Add support for CSS in the CLI. (#9)

* Add support for CSS in the CLI. Resolve #8

examples/example_diagrams.rs

@@ -1,6 +1,7 @@
 use htmlescape;
 use railroad_dsl;
 
+use railroad::DEFAULT_CSS;
 use std::fs;
 use std::io;
 use std::io::{Read, Write};
@@ -23,7 +24,7 @@ fn main() -> Result<(), io::Error> {
                 println!("Generating from `{}`", filename);
                 let mut buffer = String::new();
                 fs::File::open(path.path())?.read_to_string(&mut buffer)?;
-                let diagram = railroad_dsl::compile(&buffer).unwrap();
+                let diagram = railroad_dsl::compile(&buffer, DEFAULT_CSS).unwrap();
                 write!(outp, "<h3>Generated from <i>`{}`</i></h3>", filename)?;
                 write!(
                     outp,

src/bin/railroad.rs

@@ -1,3 +1,4 @@
+use railroad::DEFAULT_CSS;
 use std::fs;
 use std::io::{self, Read};
 use std::path::PathBuf;
@@ -12,21 +13,27 @@ the file extension replaced by `.svg`.")]
 struct Options {
     #[structopt(help = "Input files to process")]
     inputs: Vec<String>,
+    #[structopt(
+        help = "Alternative CSS file for the SVG",
+        long = "css",
+        parse(from_os_str)
+    )]
+    css: Option<PathBuf>,
 }
 
 enum Error {
     Parser(Box<pest::error::Error<railroad_dsl::Rule>>),
     IO(io::Error),
 }
 
-fn dia_from_stdin() -> Result<(), Error> {
+fn dia_from_stdin(css: &str) -> Result<(), Error> {
     let mut buf = String::new();
     match io::stdin().read_to_string(&mut buf) {
         Err(e) => {
             eprintln!("error reading stdin: {e}");
             Err(Error::IO(e))
         }
-        Ok(_) => match railroad_dsl::compile(&buf) {
+        Ok(_) => match railroad_dsl::compile(&buf, css) {
             Err(e) => {
                 eprintln!("syntax error:\n{}", e.clone().with_path("<stdin>"));
                 Err(Error::Parser(e))
@@ -39,7 +46,7 @@ fn dia_from_stdin() -> Result<(), Error> {
     }
 }
 
-fn dia_from_files(inputs: &[String]) -> Result<(), Error> {
+fn dia_from_files(inputs: &[String], css: &str) -> Result<(), Error> {
     let mut err = Ok(());
     for input in inputs {
         let output = PathBuf::from(&input).with_extension("svg");
@@ -48,7 +55,7 @@ fn dia_from_files(inputs: &[String]) -> Result<(), Error> {
                 eprintln!("error reading file {input}: {e}");
                 err = Err(Error::IO(e));
             }
-            Ok(buf) => match railroad_dsl::compile(&buf) {
+            Ok(buf) => match railroad_dsl::compile(&buf, css) {
                 Err(e) => {
                     eprintln!("syntax error:\n{}", e.clone().with_path(input));
                     err = Err(Error::Parser(e));
@@ -66,10 +73,17 @@ fn dia_from_files(inputs: &[String]) -> Result<(), Error> {
 }
 
 fn run(args: &Options) -> Result<(), Error> {
+    let css = args
+        .css
+        .as_deref()
+        .map(|f| fs::read_to_string(f))
+        .unwrap_or_else(|| Ok(DEFAULT_CSS.to_string()))
+        .map_err(Error::IO)?;
+
     if args.inputs.is_empty() {
-        dia_from_stdin()
+        dia_from_stdin(&css)
     } else {
-        dia_from_files(&args.inputs)
+        dia_from_files(&args.inputs, &css)
     }
 }
 

src/lib.rs

@@ -4,6 +4,7 @@ use railroad as rr;
 
 use pest::iterators::Pair;
 use pest::Parser;
+use railroad::svg;
 
 #[derive(Parser)]
 #[grammar = "parser.pest"]
@@ -73,7 +74,7 @@ fn start_to_end(root: Box<dyn rr::Node>) -> Box<dyn rr::Node> {
     ]))
 }
 
-pub fn compile(src: &str) -> Result<Diagram, Box<pest::error::Error<Rule>>> {
+pub fn compile(src: &str, css: &str) -> Result<Diagram, Box<pest::error::Error<Rule>>> {
     let mut result = RRParser::parse(Rule::input, src)?;
     let trees = result.next().expect("expected root_expr").into_inner();
     let mut trees: Vec<_> = trees.map(|p| start_to_end(make_node(p))).collect();
@@ -82,7 +83,14 @@ pub fn compile(src: &str) -> Result<Diagram, Box<pest::error::Error<Rule>>> {
     } else {
         Box::new(rr::VerticalGrid::new(trees))
     };
-    let diagram = rr::Diagram::with_default_css(root);
+
+    let mut diagram = rr::Diagram::new(root);
+    diagram.add_element(
+        svg::Element::new("style")
+            .set("type", "text/css")
+            .raw_text(css),
+    );
+
     let width = (&diagram as &dyn rr::Node).width();
     let height = (&diagram as &dyn rr::Node).height();
     Ok(Diagram {
@@ -95,6 +103,7 @@ pub fn compile(src: &str) -> Result<Diagram, Box<pest::error::Error<Rule>>> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use railroad::DEFAULT_CSS;
     use std::env;
     use std::fs;
     use std::io::Read;
@@ -114,7 +123,7 @@ mod tests {
                         .unwrap()
                         .read_to_string(&mut buffer)
                         .unwrap();
-                    if let Err(e) = compile(&buffer) {
+                    if let Err(e) = compile(&buffer, DEFAULT_CSS) {
                         panic!("Failed to compile {}", e.with_path(filename));
                     }
                 }