angular-base64-upload

Converts files from file input into base64 encoded models. This directive is based from one of the answers in this SO question.

Requires angular version greater than or equal to 1.2.0. Tested on angular versions 1.2.0 through 1.3.15.

  <input type="file" ng-model="myfile" base-sixty-four-input>

$scope.myfile :

  {
    "filesize": 54836, /* bytes */
    "filetype": "image/jpeg",
    "filename": "profile.jpg",
    "base64":   "/9j/4AAQSkZJRgABAgAAAQABAAD//gAEKgD/4gIctcwIQA..."
  }

Installation

• Bower - bower install angular-base64-upload
• NPM - npm install angular-base64-upload

Example

See plunker.

Usage

Include angular.js and angular-base64-upload.js in your application and add naif.base64 as dependency to your main module.

angular.module('myApp', ['naif.base64']);

<form>
  <input type='file' ng-model='yourModel' base-sixty-four-input>
</form>

Multiple File Selection

Just add multiple attribute to the input element. yourModel will be an array of base64 file objects.

  <form>
    <input  type="file" ng-model="yourModel" multiple base-sixty-four-input>
  </form>

Validations

• maxsize = Maximum file size in kilobytes (KB) (applied to all files when multi-select is enabled)
• minsize = Minimum file size in kilobytes (KB) (applied to all files when multi-select is enabled)
• maxnum = Maximum number of items to select (applicable only for multi-select)
• minnum = Minimum number of items to select (applicable only for multi-select)
• accept = Input file accept attribute. file_extension|audio/*|video/*|image/*|media_type comma separated
• required = Checks if the model value is null, empty array [] or empty object {}

<form name="form">
  <input type="file" ng-model="files" name="files" multiple accept="image/*, .zip" maxsize="5000" required base-sixty-four-input>
  <span ng-show="form.files.$error.maxsize">Files must not exceed 5000 KB</span>
</form>

Options

• do-not-parse-if-oversize = Prevents the image from being converted to base64 whenever its size exceeds the maximum file size; this can be useful to prevent the browser from freezing whenever an exceedingly large file is uploaded. If this flag is set, the base64 attribute in the model will be set to null whenever an oversized image is uploaded.

• allow-same-file = boolean allow or disallow selecting same file

<form name="form">
  <input type="file" ng-model="files" name="files" base-sixty-four-input do-not-parse-if-oversize>
</form>

Custom Parser

You can implement your own parsing logic before the data gets added into the model.

Use case: You want images to be auto-resized after selecting files and add custom model attributes (Jimp has been used in the example below).

app.controller('ctrl', function ($scope, $q) {

  $scope.resizeImage = function ( file, base64_object ) {
    // file is an instance of File constructor.
    // base64_object is an object that contains compiled base64 image data from file.
    var deferred = $q.defer();
    var url = URL.createObjectURL(file);// creates url for file object.
    Jimp.read(url)
    .then(function (item) {
      item
      .resize(1280, Jimp.AUTO)// width of 1280px, auto-adjusted height
      .quality(50)//drops the image quality to 50%
      .getBase64(file.type, function (err, newBase64) {
        if (err) {throw err;}
        var bytes = Math.round((3/4)*newBase64.length);
        base64Object.filetype = file.type;
        base64Object.filesize = bytes;
        base64Object.base64 = newBase64;
        // Note that base64 in this package doesn't contain "data:image/jpeg;base64," part,
        // while base64 string from Jimp does. It should be taken care of in back-end side.
        deferred.resolve(base64Object);
      });
    })
    .catch(function (err) {
      return console.log(err);// error handling
    });
    return deferred.promise;
  };

});

<script src='/js/jimp.min.js'></script>
<input type="file" base-sixty-four-input ng-model="images" parser="resizeImage" multiple>

Params: - File - File object - Object - base64 encoded representation of file

Note: The parser handler can return a value or a promise. In case of a promise, it's resolved value will be appended to the model.

Events

FileReader Events - You can listen to all FileReader events by adding attributes to the input element using the format event_name="handler". Ex: onerror="errorHandlerFunc". - List of file reader event names: - onabort - onerror - onload - onloadstart - onloadend - onprogress - Params - EventObject - File reader event object depending on the event type. This can be an abort, error, load, loadstart, loadend, or progress event object. - FileReader - A File Reader instance used to read the file. Each file is read by respective file reader instance. - File - Current file being read by the file reader. - FileList - Array of selected files. - FileObjects - Array of base64 file objects that are done reading. - Object - Result of reading the file. In case of reading error, object.base64 might be undefined.

on-change - Unfortunately, Angular's ng-change directive doesn't work so well with input type file. This is the alternative way of binding to input's onchange event.

<input on-change="onChangeHandlerFunc">

• Params:
  • Event - Event object.
  • FileList - Array of selected files.

on-after-validate - Ran after the validations are executed and after file object(s) are added to the model.

<input on-after-validate="onAfterValidateFunc">

• Params:
  • Event - Event object.
  • FileObjects - Array of base64-encoded files.
  • FileList - Array of selected files.

Example event handler implementation: ``` $scope.errorHandler = function (event, reader, file, fileList, fileObjs, object) { console.log("An error occurred while reading file: "+file.name); reader.abort(); };

def create
  @resource.attachment = decode_base64
  # save resource and render response ...
end

def decode_base64
  # decode base64 string
  Rails.logger.info 'decoding base64 file'
  decoded_data = Base64.decode64(params[:your_model][:base64])
  # create 'file' understandable by Paperclip
  data = StringIO.new(decoded_data)
  data.class_eval do
    attr_accessor :content_type, :original_filename
  end

  # set file properties
  data.content_type = params[:your_model][:filetype]
  data.original_filename = params[:your_model][:filename]

  # return data to be used as the attachment file (paperclip)
  data
end