Implement Serialize/Deserialize for Many

Requires allowing a table name in a Query to be a Cow instead of
always a &'static str, hence the bump to 0.4

butane/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "butane"
-version = "0.3.1"
+version = "0.4.0"
 authors = ["James Oakley <james@electronstudio.org>"]
 edition = "2018"
 description = "An ORM with a focus on simplicity and on writing Rust, not SQL."
@@ -23,8 +23,8 @@ tls = ["butane_core/tls"]
 uuid = ["butane_core/uuid", "butane_codegen/uuid"]
 
 [dependencies]
-butane_codegen = { path = "../butane_codegen", version = "0.3.1" }
-butane_core = { path = "../butane_core", version = "0.3.1" }
+butane_codegen = { path = "../butane_codegen", version = "0.4" }
+butane_core = { path = "../butane_core", version = "0.4" }
 
 
 [dev-dependencies]
@@ -39,6 +39,7 @@ once_cell="1.5.2"
 postgres = { version = "0.19", features=["with-geo-types-0_7"] }
 r2d2_for_test = {package="r2d2", version = "0.8"}
 rusqlite = "0.25"
+serde_json = "1.0"
 uuid_for_test = {package="uuid", version = "0.8", features=["v4"] }
 
 [package.metadata.docs.rs]

butane/tests/query.rs

@@ -1,9 +1,10 @@
 use butane::db::Connection;
 use butane::prelude::*;
 use butane::query::BoolExpr;
-use butane::{colname, filter, find, query};
+use butane::{colname, filter, find, query, Many};
 use chrono::{TimeZone, Utc};
 use paste;
+use serde_json;
 
 mod common;
 use common::blog;
@@ -130,6 +131,19 @@ fn many_load(conn: Connection) {
 }
 testall!(many_load);
 
+fn many_serialize(conn: Connection) {
+    blog::setup_blog(&conn);
+    let post: Post = find!(Post, title == "The Tiger", &conn).unwrap();
+    let tags_json: String = serde_json::to_string(&post.tags).unwrap();
+    let tags: Many<Tag> = serde_json::from_str(&tags_json).unwrap();
+    let tags = tags.load(&conn).unwrap();
+    let mut tags: Vec<&Tag> = tags.collect();
+    tags.sort_by(|t1, t2| (*t1).tag.partial_cmp(&t2.tag).unwrap());
+    assert_eq!(tags[0].tag, "asia");
+    assert_eq!(tags[1].tag, "danger");
+}
+testall!(many_serialize);
+
 fn many_objects_with_tag(conn: Connection) {
     blog::setup_blog(&conn);
     let mut posts = query!(Post, tags.contains("danger")).load(&conn).unwrap();

butane_cli/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "butane_cli"
-version = "0.3.1"
+version = "0.4.0"
 authors = ["James Oakley <james@electronstudio.org>"]
 edition = "2018"
 description = "The CLI for the Butane ORM"
@@ -15,7 +15,7 @@ path = "src/main.rs"
 
 [dependencies]
 anyhow = "1.0"
-butane = { path="../butane", version="0.3.1", features=["default", "sqlite", "pg"] }
+butane = { path="../butane", version="0.4", features=["default", "sqlite", "pg"] }
 chrono = "0.4"
 clap = "2.33"
 quote = "1.0"

butane_codegen/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "butane_codegen"
-version = "0.3.1"
+version = "0.4.0"
 authors = ["James Oakley <james@electronstudio.org>"]
 edition = "2018"
 description = "Macros for Butane. Do not use this crate directly -- use the butane crate."
@@ -13,7 +13,7 @@ datetime = []
 
 [dependencies]
 proc-macro2 = "1.0"
-butane_core = { path = "../butane_core", version = "0.3.1" }
+butane_core = { path = "../butane_core", version = "0.4" }
 quote = "1.0"
 syn = { version = "1.0", features = ["full", "extra-traits"] }
 uuid = {version = "0.8", optional=true}

butane_core/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "butane_core"
-version = "0.3.1"
+version = "0.4.0"
 authors = ["James Oakley <james@electronstudio.org>"]
 edition = "2018"
 description = "Internals for Butane. Do not use this crate directly -- use the butane crate."

butane_core/src/many.rs

@@ -2,6 +2,12 @@ use crate::db::{Column, ConnectionMethods};
 use crate::query::{BoolExpr, Expr};
 use crate::{DataObject, Error, FieldType, Result, SqlType, SqlVal, ToSql};
 use once_cell::unsync::OnceCell;
+use serde::{Deserialize, Serialize};
+use std::borrow::Cow;
+
+fn default_oc<T>() -> OnceCell<Vec<T>> {
+    OnceCell::default()
+}
 
 /// Used to implement a many-to-many relationship between models.
 ///
@@ -10,15 +16,18 @@ use once_cell::unsync::OnceCell;
 /// U::PKType. Table name is T_ManyToMany_foo where foo is the name of
 /// the Many field
 //
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
 pub struct Many<T>
 where
     T: DataObject,
 {
-    item_table: &'static str,
+    item_table: Cow<'static, str>,
     owner: Option<SqlVal>,
     owner_type: SqlType,
+    #[serde(skip)]
     new_values: Vec<SqlVal>,
+    #[serde(skip)]
+    #[serde(default = "default_oc")]
     all_values: OnceCell<Vec<T>>,
 }
 impl<T> Many<T>
@@ -33,7 +42,7 @@ where
     /// [`DataObject`]: super::DataObject
     pub fn new() -> Self {
         Many {
-            item_table: "not_initialized",
+            item_table: Cow::Borrowed("not_initialized"),
             owner: None,
             owner_type: SqlType::Int,
             new_values: Vec::new(),
@@ -46,7 +55,7 @@ where
         if self.owner.is_some() {
             return;
         }
-        self.item_table = item_table;
+        self.item_table = Cow::Borrowed(item_table);
         self.owner = Some(owner);
         self.owner_type = owner_type;
         self.all_values = OnceCell::new();
@@ -72,7 +81,7 @@ where
         let owner = self.owner.as_ref().ok_or(Error::NotInitialized)?;
         while !self.new_values.is_empty() {
             conn.insert_only(
-                self.item_table,
+                &self.item_table,
                 &self.columns(),
                 &[
                     owner.as_ref(),
@@ -96,7 +105,7 @@ where
             let mut vals = T::query()
                 .filter(BoolExpr::Subquery {
                     col: T::PKCOL,
-                    tbl2: self.item_table,
+                    tbl2: self.item_table.clone(),
                     tbl2_col: "has",
                     expr: Box::new(BoolExpr::Eq("owner", Expr::Val(owner.clone()))),
                 })

butane_core/src/query/fieldexpr.rs

@@ -4,7 +4,7 @@ use crate::fkey::ForeignKey;
 use crate::query::{BoolExpr, Column, Expr, Join};
 use crate::sqlval::{FieldType, SqlVal, ToSql};
 use crate::DataObject;
-use std::borrow::Borrow;
+use std::borrow::{Borrow, Cow};
 use std::cmp::{PartialEq, PartialOrd};
 use std::marker::PhantomData;
 
@@ -78,7 +78,7 @@ impl<F: DataObject> FieldExpr<ForeignKey<F>> {
     pub fn subfilter(&self, q: BoolExpr) -> BoolExpr {
         BoolExpr::Subquery {
             col: self.name,
-            tbl2: F::TABLE,
+            tbl2: Cow::Borrowed(F::TABLE),
             tbl2_col: F::PKCOL,
             expr: Box::new(q),
         }
@@ -119,7 +119,7 @@ where
         //let many_tbl = format!("{}_{}_Many", O::TABLE, self.name);
         BoolExpr::SubqueryJoin {
             col: O::PKCOL,
-            tbl2: T::TABLE,
+            tbl2: Cow::Borrowed(T::TABLE),
             col2: Column::new(self.many_table, "owner"),
             joins: vec![Join::Inner {
                 join_table: self.many_table,

butane_core/src/query/mod.rs

@@ -5,12 +5,15 @@
 use crate::db::{BackendRows, ConnectionMethods, QueryResult};
 use crate::{DataResult, Result, SqlVal};
 use fallible_iterator::FallibleIterator;
+use std::borrow::Cow;
 use std::marker::PhantomData;
 
 mod fieldexpr;
 
 pub use fieldexpr::{DataOrd, FieldExpr, ManyFieldExpr};
 
+type TblName = Cow<'static, str>;
+
 /// Abstract representation of a database expression.
 #[derive(Clone)]
 pub enum Expr {
@@ -44,7 +47,7 @@ pub enum BoolExpr {
     /// in `tbl2` is true.
     Subquery {
         col: &'static str,
-        tbl2: &'static str,
+        tbl2: TblName,
         tbl2_col: &'static str,
         expr: Box<BoolExpr>,
     },
@@ -54,7 +57,7 @@ pub enum BoolExpr {
     /// in `tbl2` with the specified joins is true.
     SubqueryJoin {
         col: &'static str,
-        tbl2: &'static str,
+        tbl2: TblName,
         col2: Column,
         joins: Vec<Join>,
         expr: Box<BoolExpr>,
@@ -88,21 +91,21 @@ pub enum Join {
 
 #[derive(Clone)]
 pub struct Column {
-    table: Option<&'static str>,
+    table: Option<TblName>,
     name: &'static str,
 }
 impl Column {
     pub fn new(table: &'static str, name: &'static str) -> Self {
         Column {
-            table: Some(table),
+            table: Some(Cow::Borrowed(table)),
             name,
         }
     }
     pub fn unqualified(name: &'static str) -> Self {
         Column { table: None, name }
     }
-    pub fn table(&self) -> Option<&'static str> {
-        self.table
+    pub fn table(&self) -> Option<&str> {
+        self.table.as_ref().map(|t| t.as_ref())
     }
     pub fn name(&self) -> &'static str {
         self.name
@@ -112,7 +115,7 @@ impl Column {
 /// Representation of a database query.
 #[derive(Clone)]
 pub struct Query<T: DataResult> {
-    table: &'static str,
+    table: TblName,
     filter: Option<BoolExpr>,
     limit: Option<i32>,
     sort: Vec<Order>,
@@ -124,7 +127,7 @@ impl<T: DataResult> Query<T> {
     /// `limit`.
     pub fn new(table: &'static str) -> Query<T> {
         Query {
-            table,
+            table: Cow::Borrowed(table),
             filter: None,
             limit: None,
             sort: Vec::new(),
@@ -168,7 +171,7 @@ impl<T: DataResult> Query<T> {
 
     /// Executes the query against `conn` and returns the first result (if any).
     pub fn load_first(self, conn: &impl ConnectionMethods) -> Result<Option<T>> {
-        conn.query(self.table, T::COLUMNS, self.filter, Some(1), None)?
+        conn.query(&self.table, T::COLUMNS, self.filter, Some(1), None)?
             .mapped(T::from_row)
             .nth(0)
     }
@@ -180,13 +183,13 @@ impl<T: DataResult> Query<T> {
         } else {
             Some(self.sort.as_slice())
         };
-        conn.query(self.table, T::COLUMNS, self.filter, self.limit, sort)?
+        conn.query(&self.table, T::COLUMNS, self.filter, self.limit, sort)?
             .mapped(T::from_row)
             .collect()
     }
 
     /// Executes the query against `conn` and deletes all matching objects.
     pub fn delete(self, conn: &impl ConnectionMethods) -> Result<usize> {
-        conn.delete_where(self.table, self.filter.unwrap_or(BoolExpr::True))
+        conn.delete_where(&self.table, self.filter.unwrap_or(BoolExpr::True))
     }
 }