Decreasing Font Size If Text Is Too Long - javascript

I want to change the font size to 36px if my h1 has more than two words and keep it as is if not.
This is my code:
window.addEvent('domready',function() {
var $quote = ('#header .col-sm-12 h1');
var $numWords = $quote.get('text').split(' ').length;
if (2 < $numWords) {
$quote.setStyle('font-size','36px'); }
});
However, it doesn't work. What's wrong with it?
The site in question is 6wo.de
Please note: Changing the size via CSS by using the viewport unit is not an option in this case.

First of all it's not addEvent but addEventListener. Then you probably mean DOMContentLoaded, because domready is not an event.
To make the title smaller give an id or class to identify it easier in JavaScript.
<h1 id="page-title">My page title</h1>
Now you can make the title smaller like this.
window.addEventListener('DOMContentLoaded', function() {
const title = $('#page-title');
var numWords = title.text().split(' ').length;
if (numWords > 2) {
title.css('font-size', '36px');
}
});
UPDATE
If you don't want to give an id to the title for some reason, you can do like this.
window.addEventListener('DOMContentLoaded', function() {
const title = $('#header .bottom-header h1');
var numWords = title.text().split(' ').length;
if (numWords > 2) {
title.css('font-size', '36px');
}
});

Related

making multiple sliders with one set of jQuery code

I've made a slider with jQuery using html tags which have classes instead of IDs so that I will be able to use the same jQuery code for other duplicated sliders.
The problem is, I want the width of my ul to be calculated based on the number of lis, instead of setting it manually in CSS. When there is only one slider I can set my vars outside of the function, but when I have to use it though event attributes on my html parts so that I will be able to use them for multiple sliders, I have to move the vars inside of my function, which sets the wrong width.
This is my code:
function OLAR(direction,span) {
var OurNexNPrv = $(span);
var Parent_OLAR = OurNexNPrv.parents('.OLAR');
var UL_OF_OLAR = Parent_OLAR.find('.OLAR_CONTENT ul');
var LI_OF_OLAR = UL_OF_OLAR.find('li');
var LI_OF_OLAR_LENGTH = LI_OF_OLAR.length;
var Quantity_OF_OLAR_PAGES = LI_OF_OLAR_LENGTH / 3;
var Max_Margin_LEFT = -(Quantity_OF_OLAR_PAGES - 1) * 576;
UL_OF_OLAR.css('width',LI_OF_OLAR_LENGTH*192);
var AffectedLeftMargin;
var CurrentLeftMargin = UL_OF_OLAR.css('margin-left');
CurrentLeftMargin = parseFloat(CurrentLeftMargin);
if (direction == 'right') {
AffectedLeftMargin = CurrentLeftMargin - 576;
}
if (direction == 'left') {
AffectedLeftMargin = CurrentLeftMargin + 576;
}
if (AffectedLeftMargin < Max_Margin_LEFT) {
AffectedLeftMargin = 0;
}
if (AffectedLeftMargin > 0) {
AffectedLeftMargin = Max_Margin_LEFT;
}
UL_OF_OLAR.animate({'marginLeft': AffectedLeftMargin}, 1000);
}
$('.CIRCLE_LOAD_RIGHT').click(function () {
OLAR('right');
});
$('.CIRCLE_LOAD_LEFT').click(function () {
OLAR('left');
});
How can I set the width for each of my uls individually, through css commands outside of that function?
Okay, my ul tag did not have the absolute position; after giving it the right position and left:0 and bottom:0 or right:0 and bottom:0 (based on your language)the given width which comes from JQuery code can rhyme perfectly with everything else. I've tried it with multiple sliders and it works perfectly :)
So, we need an anchor point in order to make this work. And there is nothing wrong with this JQuery code which has been mentioned above!
Have a great day.

How to generate a html2canvas images with a hidden source (html) div

I am working in a project where I need to generate a profile picture of any member and its reviews, and some data, I started working with GDI, but it was so hard to understand, so I searched for other options and found Html2Canvas that works with javascript/jquery, everything is fine, the only thing I couldn't handle, and would like to know if there is a way to hide the source html div without breaking the result image.
Ex:
This is how is it now
This is how it should look
So, when I apply display:none on the css of the source div, the image result is like this:
And finally here is the code that I have so far
var div_to_hide = $("#mydiv:hidden");
$(function() {
$('span.stars').stars();
});
html2canvas([document.getElementById('mydiv')], {
onrendered: function (canvas) {
document.getElementById('canvas').appendChild(canvas);
var data = canvas.toDataURL('image/png');
var image = new Image();
image.src = data;
document.getElementById('image').appendChild(image);
}
});
$.fn.stars = function() {
return $(this).each(function() {
var val = parseFloat($(this).html());
val = Math.round(val * 4) / 4;
var size = Math.max(0, (Math.min(5, val))) * 16;
var $span = $('<span />').width(size);
$(this).html($span);
});
}
https://jsfiddle.net/ricardojriosr/6ap9Lx1f/8/
Now the question is how do I made this work showing only the image and not the HTML source. Thanks in advace.
Instead of trying to hide it before, hide (or remove) it after the canvas is rendered.
I'm not sure why var div_to_hide equals $("#mydiv:hidden"); but if you change it to var div_to_hide = $("#mydiv"); then, on line 12, after appending the image, you can run div_to_hide.hide();
And to avoid a flash of the HTML content, you can use some CSS trickery to cover up the original HTML. I made an example here, but you can adjust to fit whatever your actual needs are. https://jsfiddle.net/m5zq2kzn/
I had the same issue.
The solution that worked for me is a css trickery to position the div that I want to hide offscreen:
.offscreen {
position:absolute;
left:-10000px;
top:auto;
width:1px;
height:1px;
overflow:hidden;
}
Then use it like this:
html2canvas(document.getElementById("ticket_template"))
.then((canvas) => {
let imgData = canvas.toDataURL('image/png');
});

How can I have two of these on one page with different variables? (JQuery)

I need to have 2 of these one page but each with different percentages. When I try re-writing the JS or even use different class/ID names it still always pulls from the first SPAN.
http://jsfiddle.net/K62Ra/
<div class="container">
<div class="bw"></div>
<div class="show"></div>
<div id="bar" data-total="100">
<div class="text">Currently at <br/><span>70</span><br><i>Click To Give</div>
</div>
JS and CSS in the Fiddle.
Much Thanks.
This one will work smoothly:
http://jsfiddle.net/K62Ra/7/
$('.bar').each(function() {
var percentStart = 0;
var total = $(this).data('total');
var percent = parseInt($(this).find('span').html());
$(this).find('> div').addClass("load");
var that = this;
var timer = setInterval(function() {
$(that).siblings('.show').css('height', percentStart/total*100+'%');
$(that).css('height', percentStart/total*100+'%');
$(that).find('span').html('%'+percentStart);
if(percentStart<percent) { percentStart=percentStart+1; return; }
clearInterval(timer);
}, 35);
});
The interval has to be terminated as well, or it will run infinitely (though not doing anything).
I've changed your id="bar" into a class. Then I'm running a each loop for the .bar classes. here is the fiddle: http://jsfiddle.net/K62Ra/3/
here is the code:
$('.bar').each(function (index, element) {
percent = $(this).find('span').html();
total = $(this).attr('data-total');
percentStart = 0;
setInterval(function () {
$('.show').css('height', percentStart / total * 100 + '%');
$(this).css('height', percentStart / total * 100 + '%');
$(this).find('span').html('%' + percentStart);
if (percentStart < percent) {
percentStart = percentStart + 1;
}
}, 35);
});
$(".bar div").addClass("load");
Like some of the comments have stated, having duplicate ids is bad design and can cause some weird errors.
You can find a solution to your problem by changing a number of things. One, instead of
referring to divs in you selectors by id'#', you can infer them by class '.' like
$('.bar')
The next step would be to ensure exclusivity for each div with class 'container' by using a closure
$('.container').each(function(){
var x
var y
.
.
});
And finally, avoid 'selecting' elements in the selector directly, but use $(this) and .find() to ensure you are within the current div with class 'container'.
http://jsfiddle.net/K62Ra/5/
$('.container').each(function(){
var percent = $(this).find('div.bar div span').html();
var total = $(this).find('div.bar').attr('data-total');
var percentStart = 0;
var that = $(this);
setInterval(function() {
that.find('.show').css('height',percentStart/total*100+'%');
that.find('div.bar').css('height',percentStart/total*100+'%');
that.find('div.bar div span').html('%'+percentStart);
if(percentStart<percent) {percentStart=percentStart+1;}
},35);
$(this).find("div.bar div").addClass("load");
});
There are already several good answers here. I would recommend validating your html. Also some of your css was causing weirdness when there was scrolling involved (fixed background images weren't scrolling.)
I took a slightly different approach than everyone else. Instead of using a setInterval I went with $.animate and a step function. Like others, I chose a class to target each of the items: 'fill-me-up'.
Fiddle: http://jsfiddle.net/LFbKs/6/
NOTE: Check the fiddle since I modified the HTML (very slightly) and the css to a larger degree.
// for each item we need to "fill up"
$('.fill-me-up').each(function(){
// cache DOM references
var this$ = $(this)
, bar$ = this$.find('.bar')
, show$ = this$.find('.show')
, span$ = bar$.find('div span')
// the target percentage height for this item
, p = span$.text()
// combine '.bar' and '.show' so we can apply the animation to both
, toAnimate = $().add(bar$).add(show$);
// add class causing fade-in
bar$.find('div').addClass('is-visible');
// animate height to target height over 2 seconds and
// at each step, update the span with a truncated value
toAnimate.animate(
{ height: p+'%' },
{
duration: 2000,
step: function( currentStep ) {
span$.html('%'+currentStep.toFixed(0));
}
}
);
});
Cheers

JavaScript, How to change the background of a div tag every x seconds

I'm trying to make some JavaScript code to change the background of two div tags every X seconds. Here is my code:
HTML
<div id="bg_left"></div>
<div id="bg_right"></div>
CSS
body{
height:100%;
}
#bg_left{
height:100%;
width:50%;
left:0;
position:fixed;
background-position:left;
}
#bg_right{
height:100%;
width:50%;
right:0;
position:fixed;
background-image:url(http://presotto.daterrawebdev.com/d/img/pp_hey_you_bg.png);
background-position:right;
}
JAVA SCRIPT
function carousel_bg(id) {
var bgimgs = [ 'pp_hey_you_bg.png', 'burningman_bg.png' ];
var img1 = bgimgs[id];
var img2 = bgimgs[id+1];
var cnt = 2;
$('#bg_left').css("background-image", "url(http://presotto.daterrawebdev.com/d/img/"+img1+")");
$('#bg_right').css("background-image", "url(http://presotto.daterrawebdev.com/d/img/"+img2+")");
id = id + 1;
if (id==cnt) id = 0;
setTimeout("carousel_bg("+id+")", 10000);
}
$(document).ready(function() {
carousel_bg(0);
});
​
The background-images should be changing randomly, but they don't even change at all.
OK, I see the issue in your jsFiddle. Because you're passing a string to setTimeout() that string will be evaluated only at the top level scope. But, the function name you were passing is not at the top level scope (it's in an onload handler for the jsFiddle). So, I changed the way your JS is positioned in the jsFiddle so it is now at the top level scope. I also fixed up the logic for selecting an image and it now works here: http://jsfiddle.net/jfriend00/awVYP/
And, here's a cleaned up version that does not pass a string to setTimeout() (a much better way to write javascript) that passes a local function and uses a closure to keep track of the current index: http://jsfiddle.net/jfriend00/LVGNN/
function carousel_bg(id) {
var bgimgs = [ 'pp_hey_you_bg.png', 'burningman_bg.png' ]; // add images here..
function next() {
if (id >= bgimgs.length) {
id = 0;
}
var img1 = bgimgs[id];
id++;
if (id >= bgimgs.length){
id = 0;
}
var img2 = bgimgs[id];
$('#bg_left').css("background-image", "url(http://presotto.daterrawebdev.com/d/img/"+img1+")");
$('#bg_right').css("background-image", "url(http://presotto.daterrawebdev.com/d/img/"+img2+")");
setTimeout(next, 1000);
}
next();
}
$(document).ready(function() {
carousel_bg(0);
});
Previous comments on earlier version so of the OP's code:
$('#body')
should be:
$('body')
or even faster:
$(document.body)
Also, your jsFiddle shows a bit of an odd issue. Your CSS has a background image on the HTML tag, but your javascript sets a semi-transparent background image on the body tag. Is that really what you want?
For testing I added another image to the array so that we got some distinction in the sorting.
function carousel_bg(id) {
var bgimgs = [ 'http://presotto.daterrawebdev.com/d/img/pp_hey_you_bg.png', 'http://presotto.daterrawebdev.com/d/img/burningman_bg.png', 'http://gallery.orobouros.net/var/albums/2012/NewYorkComicCon2012/Legend-of-Korra/nycc_20121013_164625_0041.jpg?m=1354760251' ]; // add images here..
var img1 = bgimgs[id+1];
var img2 = bgimgs[id];
var cnt = bgimgs.length; // change this number when adding images..
$('#bg_left').css("background-image", "url("+img1+")");
$('#bg_right').css("background-image", "url("+img2+")");
id = id + 1;
if (id== (cnt - 1) ) id = 0;
setTimeout("carousel_bg("+id+")", 10000);
}
Two changes here:
For your total image count, I am retrieving the total count of images in the array dynamically instead of by hand (bgimgs.length)
In your conditional to reset the id value, subtract the total count by 1. Since JS has zero-based indexes, not doing this will get you an undefined error (a 3 item array will spit out a value of 4 in your original code on the last iteration).
While this code does loop through your array, it's not random. That's another topic.
For those not using JQuery, simply do the following:
document.body.style.backgroundImage="url(images/mybackgroundimage.jpg)";

How to autosize a textarea using Prototype?

I'm currently working on an internal sales application for the company I work for, and I've got a form that allows the user to change the delivery address.
Now I think it would look much nicer, if the textarea I'm using for the main address details would just take up the area of the text in it, and automatically resize if the text was changed.
Here's a screenshot of it currently.
Any ideas?
#Chris
A good point, but there are reasons I want it to resize. I want the area it takes up to be the area of the information contained in it. As you can see in the screen shot, if I have a fixed textarea, it takes up a fair wack of vertical space.
I can reduce the font, but I need address to be large and readable. Now I can reduce the size of the text area, but then I have problems with people who have an address line that takes 3 or 4 (one takes 5) lines. Needing to have the user use a scrollbar is a major no-no.
I guess I should be a bit more specific. I'm after vertical resizing, and the width doesn't matter as much. The only problem that happens with that, is the ISO number (the large "1") gets pushed under the address when the window width is too small (as you can see on the screenshot).
It's not about having a gimick; it's about having a text field the user can edit that won't take up unnecessary space, but will show all the text in it.
Though if someone comes up with another way to approach the problem I'm open to that too.
I've modified the code a little because it was acting a little odd. I changed it to activate on keyup, because it wouldn't take into consideration the character that was just typed.
resizeIt = function() {
var str = $('iso_address').value;
var cols = $('iso_address').cols;
var linecount = 0;
$A(str.split("\n")).each(function(l) {
linecount += 1 + Math.floor(l.length / cols); // Take into account long lines
})
$('iso_address').rows = linecount;
};
Facebook does it, when you write on people's walls, but only resizes vertically.
Horizontal resize strikes me as being a mess, due to word-wrap, long lines, and so on, but vertical resize seems to be pretty safe and nice.
None of the Facebook-using-newbies I know have ever mentioned anything about it or been confused. I'd use this as anecdotal evidence to say 'go ahead, implement it'.
Some JavaScript code to do it, using Prototype (because that's what I'm familiar with):
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<script src="http://www.google.com/jsapi"></script>
<script language="javascript">
google.load('prototype', '1.6.0.2');
</script>
</head>
<body>
<textarea id="text-area" rows="1" cols="50"></textarea>
<script type="text/javascript" language="javascript">
resizeIt = function() {
var str = $('text-area').value;
var cols = $('text-area').cols;
var linecount = 0;
$A(str.split("\n")).each( function(l) {
linecount += Math.ceil( l.length / cols ); // Take into account long lines
})
$('text-area').rows = linecount + 1;
};
// You could attach to keyUp, etc. if keydown doesn't work
Event.observe('text-area', 'keydown', resizeIt );
resizeIt(); //Initial on load
</script>
</body>
</html>
PS: Obviously this JavaScript code is very naive and not well tested, and you probably don't want to use it on textboxes with novels in them, but you get the general idea.
One refinement to some of these answers is to let CSS do more of the work.
The basic route seems to be:
Create a container element to hold the textarea and a hidden div
Using Javascript, keep the textarea’s contents synced with the div’s
Let the browser do the work of calculating the height of that div
Because the browser handles rendering / sizing the hidden div, we avoid
explicitly setting the textarea’s height.
document.addEventListener('DOMContentLoaded', () => {
textArea.addEventListener('change', autosize, false)
textArea.addEventListener('keydown', autosize, false)
textArea.addEventListener('keyup', autosize, false)
autosize()
}, false)
function autosize() {
// Copy textarea contents to div browser will calculate correct height
// of copy, which will make overall container taller, which will make
// textarea taller.
textCopy.innerHTML = textArea.value.replace(/\n/g, '<br/>')
}
html, body, textarea {
font-family: sans-serif;
font-size: 14px;
}
.textarea-container {
position: relative;
}
.textarea-container > div, .textarea-container > textarea {
word-wrap: break-word; /* make sure the div and the textarea wrap words in the same way */
box-sizing: border-box;
padding: 2px;
width: 100%;
}
.textarea-container > textarea {
overflow: hidden;
position: absolute;
height: 100%;
}
.textarea-container > div {
padding-bottom: 1.5em; /* A bit more than one additional line of text. */
visibility: hidden;
}
<div class="textarea-container">
<textarea id="textArea"></textarea>
<div id="textCopy"></div>
</div>
Here's another technique for autosizing a textarea.
Uses pixel height instead of line height: more accurate handling of line wrap if a proportional font is used.
Accepts either ID or element as input
Accepts an optional maximum height parameter - useful if you'd rather not let the text area grow beyond a certain size (keep it all on-screen, avoid breaking layout, etc.)
Tested on Firefox 3 and Internet Explorer 6
Code:
(plain vanilla JavaScript)
function FitToContent(id, maxHeight)
{
var text = id && id.style ? id : document.getElementById(id);
if (!text)
return;
/* Accounts for rows being deleted, pixel value may need adjusting */
if (text.clientHeight == text.scrollHeight) {
text.style.height = "30px";
}
var adjustedHeight = text.clientHeight;
if (!maxHeight || maxHeight > adjustedHeight)
{
adjustedHeight = Math.max(text.scrollHeight, adjustedHeight);
if (maxHeight)
adjustedHeight = Math.min(maxHeight, adjustedHeight);
if (adjustedHeight > text.clientHeight)
text.style.height = adjustedHeight + "px";
}
}
Demo:
(uses jQuery, targets on the textarea I'm typing into right now - if you have Firebug installed, paste both samples into the console and test on this page)
$("#post-text").keyup(function()
{
FitToContent(this, document.documentElement.clientHeight)
});
Probably the shortest solution:
jQuery(document).ready(function(){
jQuery("#textArea").on("keydown keyup", function(){
this.style.height = "1px";
this.style.height = (this.scrollHeight) + "px";
});
});
This way you don't need any hidden divs or anything like that.
Note: you might have to play with this.style.height = (this.scrollHeight) + "px"; depending on how you style the textarea (line-height, padding and that kind of stuff).
Here's a Prototype version of resizing a text area that is not dependent on the number of columns in the textarea. This is a superior technique because it allows you to control the text area via CSS as well as have variable width textarea. Additionally, this version displays the number of characters remaining. While not requested, it's a pretty useful feature and is easily removed if unwanted.
//inspired by: http://github.com/jaz303/jquery-grab-bag/blob/63d7e445b09698272b2923cb081878fd145b5e3d/javascripts/jquery.autogrow-textarea.js
if (window.Widget == undefined) window.Widget = {};
Widget.Textarea = Class.create({
initialize: function(textarea, options)
{
this.textarea = $(textarea);
this.options = $H({
'min_height' : 30,
'max_length' : 400
}).update(options);
this.textarea.observe('keyup', this.refresh.bind(this));
this._shadow = new Element('div').setStyle({
lineHeight : this.textarea.getStyle('lineHeight'),
fontSize : this.textarea.getStyle('fontSize'),
fontFamily : this.textarea.getStyle('fontFamily'),
position : 'absolute',
top: '-10000px',
left: '-10000px',
width: this.textarea.getWidth() + 'px'
});
this.textarea.insert({ after: this._shadow });
this._remainingCharacters = new Element('p').addClassName('remainingCharacters');
this.textarea.insert({after: this._remainingCharacters});
this.refresh();
},
refresh: function()
{
this._shadow.update($F(this.textarea).replace(/\n/g, '<br/>'));
this.textarea.setStyle({
height: Math.max(parseInt(this._shadow.getHeight()) + parseInt(this.textarea.getStyle('lineHeight').replace('px', '')), this.options.get('min_height')) + 'px'
});
var remaining = this.options.get('max_length') - $F(this.textarea).length;
this._remainingCharacters.update(Math.abs(remaining) + ' characters ' + (remaining > 0 ? 'remaining' : 'over the limit'));
}
});
Create the widget by calling new Widget.Textarea('element_id'). The default options can be overridden by passing them as an object, e.g. new Widget.Textarea('element_id', { max_length: 600, min_height: 50}). If you want to create it for all textareas on the page, do something like:
Event.observe(window, 'load', function() {
$$('textarea').each(function(textarea) {
new Widget.Textarea(textarea);
});
});
Here is a solution with JQuery:
$(document).ready(function() {
var $abc = $("#abc");
$abc.css("height", $abc.attr("scrollHeight"));
})
abc is a teaxtarea.
Check the below link:
http://james.padolsey.com/javascript/jquery-plugin-autoresize/
$(document).ready(function () {
$('.ExpandableTextCSS').autoResize({
// On resize:
onResize: function () {
$(this).css({ opacity: 0.8 });
},
// After resize:
animateCallback: function () {
$(this).css({ opacity: 1 });
},
// Quite slow animation:
animateDuration: 300,
// More extra space:
extraSpace:20,
//Textarea height limit
limit:10
});
});
Just revisiting this, I've made it a little bit tidier (though someone who is full bottle on Prototype/JavaScript could suggest improvements?).
var TextAreaResize = Class.create();
TextAreaResize.prototype = {
initialize: function(element, options) {
element = $(element);
this.element = element;
this.options = Object.extend(
{},
options || {});
Event.observe(this.element, 'keyup',
this.onKeyUp.bindAsEventListener(this));
this.onKeyUp();
},
onKeyUp: function() {
// We need this variable because "this" changes in the scope of the
// function below.
var cols = this.element.cols;
var linecount = 0;
$A(this.element.value.split("\n")).each(function(l) {
// We take long lines into account via the cols divide.
linecount += 1 + Math.floor(l.length / cols);
})
this.element.rows = linecount;
}
}
Just it call with:
new TextAreaResize('textarea_id_name_here');
I've made something quite easy. First I put the TextArea into a DIV. Second, I've called on the ready function to this script.
<div id="divTable">
<textarea ID="txt" Rows="1" TextMode="MultiLine" />
</div>
$(document).ready(function () {
var heightTextArea = $('#txt').height();
var divTable = document.getElementById('divTable');
$('#txt').attr('rows', parseInt(parseInt(divTable .style.height) / parseInt(altoFila)));
});
Simple. It is the maximum height of the div once it is rendered, divided by the height of one TextArea of one row.
I needed this function for myself, but none of the ones from here worked as I needed them.
So I used Orion's code and changed it.
I added in a minimum height, so that on the destruct it does not get too small.
function resizeIt( id, maxHeight, minHeight ) {
var text = id && id.style ? id : document.getElementById(id);
var str = text.value;
var cols = text.cols;
var linecount = 0;
var arStr = str.split( "\n" );
$(arStr).each(function(s) {
linecount = linecount + 1 + Math.floor(arStr[s].length / cols); // take into account long lines
});
linecount++;
linecount = Math.max(minHeight, linecount);
linecount = Math.min(maxHeight, linecount);
text.rows = linecount;
};
Like the answer of #memical.
However I found some improvements. You can use the jQuery height() function. But be aware of padding-top and padding-bottom pixels. Otherwise your textarea will grow too fast.
$(document).ready(function() {
$textarea = $("#my-textarea");
// There is some diff between scrollheight and height:
// padding-top and padding-bottom
var diff = $textarea.prop("scrollHeight") - $textarea.height();
$textarea.live("keyup", function() {
var height = $textarea.prop("scrollHeight") - diff;
$textarea.height(height);
});
});
My solution not using jQuery (because sometimes they don't have to be the same thing) is below. Though it was only tested in Internet Explorer 7, so the community can point out all the reasons this is wrong:
textarea.onkeyup = function () { this.style.height = this.scrollHeight + 'px'; }
So far I really like how it's working, and I don't care about other browsers, so I'll probably apply it to all my textareas:
// Make all textareas auto-resize vertically
var textareas = document.getElementsByTagName('textarea');
for (i = 0; i<textareas.length; i++)
{
// Retain textarea's starting height as its minimum height
textareas[i].minHeight = textareas[i].offsetHeight;
textareas[i].onkeyup = function () {
this.style.height = Math.max(this.scrollHeight, this.minHeight) + 'px';
}
textareas[i].onkeyup(); // Trigger once to set initial height
}
Here is an extension to the Prototype widget that Jeremy posted on June 4th:
It stops the user from entering more characters if you're using limits in textareas. It checks if there are characters left. If the user copies text into the textarea, the text is cut off at the max. length:
/**
* Prototype Widget: Textarea
* Automatically resizes a textarea and displays the number of remaining chars
*
* From: http://stackoverflow.com/questions/7477/autosizing-textarea
* Inspired by: http://github.com/jaz303/jquery-grab-bag/blob/63d7e445b09698272b2923cb081878fd145b5e3d/javascripts/jquery.autogrow-textarea.js
*/
if (window.Widget == undefined) window.Widget = {};
Widget.Textarea = Class.create({
initialize: function(textarea, options){
this.textarea = $(textarea);
this.options = $H({
'min_height' : 30,
'max_length' : 400
}).update(options);
this.textarea.observe('keyup', this.refresh.bind(this));
this._shadow = new Element('div').setStyle({
lineHeight : this.textarea.getStyle('lineHeight'),
fontSize : this.textarea.getStyle('fontSize'),
fontFamily : this.textarea.getStyle('fontFamily'),
position : 'absolute',
top: '-10000px',
left: '-10000px',
width: this.textarea.getWidth() + 'px'
});
this.textarea.insert({ after: this._shadow });
this._remainingCharacters = new Element('p').addClassName('remainingCharacters');
this.textarea.insert({after: this._remainingCharacters});
this.refresh();
},
refresh: function(){
this._shadow.update($F(this.textarea).replace(/\n/g, '<br/>'));
this.textarea.setStyle({
height: Math.max(parseInt(this._shadow.getHeight()) + parseInt(this.textarea.getStyle('lineHeight').replace('px', '')), this.options.get('min_height')) + 'px'
});
// Keep the text/character count inside the limits:
if($F(this.textarea).length > this.options.get('max_length')){
text = $F(this.textarea).substring(0, this.options.get('max_length'));
this.textarea.value = text;
return false;
}
var remaining = this.options.get('max_length') - $F(this.textarea).length;
this._remainingCharacters.update(Math.abs(remaining) + ' characters remaining'));
}
});
#memical had an awesome solution for setting the height of the textarea on pageload with jQuery, but for my application I wanted to be able to increase the height of the textarea as the user added more content. I built off memical's solution with the following:
$(document).ready(function() {
var $textarea = $("p.body textarea");
$textarea.css("height", ($textarea.attr("scrollHeight") + 20));
$textarea.keyup(function(){
var current_height = $textarea.css("height").replace("px", "")*1;
if (current_height + 5 <= $textarea.attr("scrollHeight")) {
$textarea.css("height", ($textarea.attr("scrollHeight") + 20));
}
});
});
It's not very smooth but it's also not a client-facing application, so smoothness doesn't really matter. (Had this been client-facing, I probably would have just used an auto-resize jQuery plugin.)
For those that are coding for IE and encounter this problem. IE has a little trick that makes it 100% CSS.
<TEXTAREA style="overflow: visible;" cols="100" ....></TEXTAREA>
You can even provide a value for rows="n" which IE will ignore, but other browsers will use. I really hate coding that implements IE hacks, but this one is very helpful. It is possible that it only works in Quirks mode.
Internet Explorer, Safari, Chrome and Opera users need to remember to explicidly set the line-height value in CSS. I do a stylesheet that sets the initial properites for all text boxes as follows.
<style>
TEXTAREA { line-height: 14px; font-size: 12px; font-family: arial }
</style>
Here is a function I just wrote in jQuery to do it - you can port it to Prototype, but they don't support the "liveness" of jQuery so elements added by Ajax requests will not respond.
This version not only expands, but it also contracts when delete or backspace is pressed.
This version relies on jQuery 1.4.2.
Enjoy ;)
http://pastebin.com/SUKeBtnx
Usage:
$("#sometextarea").textareacontrol();
or (any jQuery selector for example)
$("textarea").textareacontrol();
It was tested on Internet Explorer 7/Internet Explorer 8, Firefox 3.5, and Chrome. All works fine.
Using ASP.NET, just simply do this:
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Automatic Resize TextBox</title>
<script type="text/javascript">
function setHeight(txtarea) {
txtarea.style.height = txtdesc.scrollHeight + "px";
}
</script>
</head>
<body>
<form id="form1" runat="server">
<asp:TextBox ID="txtarea" runat= "server" TextMode="MultiLine" onkeyup="setHeight(this);" onkeydown="setHeight(this);" />
</form>
</body>
</html>

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