extract and test dynamic component

src/dynamic_component.rs

@@ -0,0 +1,65 @@
+use anyhow::{self, Context as _};
+use serde_json::Value as JsonValue;
+
+use crate::webserver::database::DbItem;
+
+const MAX_RECURSION_DEPTH: u8 = 127;
+
+/// the raw query results can include (potentially nested) rows with a 'component' column that has the value 'dynamic'.
+/// in that case we need to parse the JSON in the 'properties' column, and emit a row for each value in the resulting json array.
+#[must_use] pub fn parse_dynamic_rows(db_item: DbItem) -> Box<dyn Iterator<Item = DbItem>> {
+    if let DbItem::Row(row) = db_item {
+        parse_dynamic_rows_json(row, 0)
+    } else {
+        Box::new(std::iter::once(db_item))
+    }
+}
+
+fn parse_dynamic_rows_json(mut row: JsonValue, depth: u8) -> Box<dyn Iterator<Item = DbItem>> {
+    if depth >= MAX_RECURSION_DEPTH {
+        return Box::new(std::iter::once(DbItem::Error(anyhow::anyhow!(
+            "Too many nested dynamic components: \n\
+            The 'dynamic' component can be used to render another 'dynamic' component, \
+            but the recursion cannot exceed {depth} layers."
+        ))));
+    }
+    if let Some(properties) = extract_dynamic_properties(&mut row) {
+        match dynamic_properties_to_iter(properties) {
+            Ok(iter) => Box::new(iter.flat_map(move |v| parse_dynamic_rows_json(v, depth + 1))),
+            Err(e) => Box::new(std::iter::once(DbItem::Error(e))),
+        }
+    } else {
+        Box::new(std::iter::once(DbItem::Row(row)))
+    }
+}
+
+/// if row.component == 'dynamic', return Some(row.properties), otherwise return None
+fn extract_dynamic_properties(data: &mut JsonValue) -> Option<JsonValue> {
+    let component = data.get("component").and_then(|v| v.as_str());
+    if component == Some("dynamic") {
+        let properties = data.get_mut("properties").map(JsonValue::take);
+        Some(properties.unwrap_or_default())
+    } else {
+        None
+    }
+}
+
+fn dynamic_properties_to_iter(
+    mut properties_obj: JsonValue,
+) -> anyhow::Result<Box<dyn Iterator<Item = JsonValue>>> {
+    if let JsonValue::String(s) = properties_obj {
+        properties_obj = serde_json::from_str::<JsonValue>(&s).with_context(|| {
+            format!(
+                "Unable to parse the 'properties' property of the dynamic component as JSON.\n\
+                    Invalid json: {s}"
+            )
+        })?;
+    }
+    match properties_obj {
+        obj @ JsonValue::Object(_) => Ok(Box::new(std::iter::once(obj))),
+        JsonValue::Array(values) => Ok(Box::new(values.into_iter())),
+        other => anyhow::bail!(
+            "Dynamic component expected properties of type array or object, got {other} instead."
+        ),
+    }
+}

src/lib.rs

@@ -4,6 +4,7 @@
 extern crate core;
 
 pub mod app_config;
+pub mod dynamic_component;
 pub mod file_cache;
 pub mod filesystem;
 pub mod render;

src/webserver/database/execute_queries.rs

@@ -7,20 +7,18 @@ use std::pin::Pin;
 
 use super::csv_import::run_csv_import;
 use super::sql::{ParsedSqlFile, ParsedStatement, StmtWithParams};
+use crate::dynamic_component::parse_dynamic_rows;
 use crate::webserver::database::sql_pseudofunctions::extract_req_param;
 use crate::webserver::database::sql_to_json::row_to_string;
 use crate::webserver::http::SingleOrVec;
 use crate::webserver::http_request_info::RequestInfo;
 
+use super::sql_pseudofunctions::StmtParam;
+use super::{highlight_sql_error, Database, DbItem};
 use sqlx::any::{AnyArguments, AnyQueryResult, AnyRow, AnyStatement, AnyTypeInfo};
 use sqlx::pool::PoolConnection;
 use sqlx::{Any, AnyConnection, Arguments, Either, Executor, Statement};
 
-use serde_json::Value as JsonValue;
-
-use super::sql_pseudofunctions::StmtParam;
-use super::{highlight_sql_error, Database, DbItem};
-
 impl Database {
     pub(crate) async fn prepare_with(
         &self,
@@ -34,55 +32,6 @@ impl Database {
             .map_err(|e| highlight_sql_error("Failed to prepare SQL statement", query, e))
     }
 }
-
-/// the raw query results can include (potentially nested) rows with a 'component' column that has the value 'dynamic'.
-/// in that case we need to parse the JSON in the 'properties' column, and emit a row for each value in the resulting json array.
-pub fn parse_dynamic_rows(db_item: DbItem) -> Box<dyn Iterator<Item = DbItem>> {
-    if let DbItem::Row(mut row) = db_item {
-        if let Some(properties) = extract_dynamic_properties(&mut row) {
-            match dynamic_properties_to_iter(properties) {
-                Ok(iter) => Box::new(iter.map(DbItem::Row)),
-                Err(e) => Box::new(std::iter::once(DbItem::Error(e))),
-            }
-        } else {
-            Box::new(std::iter::once(DbItem::Row(row)))
-        }
-    } else {
-        Box::new(std::iter::once(db_item))
-    }
-}
-
-/// if row.component == 'dynamic', return Some(row.properties), otherwise return None
-fn extract_dynamic_properties(data: &mut JsonValue) -> Option<JsonValue> {
-    let component = data.get("component").and_then(|v| v.as_str());
-    if component == Some("dynamic") {
-        let properties = data.get_mut("properties").map(JsonValue::take);
-        Some(properties.unwrap_or_default())
-    } else {
-        None
-    }
-}
-
-fn dynamic_properties_to_iter(
-    mut properties_obj: JsonValue,
-) -> anyhow::Result<Box<dyn Iterator<Item = JsonValue>>> {
-    if let JsonValue::String(s) = properties_obj {
-        properties_obj = serde_json::from_str::<JsonValue>(&s).with_context(|| {
-            format!(
-                "Unable to parse the 'properties' property of the dynamic component as JSON.\n\
-                    Invalid json: {s}"
-            )
-        })?;
-    }
-    match properties_obj {
-        obj @ JsonValue::Object(_) => Ok(Box::new(std::iter::once(obj))),
-        JsonValue::Array(values) => Ok(Box::new(values.into_iter())),
-        other => anyhow::bail!(
-            "Dynamic component expected properties of type array or object, got {other} instead."
-        ),
-    }
-}
-
 pub fn stream_query_results<'a>(
     db: &'a Database,
     sql_file: &'a ParsedSqlFile,

tests/sql_test_files/error_too_many_nested_dynamic_components.sql

@@ -0,0 +1,129 @@
+select 'dynamic' as component,'{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"dynamic","properties":
+{"component":"text", "contents": "It works ! (but it shouldn''t)"}
+}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}
+' as properties;

tests/sql_test_files/it_works_dynamic_nested.sql

@@ -0,0 +1,8 @@
+-- Checks that we can have a page with a single dynamic component containing multiple children
+select 'dynamic' as component,
+    '[
+        {"component":"dynamic", "properties": [
+            {"component":"text"},
+            {"contents":"It works !", "bold":true}
+        ]}
+    ]' as properties;