feat: add django-diagrams hook

.pre-commit-hooks.yaml

@@ -20,3 +20,9 @@
   entry: (has_perm|@permission_required)\(["'][^\."']+["']\)
   language: pygrep
   types: [python]
+#  when calling this hook in a repo you must add args: [<path to local settings e.g. qrhub.settings.local>] in the repo .pre-commit-config.yaml file
+- id: create-django-diagrams
+  name: Create Django Diagrams
+  entry: bash generate_diagrams.sh
+  language: system
+  files: ^.*/migrations/.*\.py$

generate_diagrams.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+
+DIRECTORY="./docs/model_diagrams/"
+
+# If the directory doesn't exist, create it
+mkdir -p $DIRECTORY
+
+# the settings module is the first argument
+SETTINGS_MODULE="$1"
+
+# remove the first argument passed to the script
+shift
+
+# the rest of the arguments are migration file names
+MIGRATIONS=$@
+
+# declare an array to hold the app names
+declare -a APP_NAMES=()
+
+# loop through the migrations and get the app names
+for migration in $MIGRATIONS; do
+    APP_NAMES+=("$(echo "$migration" | cut -d'/' -f1)")
+done
+
+# declare an array and use it to get the unique app names
+FINAL_APP_NAMES=($(echo "${APP_NAMES[@]}" | tr ' ' '\n' | sort -u | tr '\n' ' '))
+
+# loop through the unique app names and generate the diagrams
+for APP in "${FINAL_APP_NAMES[@]}"; do
+    python -m django_diagram -a $APP -o $DIRECTORY/$APP.md -s $SETTINGS_MODULE
+done
+
+# add the diagrams to git
+git add $DIRECTORY