Task:
Make a comment input field (textarea) on the form so that its size (height) is changed according to the number (lines) of the text.
The user can enter a couple of words on a single line or insert a table twenty lines high from Excel - the input field should automatically increase / decrease.
The length of the lines is different (the form is rubber and depends on the size of the browser window), the lines can be transferred either along the \ r \ n or simply, if they do not fit in the width.
In principle, we need a formula for counting the number of lines of text in order to change the rows attribute of textarea.
Javascript is welcome. If the solution is possible only by means of html / css, then even better.
Solutions:
For IE, the ingenious solution was suggested by
kosiasik :
in textarea style register overflow: visible
The universal solution suggested
drJonnie :
the textarea sets the height in pixels and hangs the event on pressing any key (including the mouse). This event each time compares scrollHeight and clientHeight; if the first is greater, then the height of the textarea is updated.
I almost implemented this solution:
function adjustHeight (textarea) {
var dif = textarea.scrollHeight - textarea.clientHeight
if (dif) {
if (isNaN (parseInt (textarea.style.height))) {
textarea.style.height = textarea.scrollHeight + "px"
} else {
textarea.style.height = parseInt (textarea.style.height) + dif + "px"
}
}
}
it remains to hang it on the events onFocus, onBlur, onKeyPress, etc., by choice
drJonnie brought his decision
below in the commentslahmatiy gave a solution using jQuery (
use case ), but I didn’t want to connect the whole framework for the sake of a single function
I thank all the participants in the discussion.