Calling YouTube API from commandline (requires jsonCLI.py)

call_yt_api.sh

#!/bin/bash
#    Call YouTube API from command line.
#    Copyright (C) 2015 Christoph "criztovyl" Schulz
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

###
# Requires jsonCLI.py: https://github.com/criztovyl/jsonCLI/blob/master/jsonCLI.py
###

###
# ToDO
#  - different behaviour if sourced
#  - cache
#   + cache the result, as ~/.call_yt_api/$1_$2.json
#   + should give the user access to the file without redownloading
#   + should be removed if the user gets his result (handle via "end" arg? Backwards compatible.)

###
# Script
# Do not edit below this line.
#

###
# Read in the help
#

# The text
readarray help <<-API_KEY_HELP
# How to get your API Key
- got to https://console.developers.google.com/project
- select your project (if have no project, see "Create Project" and continue below afterwards)
- select APIs & auth on left navigation
- select Credentials
- your key is the "API Key" from "Public API access" (see "Create API Key" if you have none)

# Create a Project
- click on "Create Project"
- give the project a name and click on "Create"
- wait until Google created the project, it will open as soon its ready

# Create API Key
- click on "Create new Key" below "Public API access"
- select "Browser Key"
- enter nothing and click "Create"
- your key will appear as soon as its created.

# The key file
- the key is stored in the first line of ~/.google_api_key
API_KEY_HELP

##
# Store help into variable

# Clear variable
helpvar=

# Iterate over help lines; join by newline
for i in "${help[@]}"; do

    # Append line and newline to variable
    helpvar=$helpvar$i"\n"

done

# Remove last newline
helpvar=${helpvar%\\n}

# Finally replace help-lines array with joined lines
help=$helpvar

###
# The API key
#

# The keyfile
keyfile=$HOME"/.google_api_key"

# read key from keyfile
[ -f $keyfile ] && read key <$keyfile

# Loop for key if no key was found.
while true;
do
    if [ -z "$key" ]; then

        #Ask for key on stdin

        #Variables
        yes_lc="y"
        question="The API Key is empty, set now? [Y]es [N]o [H]elp [Q]uit"
        action="read -p \"Enter your API Key: \" key"

        # Read single yes/no character
        read -n 1 -p "$question " char

        # To lower case
        char=${char,,}

        # Determine answer and executes action on yes (y) or on nothing (newline)
        # Also determines if need to add a newline (if entered single character, not newline)
        nl="\n"
        [ -z "$char" ] && nl="" || [ "$char" == "y" ] && echo -ne "$nl" && eval "$action" || { \
            echo -ne "$nl"; \
            [ "$char" == "h" ] && echo -e $help && exit 0 || \
            [ "$char" == "n" ] && echo "Continue without API key." && break || \
            [ "$char" == "q" ] && exit 1
        }
    else
        break;
    fi
done

# Save key to keyfile
echo $key > $keyfile

###
# Usage: call_yt_api action data jsonPath
#  resource: e.g. channels, see https://developers.google.com/youtube/v3/docs/#resource_types
#   (method is currently "list" only)
#  parameters: e.g. part=snippet&id=... (name1=value1&name2=value2&...&nameN=valueN)
#   You can leave out "part=snippet", it will be added by default, if no other "part=" is given.
#  jsonPath: arguments for jsonCLI, normally wich JSON Object should be returned.
#   I.e. "items 0 snippet id" (you can put here other jsonCLI args also)
function call_yt_api()
{
    # Variables
    resource=$1
    params=$2
    jsonPath=${@:3}

    # Add default part=snippet if no part is given
    [ "$params" != *"part="* ] && params=$params"&part=snippet"

    # If available, append API key to params
    [ "$key" ] && params=$params"&key="$key

    # Remove & from beginning of params (if there)
    params=${params/#\&/}

    # Insert into URL
    url="https://www.googleapis.com/youtube/v3/$resource?$params"

    # Download and get json data
    echo `curl -s $url | jsonCLI $jsonPath`
}
call_yt_api $@