Watcher for PlantUML on MacOS

README.md

Install

brew install plantuml fswatch
# Download plantuml-watch.sh
chmod +x ./plantuml-watch.sh
mkdir -p /usr/local/bin
mv ./plantuml-watch.sh /usr/local/bin/plantuml-watch
# Confirm /usr/local/bin is in PATH or mv script to directory in PATH
echo $PATH

Usage

Use plantuml-watch exactly as you would plantuml. Assuming the file foobar.puml is in the current directory, you should see the output below and the default app for the output filetype should open automatically and refresh after every saved change to the the source file.

$ plantuml-watch "*.puml"
Watching for changes in:
foo.puml
bar.puml

plantuml-watch.sh

#!/bin/bash

# Check if at least one argument is provided
if [ $# -lt 1 ]; then
    echo "Usage: $0 \"<file.puml or wildcard>\" [additional arguments for plantuml]"
    exit 1
fi

# Expand wildcard pattern into a list of files
WATCH_FILES=$(ls $1 2>/dev/null)
if [ -z "$WATCH_FILES" ]; then
    echo "No files matching pattern: $1"
    exit 1
fi

shift
PLANTUML_ARGS="$@"

# Function to process a single file
process_file() {
    local file="$1"
    local base_name=$(basename "$file" .puml)
    local dir_name=$(dirname "$file")

    # Determine the output format and file extension
    local output_format="png"  # Default output format
    local extension="png"      # Default extension

    for arg in $PLANTUML_ARGS; do
        if [[ "$arg" == "-t"* ]]; then
            output_format="${arg#-t}"
            extension="${output_format}"
            break
        fi
    done

    if [[ "$extension" == "xmi" || "$extension" == "dot" || "$extension" == "txt" || "$extension" == "pdf" ]]; then
        extension="${output_format}"
    elif [[ "$extension" == "svg" ]]; then
        extension="svg"
    elif [[ "$extension" == "eps" ]]; then
        extension="eps"
    else
        extension="png"
    fi

    local output_file="${dir_name}/${base_name}.${extension}"

    echo "Generating diagram for $file..."
    plantuml "$file" $PLANTUML_ARGS

    if [ -f "$output_file" ]; then
        open "$output_file"
    else
        echo "Output file not found: $output_file"
    fi
}

# Initial run for all matched files
for file in $WATCH_FILES; do
    process_file "$file"
done

# Watch for changes using fswatch
echo "Watching for changes in:"
for file in $WATCH_FILES; do
    echo "$file"
done

# Use fswatch and ensure the output is properly handled
fswatch $WATCH_FILES | while read -r changed_file; do
    # Check if the detected file is valid
    if [ -f "$changed_file" ]; then
        echo "File $changed_file changed, re-running plantuml..."
        process_file "$changed_file"
    else
        echo "Change detected, but no valid file found: $changed_file"
    fi
done