streamlit-pdf-viewer

Streamlit component that allows the visualisation and enrichment of PDF documents. You can see an application in action here.

Features

Show PDF files in a Streamlit application with a simple command
Based on the pdf.js library
Support showing the PDF with the native pdf.js browser's viewer: "legacy" (with limitations, no annotations, no scrolling, etc..)
Visualize annotations on top of the PDF documents
Render text on top of the PDF document, allowing copy-paste
Allow to render specific pages of the PDF document
Scroll to a specific page
Scroll to a specific annotation

Limitations

Tested and developed to support Firefox and Chrome.
The legacy visualization works only on Firefox and does not support annotations
Our Javascript skills are limited, so all troubleshooting may take time
The component is still in development, so expect some bugs and limitations
The streamlit reload at each action may render slowly for complex PDF documents

Getting started

pip install streamlit-pdf-viewer

In your streamlit application, you can use it as:

import streamlit as st
from streamlit_pdf_viewer import pdf_viewer

pdf_viewer("str, path or bytes")

Caveats

Here some caveats to be aware of:

Is mandatory to specify a width to show PDF document on tabs and expanders, otherwise, the viewer will not be displayed on tabs not immediately visible.
The legacy rendering is not supported on Chrome, due to security reasons.

Params

In the following table the list of parameters that can be provided to the pdf_viewer function:

name	description
input	The source of the PDF file. Accepts a file path, URL, or binary data.
width	Width of the PDF viewer in pixels. It defaults to 700 pixels.
height	Height of the PDF viewer in pixels. If not provided, the viewer shows the whole content.
annotations	A list of annotations to be overlaid on the PDF. Format is described here.
pages_vertical_spacing	The vertical space (in pixels) between each page of the PDF. Defaults to 2 pixels.
annotation_outline_size	Size of the outline around each annotation in pixels. Defaults to 1 pixel.
rendering	Type of rendering: `unwrap` (default), `legacy_iframe`, or `legacy_embed`. The default value, `unwrap` shows the PDF document using pdf.js, and supports the visualisation of annotations. Other values are `legacy_iframe` and `legacy_embed` which use the legacy approach of injecting the document into an `<embed>` or `<iframe>`. They allow viewing the PDF using the viewer of the browser that contains additional features we are still working to implement in this component. IMPORTANT: ⚠️ The "legacy" methods work only with Firefox, and do not support annotations. ⚠️
pages_to_render	Filter the rendering to a specific set of pages. By default, all pages are rendered.
render_text	Enable a layer of text on top of the PDF document. The text may be selected and copied. NOTE to avoid breaking existing deployments, we made this optional at first, also considering that having many annotations might interfere with the copy-paste.
scroll_to_page	Scroll to a specific page when the component is rendered. Default is None. Require ints and ignores the parameters below zero.
scroll_to_annotation	Scroll to a specific annotation when the component is rendered. Default is None. Mutually exclusive with `scroll_to_page`. Raise an exception if used with `scroll_to_page`

Annotation format

The annotations format has been derived from the Grobid's coordinate formats, which are described as a list of "bounding boxes". The annotations are expressed as a dictionary of six elements, the page, x and y indicate the top left point. The color can be expressed following the html CSS convention.

Here an example:

[
   {
      "page": 1,
      "x": 220,
      "y": 155,
      "height": 22,
      "width": 65,
      "color": "red"
   },
[...]

The example shown in our screenshot can be found here.

Developers notes

Environment

Python >= 3.8
Node.js >= 16
Streamlit >= 1.28.2

Configure environment for development

First, make sure that _RELEASE = False in streamlit_pdf_viewer/__init__.py. To run the component in development mode, use the following commands:

streamlit run streamlit_pdf_viewer/__init__.py

cd frontend
npm run serve

These commands will start the Streamlit application and serve the Node.js component. Please make sure you're in the correct directory before running these commands.

Integrate into a streamlit application

Build the frontend part:

cd frontend
export NODE_OPTIONS=--openssl-legacy-provider
npm run build

Make sure that _RELEASE = True in streamlit_pdf_viewer/__init__.py.
move to the streamlit_application and run
```
pip install -e {path of component}
```

Release

bump-my-version bump patch | minor | major

git push
git push --tags

Acknowledgement

The project was initiated at the National Institute for Materials Science (NIMS) in Japan. Currently, the development is possible thanks to ScienciLAB. Main collaborator: Tomoya Mato very helpful to attenuate the pain of Javascript.

lfoppiano/streamlit-pdf-viewer