ipyupload 0.1.0

# Jupyter custom ipywidget: **ipyupload**

## 1 - Overview

This repo contains the source code and the building scripts for **ipyupload** a custom [ipywidget](https://ipywidgets.readthedocs.io/en/stable/).

It enables to upload a file from a Jupyter notebook - classic or JupyterLab.

It allows:

- single or multiple file upload
- to restrict the upload to certain file types
- to disable the file upload

Under the hood:

- The [FileReader](https://developer.mozilla.org/en-US/docs/Web/API/FileReader) Web API is used.
- Data is read throught the [readAsArrayBuffer()](https://developer.mozilla.org/en-US/docs/Web/API/FileReader/readAsArrayBuffer) method, then converted to a [DataView](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView) before syncing back to Python.
- The convertion to Python bytes uses the ipywidgets deserializer [bytes_serialization](https://github.com/jupyter-widgets/ipywidgets/blob/a5709728f71e21c81a89e8d123dde2068dd1e74d/ipywidgets/widgets/trait_types.py#L196) already used for the [Media core widget](https://github.com/jupyter-widgets/ipywidgets/blob/a5709728f71e21c81a89e8d123dde2068dd1e74d/ipywidgets/widgets/widget_media.py#L36).
- The metadata are synced back as a `List(Dict)`.
- The file contents are synced back as a `List(Bytes)`.
- An `Int` counter is observed and upon change triggers the aggregation of the data and presentation to the user as a dict {filename: {metadata, file content in bytes}) in the `.value` property.

After an upload the button displays the number of files uploaded, to provide feedback to the user.

Naturally such an upload widget is mostly useful in a widgetized notebook and/or in a JupyterHub context, with a remote kernel.

## 2 - Install

## 2.1 - User Install

>From terminal:

```bash
# for notebook >= 5.3
$ pip install ipyupload

# for notebook < 5.3
$ pip install ipyupload
$ jupyter nbextension install ipyupload --py --sys-prefix
```

## 2.2 - Developer Install

>From terminal:

```bash
$ git clone https://gitlab.com/oscar6echo/ipyupload.git
$ cd ipyupload/js
$ npm install
$ cd ..
$ pip install -e .
$ jupyter nbextension install --py --symlink --sys-prefix ipyupload
$ jupyter nbextension enable --py --sys-prefix ipyupload
```

# 3 - Use

```python
from IPython.display import display
from ipyupload import FileUpload

w = FileUpload(
# https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input#attr-accept
# eg. '.txt', '.pdf', 'image/*', 'image/*,.pdf'
accept='', # default
# True to accept multiple files upload else False
multiple=False, # default
# True to disable the button else False to enable it
disabled=False, # default
# CSS transparently passed to button (in a fact a label element)
# e.g. 'color: darkblue; background-color: lightsalmon; width: 180px;'
style_button='' # default
)
display(w)
```

See the [demo notebook](https://nbviewer.jupyter.org/urls/gitlab.com/oscar6echo/ipyupload/blob/master/notebooks/demo-ipyupload.ipynb) for samples.