Discover the magic of instant image previews with paperclip in your ruby on rails application

Question

Discover the magic of instant image previews with paperclip in your ruby on rails application

Essentially, my goal is to provide users with a preview of their uploaded image before they finalize the submission.

Within the controller, I have the following:

def index
    @temp = Temp.new
end

Given that @temp is not saved, can I still implement the solution outlined in Rails: Paperclip & previews? If not, could I potentially execute some JavaScript or other method to incorporate Ruby code?

This is an excerpt from my HTML:

= form_for @temp, :url => temp_path, :html => { :multipart => true } do |form|
   = form.file_field :image
= image_tag @temp.image.url

= image_tag @temp.image.url(:medium)

= image_tag @temp.image.url(:thumb)

javascript ruby-on-rails ruby

Answer 1

Answer №1

If you're looking to preview an image before uploading it, there's a cool trick you can do with some javascript.

Simply set the width and height attributes of the image tag to create a thumbnail-like effect.

$(function() {
  $('#pictureInput').on('change', function(event) {
    var files = event.target.files;
    var image = files[0]
    var reader = new FileReader();
    reader.onload = function(file) {
      var img = new Image();
      console.log(file);
      img.src = file.target.result;
      $('#target').html(img);
    }
    reader.readAsDataURL(image);
    console.log(files);
  });
});

Here's the HTML snippet:

<form>
  <input type="file" id="pictureInput"> 
</form>
<div id="target">
</div>

You can see this in action on CodePen.

Answer 2

If you're looking to preview an image before uploading it, there's a cool trick you can do with some javascript.

Simply set the width and height attributes of the image tag to create a thumbnail-like effect.

$(function() {
  $('#pictureInput').on('change', function(event) {
    var files = event.target.files;
    var image = files[0]
    var reader = new FileReader();
    reader.onload = function(file) {
      var img = new Image();
      console.log(file);
      img.src = file.target.result;
      $('#target').html(img);
    }
    reader.readAsDataURL(image);
    console.log(files);
  });
});

Here's the HTML snippet:

<form>
  <input type="file" id="pictureInput"> 
</form>
<div id="target">
</div>

You can see this in action on CodePen.

Answer 3

Answer №2

Here's the solution that solved my problem:

  $('.file-input').on 'change', (event) ->
    $('.image').attr('src', URL.createObjectURL(this.files[0]))

Answer 4

Here's the solution that solved my problem:

  $('.file-input').on 'change', (event) ->
    $('.image').attr('src', URL.createObjectURL(this.files[0]))

Answer 5

Answer №3

Avoid using jQuery for this task. A more efficient approach can be achieved with modern JavaScript:

const imageInput = document.querySelector('#pictureInput');

imageInput.addEventListener('change', (event) => {
  let files = event.target.files;
  let selectedImage = files[0];
  let reader = new FileReader();
  reader.onload = function(file) {
    let imgElement = new Image();
    console.log(file);
    imgElement.src = file.target.result;
    let targetElement = document.querySelector('#target')
    while (targetElement.firstChild) {
      targetElement.removeChild(targetElement.firstChild);
    }
    document.querySelector('#target').appendChild(imgElement)
  }
  reader.readAsDataURL(selectedImage);
  console.log(files);
});

Answer 6

Avoid using jQuery for this task. A more efficient approach can be achieved with modern JavaScript:

const imageInput = document.querySelector('#pictureInput');

imageInput.addEventListener('change', (event) => {
  let files = event.target.files;
  let selectedImage = files[0];
  let reader = new FileReader();
  reader.onload = function(file) {
    let imgElement = new Image();
    console.log(file);
    imgElement.src = file.target.result;
    let targetElement = document.querySelector('#target')
    while (targetElement.firstChild) {
      targetElement.removeChild(targetElement.firstChild);
    }
    document.querySelector('#target').appendChild(imgElement)
  }
  reader.readAsDataURL(selectedImage);
  console.log(files);
});

Discover the magic of instant image previews with paperclip in your ruby on rails application

Answer №1

Answer №2

Answer №3

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