace(/((\r\n)|(\r)|(\n))/gi, " <br/>");
decoderEl.innerHTML = str;
/*
We use innerText first as IE strips newlines out with textContent.
There is said to be a performance hit for this, but sometimes
correctness of data (keeping newlines) must take precedence.
*/
str = decoderEl.innerText || decoderEl.textContent;
//clean up the decoding element
decoderEl = null;
//replace back in the newlines
return str.replace(/<br((\/)|( \/))?>/gi, "\r\n");
};
}
/*
Usage:
var str = ">";
return str.HTMLDecode();
returned value:
(String) >
*/

Here is a "class" for decoding whole HTML document.
HTMLDecoder = {
tempElement: document.createElement('span'),
decode: function(html) {
var _self = this;
html.replace(/&(#(?:x[0-9a-f]+|\d+)|[a-z]+);/gi,
function(str) {
_self.tempElement.innerHTML= str;
str = _self.tempElement.textContent || _self.tempElement.innerText;
return str;
}
);
}
}
Note that I used Gumbo's regexp for catching entities but for fully valid HTML documents (or XHTML) you could simpy use /&[^;]+;/g.

There is nothing built in, but there are many libraries that have been written to do this.
Here is one.
And here one that is a jQuery plugin.

Detect difference between & and %26 in location.hash

Analyzing the location.hash with this simple javascript code:
<script type="text/javascript">alert(location.hash);</script>
I have a difficult time separating out GET variables that contain a & (encoded as %26) and a & used to separate variables.
Example one:
code=php&age=15d
Example two:
code=php%20%26%20code&age=15d
As you can see, example 1 has no problems, but getting javascript to know that "code=php & code" in example two is beyond my abilities:
(Note: I'm not really using these variable names, and changing them to something else will only work so long as a search term does not match a search key, so I wouldn't consider that a valid solution.)

There is no difference between %26 and & in a fragment identifier (‘hash’). ‘&’ is only a reserved character with special meaning in a query (‘search’) segment of a URI. Escaping ‘&’ to ‘%26’ need be given no more application-level visibility than escaping ‘a’ to ‘%61’.
Since there is no standard encoding scheme for hiding structured data within a fragment identifier, you could make your own. For example, use ‘+XX’ hex-encoding to encode a character in a component:
hxxp://www.example.com/page#code=php+20+2B+20php&age=15d
function encodeHashComponent(x) {
return encodeURIComponent(x).split('%').join('+');
}
function decodeHashComponent(x) {
return decodeURIComponent(x.split('+').join('%'));
}
function getHashParameters() {
var parts= location.hash.substring(1).split('&');
var pars= {};
for (var i= parts.length; i-->0;) {
var kv= parts[i].split('=');
var k= kv[0];
var v= kv.slice(1).join('=');
pars[decodeHashComponent(k)]= decodeHashComponent(v);
}
return pars;
}

Testing on Firefox 3.1, it looks as if the browser converts hex codes to the appropriate characters when populating the location.hash variable, so there is no way JavaScript can know how the original was a single character or a hex code.
If you're trying to encode a character like & inside of your hash variables, I would suggest replacing it with another string.
You can also parse the string in weird ways, like (JS 1.6 here):
function pairs(xs) {
return xs.length > 1 ? [[xs[0], xs[1]]].concat(pairs(xs.slice(2))) : []
}
function union(xss) {
return xss.length == 0 ? [] : xss[0].concat(union(xss.slice(1)));
}
function splitOnLast(s, sub) {
return s.indexOf(sub) == -1 ? [s] :
[s.substr(0, s.lastIndexOf(sub)),
s.substr(s.lastIndexOf(sub) + sub.length)];
}
function objFromPairs(ps) {
var o = {};
for (var i = 0; i < ps.length; i++) {
o[ps[i][0]] = ps[i][1];
}
return o;
}
function parseHash(hash) {
return objFromPairs(
pairs(
union(
location.hash
.substr(1)
.split("=")
.map(
function (s) splitOnLast(s, '&')))))
}
>>> location.hash
"#code=php & code&age=15d"
>>> parseHash(location.hash)
{ "code": "php & code", "age": "15d" }

Just do the same as you do with the first example, but after you have split on the & then call unescape() to convert the %26 to & and the %20 to a space.
Edit:
Looks like I'm a bit out of date and you should be using decodeURIComponent() now, though I don't see any clear explanation on what it does differently to unescape(), apart from a suggestion that it doesn't handle Unicode properly.

This worked fine for me:
var hash = [];
if (location.hash) {
hash = location.href.split('#')[1].split('&');
}