Cs-angular-base64-upload NPM

angular-base64-upload

Alt text

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 or the ./demo folder.

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 = required

<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>

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.

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

  $scope.resizeImage = function ( file, base64_object ) {

    var deferred = $q.defer();

    imageProcessor.run(file).then(function (resized) {
      var modelVal = {
        file: file,
        resized: resized
      };
      deferred.resolve(modelVal); // resolved value is appended to the model
    });

    return deferred.promise;
  };

});

<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.

Example event handler implementation:

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

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

Server-Side

You will have to decode the base64 file in your backend on your own. Sample PHP code for decoding base64 file in demo folder. Start it by cd-ing to this directory and running:

php -S 0.0.0.0:8000

Then point your browser to http://localhost:8000.

Below is a ruby code for decoding the base64-encoded file to be passed to paperclip:

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