Misc · Export and import: export, field mapping and a CSV importer

misc::ExportDialog offers the owner's formats as cards and hands the
chosen one over for the owner to write. misc::ImportDialog maps the
file's columns to the app's fields, matched by name to start, over a
preview, and asks for each required field's column. misc::CsvImporter
reads CSV as RFC 4180, lets the first row name the columns or not, and
maps it through the ImportDialog into records; text that does not read
says why.

examples/gallery/pages/misc/mod.rs

@@ -10,13 +10,14 @@ use crate::ui::{section, specimen, specimens};
 mod asking;
 mod codes;
 mod notices;
+mod transfer;
 mod web;
 
 pub const PAGE: Page = Page {
     number: 42,
     slug: "misc",
     title: "Misc",
-    summary: "Small tools that stand alone: clocks, a stopwatch, a calculator, a unit converter, a QR code scanner, a captcha, a poll, a survey, a quiz, flashcards, licenses, terms, a cookie banner and web views.",
+    summary: "Small tools that stand alone: clocks, a stopwatch, a calculator, a unit converter, a QR code scanner, a captcha, a poll, a survey, a quiz, flashcards, licenses, terms, a cookie banner, data out and in, and web views.",
     render,
     script: &[
         Step::DownAt("stopwatch-start", 30.0, 62.0),
@@ -66,6 +67,14 @@ pub const PAGE: Page = Page {
         Step::UpAt("cookies", 230.0, 84.0),
         Step::HoverAt("cookies", 20.0, 20.0),
         Step::Shot("cookies-choosing"),
+        Step::DownAt("open-export", 20.0, 16.0),
+        Step::UpAt("open-export", 20.0, 16.0),
+        Step::Shot("export"),
+        Step::Key("escape"),
+        Step::DownAt("open-csv", 20.0, 16.0),
+        Step::UpAt("open-csv", 20.0, 16.0),
+        Step::Shot("csv-import"),
+        Step::Key("escape"),
         Step::DownAt("web", 240.0, 100.0),
         Step::UpAt("web", 240.0, 100.0),
         Step::DownAt("converter", 24.0, 60.0),
@@ -89,6 +98,7 @@ fn render(window: &mut Window, cx: &mut App) -> AnyElement {
         .child(codes::render(window, cx))
         .child(asking::render(window, cx))
         .child(notices::render(window, cx))
+        .child(transfer::render(window, cx))
         .child(web::render(cx))
         .into_any_element()
 }

examples/gallery/pages/misc/transfer.rs

@@ -0,0 +1,144 @@
+use ely_gpui_component::{
+    buttons::Button,
+    misc::{CsvImporter, ExportDialog, ExportFormat, ImportDialog, ImportField},
+    theme::ActiveTheme,
+};
+use gpui::{App, IntoElement, ParentElement, SharedString, Styled, Window, div};
+
+use crate::probe::probe;
+use crate::ui::section;
+
+const PEOPLE: &str = "Name,Email,Team\nAda Lovelace,ada@example.com,Engines\n\"Lin, Wei\",lin@example.com,Maps\nGrace Hopper,grace@example.com,Compilers\n";
+
+/// Which dialog is open.
+#[derive(Clone, Copy, PartialEq)]
+enum Open {
+    None,
+    Export,
+    Import,
+    Csv,
+}
+
+fn fields() -> [ImportField; 3] {
+    [
+        ImportField::new("name").required(),
+        ImportField::new("email").required(),
+        ImportField::new("phone"),
+    ]
+}
+
+pub fn render(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let open = window.use_keyed_state("transfer-open", cx, |_, _| Open::None);
+    let said = window.use_keyed_state("transfer-said", cx, |_, _| SharedString::default());
+    let shut = |words: String,
+                open: &gpui::Entity<Open>,
+                said: &gpui::Entity<SharedString>,
+                cx: &mut App| {
+        open.update(cx, |open, cx| {
+            *open = Open::None;
+            cx.notify();
+        });
+        said.update(cx, |said, cx| {
+            *said = words.into();
+            cx.notify();
+        });
+    };
+    let opener = |which: Open, label: &'static str, key: &'static str| {
+        let open = open.clone();
+        probe(
+            key,
+            div().child(Button::new(key, label).on_click(move |_, _, cx| {
+                open.update(cx, |open, cx| {
+                    *open = which;
+                    cx.notify();
+                })
+            })),
+        )
+    };
+    let (o, s) = (open.clone(), said.clone());
+    let answer = move |words: String, cx: &mut App| shut(words, &o, &s, cx);
+    let dialog = match *open.read(cx) {
+        Open::None => None,
+        Open::Export => {
+            let (done, cancel) = (answer.clone(), answer.clone());
+            Some(
+                ExportDialog::new(
+                    "export",
+                    "Export the table",
+                    [
+                        ExportFormat::Pdf,
+                        ExportFormat::Png,
+                        ExportFormat::Csv,
+                        ExportFormat::Json,
+                    ],
+                    move |format, _, cx| done(format!("Export as .{}", format.extension()), cx),
+                    move |_, cx| cancel("Export cancelled.".into(), cx),
+                )
+                .into_any_element(),
+            )
+        }
+        Open::Import => {
+            let (done, cancel) = (answer.clone(), answer.clone());
+            Some(
+                ImportDialog::new(
+                    "import",
+                    "Import people",
+                    ["Full name", "E-mail", "Team"],
+                    fields(),
+                    move |mapping, _, cx| done(format!("Columns by field: {mapping:?}"), cx),
+                    move |_, cx| cancel("Import cancelled.".into(), cx),
+                )
+                .preview([
+                    vec![
+                        "Ada Lovelace".into(),
+                        "ada@example.com".into(),
+                        "Engines".into(),
+                    ],
+                    vec![
+                        "Grace Hopper".into(),
+                        "grace@example.com".into(),
+                        "Compilers".into(),
+                    ],
+                ])
+                .into_any_element(),
+            )
+        }
+        Open::Csv => {
+            let (done, cancel) = (answer.clone(), answer.clone());
+            Some(
+                CsvImporter::new(
+                    "csv",
+                    "Import people.csv",
+                    PEOPLE,
+                    fields(),
+                    move |records, _, cx| done(format!("{} people imported.", records.len()), cx),
+                    move |_, cx| cancel("CSV import cancelled.".into(), cx),
+                )
+                .into_any_element(),
+            )
+        }
+    };
+    div()
+        .child(
+            section(
+                "ExportDialog / ImportDialog / CSVImporter",
+                "Data out in a format the owner writes, and data in: columns mapped to the app's fields, matched by name to start, and a CSV file read into records through the same mapping.",
+                cx,
+            )
+            .child(
+                div()
+                    .flex()
+                    .flex_wrap()
+                    .gap_2()
+                    .child(opener(Open::Export, "Export…", "open-export"))
+                    .child(opener(Open::Import, "Import…", "open-import"))
+                    .child(opener(Open::Csv, "Import people.csv…", "open-csv")),
+            )
+            .child(
+                div()
+                    .text_color(cx.theme().colors.fg_muted)
+                    .child(said.read(cx).clone()),
+            ),
+        )
+        .children(dialog)
+}

src/misc/csv.rs

@@ -0,0 +1,258 @@
+use std::rc::Rc;
+
+use gpui::{
+    App, ElementId, InteractiveElement, IntoElement, ParentElement, RenderOnce, SharedString,
+    Window, div,
+};
+
+use super::{ImportDialog, ImportField};
+use crate::{
+    buttons::{Button, ButtonVariant},
+    feedback::InlineMessage,
+    forms::{Checkbox, Run},
+    overlays::Dialog,
+    primitives::Severity,
+};
+
+type OnRecords = Rc<dyn Fn(&[Vec<SharedString>], &mut Window, &mut App)>;
+
+/// Rows of fields from CSV text, as RFC 4180 has it: commas between fields, quotes around a field that holds a comma, a quote or a line break, a doubled quote for a quote inside, and CRLF or LF between rows. A last line break adds no row. Fails on a quote that never closes, text after a closing quote, or a row whose field count differs from the first's.
+pub fn read_csv(text: &str) -> Result<Vec<Vec<String>>, String> {
+    let (mut rows, mut row, mut field) = (Vec::new(), Vec::new(), String::new());
+    let (mut quoted, mut closed, mut line) = (false, false, 1);
+    let mut chars = text.chars().peekable();
+    while let Some(ch) = chars.next() {
+        match (quoted, ch) {
+            (true, '"') if chars.peek() == Some(&'"') => {
+                chars.next();
+                field.push('"');
+            }
+            (true, '"') => (quoted, closed) = (false, true),
+            (true, ch) => {
+                line += usize::from(ch == '\n');
+                field.push(ch);
+            }
+            (false, '"') if field.is_empty() && !closed => quoted = true,
+            (false, '"') => {
+                return Err(format!(
+                    "line {line}: a quote inside a field it did not open"
+                ));
+            }
+            (false, ',') => {
+                row.push(std::mem::take(&mut field));
+                closed = false;
+            }
+            (false, '\r') if chars.peek() == Some(&'\n') => {}
+            (false, '\n') => {
+                row.push(std::mem::take(&mut field));
+                rows.push(std::mem::take(&mut row));
+                (closed, line) = (false, line + 1);
+            }
+            (false, _) if closed => return Err(format!("line {line}: text after a closing quote")),
+            (false, ch) => field.push(ch),
+        }
+    }
+    if quoted {
+        return Err(format!("line {line}: a quote never closes"));
+    }
+    if !field.is_empty() || !row.is_empty() || closed {
+        row.push(field);
+        rows.push(row);
+    }
+    if let Some(first) = rows.first() {
+        let width = first.len();
+        if let Some((ix, ragged)) = rows.iter().enumerate().find(|(_, row)| row.len() != width) {
+            return Err(format!(
+                "row {} has {} fields; the first has {width}",
+                ix + 1,
+                ragged.len()
+            ));
+        }
+    }
+    Ok(rows)
+}
+
+/// What the importer read: the text, and its rows or why it does not read as CSV.
+struct Reading {
+    text: SharedString,
+    rows: Result<Vec<Vec<String>>, String>,
+}
+
+/// CSV text into records: read as RFC 4180, its first row naming the columns unless the box says otherwise, then mapped to the owner's fields through an `ImportDialog`. Text that does not read as CSV, or holds no rows, says why, with only Cancel. Each way out answers once. Render it while open.
+#[derive(IntoElement)]
+pub struct CsvImporter {
+    id: ElementId,
+    title: SharedString,
+    text: SharedString,
+    fields: Vec<ImportField>,
+    on_import: OnRecords,
+    on_cancel: Run,
+}
+
+impl CsvImporter {
+    /// `on_import` gets a record per row, its fields in field order, empty where a field was left empty.
+    pub fn new(
+        id: impl Into<ElementId>,
+        title: impl Into<SharedString>,
+        text: impl Into<SharedString>,
+        fields: impl IntoIterator<Item = ImportField>,
+        on_import: impl Fn(&[Vec<SharedString>], &mut Window, &mut App) + 'static,
+        on_cancel: impl Fn(&mut Window, &mut App) + 'static,
+    ) -> Self {
+        Self {
+            id: id.into(),
+            title: title.into(),
+            text: text.into(),
+            fields: fields.into_iter().collect(),
+            on_import: Rc::new(on_import),
+            on_cancel: Rc::new(on_cancel),
+        }
+    }
+}
+
+impl RenderOnce for CsvImporter {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let id = self.id;
+        let reading = window.use_keyed_state((id.clone(), "reading"), cx, {
+            let text = self.text.clone();
+            move |_, _| Reading {
+                rows: read_csv(&text),
+                text,
+            }
+        });
+        if reading.read(cx).text != self.text {
+            let rows = read_csv(&self.text);
+            reading.update(cx, |reading, _| {
+                *reading = Reading {
+                    text: self.text.clone(),
+                    rows,
+                }
+            });
+        }
+        let headed = window.use_keyed_state((id.clone(), "headed"), cx, |_, _| true);
+        let rows = match &reading.read(cx).rows {
+            Ok(rows) if rows.is_empty() => Err("it holds no rows".to_string()),
+            Ok(rows) => Ok(rows.clone()),
+            Err(why) => Err(why.clone()),
+        };
+        let cancel = self.on_cancel;
+        let rows = match rows {
+            Ok(rows) => rows,
+            Err(why) => {
+                log::warn!("csv importer {id:?}: {why}");
+                return Dialog::new(id.clone(), self.title, move |window, cx| cancel(window, cx))
+                    .child(
+                        div()
+                            .debug_selector(|| "csv-unread".into())
+                            .child(InlineMessage::new(
+                                Severity::Danger,
+                                format!("This file does not read as CSV: {why}."),
+                            )),
+                    )
+                    .action(move |close| {
+                        Button::new((id, "cancel"), "Cancel")
+                            .variant(ButtonVariant::Ghost)
+                            .on_click(move |_, window, cx| close(window, cx))
+                    })
+                    .into_any_element();
+            }
+        };
+        let first_names = *headed.read(cx);
+        let width = rows[0].len();
+        let (columns, data): (Vec<SharedString>, Vec<Vec<SharedString>>) = {
+            let shared = |row: &Vec<String>| {
+                row.iter()
+                    .map(|field| SharedString::from(field.clone()))
+                    .collect::<Vec<_>>()
+            };
+            match first_names {
+                true => (shared(&rows[0]), rows[1..].iter().map(shared).collect()),
+                false => (
+                    (1..=width).map(|n| format!("Column {n}").into()).collect(),
+                    rows.iter().map(shared).collect(),
+                ),
+            }
+        };
+        let (import, turned) = (self.on_import, headed);
+        let records = Rc::new(data);
+        let given = records.clone();
+        ImportDialog::new(
+            id.clone(),
+            self.title,
+            columns,
+            self.fields,
+            move |mapping, window, cx| {
+                let rows: Vec<Vec<SharedString>> = given
+                    .iter()
+                    .map(|row| {
+                        mapping
+                            .iter()
+                            .map(|column| {
+                                column.map(|column| row[column].clone()).unwrap_or_default()
+                            })
+                            .collect()
+                    })
+                    .collect();
+                log::info!("csv importer: {} records", rows.len());
+                import(&rows, window, cx)
+            },
+            move |window, cx| cancel(window, cx),
+        )
+        .preview(records.iter().cloned())
+        .child(
+            Checkbox::new((id, "headed"), first_names)
+                .label("The first row names the columns")
+                .on_change(move |on, _, cx| {
+                    turned.update(cx, |headed, cx| {
+                        *headed = on;
+                        cx.notify();
+                    })
+                }),
+        )
+        .into_any_element()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::read_csv;
+
+    #[test]
+    fn csv_reads_quotes_commas_and_line_breaks() {
+        let rows = read_csv("name,note\r\n\"Doe, Jane\",\"says \"\"hi\"\"\"\nAda,\"two\nlines\"\n")
+            .expect("valid CSV");
+        assert_eq!(
+            rows,
+            [
+                vec!["name".to_string(), "note".to_string()],
+                vec!["Doe, Jane".into(), "says \"hi\"".into()],
+                vec!["Ada".into(), "two\nlines".into()],
+            ]
+        );
+        assert_eq!(
+            read_csv("a,,b").expect("empty middle"),
+            [vec!["a".to_string(), String::new(), "b".into()]]
+        );
+        assert_eq!(read_csv("").expect("nothing"), Vec::<Vec<String>>::new());
+    }
+
+    #[test]
+    fn csv_names_what_breaks_it() {
+        assert_eq!(
+            read_csv("a,\"open"),
+            Err("line 1: a quote never closes".into())
+        );
+        assert_eq!(
+            read_csv("\"a\"b,c"),
+            Err("line 1: text after a closing quote".into())
+        );
+        assert_eq!(
+            read_csv("ab\"c"),
+            Err("line 1: a quote inside a field it did not open".into())
+        );
+        assert_eq!(
+            read_csv("a,b\nc"),
+            Err("row 2 has 1 fields; the first has 2".into())
+        );
+    }
+}

src/misc/export.rs

@@ -0,0 +1,147 @@
+use std::{cell::Cell, rc::Rc};
+
+use gpui::{
+    App, ElementId, IntoElement, ParentElement, RenderOnce, SharedString, Styled, Window, div,
+};
+
+use crate::{
+    buttons::{Button, ButtonVariant},
+    forms::{RadioCard, Run},
+    overlays::Dialog,
+    primitives::IconName,
+};
+
+type OnExport = Rc<dyn Fn(ExportFormat, &mut Window, &mut App)>;
+
+/// A way to save data out.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum ExportFormat {
+    Pdf,
+    Png,
+    Csv,
+    Json,
+}
+
+impl ExportFormat {
+    /// The file extension it takes, without the dot.
+    pub fn extension(self) -> &'static str {
+        match self {
+            Self::Pdf => "pdf",
+            Self::Png => "png",
+            Self::Csv => "csv",
+            Self::Json => "json",
+        }
+    }
+
+    fn label(self) -> &'static str {
+        match self {
+            Self::Pdf => "PDF",
+            Self::Png => "PNG",
+            Self::Csv => "CSV",
+            Self::Json => "JSON",
+        }
+    }
+
+    fn detail(self) -> &'static str {
+        match self {
+            Self::Pdf => "A document to print or share",
+            Self::Png => "A picture of what shows",
+            Self::Csv => "Rows for a spreadsheet",
+            Self::Json => "Data for other programs",
+        }
+    }
+
+    fn icon(self) -> IconName {
+        match self {
+            Self::Pdf => IconName::FileText,
+            Self::Png => IconName::FileImage,
+            Self::Csv => IconName::FileSpreadsheet,
+            Self::Json => IconName::FileJson,
+        }
+    }
+}
+
+/// Saves data out: the owner's formats as cards, the first chosen, then Export or Cancel. Each way out answers once: Export hands the chosen format to the owner, who writes the file; Cancel, Escape and a press on the scrim cancel. Render it while open.
+#[derive(IntoElement)]
+pub struct ExportDialog {
+    id: ElementId,
+    title: SharedString,
+    formats: Vec<ExportFormat>,
+    on_export: OnExport,
+    on_cancel: Run,
+}
+
+impl ExportDialog {
+    pub fn new(
+        id: impl Into<ElementId>,
+        title: impl Into<SharedString>,
+        formats: impl IntoIterator<Item = ExportFormat>,
+        on_export: impl Fn(ExportFormat, &mut Window, &mut App) + 'static,
+        on_cancel: impl Fn(&mut Window, &mut App) + 'static,
+    ) -> Self {
+        Self {
+            id: id.into(),
+            title: title.into(),
+            formats: formats.into_iter().collect(),
+            on_export: Rc::new(on_export),
+            on_cancel: Rc::new(on_cancel),
+        }
+    }
+}
+
+impl RenderOnce for ExportDialog {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let id = self.id;
+        let first = *self
+            .formats
+            .first()
+            .unwrap_or_else(|| panic!("export dialog {id:?} has no formats"));
+        let chosen = window.use_keyed_state((id.clone(), "chosen"), cx, move |_, _| first);
+        let format = *chosen.read(cx);
+        assert!(
+            self.formats.contains(&format),
+            "export dialog {id:?} lost its format {format:?}"
+        );
+        let cards = self.formats.iter().map(|&each| {
+            let pick = chosen.clone();
+            RadioCard::new((id.clone(), each.label()), each == format, each.label())
+                .description(each.detail())
+                .icon(each.icon())
+                .on_select(move |_, cx| {
+                    pick.update(cx, |chosen, cx| {
+                        *chosen = each;
+                        cx.notify();
+                    })
+                })
+        });
+        let (cancel, export) = (self.on_cancel, self.on_export);
+        let (cancelled, exported) = (id.clone(), id.clone());
+        let answered = Rc::new(Cell::new(false));
+        let answer = answered.clone();
+        Dialog::new(id.clone(), self.title, move |window, cx| {
+            if !answered.get() {
+                log::info!("export dialog {cancelled:?}: cancelled");
+                cancel(window, cx)
+            }
+        })
+        .child(div().flex().flex_col().gap_2().children(cards))
+        .action({
+            let id = id.clone();
+            move |close| {
+                Button::new((id, "cancel"), "Cancel")
+                    .variant(ButtonVariant::Ghost)
+                    .on_click(move |_, window, cx| close(window, cx))
+            }
+        })
+        .action(move |close| {
+            Button::new((id, "export"), "Export")
+                .primary()
+                .on_click(move |_, window, cx| {
+                    log::info!("export dialog {exported:?}: {format:?}");
+                    answer.set(true);
+                    close(window, cx);
+                    export(format, window, cx);
+                })
+        })
+    }
+}

src/misc/import.rs

@@ -0,0 +1,286 @@
+use std::{cell::Cell, rc::Rc};
+
+use gpui::{
+    AnyElement, App, ElementId, IntoElement, ParentElement, RenderOnce, SharedString, Styled,
+    Window, div, prelude::*,
+};
+use smallvec::SmallVec;
+
+use crate::{
+    buttons::{Button, ButtonVariant},
+    forms::{Choice, Run, Select},
+    overlays::Dialog,
+    tables::Table,
+    theme::{ActiveTheme, TextSize},
+};
+
+type OnMap = Rc<dyn Fn(&[Option<usize>], &mut Window, &mut App)>;
+
+/// A field the app keeps: its name, and whether an import must fill it.
+#[derive(Clone, Debug, PartialEq)]
+pub struct ImportField {
+    name: SharedString,
+    required: bool,
+}
+
+impl ImportField {
+    pub fn new(name: impl Into<SharedString>) -> Self {
+        Self {
+            name: name.into(),
+            required: false,
+        }
+    }
+
+    pub fn required(mut self) -> Self {
+        self.required = true;
+        self
+    }
+}
+
+/// How far two names match: equal once case, spaces, dashes and underscores are set aside.
+fn same(field: &str, column: &str) -> bool {
+    let plain = |name: &str| {
+        name.chars()
+            .filter(|ch| !matches!(ch, ' ' | '-' | '_'))
+            .flat_map(char::to_lowercase)
+            .collect::<String>()
+    };
+    plain(field) == plain(column)
+}
+
+/// Each field's column to start: the first whose name matches, or none.
+pub(crate) fn matched(fields: &[ImportField], columns: &[SharedString]) -> Vec<Option<usize>> {
+    fields
+        .iter()
+        .map(|field| columns.iter().position(|column| same(&field.name, column)))
+        .collect()
+}
+
+/// The mapping as the owner set it last, and the columns it was made for.
+struct Mapping {
+    columns: Vec<SharedString>,
+    picked: Vec<Option<usize>>,
+    nudged: bool,
+}
+
+/// Columns from a file mapped to the fields the app keeps: a Select of the columns for each field, matched by name to start, over the first rows as they would come in. Import asks for a column for every required field, then hands the mapping over; each way out answers once, import or cancel. Render it while open.
+#[derive(IntoElement)]
+pub struct ImportDialog {
+    id: ElementId,
+    title: SharedString,
+    columns: Vec<SharedString>,
+    rows: Vec<Vec<SharedString>>,
+    fields: Vec<ImportField>,
+    body: SmallVec<[AnyElement; 1]>,
+    on_import: OnMap,
+    on_cancel: Run,
+}
+
+impl ImportDialog {
+    /// `on_import` gets each field's column, in field order, or none for a field left empty.
+    pub fn new(
+        id: impl Into<ElementId>,
+        title: impl Into<SharedString>,
+        columns: impl IntoIterator<Item = impl Into<SharedString>>,
+        fields: impl IntoIterator<Item = ImportField>,
+        on_import: impl Fn(&[Option<usize>], &mut Window, &mut App) + 'static,
+        on_cancel: impl Fn(&mut Window, &mut App) + 'static,
+    ) -> Self {
+        Self {
+            id: id.into(),
+            title: title.into(),
+            columns: columns.into_iter().map(Into::into).collect(),
+            rows: Vec::new(),
+            fields: fields.into_iter().collect(),
+            body: SmallVec::new(),
+            on_import: Rc::new(on_import),
+            on_cancel: Rc::new(on_cancel),
+        }
+    }
+
+    /// The first rows, by column, to show as they would come in.
+    pub fn preview(mut self, rows: impl IntoIterator<Item = Vec<SharedString>>) -> Self {
+        self.rows = rows.into_iter().take(PREVIEW).collect();
+        self
+    }
+}
+
+impl ParentElement for ImportDialog {
+    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
+        self.body.extend(elements);
+    }
+}
+
+/// How many rows the preview shows.
+const PREVIEW: usize = 3;
+
+impl RenderOnce for ImportDialog {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let id = self.id;
+        assert!(
+            !self.fields.is_empty(),
+            "import dialog {id:?} has no fields"
+        );
+        assert!(
+            !self.columns.is_empty(),
+            "import dialog {id:?} has no columns"
+        );
+        let (fields, columns) = (Rc::new(self.fields), self.columns);
+        let mapping = window.use_keyed_state((id.clone(), "mapping"), cx, {
+            let (fields, columns) = (fields.clone(), columns.clone());
+            move |_, _| Mapping {
+                picked: matched(&fields, &columns),
+                columns,
+                nudged: false,
+            }
+        });
+        if mapping.read(cx).columns != columns {
+            let picked = matched(&fields, &columns);
+            mapping.update(cx, |mapping, _| {
+                *mapping = Mapping {
+                    columns: columns.clone(),
+                    picked,
+                    nudged: false,
+                }
+            });
+        }
+        let (picked, nudged) = (mapping.read(cx).picked.clone(), mapping.read(cx).nudged);
+        let missing: Vec<SharedString> = fields
+            .iter()
+            .zip(&picked)
+            .filter(|(field, column)| field.required && column.is_none())
+            .map(|(field, _)| field.name.clone())
+            .collect();
+        let theme = cx.theme();
+        let colors = &theme.colors;
+        let rows = fields.iter().enumerate().map(|(ix, field)| {
+            let skip = (!field.required).then(|| Choice::new("none", "Leave empty"));
+            let choices = skip.into_iter().chain(
+                columns
+                    .iter()
+                    .enumerate()
+                    .map(|(column, name)| Choice::new(column.to_string(), name.clone())),
+            );
+            let set = mapping.clone();
+            let select = Select::new((id.clone(), format!("field-{ix}")), choices)
+                .placeholder("Choose a column")
+                .on_change(move |value, _, cx| {
+                    let column = (value.as_ref() != "none")
+                        .then(|| value.parse().expect("a column's place"));
+                    set.update(cx, |mapping, cx| {
+                        mapping.picked[ix] = column;
+                        cx.notify();
+                    })
+                });
+            let select = match (picked[ix], field.required) {
+                (Some(column), _) => select.selected(column.to_string()),
+                (None, false) => select.selected("none"),
+                (None, true) => select,
+            };
+            div()
+                .flex()
+                .flex_wrap()
+                .items_center()
+                .gap_2()
+                .child(
+                    div()
+                        .flex_1()
+                        .min_w(theme.label_width())
+                        .text_color(colors.fg)
+                        .child(match field.required {
+                            true => format!("{} (required)", field.name),
+                            false => field.name.to_string(),
+                        }),
+                )
+                .child(div().flex_1().min_w(theme.label_width()).child(select))
+        });
+        let preview = self.rows.iter().fold(
+            Table::new(fields.iter().map(|field| field.name.clone())),
+            |table, row| {
+                table.row(picked.iter().map(|column| {
+                    column
+                        .map(|column| row[column].clone())
+                        .unwrap_or_else(|| "—".into())
+                }))
+            },
+        );
+        let (cancel, import) = (self.on_cancel, self.on_import);
+        let (cancelled, imported, asked) = (id.clone(), id.clone(), mapping.clone());
+        let answered = Rc::new(Cell::new(false));
+        let answer = answered.clone();
+        Dialog::new(id.clone(), self.title, move |window, cx| {
+            if !answered.get() {
+                log::info!("import dialog {cancelled:?}: cancelled");
+                cancel(window, cx)
+            }
+        })
+        .children(self.body)
+        .child(
+            div()
+                .flex()
+                .flex_col()
+                .gap_3()
+                .text_size(theme.text_size(TextSize::Sm))
+                .children(rows),
+        )
+        .when(!self.rows.is_empty(), |dialog| {
+            dialog.child(
+                div()
+                    .debug_selector(|| "import-preview".into())
+                    .child(preview),
+            )
+        })
+        .when(nudged && !missing.is_empty(), |dialog| {
+            dialog.child(
+                div()
+                    .debug_selector(|| format!("import-missing-{}", missing.join(",")))
+                    .text_size(theme.text_size(TextSize::Sm))
+                    .text_color(colors.danger)
+                    .child(format!("Choose a column for {}.", missing.join(", "))),
+            )
+        })
+        .action({
+            let id = id.clone();
+            move |close| {
+                Button::new((id, "cancel"), "Cancel")
+                    .variant(ButtonVariant::Ghost)
+                    .on_click(move |_, window, cx| close(window, cx))
+            }
+        })
+        .action(move |close| {
+            Button::new((id, "import"), "Import")
+                .primary()
+                .on_click(move |_, window, cx| {
+                    if !missing.is_empty() {
+                        asked.update(cx, |mapping, cx| {
+                            mapping.nudged = true;
+                            cx.notify();
+                        });
+                        return;
+                    }
+                    log::info!("import dialog {imported:?}: imported with {picked:?}");
+                    answer.set(true);
+                    close(window, cx);
+                    import(&picked, window, cx);
+                })
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use gpui::SharedString;
+
+    use super::{ImportField, matched};
+
+    #[test]
+    fn fields_find_their_columns_by_name() {
+        let columns: Vec<SharedString> = ["E-mail", "Full name", "Age"].map(Into::into).into();
+        let fields = [
+            ImportField::new("full_name").required(),
+            ImportField::new("email"),
+            ImportField::new("phone"),
+        ];
+        assert_eq!(matched(&fields, &columns), [Some(1), Some(0), None]);
+    }
+}

src/misc/mod.rs

@@ -3,7 +3,10 @@ mod captcha;
 mod clock;
 mod consent;
 mod cookies;
+mod csv;
+mod export;
 mod flashcards;
+mod import;
 mod licenses;
 mod poll;
 mod quiz;
@@ -20,7 +23,10 @@ pub use captcha::{Captcha, CaptchaState};
 pub use clock::{Clock, WorldClock};
 pub use consent::ConsentDialog;
 pub use cookies::CookieBanner;
+pub use csv::{CsvImporter, read_csv};
+pub use export::{ExportDialog, ExportFormat};
 pub use flashcards::Flashcards;
+pub use import::{ImportDialog, ImportField};
 pub use licenses::{LicenseViewer, Package};
 pub use poll::Poll;
 pub use quiz::{Quiz, QuizQuestion};

src/misc/tests/mod.rs

@@ -17,6 +17,7 @@ mod asking;
 mod codes;
 mod notices;
 mod numbers;
+mod transfer;
 
 struct Stage {
     root: FocusHandle,

src/misc/tests/transfer.rs

@@ -0,0 +1,167 @@
+use std::cell::{Cell, RefCell};
+
+use gpui::{AnyElement, IntoElement, TestAppContext, div};
+
+use super::{press, shown, stage};
+use crate::misc::{CsvImporter, ExportDialog, ExportFormat, ImportDialog, ImportField};
+
+thread_local! {
+    static SAID: RefCell<Vec<String>> = const { RefCell::new(Vec::new()) };
+    static OPEN: Cell<bool> = const { Cell::new(true) };
+    static TEXT: RefCell<&'static str> = const { RefCell::new("") };
+}
+
+fn said() -> Vec<String> {
+    SAID.with(|said| said.borrow().clone())
+}
+
+/// Closes the dialog and notes the answer.
+fn say(text: impl Into<String>) {
+    OPEN.set(false);
+    SAID.with(|said| said.borrow_mut().push(text.into()));
+}
+
+fn export() -> AnyElement {
+    match OPEN.get() {
+        true => ExportDialog::new(
+            "export",
+            "Export",
+            [ExportFormat::Pdf, ExportFormat::Png, ExportFormat::Csv],
+            |format, _, _| say(format!("{format:?}")),
+            |_, _| say("cancelled"),
+        )
+        .into_any_element(),
+        false => div().into_any_element(),
+    }
+}
+
+/// A card picks the format and Export hands it over, once.
+#[gpui::test]
+fn export_hands_over_the_chosen_format(cx: &mut TestAppContext) {
+    let (_, cx) = stage(export, cx);
+    press("tab", cx);
+    press("tab", cx);
+    press("space", cx);
+    for _ in 0..3 {
+        press("tab", cx);
+    }
+    press("enter", cx);
+    assert_eq!(said(), ["Png"]);
+}
+
+/// Escape cancels, once.
+#[gpui::test]
+fn escape_cancels_the_export(cx: &mut TestAppContext) {
+    let (_, cx) = stage(export, cx);
+    press("tab", cx);
+    press("escape", cx);
+    assert_eq!(said(), ["cancelled"]);
+}
+
+fn import() -> AnyElement {
+    match OPEN.get() {
+        true => ImportDialog::new(
+            "import",
+            "Import people",
+            ["Mail", "Who"],
+            [
+                ImportField::new("name").required(),
+                ImportField::new("email"),
+            ],
+            |mapping, _, _| say(format!("{mapping:?}")),
+            |_, _| say("cancelled"),
+        )
+        .preview([vec!["ada@x.io".into(), "Ada".into()]])
+        .into_any_element(),
+        false => div().into_any_element(),
+    }
+}
+
+/// Import asks for each required field's column, then hands the mapping over.
+#[gpui::test]
+fn import_asks_for_required_columns(cx: &mut TestAppContext) {
+    let (_, cx) = stage(import, cx);
+    assert!(shown("import-preview", cx));
+    for _ in 0..4 {
+        press("tab", cx);
+    }
+    press("enter", cx);
+    assert!(said().is_empty() && shown("import-missing-name", cx));
+    for _ in 0..3 {
+        press("shift-tab", cx);
+    }
+    for key in ["down", "down", "enter"] {
+        press(key, cx);
+    }
+    for _ in 0..3 {
+        press("tab", cx);
+    }
+    press("enter", cx);
+    assert_eq!(said(), ["[Some(1), None]"]);
+}
+
+fn csv() -> AnyElement {
+    match OPEN.get() {
+        true => CsvImporter::new(
+            "csv",
+            "Import people",
+            TEXT.with(|text| *text.borrow()),
+            [
+                ImportField::new("name").required(),
+                ImportField::new("email"),
+            ],
+            |records, _, _| say(format!("{records:?}")),
+            |_, _| say("cancelled"),
+        )
+        .into_any_element(),
+        false => div().into_any_element(),
+    }
+}
+
+/// Columns named by the first row match the fields, and Import hands over a record per row.
+#[gpui::test]
+fn a_csv_file_imports_as_records(cx: &mut TestAppContext) {
+    TEXT.with(|text| text.replace("Name,Email\nAda,ada@x.io\n\"Lin, Wei\",lin@x.io\n"));
+    let (_, cx) = stage(csv, cx);
+    for _ in 0..5 {
+        press("tab", cx);
+    }
+    press("enter", cx);
+    assert_eq!(
+        said(),
+        [r#"[["Ada", "ada@x.io"], ["Lin, Wei", "lin@x.io"]]"#]
+    );
+}
+
+/// Unticked, the first row is data, its columns go by number, and the required field waits for one.
+#[gpui::test]
+fn the_first_row_can_be_data(cx: &mut TestAppContext) {
+    TEXT.with(|text| text.replace("Name,Email\nAda,ada@x.io\n"));
+    let (_, cx) = stage(csv, cx);
+    press("tab", cx);
+    press("space", cx);
+    for _ in 0..4 {
+        press("tab", cx);
+    }
+    press("enter", cx);
+    assert!(said().is_empty() && shown("import-missing-name", cx));
+}
+
+/// Text that does not read as CSV says why, and Escape cancels.
+#[gpui::test]
+fn broken_csv_says_why(cx: &mut TestAppContext) {
+    TEXT.with(|text| text.replace("a,\"b"));
+    let (_, cx) = stage(csv, cx);
+    assert!(shown("csv-unread", cx));
+    press("tab", cx);
+    press("escape", cx);
+    assert_eq!(said(), ["cancelled"]);
+}
+
+/// Text with no rows says so.
+#[gpui::test]
+fn empty_csv_says_why(cx: &mut TestAppContext) {
+    TEXT.with(|text| text.replace(""));
+    let (_, cx) = stage(csv, cx);
+    assert!(shown("csv-unread", cx));
+}

tasks/ch31-43.md

@@ -348,9 +348,9 @@
 
 ## T42g Misc · Export and import
 
-- [ ] ExportDialog — PDF, PNG, CSV, JSON
-- [ ] ImportDialog — field mapping
-- [ ] CSVImporter
+- [x] ExportDialog — PDF, PNG, CSV, JSON → `misc::ExportDialog`: the owner's formats as cards, and Export hands the chosen one over for the owner to write; each way out answers once
+- [x] ImportDialog — field mapping → `misc::ImportDialog`: a Select of the columns for each field, matched by name to start, over a preview of the first rows; Import asks for each required field's column
+- [x] CSVImporter → `misc::CsvImporter`: CSV read as RFC 4180 (`misc::read_csv`), its first row naming the columns unless the box says otherwise, mapped through the ImportDialog into records; text that does not read says why
 
 ## T43 Library Tooling — `src/tooling`