vegafusion_core/spec/transform/
extent.rs

1use crate::expression::column_usage::{ColumnUsage, DatasetsColumnUsage, VlSelectionFields};
2use crate::spec::transform::{TransformColumns, TransformSpecTrait};
3use crate::task_graph::graph::ScopedVariable;
4use crate::task_graph::scope::TaskScope;
5use serde::{Deserialize, Serialize};
6use serde_json::Value;
7use std::collections::HashMap;
8use vegafusion_common::escape::unescape_field;
9
10#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
11pub struct ExtentTransformSpec {
12    pub field: String, // TODO: support field object
13
14    #[serde(skip_serializing_if = "Option::is_none")]
15    pub signal: Option<String>,
16
17    #[serde(flatten)]
18    pub extra: HashMap<String, Value>,
19}
20
21impl TransformSpecTrait for ExtentTransformSpec {
22    fn output_signals(&self) -> Vec<String> {
23        self.signal.clone().into_iter().collect()
24    }
25
26    fn transform_columns(
27        &self,
28        datum_var: &Option<ScopedVariable>,
29        _usage_scope: &[u32],
30        _task_scope: &TaskScope,
31        _vl_selection_fields: &VlSelectionFields,
32    ) -> TransformColumns {
33        if let Some(datum_var) = datum_var {
34            let usage = DatasetsColumnUsage::empty().with_column_usage(
35                datum_var,
36                ColumnUsage::empty().with_column(&unescape_field(&self.field)),
37            );
38            TransformColumns::PassThrough {
39                usage,
40                produced: ColumnUsage::empty(),
41            }
42        } else {
43            TransformColumns::Unknown
44        }
45    }
46
47    fn local_datetime_columns_produced(
48        &self,
49        input_local_datetime_columns: &[String],
50    ) -> Vec<String> {
51        // Keep input local datetime columns as extent passes through all input columns
52        // and doesn't create an columns
53        Vec::from(input_local_datetime_columns)
54    }
55}
vegafusion_core/spec/transform/extent.rs

vegafusion_core/spec/transform/
extent.rs
