chore: allow specifying path for temporary export files (#518)

mfontanini · web-flow · commit b52fd4ce8fbf · 2025-03-22T09:11:12.000-07:00
This adds a `--export-temporary-path` that allows using some specific path to store intermediate files used when exporting to pdf (currently an html and a css file) rather than using a temporary path. This helps debugging #516 but is also generally useful.
diff --git a/src/export/exporter.rs b/src/export/exporter.rs
@@ -24,7 +24,38 @@ use crossterm::{
     terminal::{Clear, ClearType},
 };
 use image::ImageError;
-use std::{fs, io, path::Path, rc::Rc, thread::sleep, time::Duration};
+use std::{
+    fs, io,
+    path::{Path, PathBuf},
+    rc::Rc,
+    thread::sleep,
+    time::Duration,
+};
+use tempfile::TempDir;
+
+pub enum OutputDirectory {
+    Temporary(TempDir),
+    External(PathBuf),
+}
+
+impl OutputDirectory {
+    pub fn temporary() -> io::Result<Self> {
+        let dir = TempDir::with_suffix("presenterm")?;
+        Ok(Self::Temporary(dir))
+    }
+
+    pub fn external(path: PathBuf) -> io::Result<Self> {
+        fs::create_dir_all(&path)?;
+        Ok(Self::External(path))
+    }
+
+    pub(crate) fn path(&self) -> &Path {
+        match self {
+            Self::Temporary(temp) => temp.path(),
+            Self::External(path) => path,
+        }
+    }
+}
 
 /// Allows exporting presentations into PDF.
 pub struct Exporter<'a> {
@@ -65,7 +96,11 @@ impl<'a> Exporter<'a> {
     /// Export the given presentation into PDF.
     ///
     /// This uses a separate `presenterm-export` tool.
-    pub fn export_pdf(mut self, presentation_path: &Path) -> Result<(), ExportError> {
+    pub fn export_pdf(
+        mut self,
+        presentation_path: &Path,
+        output_directory: OutputDirectory,
+    ) -> Result<(), ExportError> {
         println!(
             "exporting using rows={}, columns={}, width={}, height={}",
             self.dimensions.rows, self.dimensions.columns, self.dimensions.width, self.dimensions.height
@@ -91,7 +126,7 @@ impl<'a> Exporter<'a> {
         .build(elements)?;
         Self::validate_theme_colors(&presentation)?;
 
-        let mut render = PdfRender::new(self.dimensions)?;
+        let mut render = PdfRender::new(self.dimensions, output_directory);
         Self::log("waiting for images to be generated and code to be executed, if any...")?;
         for slide in presentation.iter_slides_mut() {
             Self::render_async_images(slide);
diff --git a/src/export/pdf.rs b/src/export/pdf.rs
@@ -1,4 +1,4 @@
-use super::exporter::ExportError;
+use super::exporter::{ExportError, OutputDirectory};
 use crate::{
     markdown::text_style::{Color, TextStyle},
     presentation::Slide,
@@ -18,7 +18,6 @@ use std::{
     fs, io,
     path::{Path, PathBuf},
 };
-use tempfile::TempDir;
 
 // A magical multiplier that converts a font size in pixels to a font width.
 //
@@ -130,14 +129,13 @@ impl HtmlSlide {
 }
 
 pub(crate) struct ContentManager {
-    output_directory: TempDir,
+    output_directory: OutputDirectory,
     image_count: usize,
 }
 
 impl ContentManager {
-    pub(crate) fn new() -> io::Result<Self> {
-        let output_directory = TempDir::with_suffix("presenterm")?;
-        Ok(Self { output_directory, image_count: 0 })
+    pub(crate) fn new(output_directory: OutputDirectory) -> Self {
+        Self { output_directory, image_count: 0 }
     }
 
     fn persist_image(&mut self, image: &Image) -> Result<PathBuf, ExportError> {
@@ -177,9 +175,9 @@ pub(crate) struct PdfRender {
 }
 
 impl PdfRender {
-    pub(crate) fn new(dimensions: WindowSize) -> io::Result<Self> {
-        let image_manager = ContentManager::new()?;
-        Ok(Self { content_manager: image_manager, dimensions, html_body: "".to_string(), background_color: None })
+    pub(crate) fn new(dimensions: WindowSize, output_directory: OutputDirectory) -> Self {
+        let image_manager = ContentManager::new(output_directory);
+        Self { content_manager: image_manager, dimensions, html_body: "".to_string(), background_color: None }
     }
 
     pub(crate) fn process_slide(&mut self, slide: Slide) -> Result<(), ExportError> {
diff --git a/src/main.rs b/src/main.rs
@@ -25,6 +25,7 @@ use crossterm::{
     style::{PrintStyledContent, Stylize},
 };
 use directories::ProjectDirs;
+use export::exporter::OutputDirectory;
 use render::properties::WindowSize;
 use std::{
     env::{self, current_dir},
@@ -69,6 +70,10 @@ struct Cli {
     #[clap(short, long)]
     export_pdf: bool,
 
+    /// The path in which to store temporary files used when exporting.
+    #[clap(long, requires = "export_pdf")]
+    export_temporary_path: Option<PathBuf>,
+
     /// Generate a JSON schema for the configuration file.
     #[clap(long)]
     generate_config_file_schema: bool,
@@ -407,7 +412,11 @@ fn run(cli: Cli) -> Result<(), Box<dyn std::error::Error>> {
             builder_options,
             dimensions,
         );
-        exporter.export_pdf(&path)?;
+        let output_directory = match cli.export_temporary_path {
+            Some(path) => OutputDirectory::external(path),
+            None => OutputDirectory::temporary(),
+        }?;
+        exporter.export_pdf(&path, output_directory)?;
     } else {
         let SpeakerNotesComponents { events_listener, events_publisher } =
             SpeakerNotesComponents::new(&cli, &config, &path)?;
