BigBlueButton PDF Annotations Server

Development environment

If you want to use virtualisation to run the project, you need to have vagrant installed.

Env vars

Add the following lines to your .profile

export GOROOT=/usr/local/go
export PATH=$GOPATH/bin:$GOROOT/bin:$PATH 

source .profile

How to run?

cd /app or app alias if you are under vagrant

go get github.com/gorilla/mux

go get github.com/jung-kurt/gofpdf

go get github.com/llgcode/draw2d

go get github.com/spf13/viper

go get github.com/sirupsen/logrus

go get github.com/01walid/goarabic

go get github.com/pdfcpu/pdfcpu

Required packages for Python scripts: pip install PyPDF2

librsvg2-bin required for svg to pdf conversion (rsvg-convert)

sudo apt-get install librsvg2-bin Run with go run main.go

• start local server on port 8100

  • Listen for GET request on : http://127.0.0.1:8100/{meetingID}/{presentationID}

    Response: Download pdf file (local location : /tmp/presentationID-final/presentationID.pdf)

  • Listen for POST request on : http://127.0.0.1:8100/{meetingID}/{presentationID} example request (post.sh) Response: Download pdf file (local location : /tmp/presentationID-final/presentationID.pdf)

  • Listen for GET request on : http://127.0.0.1:8100/{meetingID}/{presentationID}/{PageNumber}

    Response: Download pdf file of the wanted page only (local location : /tmp/presentationID-pages-done/presentationID_PageNumber.pdf)

• Create pdf file of the desired presentation with annotations on it

  • go fetch on /var/bigbluebutton/meetingID/meetingID/presentationID
    • if pdf file (presentationID.pdf) exists
      • split the pdf file into single pdf pages and save them on /tmp/presentationID-pages
      • add annotations on every page
        • get the annotations details of each page from /var/bigbluebutton/MeetingID/events.xml
        • draw on each page it's annotations and save the page on /tmp/presentationID-done
      • merge the pdf pages on /tmp/presentationID-done on one pdf file and save in /tmp/presentationID-final
    • if the source presentation is in other format than pdf
      • convert the svgs /var/bigbluebutton/meetingID/presentationID/svgs to pdf files and save them to /tmp/presentationID-pages
      • add annotations on every page
        • get the annotations details of each page from /var/bigbluebutton/MeetingID/events.xml
        • draw on each page it's annotations and save the page on /tmp/presentationID-done
      • merge the pdf pages on /tmp/presentationID-done on one pdf file and save in /tmp/presentationID-final

PDF export API

Run API with go run main.go

Main options

• Download Presentation PDF

  • [From events.xml] : GET /MeetingID/PresentationID
  • [From JSON body] : GET /MeetingID/PresentationID

• Download one page from Presentation PDF

  • [from events.xml] : GET /MeetingID/PresentationID/PageNumber

Configuration variables

• port (listening port for api , 8100)
• OutputPath: (temp path , /tmp/)
• BBBPresPath: (presentation location , /var/bigbluebutton/)
• ScriptDir: (python scripts location , /usr/share/bbb-api-pyscript/)
• EventsPath: (events.xml file location , /var/bigbluebutton/)
• FontPath: ( Arial.ttf font location , /usr/share/fonts/)

Example Requests:

• GET http://127.0.0.1:8100/a49e87847170b7bfa6dbd633004657683499034d-1634463938342/07bfb86c086066090f39d810096a329151261aec-1634463976664

  • In the meeting a49e87847170b7bfa6dbd633004657683499034d-1634463938342 the presentation pdf file 07bfb86c086066090f39d810096a329151261aec-1634463976664 will be downloaded with it's annotations extracted from: EventsPath/a49e87847170b7bfa6dbd633004657683499034d-1634463938342/events.xml

• GET http://127.0.0.1:8100/a49e87847170b7bfa6dbd633004657683499034d-1634463938342/07bfb86c086066090f39d810096a329151261aec-1634463976664/1

  • In the meeting a49e87847170b7bfa6dbd633004657683499034d-1634463938342 the page number 1 from the presentation pdf 07bfb86c086066090f39d810096a329151261aec-1634463976664 will be downloaded with it's annotations extracted from: EventsPath/a49e87847170b7bfa6dbd633004657683499034d-1634463938342/events.xml

• POST exemple

  • curl --request POST
    --url http://127.0.0.1:8100/a49e87847170b7bfa6dbd633004657683499034d-1634463938342/07bfb86c086066090f39d810096a329151261aec-1634463976664
    --header 'Content-Type: application/json'
    --data

 {
  "_eventname": "AddShapeEvent",
  "presentation": "07bfb86c086066090f39d810096a329151261aec-1634463976664",
  "whiteboardId": "07bfb86c086066090f39d810096a329151261aec-1634463976664/1",
  "pageNumber": 0,
  "type": "pencil",
  "position": 0,
  "dataPoints": "20.768291,44.483734,28.794786,43.68109,36.86562,44.239834,44.91463,44.239834",
  "color": 16711680,
  "thickness": 0.3658536585365854,
  "dimensions": "List(547, 410)",
  "commands": "1,4"
 },
 {
  "_eventname": "AddShapeEvent",
  "presentation": "07bfb86c086066090f39d810096a329151261aec-1634463976664",
  "whiteboardId": "07bfb86c086066090f39d810096a329151261aec-1634463976664/2",
  "pageNumber": 1,
  "type": "text",
  "x": 52.42053561740452,
  "y": 52.905454282407405,
  "fontColor": 255,
  "textBoxWidth": 31.723717583550346,
  "textBoxHeight": 8.80195900245949,
  "text": "Test text",
  "fontSize": 20,
  "calcedFontSize": 4.88997555012225,
  "position": 0,
  "dataPoints": "52.42053561740452,52.905454282407405"
 }
]'

Convert XML to json annotations

Just use test.go application