Merge PR #1590 from ramox81/codex/field-table-placeholders: table formula buttons, block placeholders, attribute fields on insert, plot-time fields

The PR pinned the codec to its fork through [patch]; codec #81 is merged
upstream and main already points at it, so the patch section is dropped.

locales/ar-SA/opencadstudio.ftl

@@ -4105,6 +4105,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/bg-BG/opencadstudio.ftl

@@ -4092,6 +4092,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/cs-CZ/opencadstudio.ftl

@@ -4090,6 +4090,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/de-DE/opencadstudio.ftl

@@ -4091,6 +4091,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/el-GR/opencadstudio.ftl

@@ -4093,6 +4093,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/en-US/opencadstudio.ftl

@@ -4094,6 +4094,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/es-ES/opencadstudio.ftl

@@ -4093,6 +4093,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/fi-FI/opencadstudio.ftl

@@ -4092,6 +4092,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/fr-FR/opencadstudio.ftl

@@ -4093,6 +4093,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/hi-IN/opencadstudio.ftl

@@ -4081,6 +4081,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/hu-HU/opencadstudio.ftl

@@ -4092,6 +4092,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/it-IT/opencadstudio.ftl

@@ -4092,6 +4092,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/ja-JP/opencadstudio.ftl

@@ -4081,6 +4081,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/ko-KR/opencadstudio.ftl

@@ -4092,6 +4092,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/nl-NL/opencadstudio.ftl

@@ -4091,6 +4091,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/pl-PL/opencadstudio.ftl

@@ -4092,6 +4092,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/pt-BR/opencadstudio.ftl

@@ -4093,6 +4093,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/ru-RU/opencadstudio.ftl

@@ -4094,6 +4094,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/tr-TR/opencadstudio.ftl

@@ -4053,6 +4053,12 @@ insert =
     .field-select-object = Nesne seç
     .field-expression = Alan ifadesi
     .field-help = Bir alan ekler: çizimden, tarihten veya başka bir kaynaktan güncellenen metin.
+    .field-average = Ortalama
+    .field-sum = Toplam
+    .field-object-name = Nesne adı
+    .field-block-placeholder = Blok yer tutucusu
+    .field-block-editor-only = Yalnız blok düzenleyicide kullanılabilir
+    .field-block-reference-property = Blok başvurusu özelliği
     .field-cat-linked = Bağlantılı
     .field-current-precision = Geçerli hassasiyet
     .field-evaluate = Hesapla

locales/zh-CN/opencadstudio.ftl

@@ -4076,6 +4076,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

locales/zh-TW/opencadstudio.ftl

@@ -4088,6 +4088,12 @@ insert =
     .field-select-object = Select object
     .field-expression = Field expression
     .field-help = Inserts a field: text that updates from the drawing, the date or another source.
+    .field-average = Average
+    .field-sum = Sum
+    .field-object-name = Object name
+    .field-block-placeholder = Block placeholder
+    .field-block-editor-only = Only accessible in the block editor
+    .field-block-reference-property = Block reference property
     .field-cat-linked = Linked
     .field-current-precision = Current precision
     .field-evaluate = Evaluate

src/app/command_driver/entity_commit.rs

@@ -231,7 +231,15 @@ impl OpenCADStudio {
         // objects are not part of the add delta, so the step is a snapshot.
         let text_field = self.tabs[i].active_cmd.as_ref().and_then(|cmd| cmd.text_field());
         let label = self.history_label_from_active_cmd(i, "ENTITY");
-        let delta_safe = text_field.is_none() && self.delta_add_safe(i, &entity);
+        // A block reference whose attribute definitions carry fields gets
+        // them copied onto its attributes (field objects: snapshot step).
+        let attribute_fields = match &entity {
+            codec::EntityType::Insert(insert) if !insert.attributes.is_empty() => {
+                crate::entities::field::block_has_attribute_fields(&self.tabs[i].scene.document, &insert.block_name)
+            }
+            _ => false,
+        };
+        let delta_safe = text_field.is_none() && !attribute_fields && self.delta_add_safe(i, &entity);
         let field_value = match &entity {
             codec::EntityType::MText(m) => m.value.clone(),
             codec::EntityType::AttributeDefinition(a) => a.default_value.clone(),
@@ -264,6 +272,10 @@ impl OpenCADStudio {
                 &field_value,
             );
         }
+        if let (Some(handle), true) = (committed, attribute_fields) {
+            crate::entities::field::attach_attribute_fields(&mut self.tabs[i].scene.document, handle);
+            self.tabs[i].scene.bump_entities(&[(handle, crate::scene::ChangeKind::Modified)]);
+        }
         if let Some(handle) = committed {
             self.apply_continuous_constraints(i, &[handle]);
         }
@@ -972,7 +984,7 @@ impl OpenCADStudio {
         let i = self.active_tab;
         // Collect the full AttributeDefinitions owned by this block
         // record so each created attribute keeps its geometry (#255).
-        let attdefs: Vec<codec::entities::AttributeDefinition> = {
+        let mut attdefs: Vec<codec::entities::AttributeDefinition> = {
             let doc = &self.tabs[i].scene.document;
             if let Some(br) = doc.block_records.get(&block_name) {
                 br.entity_handles
@@ -992,6 +1004,12 @@ impl OpenCADStudio {
             }
         };
 
+        // ATTREQ 0: attributes take their defaults without prompting.
+        if !self.tabs[i].scene.document.header.attribute_request {
+            for attdef in &mut attdefs {
+                attdef.flags.preset = true;
+            }
+        }
         if attdefs.is_empty() {
             // No attribute definitions — commit the INSERT directly.
             let entity = self.tabs[i]

src/app/commands/field.rs

@@ -3,7 +3,7 @@
 
 use crate::app::{Message, OpenCADStudio};
 use crate::command::CadCommand;
-use crate::modules::annotate::field_cmd::{FieldObjectPickCommand, FieldPlaceCommand};
+use crate::modules::annotate::field_cmd::{FieldObjectPickCommand, FieldPlaceCommand, FieldTablePickCommand};
 use crate::ui::window::field_dialog::{
     fields_of, object_properties, FieldDialogMsg, FieldDialogState, FieldTarget, DATE_FORMATS,
     NAMED_TYPES,
@@ -35,13 +35,70 @@ impl OpenCADStudio {
                 }
                 Some(Task::none())
             }
+            cmd if cmd == "_FIELD_CELL" || cmd.starts_with("_FIELD_CELL ") => {
+                let parts: Vec<&str> = cmd.split_whitespace().skip(1).collect();
+                if let Some(expression) = self.table_cell_expression(i, &parts) {
+                    if let Some(state) = self.field_dialog.as_mut() {
+                        // The reference appends at the end, with no operator.
+                        state.formula.push_str(&expression);
+                    }
+                    self.refresh_field_preview();
+                    // A real result gets the Decimal format, as the reference picks it.
+                    if let Some(state) = self.field_dialog.as_mut() {
+                        if state.formula_format == 0 && state.preview.contains('.') {
+                            state.formula_format = 2;
+                        }
+                    }
+                }
+                if self.field_dialog.is_some() {
+                    self.active_modal = Some(crate::app::ModalKind::Field);
+                    self.refresh_field_preview();
+                }
+                Some(Task::none())
+            }
             _ => None,
         }
     }
 
+    /// The formula text for a picked table cell or cell range:
+    /// `Table(%<\_ObjId H>%).B4` or `Table(%<\_ObjId H>%).Evaluate(Sum(A3:B5))`.
+    fn table_cell_expression(&self, i: usize, parts: &[&str]) -> Option<String> {
+        let function = *parts.first()?;
+        let cell = |at: &[&str]| -> Option<(codec::Handle, usize, usize)> {
+            let handle = codec::Handle::new(u64::from_str_radix(at.first()?, 16).ok()?);
+            let point = glam::DVec3::new(at.get(1)?.parse().ok()?, at.get(2)?.parse().ok()?, at.get(3)?.parse().ok()?);
+            let document = &self.tabs[i].scene.document;
+            let codec::EntityType::Table(table) = document.get_entity(handle)? else {
+                return None;
+            };
+            let hit = crate::modules::annotate::table_cmd::table_cell_at(table, None, point)?;
+            Some((handle, hit.row, hit.column))
+        };
+        let name = |row: usize, column: usize| format!("{}{}", column_letters(column), row + 1);
+        let (table, row, column) = cell(parts.get(1..5)?)?;
+        if function == "Cell" {
+            return Some(format!("Table(%<\\_ObjId {:X}>%).{}", table.value(), name(row, column)));
+        }
+        let (second_table, row2, column2) = cell(parts.get(5..9)?)?;
+        if second_table != table {
+            return None;
+        }
+        Some(format!(
+            "Table(%<\\_ObjId {:X}>%).Evaluate({function}({}:{}))",
+            table.value(),
+            name(row.min(row2), column.min(column2)),
+            name(row.max(row2), column.max(column2)),
+        ))
+    }
+
     /// Open the Field dialog for `target`.
     pub(in crate::app) fn open_field_dialog(&mut self, target: FieldTarget) {
         let mut state = FieldDialogState::new(target);
+        if !matches!(target, FieldTarget::NewText) {
+            state.placeholder_block = self.tabs[self.active_tab]
+                .active_block_edit_session()
+                .map(|session| session.block_name.clone());
+        }
         state.examples = DATE_FORMATS
             .iter()
             .map(|f| self.field_value(&format!("\\AcVar Date \\f \"{f}\""), &[]))
@@ -62,7 +119,17 @@ impl OpenCADStudio {
             return;
         };
         let (code, objects) = state.code();
-        let preview = if state.complete() { self.field_value(&code, &objects) } else { String::new() };
+        let preview = if state.complete() {
+            if state.name == "BlockPlaceholder" {
+                // A placeholder shows its property name until a block reference resolves it.
+                let (label, _, _) = codec::fields::BLOCK_PLACEHOLDER_PROPERTIES[state.placeholder_property];
+                text_case(label, state.text_case)
+            } else {
+                self.field_value(&code, &objects)
+            }
+        } else {
+            String::new()
+        };
         if let Some(state) = self.field_dialog.as_mut() {
             state.preview = preview;
         }
@@ -155,6 +222,18 @@ impl OpenCADStudio {
                 );
             }
             FieldDialogMsg::PlotScale(k) => state.plot_scale = k,
+            FieldDialogMsg::PlaceholderProperty(k) => {
+                state.placeholder_property = k;
+                state.text_case = 0;
+            }
+            FieldDialogMsg::TableFunction(function) => {
+                // The dialog waits while the cells are picked.
+                self.active_modal = None;
+                let command = FieldTablePickCommand::new(function);
+                self.command_line.push_info(&command.prompt());
+                self.tabs[i].active_cmd = Some(Box::new(command));
+                return Task::none();
+            }
             FieldDialogMsg::SelectObject => {
                 // The dialog waits while one object is picked.
                 self.active_modal = None;
@@ -226,3 +305,40 @@ impl OpenCADStudio {
         };
     }
 }
+
+/// Spreadsheet column letters: A … Z, AA, AB …
+fn column_letters(mut column: usize) -> String {
+    let mut letters = Vec::new();
+    loop {
+        letters.push(b'A' + (column % 26) as u8);
+        if column < 26 {
+            break;
+        }
+        column = column / 26 - 1;
+    }
+    letters.reverse();
+    String::from_utf8(letters).unwrap_or_default()
+}
+
+/// The Field dialog's text cases: (none), Uppercase, Lowercase, First capital, Title case.
+fn text_case(value: &str, case: usize) -> String {
+    match case {
+        1 => value.to_uppercase(),
+        2 => value.to_lowercase(),
+        3 => {
+            let lower = value.to_lowercase();
+            let mut chars = lower.chars();
+            chars.next().map(|c| c.to_uppercase().chain(chars).collect()).unwrap_or_default()
+        }
+        4 => value
+            .split(' ')
+            .map(|word| {
+                let lower = word.to_lowercase();
+                let mut chars = lower.chars();
+                chars.next().map(|c| c.to_uppercase().chain(chars).collect::<String>()).unwrap_or_default()
+            })
+            .collect::<Vec<_>>()
+            .join(" "),
+        _ => value.to_string(),
+    }
+}

src/app/control/actions.rs

@@ -475,6 +475,7 @@ impl OpenCADStudio {
         if !path.to_ascii_lowercase().ends_with(".pdf") {
             return Err(failure("invalid_path", "plot writes .pdf files"));
         }
+        self.stamp_plot_fields();
         let i = self.active_tab;
         let names = self.tabs[i].scene.layout_names();
         let requested = req["layout"].as_str().unwrap_or("Model").to_owned();
@@ -1132,6 +1133,13 @@ impl OpenCADStudio {
                     "link_text" => F::HyperlinkText(v.into()),
                     "link_url" => F::HyperlinkUrl(v.into()),
                     "plot_scale" => F::PlotScale(index(codec::fields::PLOT_SCALE_FORMATS.len())?),
+                    "placeholder" => F::PlaceholderProperty(index(codec::fields::BLOCK_PLACEHOLDER_PROPERTIES.len())?),
+                    "table_function" => F::TableFunction(
+                        ["Average", "Sum", "Count", "Cell"]
+                            .into_iter()
+                            .find(|f| f.eq_ignore_ascii_case(v))
+                            .ok_or_else(|| failure("invalid_value", "Average|Sum|Count|Cell"))?,
+                    ),
                     _ => return Err(failure("invalid_value", "Unknown field dialog key")),
                 })
             }

src/app/update/file.rs

@@ -3764,7 +3764,20 @@ impl OpenCADStudio {
         task
     }
 
+    /// A plot gives its fields (PlotDate) the plot time, as the reference
+    /// stores it; the hosts are redrawn before the plot reads the scene.
+    pub(in crate::app) fn stamp_plot_fields(&mut self) {
+        let i = self.active_tab;
+        let hosts = crate::entities::field::stamp_plot_fields(&mut self.tabs[i].scene.document);
+        if !hosts.is_empty() {
+            let changes: Vec<_> = hosts.into_iter().map(|h| (h, crate::scene::ChangeKind::Modified)).collect();
+            self.tabs[i].scene.bump_entities(&changes);
+            self.tabs[i].dirty = true;
+        }
+    }
+
     fn print_all_pages(&mut self) -> Result<Vec<crate::io::pdf_export::PdfPageInput>, String> {
+        self.stamp_plot_fields();
         let available = self.tabs[self.active_tab].scene.layout_names();
         let selected: Vec<String> = self
             .print_all_layouts
@@ -5337,6 +5350,9 @@ impl OpenCADStudio {
         }
         self.active_modal = None;
         self.reset_modal_geometry();
+        if !preview {
+            self.stamp_plot_fields();
+        }
 
         // Extents, Window and Display use one plot path in both spaces. Only
         // Paper-space Layout is special: it uses the physical sheet bounds.

src/entities/field.rs

@@ -360,3 +360,59 @@ fn display_name() -> Option<String> {
     #[cfg(not(target_os = "windows"))]
     None
 }
+
+/// Copy each attribute definition's field onto the matching attribute of a
+/// new block reference (block placeholders resolve against the reference).
+/// Returns the attributes that received a field.
+pub fn attach_attribute_fields(document: &mut CadDocument, insert: Handle) -> Vec<Handle> {
+    let context = OcsFieldContext(None);
+    document.attach_attribute_fields(insert, &context)
+}
+
+/// Whether any attribute definition of `block` hosts a field.
+pub fn block_has_attribute_fields(document: &CadDocument, block: &str) -> bool {
+    let Some(record) = document.block_records.iter().find(|r| r.name.eq_ignore_ascii_case(block)) else {
+        return false;
+    };
+    record.entity_handles.iter().filter_map(|h| document.get_entity(*h)).any(|e| {
+        matches!(e, codec::entities::EntityType::AttributeDefinition(_)) && hosts_field(document, e)
+    })
+}
+
+/// Give plot-time fields (PlotDate) the plot's time; returns the hosts whose
+/// text changed.
+pub fn stamp_plot_fields(document: &mut CadDocument) -> Vec<Handle> {
+    let snapshot = document.clone();
+    let context = PlotContext(OcsFieldContext(Some(&snapshot)));
+    document.stamp_plot_fields(&context)
+}
+
+/// The app context while a plot is produced.
+struct PlotContext<'a>(OcsFieldContext<'a>);
+
+impl FieldContext for PlotContext<'_> {
+    fn now_julian(&self) -> f64 {
+        self.0.now_julian()
+    }
+    fn file_times(&self) -> Option<(f64, f64)> {
+        self.0.file_times()
+    }
+    fn plotting(&self) -> bool {
+        true
+    }
+    fn login(&self) -> Option<String> {
+        self.0.login()
+    }
+    fn getvar(&self, name: &str) -> Option<String> {
+        self.0.getvar(name)
+    }
+    fn file_size(&self) -> Option<u64> {
+        self.0.file_size()
+    }
+    fn date_locale(&self) -> codec::fields::DateLocale {
+        self.0.date_locale()
+    }
+    fn getenv(&self, name: &str) -> Option<String> {
+        self.0.getenv(name)
+    }
+}

src/locale_catalog.rs

@@ -235,6 +235,12 @@ pub(super) fn message_attribute(source: &str) -> Option<(&'static str, &'static
         "Select object" => Some(("insert", "field-select-object")),
         "Field expression" => Some(("insert", "field-expression")),
         "Inserts a field: text that updates from the drawing, the date or another source." => Some(("insert", "field-help")),
+        "Average" => Some(("insert", "field-average")),
+        "Sum" => Some(("insert", "field-sum")),
+        "Object name" => Some(("insert", "field-object-name")),
+        "Block placeholder" => Some(("insert", "field-block-placeholder")),
+        "Only accessible in the block editor" => Some(("insert", "field-block-editor-only")),
+        "Block reference property" => Some(("insert", "field-block-reference-property")),
         "Linked" => Some(("insert", "field-cat-linked")),
         "Current precision" => Some(("insert", "field-current-precision")),
         "Evaluate" => Some(("insert", "field-evaluate")),

src/modules/annotate/field_cmd.rs

@@ -189,4 +189,71 @@ impl CadCommand for FieldObjectPickCommand {
     }
 }
 
+/// The Field dialog's Average / Sum / Count / Cell buttons: a cell range (or
+/// one cell) is picked in a table and handed back as
+/// `_FIELD_CELL <function> <table> <x> <y> <z> [<table> <x> <y> <z>]`.
+pub struct FieldTablePickCommand {
+    pub function: &'static str,
+    first: Option<(Handle, DVec3)>,
+}
+
+impl FieldTablePickCommand {
+    pub fn new(function: &'static str) -> Self {
+        Self { function, first: None }
+    }
+}
+
+impl CadCommand for FieldTablePickCommand {
+    fn name(&self) -> &'static str {
+        "FIELD"
+    }
+
+    fn prompt(&self) -> String {
+        match (self.function, self.first) {
+            ("Cell", _) => "Select table cell:".into(),
+            (_, None) => "Select first corner of table cell range:".into(),
+            _ => "Select second corner of table cell range:".into(),
+        }
+    }
+
+    fn needs_entity_pick(&self) -> bool {
+        true
+    }
+
+    fn entity_pick_highlights_hover(&self) -> bool {
+        true
+    }
+
+    fn on_entity_pick(&mut self, handle: Handle, pt: DVec3) -> CmdResult {
+        if handle.is_null() {
+            return CmdResult::NeedPoint;
+        }
+        let at = |h: Handle, p: DVec3| format!("{:X} {} {} {}", h.value(), p.x, p.y, p.z);
+        match (self.function, self.first) {
+            ("Cell", _) => CmdResult::Dispatch(format!("_FIELD_CELL Cell {}", at(handle, pt))),
+            (_, None) => {
+                self.first = Some((handle, pt));
+                CmdResult::NeedPoint
+            }
+            (function, Some((first, first_pt))) => CmdResult::Dispatch(format!(
+                "_FIELD_CELL {function} {} {}",
+                at(first, first_pt),
+                at(handle, pt)
+            )),
+        }
+    }
+
+    fn on_point(&mut self, _pt: DVec3) -> CmdResult {
+        CmdResult::NeedPoint
+    }
+
+    fn on_enter(&mut self) -> CmdResult {
+        CmdResult::Dispatch("_FIELD_CELL".into())
+    }
+
+    fn on_escape(&mut self) -> CmdResult {
+        CmdResult::Dispatch("_FIELD_CELL".into())
+    }
+}
+
 inventory::submit!(crate::command::CommandRegistration { names: &["FIELD"] });

src/ui/window/field_dialog.rs

@@ -32,7 +32,7 @@ pub const CATEGORIES: &[(&str, &[&str])] = &[
         &["Author", "Comments", "Filename", "Filesize", "HyperlinkBase", "Keywords", "LastSavedBy", "Subject", "Title"],
     ),
     ("Linked", &["Hyperlink"]),
-    ("Objects", &["Formula", "NamedObject", "Object"]),
+    ("Objects", &["BlockPlaceholder", "Formula", "NamedObject", "Object"]),
     ("Other", &["DieselExpression", "SystemVariable"]),
     (
         "Plot",
@@ -77,6 +77,7 @@ pub enum FieldKind {
     Formula,
     Hyperlink,
     PlotScale,
+    BlockPlaceholder,
 }
 
 /// Formula precisions: the current one, then 0 to 8 decimals.
@@ -95,6 +96,7 @@ pub fn kind_of(name: &str) -> FieldKind {
         "Formula" => FieldKind::Formula,
         "Hyperlink" => FieldKind::Hyperlink,
         "PlotScale" => FieldKind::PlotScale,
+        "BlockPlaceholder" => FieldKind::BlockPlaceholder,
         _ => FieldKind::Text,
     }
 }
@@ -128,6 +130,11 @@ pub struct FieldDialogState {
     pub hyperlink_url: String,
     /// Index into codec PLOT_SCALE_FORMATS.
     pub plot_scale: usize,
+    /// The block being edited in the block editor; block placeholders are
+    /// only offered there.
+    pub placeholder_block: Option<String>,
+    /// Index into codec BLOCK_PLACEHOLDER_PROPERTIES.
+    pub placeholder_property: usize,
     pub preview: String,
     /// Today in each of DATE_FORMATS, for the Examples list.
     pub examples: Vec<String>,
@@ -158,6 +165,8 @@ impl FieldDialogState {
             hyperlink_text: String::new(),
             hyperlink_url: String::new(),
             plot_scale: 0,
+            placeholder_block: None,
+            placeholder_property: 7,
             preview: String::new(),
             examples: Vec::new(),
         }
@@ -195,10 +204,11 @@ impl FieldDialogState {
                     0 => String::new(),
                     n => format!("%pr{}", n - 1),
                 };
-                let body = format!("\\AcExpr ({})", self.formula.trim());
+                let (formula, objects) = indexed_object_ids(self.formula.trim());
+                let body = format!("\\AcExpr ({formula})");
                 match format!("{format}{precision}") {
-                    f if f.is_empty() => (body, vec![]),
-                    f => (format!("{body} \\f \"{f}\""), vec![]),
+                    f if f.is_empty() => (body, objects),
+                    f => (format!("{body} \\f \"{f}\""), objects),
                 }
             }
             FieldKind::Hyperlink => (
@@ -211,6 +221,21 @@ impl FieldDialogState {
                     .map_or_else(|| "\\AcVar PlotScale".to_string(), |f| f.1.to_string()),
                 vec![],
             ),
+            FieldKind::BlockPlaceholder => {
+                let (_, property, format) = codec::fields::BLOCK_PLACEHOLDER_PROPERTIES[self.placeholder_property];
+                // Text properties take the chosen case; the others keep their own format.
+                let format = match (format, self.text_case) {
+                    ("%tc4", 0) => String::new(),
+                    ("%tc4", n) => format!("%tc{n}"),
+                    (other, _) => other.to_string(),
+                };
+                let code = format!("\\AcObjProp.16.2 Object(?BlockRefId,1).{property}");
+                if format.is_empty() {
+                    (code, vec![])
+                } else {
+                    (format!("{code} \\f \"{format}\""), vec![])
+                }
+            }
             FieldKind::SystemVariable => (format!("\\AcVar {}", self.sysvar), vec![]),
             FieldKind::Diesel => (format!("\\AcDiesel {}", self.diesel), vec![]),
             FieldKind::NamedObject => match self.named.and_then(|i| self.named_names.get(i)) {
@@ -235,11 +260,35 @@ impl FieldDialogState {
             FieldKind::Diesel => !self.diesel.trim().is_empty(),
             FieldKind::Formula => !self.formula.trim().is_empty(),
             FieldKind::Hyperlink => !self.hyperlink_url.trim().is_empty(),
+            FieldKind::BlockPlaceholder => self.placeholder_block.is_some(),
             _ => true,
         }
     }
 }
 
+/// Table references in a formula are typed as `%<\_ObjId HANDLE>%`; the stored
+/// code numbers them (`%<\_ObjIdx n>%`) and lists the objects.
+fn indexed_object_ids(formula: &str) -> (String, Vec<codec::Handle>) {
+    let mut out = String::new();
+    let mut objects: Vec<codec::Handle> = Vec::new();
+    let mut rest = formula;
+    while let Some(start) = rest.find("%<\\_ObjId ") {
+        let after = &rest[start + "%<\\_ObjId ".len()..];
+        let Some(end) = after.find(">%") else { break };
+        let Ok(value) = u64::from_str_radix(after[..end].trim(), 16) else { break };
+        let handle = codec::Handle::new(value);
+        let index = objects.iter().position(|h| *h == handle).unwrap_or_else(|| {
+            objects.push(handle);
+            objects.len() - 1
+        });
+        out.push_str(&rest[..start]);
+        out.push_str(&format!("%<\\_ObjIdx {index}>%"));
+        rest = &after[end + 2..];
+    }
+    out.push_str(rest);
+    (out, objects)
+}
+
 /// The geometric properties a field can show for an object of this type.
 pub fn object_properties(entity: &codec::EntityType) -> Vec<&'static str> {
     use codec::EntityType as E;
@@ -274,6 +323,9 @@ pub enum FieldDialogMsg {
     FormulaFormat(usize),
     FormulaPrecision(usize),
     Evaluate,
+    /// Sum / Average / Count of a cell range, or one Cell, picked in a table.
+    TableFunction(&'static str),
+    PlaceholderProperty(usize),
     HyperlinkText(String),
     HyperlinkUrl(String),
     BrowseHyperlink,
@@ -334,6 +386,14 @@ impl IntoContainer for text_input::Style {
     }
 }
 
+fn table_button<'a>(label: String, function: &'static str) -> Element<'a, Message> {
+    button(text(label).size(12))
+        .on_press(msg(FieldDialogMsg::TableFunction(function)))
+        .style(button_style(false))
+        .padding([5, 10])
+        .into()
+}
+
 fn case_list<'a>(state: &FieldDialogState) -> Element<'a, Message> {
     list(
         TEXT_CASES
@@ -529,6 +589,36 @@ fn format_panel<'a>(state: &'a FieldDialogState) -> Element<'a, Message> {
         ]
         .spacing(8)
         .into(),
+        FieldKind::BlockPlaceholder => match &state.placeholder_block {
+            None => column![text(t!("Only accessible in the block editor")).size(12).style(muted_style)].into(),
+            Some(block) => {
+                let (_, _, format) = codec::fields::BLOCK_PLACEHOLDER_PROPERTIES[state.placeholder_property];
+                let mut panel = column![
+                    row![
+                        text(t!("Block name")).size(12).width(Length::Fixed(110.0)),
+                        container(text(block.clone()).size(12).style(muted_style)).padding([5, 8]).width(Fill),
+                    ]
+                    .spacing(8)
+                    .align_y(iced::Center),
+                    text(t!("Block reference property")).size(12),
+                    list(
+                        codec::fields::BLOCK_PLACEHOLDER_PROPERTIES
+                            .iter()
+                            .enumerate()
+                            .map(|(i, (label, _, _))| {
+                                (t!(*label).into_owned(), state.placeholder_property == i, FieldDialogMsg::PlaceholderProperty(i))
+                            })
+                            .collect(),
+                        150.0,
+                    ),
+                ]
+                .spacing(8);
+                if format == "%tc4" {
+                    panel = panel.push(text(t!("Format")).size(12)).push(case_list(state));
+                }
+                panel.into()
+            }
+        },
         FieldKind::PlotScale => column![
             text(t!("Format")).size(12),
             list(
@@ -617,10 +707,18 @@ pub fn view<'a>(
                         .font(iced::Font::MONOSPACE)
                         .style(field_style)
                         .on_input(|v| msg(FieldDialogMsg::Formula(v))),
-                    button(text(t!("Evaluate")).size(12))
-                        .on_press(msg(FieldDialogMsg::Evaluate))
-                        .style(button_style(false))
-                        .padding([5, 14]),
+                    row![
+                        table_button(t!("Average").into_owned(), "Average"),
+                        table_button(t!("Sum").into_owned(), "Sum"),
+                        table_button(t!("Count").into_owned(), "Count"),
+                        table_button(t!("Cell").into_owned(), "Cell"),
+                        Space::new().width(Fill),
+                        button(text(t!("Evaluate")).size(12))
+                            .on_press(msg(FieldDialogMsg::Evaluate))
+                            .style(button_style(false))
+                            .padding([5, 14]),
+                    ]
+                    .spacing(6),
                 ]
                 .spacing(8),
             ),
@@ -629,6 +727,7 @@ pub fn view<'a>(
         ]
         .spacing(10),
         FieldKind::Hyperlink => column![card(t!("Hyperlink").into_owned(), format_panel(state)), preview].spacing(10),
+        FieldKind::BlockPlaceholder => column![card(t!("Block placeholder").into_owned(), format_panel(state)), preview].spacing(10),
         _ => column![card(t!("Format").into_owned(), format_panel(state)), preview].spacing(10),
     };
     let (code, _) = state.code();