Skip to content

Instantly share code, notes, and snippets.

@thomseddon
Last active October 21, 2020 08:50
Show Gist options
  • Star 75 You must be signed in to star a gist
  • Fork 24 You must be signed in to fork a gist
  • Save thomseddon/4703968 to your computer and use it in GitHub Desktop.
Save thomseddon/4703968 to your computer and use it in GitHub Desktop.
Auto Expanding/Grow textarea directive for AngularJS
/**
* The MIT License (MIT)
*
* Copyright (c) 2013 Thom Seddon
* Copyright (c) 2010 Google
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
* Adapted from: http://code.google.com/p/gaequery/source/browse/trunk/src/static/scripts/jquery.autogrow-textarea.js
*
* Works nicely with the following styles:
* textarea {
* resize: none;
* word-wrap: break-word;
* transition: 0.05s;
* -moz-transition: 0.05s;
* -webkit-transition: 0.05s;
* -o-transition: 0.05s;
* }
*
* Usage: <textarea auto-grow></textarea>
*/
app.directive('autoGrow', function() {
return function(scope, element, attr){
var minHeight = element[0].offsetHeight,
paddingLeft = element.css('paddingLeft'),
paddingRight = element.css('paddingRight');
var $shadow = angular.element('<div></div>').css({
position: 'absolute',
top: -10000,
left: -10000,
width: element[0].offsetWidth - parseInt(paddingLeft || 0) - parseInt(paddingRight || 0),
fontSize: element.css('fontSize'),
fontFamily: element.css('fontFamily'),
lineHeight: element.css('lineHeight'),
resize: 'none'
});
angular.element(document.body).append($shadow);
var update = function() {
var times = function(string, number) {
for (var i = 0, r = ''; i < number; i++) {
r += string;
}
return r;
}
var val = element.val().replace(/</g, '&lt;')
.replace(/>/g, '&gt;')
.replace(/&/g, '&amp;')
.replace(/\n$/, '<br/>&nbsp;')
.replace(/\n/g, '<br/>')
.replace(/\s{2,}/g, function(space) { return times('&nbsp;', space.length - 1) + ' ' });
$shadow.html(val);
element.css('height', Math.max($shadow[0].offsetHeight + 10 /* the "threshold" */, minHeight) + 'px');
}
element.bind('keyup keydown keypress change', update);
update();
}
});
@enapupe
Copy link

enapupe commented Aug 28, 2014

myApp.directive("autoGrow", function(){
    return function(scope, element, attr){
        var update = function(){
            element.css("height", "auto");
            element.css("height", element[0].scrollHeight + "px");
        };
        scope.$watch(attr.ngModel, function(){
            update();
        });
        attr.$set("ngTrim", "false");
    };
});

@rafenden
Copy link

rafenden commented Sep 7, 2014

@enapupe your directive jumps always to the top of textarea if its height is bigger that window height.

@enapupe
Copy link

enapupe commented Oct 17, 2014

@rafalenden would you fiddle your issue? My approach is at https://gist.github.com/enapupe/2a59589168f33ca405d0 , and has changed a bit.

@kimardenmiller
Copy link

Inspired by @huyttq & @enapupe, with a fix to control initial height, in CoffeeScript:

autoGrow = ->
  (scope, element, attrs) ->
    update = ->
      if element[0].scrollWidth > element.outerWidth isBreaking = true else isBreaking = false
      element.css 'height', 'auto' if isBreaking
      height = element[0].scrollHeight
      element.css 'height', height + 'px'  if height > 0
    scope.$watch attrs.ngModel, update
    attrs.$set 'ngTrim', 'false'

# Register
App.Directives.directive 'autoGrow', autoGrow

@satyamsatyarthi
Copy link

@enapupe & @rafalenden - The jump issue can be fixed by setting the window scroll position after the text area is resized. Not the most elegant or clean solution but it works.

http://stackoverflow.com/questions/18262729/how-to-stop-window-jumping-when-typing-in-autoresizing-textarea/18262927#18262927

.directive("autoGrow", ['$window', function($window){
    return {
        link: function (scope, element, attr, $window) {
            var update = function () {
                var scrollLeft, scrollTop;
                scrollTop = window.pageYOffset;
                scrollLeft = window.pageXOffset;

                element.css("height", "auto");
                var height = element[0].scrollHeight;
                if (height > 0) {
                    element.css("height", height + "px");
                }
                window.scrollTo(scrollLeft, scrollTop);
            };
            scope.$watch(attr.ngModel, function () {
                update();
            });
            attr.$set("ngTrim", "false");
        }
    };
}]);

@kevincobain2000
Copy link

how about visibility

     var $shadow = angular.element('<div></div>').css({
-      position: 'absolute',
-      top: -10000,
-      left: -10000,
+      visibility: "hidden",
       width: element[0].offsetWidth - parseInt(paddingLeft || 0) - parseInt(paddingRight || 0),
       fontSize: element.css('fontSize'),
       fontFamily: element.css('fontFamily'),

``

@LFDM
Copy link

LFDM commented Mar 20, 2015

It probably makes sense to avoid an angular watch here and listen to native events of the input/textarea field.

This also makes it possible to avoid messing around with the ngTrim setting.

function uiAutoGrow($window) {
    return {
        restrict: 'A',
        link: function (scope, element, attr) {
            element.on('input propertychange', update);

            function update() {
                var scrollTop = $window.pageYOffset,
                    scrollLeft = $window.pageXOffset;

                element.css('height', 'auto');
                var height = element[0].scrollHeight;

                if (height > 0) {
                    element.css('height', height + 'px');
                }

                $window.scrollTo(scrollLeft, scrollTop);
            }
        }
    };
}

@kevinleedrum
Copy link

For anyone else that finds this page, I used LFDM's solution, but I added 'overflow:hidden' css, and I added '$timeout(update)' to apply the update on page load as well (for previously saved form data).

function($window, $timeout) {
  return {
    restrict: 'A',
    link: function(scope, element, attr) {
      element.on('input propertychange', update);
      function update() {
          var scrollTop = $window.pageYOffset,
              scrollLeft = $window.pageXOffset;
          element.css({
            height: 'auto',
            overflow: 'hidden'
          });
          var height = element[0].scrollHeight;
          if (height > 0) {
              element.css('height', height + 'px');
          }
          $window.scrollTo(scrollLeft, scrollTop);
      }
      $timeout(update);
    }
  };
}

@schmidt1024
Copy link

@huyttq good work. thank you.

@i-kaplin
Copy link

@kevinleedrum Thanks for your solution. Helped me.

@sunabozu
Copy link

sunabozu commented Nov 1, 2015

@LFDM Thanks, your solution is quite elegant. Although you may want to add focus event, so you can expand textarea by entering it, when you loaded a page and have some text inside it already.

@Dima-HAN
Copy link

Dima-HAN commented Jan 4, 2016

Good solution, I would change event handler a bit to handle paste event with the right mouse button, which is often used to copy paste stuff

element.bind('keyup paste', function(){setTimeout(update, 0);});

@dany28
Copy link

dany28 commented Apr 21, 2016

my solution, for angular and bootstrap with form-control class, using shadow textarea (without fixing input data)

function autoGrow() {
    return {
        restrict: 'A',
        link: function (scope, element, attr, ctrl) {
            var minHeight = element[0].offsetHeight;

            //create shadow textarea
            var $shadowtx = angular.element('<textarea></textarea>').css({
                position: 'absolute',
                top: -10000,
                left: -10000,
                resize: 'none',

            });
            element.css({resize: "none"}).parent().css({ position: "relative" });
            $shadowtx.addClass("form-control");
            //add to element parent
            angular.element(element.parent()[0]).append($shadowtx);

            var update = function (addtext) {
                addtext = addtext || " aaa"; //when line is ending show new line
                $shadowtx.val(element.val() + addtext);
                element.css('height', Math.max($shadowtx[0].scrollHeight + 5 /* the "threshold" */, minHeight) + 'px');
            }

            //on enter catch keydown, but simulate adding enter
            element.bind('keydown', function (event) {
                var keyc = event.keyCode || event.which;
                if (keyc == 13) {
                    update("\n aaa");
                }
            }).bind('keyup', function (event) {
                var keyc = event.keyCode || event.which;
                document.title = keyc;
                if ((keyc == 46) || (keyc==8)) { //delete, backspace, not fired by scope.$watch
                    update();
                }
            });

            //watch model binding
            scope.$watch(attr['ngModel'], function (v) {
                update();
            });
            //watch show
            scope.$watch(attr['ngShow'], function (v) {
                update();
            });

            update();
        }
    };
};

@symonny
Copy link

symonny commented Apr 29, 2016

Thanks . my adjusted version added below makes sure that there are no extra spaces added under the text

  • I used $timeout to make sure the shadow element's sizes are set after the current element is rendered and we have the correct size of the text
  • For textarea style i have set a height / min-height:
textarea{resize: none; box-sizing: content-box; height: auto; overflow: hidden;}
textarea.form-control{ min-height: 16px; height: 16px;  width: 100%;  }

  • Sample usage

<textarea class="form-control word-wrap" auto-size placeholder="Set Location…" ng-model="item.address" ui-focus="isInTabFocus(listIndex, 1)" tabindex="{{getTabIndex(listIndex,1)}}"></textarea>

  • sample result
    screen shot 2016-04-28 at 6 58 26 pm

    .directive('autoSize', ['$timeout', function($timeout) {
      return function (scope, element, attr, ctrl) {
        var minHeight;
        var $shadowtx = angular.element("<textarea class='" + attr['class'] + "'></textarea>");
        //add to element parent
        angular.element(element.parent()[0]).append($shadowtx);
        element.css({resize: "none"}).parent().css({ position: "relative" });
    
        var update = function (addtext) {
          $shadowtx.val(element.val() + (addtext ? addtext: ''));
          element.css('height', Math.max($shadowtx[0].scrollHeight, minHeight) + 'px');
        };
    
        element.bind('keydown', function (event) {
          var keyc = event.keyCode || event.which;
          if (keyc == 13) {
            update("\n");
          }
        }).bind('keyup', function (event) {
          var keyc = event.keyCode || event.which;
          if ((keyc == 46) || (keyc==8)) { //delete, backspace, not fired by scope.$watch
            update();
          }
        });
    
        $timeout(function(){
          minHeight = element[0].offsetHeight;
          $shadowtx.css({
            position: 'absolute',
            top: -10000,
            left: -10000,
            resize: 'none',
            width: element.width(),
            height: element.height()
          });
          update();
        }, 0);
    
        scope.$watch(attr['ngModel'], function(v){update();});
      }
    }]);
    

@moshewe
Copy link

moshewe commented Jul 6, 2016

@symonny - works great OOTB. Nice!

@kuldeepiitg
Copy link

It doesn't work if ng-model is set by code (controller). Like I fetch text from server and set it there on success so it doesn't set proper height.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment