to html --list now returns a table (#7080)

* `to html --list` now returns a table

* Re-add screenshots link

crates/nu-command/src/core_commands/metadata.rs

@@ -86,6 +86,15 @@ impl Command for Metadata {
                                 span: head,
                             })
                         }
+                        PipelineMetadata {
+                            data_source: DataSource::HtmlThemes,
+                        } => {
+                            cols.push("source".into());
+                            vals.push(Value::String {
+                                val: "into html --list".into(),
+                                span: head,
+                            })
+                        }
                     }
                 }
 
@@ -148,6 +157,15 @@ fn build_metadata_record(arg: &Value, metadata: &Option<PipelineMetadata>, head:
                     span: head,
                 })
             }
+            PipelineMetadata {
+                data_source: DataSource::HtmlThemes,
+            } => {
+                cols.push("source".into());
+                vals.push(Value::String {
+                    val: "into html --list".into(),
+                    span: head,
+                })
+            }
         }
     }
 

crates/nu-command/src/formats/to/html.rs

@@ -4,8 +4,8 @@ use nu_engine::CallExt;
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{
-    Category, Config, Example, IntoPipelineData, PipelineData, ShellError, Signature, Spanned,
+    Category, Config, DataSource, Example, IntoPipelineData, PipelineData, PipelineMetadata,
-    SyntaxShape, Type, Value,
+    ShellError, Signature, Spanned, SyntaxShape, Type, Value,
 };
 use rust_embed::RustEmbed;
 use serde::{Deserialize, Serialize};
@@ -109,7 +109,11 @@ impl Command for ToHtml {
                 "the name of the theme to use (github, blulocolight, ...)",
                 Some('t'),
             )
-            .switch("list", "list the names of all available themes", Some('l'))
+            .switch(
+                "list",
+                "produce a color table of all available themes",
+                Some('l'),
+            )
             .category(Category::Formats)
     }
 
@@ -143,6 +147,10 @@ impl Command for ToHtml {
         "Convert table into simple HTML"
     }
 
+    fn extra_usage(&self) -> &str {
+        "Screenshots of the themes can be browsed here: https://github.com/mbadolato/iTerm2-Color-Schemes"
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,
@@ -223,12 +231,6 @@ fn get_html_themes(json_name: &str) -> Result<HtmlThemes, Box<dyn Error>> {
     }
 }
 
-fn get_list_of_theme_names() -> Vec<String> {
-    // If asset doesn't work, make sure to return the default theme
-    let html_themes = get_html_themes("228_themes.json").unwrap_or_default();
-    html_themes.themes.into_iter().map(|n| n.name).collect()
-}
-
 fn to_html(
     input: PipelineData,
     call: &Call,
@@ -251,17 +253,76 @@ fn to_html(
     let mut output_string = String::new();
     let mut regex_hm: HashMap<u32, (&str, String)> = HashMap::with_capacity(17);
 
+    // Being essentially a 'help' option, this can afford to be relatively unoptimised
     if list {
-        // Get the list of theme names
+        // If asset doesn't work, make sure to return the default theme
-        let theme_names = get_list_of_theme_names();
+        let html_themes = get_html_themes("228_themes.json").unwrap_or_default();
 
-        // Put that list into the output string
+        let cols = vec![
-        for s in &theme_names {
+            "name".into(),
-            writeln!(&mut output_string, "{}", s).unwrap();
+            "black".into(),
+            "red".into(),
+            "green".into(),
+            "yellow".into(),
+            "blue".into(),
+            "purple".into(),
+            "cyan".into(),
+            "white".into(),
+            "brightBlack".into(),
+            "brightRed".into(),
+            "brightGreen".into(),
+            "brightYellow".into(),
+            "brightBlue".into(),
+            "brightPurple".into(),
+            "brightCyan".into(),
+            "brightWhite".into(),
+            "background".into(),
+            "foreground".into(),
+        ];
+
+        let result: Vec<Value> = html_themes
+            .themes
+            .into_iter()
+            .map(|n| {
+                let vals = vec![
+                    n.name,
+                    n.black,
+                    n.red,
+                    n.green,
+                    n.yellow,
+                    n.blue,
+                    n.purple,
+                    n.cyan,
+                    n.white,
+                    n.brightBlack,
+                    n.brightRed,
+                    n.brightGreen,
+                    n.brightYellow,
+                    n.brightBlue,
+                    n.brightPurple,
+                    n.brightCyan,
+                    n.brightWhite,
+                    n.background,
+                    n.foreground,
+                ]
+                .into_iter()
+                .map(|val| Value::String { val, span: head })
+                .collect();
+
+                Value::Record {
+                    cols: cols.clone(),
+                    vals,
+                    span: head,
+                }
+            })
+            .collect();
+        return Ok(Value::List {
+            vals: result,
+            span: head,
         }
-
+        .into_pipeline_data_with_metadata(PipelineMetadata {
-        output_string.push_str("\nScreenshots of themes can be found here:\n");
+            data_source: DataSource::HtmlThemes,
-        output_string.push_str("https://github.com/mbadolato/iTerm2-Color-Schemes\n");
+        }));
     } else {
         let theme_span = match &theme {
             Some(v) => v.span,

crates/nu-command/src/viewers/table.rs

@@ -1,5 +1,5 @@
 use lscolors::{LsColors, Style};
-use nu_color_config::{get_color_config, style_primitive};
+use nu_color_config::{color_from_hex, get_color_config, style_primitive};
 use nu_engine::{column::get_columns, env_to_string, CallExt};
 use nu_protocol::{
     ast::{Call, PathMember},
@@ -558,6 +558,7 @@ fn handle_row_stream(
     metadata: Option<PipelineMetadata>,
 ) -> Result<PipelineData, nu_protocol::ShellError> {
     let stream = match metadata {
+        // First, `ls` sources:
         Some(PipelineMetadata {
             data_source: DataSource::Ls,
         }) => {
@@ -575,6 +576,7 @@ fn handle_row_stream(
                         let mut idx = 0;
 
                         while idx < cols.len() {
+                            // Only the name column gets special colors, for now
                             if cols[idx] == "name" {
                                 if let Some(Value::String { val, span }) = vals.get(idx) {
                                     let val = render_path_name(val, &config, &ls_colors, *span);
@@ -594,6 +596,46 @@ fn handle_row_stream(
                 ctrlc,
             )
         }
+        // Next, `into html -l` sources:
+        Some(PipelineMetadata {
+            data_source: DataSource::HtmlThemes,
+        }) => {
+            let ctrlc = ctrlc.clone();
+
+            ListStream::from_stream(
+                stream.map(move |mut x| match &mut x {
+                    Value::Record { cols, vals, .. } => {
+                        let mut idx = 0;
+                        // Every column in the HTML theme table except 'name' is colored
+                        while idx < cols.len() {
+                            if cols[idx] != "name" {
+                                // Simple routine to grab the hex code, convert to a style,
+                                // then place it in a new Value::String.
+                                if let Some(Value::String { val, span }) = vals.get(idx) {
+                                    let s = match color_from_hex(val) {
+                                        Ok(c) => match c {
+                                            // .normal() just sets the text foreground color.
+                                            Some(c) => c.normal(),
+                                            None => nu_ansi_term::Style::default(),
+                                        },
+                                        Err(_) => nu_ansi_term::Style::default(),
+                                    };
+                                    vals[idx] = Value::String {
+                                        // Apply the style (ANSI codes) to the string
+                                        val: s.paint(val).to_string(),
+                                        span: *span,
+                                    };
+                                }
+                            }
+                            idx += 1;
+                        }
+                        x
+                    }
+                    _ => x,
+                }),
+                ctrlc,
+            )
+        }
         _ => stream,
     };
 

crates/nu-command/tests/format_conversions/html.rs

@@ -75,3 +75,15 @@ fn test_no_color_flag() {
         r"<html><style>body { background-color:white;color:black; }</style><body>Change directory.<br><br>Usage:<br>  &gt; cd (path) <br><br>Flags:<br>  -h, --help - Display the help message for this command<br><br>Parameters:<br>  (optional) path &lt;Directory&gt;: the path to change to<br><br>Examples:<br>  Change to your home directory<br>  &gt; cd ~<br><br>  Change to a directory via abbreviations<br>  &gt; cd d/s/9<br><br>  Change to the previous working directory ($OLDPWD)<br>  &gt; cd -<br><br></body></html>"
     );
 }
+
+#[test]
+fn test_list() {
+    let actual = nu!(
+        cwd: ".",
+        r#"to html --list | where name == C64 | get 0 | to nuon"#
+    );
+    assert_eq!(
+        actual.out,
+        r##"{name: C64, black: "#090300", red: "#883932", green: "#55a049", yellow: "#bfce72", blue: "#40318d", purple: "#8b3f96", cyan: "#67b6bd", white: "#ffffff", brightBlack: "#000000", brightRed: "#883932", brightGreen: "#55a049", brightYellow: "#bfce72", brightBlue: "#40318d", brightPurple: "#8b3f96", brightCyan: "#67b6bd", brightWhite: "#f7f7f7", background: "#40318d", foreground: "#7869c4"}"##
+    );
+}

crates/nu-protocol/src/pipeline_data.rs

@@ -56,6 +56,7 @@ pub struct PipelineMetadata {
 #[derive(Debug, Clone)]
 pub enum DataSource {
     Ls,
+    HtmlThemes,
 }
 
 impl PipelineData {
@@ -595,6 +596,7 @@ impl Iterator for PipelineIterator {
 
 pub trait IntoPipelineData {
     fn into_pipeline_data(self) -> PipelineData;
+    fn into_pipeline_data_with_metadata(self, metadata: PipelineMetadata) -> PipelineData;
 }
 
 impl<V> IntoPipelineData for V
@@ -604,6 +606,9 @@ where
     fn into_pipeline_data(self) -> PipelineData {
         PipelineData::Value(self.into(), None)
     }
+    fn into_pipeline_data_with_metadata(self, metadata: PipelineMetadata) -> PipelineData {
+        PipelineData::Value(self.into(), Some(metadata))
+    }
 }
 
 pub trait IntoInterruptiblePipelineData {