elsampsa / my_pyramid_example

Pyramid Playground

(a notebook mainly for myself)

Install

Prerequisites

sudo apt-get install redis-server

Install

pip3 install --user -e .

Run

pserve --reload development.ini 

Routes & Views

Main view

renders    : home.jinja2 => base.jinja2
route name : home
subaddress : /
view       : views/default.py

Asynchronous GET

• When pressing a button, makes an asynchronous query to the server
• Once the query is done, update the page with new data

renders    : async_get.jinja2 => base.jinja2
route name : async_get
subaddress : /async_get
view       : views/default.py

• The GET query is done to this address & it returns json:

renders    : json
route name : async_get2
subaddress : /async_get2
view       : views/default.py

Download

• Give files to the user for downloading

renders    : download.jinja2 => base.jinja2
route name : download
subaddress : /download
view       : views/default.py

• File comes from here:

renders    : (none)
route name : download2
subaddress : /download2
view       : views/default.py

Session

• Keep session-dependent data
• Each time when user clicks a button, a new entry to the session cache (redis) is created

renders    : session.jinja2 => base.jinja2
route name : session
subaddress : /session           ui
subaddress : /session_push      push more data to cache
subaddress : /session_clear     clear all data from cache
view       : views/session.py

Dash video player

• A nice videoplayer that implements dash, is google's shaka dash media player. See here
• Shaka's dist/shaka-player.compiled* dir is copied to static/shaka/
• We use dash xml file provided by google in here
• (dash xml schema files are here)
• When using dash, it all boils down to generating the mpd xml files. The look like this
• There seems to be no tool to simply generate mpd files. Alternative for generating mpd files and video are ffmpeg for which all dash options seem to be broken, and gpac
• For generating .mpd playlist, one can try to use the shaka packager. Build instructions are here
• ..it uses "gyp" to generate makefiles & build. Complicated, but the instructions are in that link. So much work just to generate a few xml files.. :/
• How to use it, see here
• After finishing the make process, dash playlist generator appears in out/Release/mpd_generator. It takes as an input file "media info files". God knows what they are.

renders    : shaka.jinja2 => base.jinja2
route name : shaka
view       : views/default.py

Web basics

• TCP server at 80. Initial negotiations by the webserver. Server & client decide upon unique TCP socket (with unique in/out ports)
• Request goes through that unique TCP socket. After the request, the socket is discarded (single use)