make embedded plotly.js as opt-in via feature flag

Signed-off-by: Andrei Gherghescu <[email protected]>

Author: andrei-ng

Diff for: CHANGELOG.md

@@ -5,7 +5,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) a
 
 ## [0.10.0] - 2024-xx-xx
 ### Added
-- [[#231](https://github.com/plotly/plotly.rs/pull/231)] Added new `plotly_noembed` feature to reduce binary sizes by not embedding `plotly.min.js`.
+- [[#231](https://github.com/plotly/plotly.rs/pull/231)] Added new `plotly_embed_js` feature to reduce binary sizes by not embedding `plotly.min.js` in the library unless explicitly enabled via the feature flag. Deprecates `use_local_plotly` in favor of explicit opt-in via the feature flag and introduce method `use_cdn_plotly` to allow users to use CDN version even behind the `plotly_embed_js` feature flag.
 
 ## [0.9.1] - 2024-09-06
 ### Added

Diff for: README.md

@@ -78,12 +78,12 @@ plot.add_trace(trace);
 plot.write_html("out.html");
 ```
 
-By default, the Plotly JavaScript library will be included via CDN, which results in a smaller filesize, but slightly slower first load as the JavaScript library has to be downloaded first. To instead embed the JavaScript library (several megabytes in size) directly into the HTML file, the following can be done:
+By default, the Plotly JavaScript library will be included via CDN, which results in a smaller filesize, but slightly slower first load as the JavaScript library has to be downloaded first. To instead embed the JavaScript library (several megabytes in size) directly into the HTML file, the library must be compiled with the feature flag `plotly_embed_js`. Once enabled, by default the JavaScript library is directly embedded in the generated HTML file. It is still possible to use the CDN version, by using the `use_cdn_plotly` method.
 
 ```rust
 // <-- Create a `Plot` -->
 
-plot.use_local_plotly();
+plot.use_cdn_plotly();
 plot.write_html("out.html");
 ```
 
@@ -201,10 +201,15 @@ Adds trait implementations so that `image::RgbImage` and `image::RgbaImage` can
 
 Adds support for creating plots directly using [ndarray](https://github.com/rust-ndarray/ndarray) types.
 
-### `plotly_noembed`
+### `plotly_embed_js`
 
-This feature can be used to reduce the binary size by not embedding `plotly.min.js`. This requires the use of the CDN version,
-and disables the `use_local_plotly` method.
+By default, the CDN version of `plotly.js` is used in the library and in the generated HTML files. This feature can be used to opt in for embedding `plotly.min.js` in the generated HTML files. The benefit is that the plot will load faster in the browser.
+
+However, there are two downsides of using this feature flag, one is that the resulting html will be much larger, as a copy of the `plotly.min.js` library is embedded in each HTML file. The second, more relevant, is that a copy of the `plotly.min.js` library needs to be compiled in the `plotly-rs` library itself which increases the size by approx `3.5 Mb`.
+
+When the feature is enabled, users can still opt in for the CDN version by using the method `use_cdn_plotly`.
+
+Note that when using `Plot::to_inline_html()`, it is assumed that the `plotly.js` library is already in scope within the HTML file, so enabling this feature flag will have no effect.
 
 ### `wasm`
 

Diff for: plotly/Cargo.toml

@@ -17,7 +17,7 @@ exclude = ["target/*"]
 kaleido = ["plotly_kaleido"]
 plotly_ndarray = ["ndarray"]
 plotly_image = ["image"]
-plotly_noembed = []
+plotly_embed_js = []
 wasm = ["getrandom", "js-sys", "wasm-bindgen", "wasm-bindgen-futures"]
 with-axum = ["rinja/with-axum", "rinja_axum"]
 

Diff for: plotly/src/plot.rs

@@ -11,40 +11,20 @@ use serde::Serialize;
 
 use crate::{Configuration, Layout};
 
-#[cfg(not(feature = "plotly_noembed"))]
 #[derive(Template)]
 #[template(path = "plot.html", escape = "none")]
 struct PlotTemplate<'a> {
     plot: &'a Plot,
-    remote_plotly_js: bool,
+    plotly_js_source: String,
 }
 
-#[cfg(feature = "plotly_noembed")]
-#[derive(Template)]
-#[template(path = "plot_noembed.html", escape = "none")]
-struct PlotTemplate<'a> {
-    plot: &'a Plot,
-}
-
-#[cfg(not(feature = "plotly_noembed"))]
 #[derive(Template)]
 #[template(path = "static_plot.html", escape = "none")]
 #[cfg(not(target_family = "wasm"))]
 struct StaticPlotTemplate<'a> {
     plot: &'a Plot,
     format: ImageFormat,
-    remote_plotly_js: bool,
-    width: usize,
-    height: usize,
-}
-
-#[cfg(feature = "plotly_noembed")]
-#[derive(Template)]
-#[template(path = "static_plot_noembed.html", escape = "none")]
-#[cfg(not(target_family = "wasm"))]
-struct StaticPlotTemplate<'a> {
-    plot: &'a Plot,
-    format: ImageFormat,
+    plotly_js_source: String,
     width: usize,
     height: usize,
 }
@@ -202,32 +182,26 @@ pub struct Plot {
     #[serde(rename = "config")]
     configuration: Configuration,
     #[serde(skip)]
-    #[cfg(not(feature = "plotly_noembed"))]
-    remote_plotly_js: bool,
+    plotly_js_source: String,
 }
 
 impl Plot {
     /// Create a new `Plot`.
     pub fn new() -> Plot {
         Plot {
             traces: Traces::new(),
-            #[cfg(not(feature = "plotly_noembed"))]
-            remote_plotly_js: true,
+            plotly_js_source: Self::plotly_js_source(),
             ..Default::default()
         }
     }
 
-    /// This option results in the plotly.js library being written directly in
-    /// the html output. The benefit is that the plot will load faster in
-    /// the browser and the downside is that the resulting html will be much
-    /// larger.
-    ///
-    /// Note that when using `Plot::to_inline_html()`, it is assumed that the
-    /// `plotly.js` library is already in scope, so setting this attribute
-    /// will have no effect.
-    #[cfg(not(feature = "plotly_noembed"))]
-    pub fn use_local_plotly(&mut self) {
-        self.remote_plotly_js = false;
+    /// Switch to CDN `plotly.js` in the generated HTML instead of the default
+    /// local `plotly.js` version. Method is only available when the feature
+    /// `plotly_embed_js` is enabled since without this feature the default
+    /// version used is always the CDN version.
+    #[cfg(feature = "plotly_embed_js")]
+    pub fn use_cdn_plotly(&mut self) {
+        self.plotly_js_source = Self::cdn_plotly_js();
     }
 
     /// Add a `Trace` to the `Plot`.
@@ -445,8 +419,7 @@ impl Plot {
     fn render(&self) -> String {
         let tmpl = PlotTemplate {
             plot: self,
-            #[cfg(not(feature = "plotly_noembed"))]
-            remote_plotly_js: self.remote_plotly_js,
+            plotly_js_source: self.plotly_js_source.clone(),
         };
         tmpl.render().unwrap()
     }
@@ -456,8 +429,7 @@ impl Plot {
         let tmpl = StaticPlotTemplate {
             plot: self,
             format,
-            #[cfg(not(feature = "plotly_noembed"))]
-            remote_plotly_js: self.remote_plotly_js,
+            plotly_js_source: self.plotly_js_source.clone(),
             width,
             height,
         };
@@ -472,6 +444,23 @@ impl Plot {
         tmpl.render().unwrap()
     }
 
+    fn plotly_js_source() -> String {
+        if cfg!(feature = "plotly_embed_js") {
+            Self::local_plotly_js()
+        } else {
+            Self::cdn_plotly_js()
+        }
+    }
+
+    fn local_plotly_js() -> String {
+        let local_plotly = include_str!("../templates/plotly.min.js");
+        format!("<script type=\"text/javascript\">{}</script>", local_plotly).to_string()
+    }
+
+    fn cdn_plotly_js() -> String {
+        r##"<script src="https://cdn.plot.ly/plotly-2.12.1.min.js"></script>"##.to_string()
+    }
+
     pub fn to_json(&self) -> String {
         serde_json::to_string(self).unwrap()
     }

Diff for: plotly/templates/plot.html

@@ -8,11 +8,8 @@
 <body>
     <div>
         <script src="https://cdn.jsdelivr.net/npm/[email protected]/es5/tex-svg.js"></script>
-        {% if remote_plotly_js -%}
-        <script src="https://cdn.plot.ly/plotly-2.12.1.min.js"></script>
-        {% else -%}
-        <script type="text/javascript">{% include "plotly.min.js" %}</script>
-        {% endif -%}
+
+        {{plotly_js_source}}
 
         <div id="plotly-html-element" class="plotly-graph-div" style="height:100%; width:100%;"></div>
 

Diff for: plotly/templates/plot_noembed.html

@@ -6,11 +6,8 @@
     <body>
         <div>
             <script src="https://cdn.jsdelivr.net/npm/[email protected]/es5/tex-mml-chtml.js"></script>
-            {% if remote_plotly_js -%}
-            <script src="https://cdn.plot.ly/plotly-2.12.1.min.js"></script>
-            {% else -%}
-            <script type="text/javascript">{% include "plotly.min.js" %}</script>
-            {% endif -%}
+
+           {{plotly_js_source}}
 
             <div id="plotly-html-element" hidden></div>
             <img id="plotly-img-element"></img>
@@ -33,4 +30,4 @@
             </script>
         </div>
     </body>
-</html>
+</html>