do not crash if there are no items to paginate

Cargo.lock

@@ -889,7 +889,7 @@ dependencies = [
 
 [[package]]
 name = "little-hesinde"
-version = "0.1.4"
+version = "0.1.5"
 dependencies = [
  "calibre-db",
  "clap",

little-hesinde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "little-hesinde"
-version = "0.1.4"
+version = "0.1.5"
 edition = "2021"
 license =  { workspace = true }
 authors =  { workspace = true }

little-hesinde/src/handlers/paginated.rs

@@ -1,16 +1,13 @@
 //! Deal with cursor pagination.
 
-use std::fmt::Debug;
+use super::error::HandlerError;
-
+use crate::templates::TEMPLATES;
 use calibre_db::data::error::DataStoreError;
 use poem::{error::InternalServerError, web::Html, IntoResponse, Response};
 use serde::Serialize;
+use std::fmt::Debug;
 use tera::Context;
 
-use crate::templates::TEMPLATES;
-
-use super::error::HandlerError;
-
 /// Render a tera template with paginated items and generate back and forth links.
 pub fn render<T: Serialize + Debug, F, S, P, M>(
     template: &str,
@@ -25,11 +22,18 @@ where
     P: Fn(&str) -> Result<bool, DataStoreError>,
     M: Fn(&str) -> Result<bool, DataStoreError>,
 {
-    let items = fetcher().map_err(HandlerError::DataError)?;
-
     let mut context = Context::new();
+    context.insert("nav", template);
+
+    let items = fetcher().map_err(HandlerError::DataError)?;
+    if items.is_empty() {
+        return Ok(TEMPLATES
+            .render("empty", &context)
+            .map_err(InternalServerError)
+            .map(Html)?
+            .into_response());
+    }
 
-    // fails already in the sql query if there is nothing returned
     let first_item = items.first().unwrap();
     let last_item = items.last().unwrap();
 
@@ -42,7 +46,6 @@ where
     context.insert("has_more", &has_more);
     context.insert("backward_cursor", &backward_cursor);
     context.insert("forward_cursor", &forward_cursor);
-    context.insert("nav", template);
     context.insert(template, &items);
 
     Ok(TEMPLATES

little-hesinde/src/lib.rs

@@ -71,7 +71,7 @@ pub mod opds {
 pub mod templates;
 
 pub const APP_NAME: &str = "little-hesinde";
-pub const VERSION: &str = "0.1.4";
+pub const VERSION: &str = "0.1.5";
 
 /// Internal marker data in lieu of a proper `Accept` header.
 #[derive(Debug, Clone, Copy)]

little-hesinde/src/templates.rs

@@ -13,6 +13,7 @@ pub static TEMPLATES: Lazy<Tera> = Lazy::new(|| {
         ("book_list", include_str!("../templates/book_list.html")),
         ("books", include_str!("../templates/books.html")),
         ("series", include_str!("../templates/series.html")),
+        ("empty", include_str!("../templates/empty.html")),
     ])
     .expect("failed to parse tera templates");
 

little-hesinde/templates/empty.html

@@ -0,0 +1,6 @@
+{% extends "base" %}
+{% block title %}
+{% endblock title %}
+{% block content %}
+<h2>No items</h2>
+{% endblock content %}