Implement EVENT clauses

lib/src/doc/event.rs

@@ -1,18 +1,62 @@
+use crate::ctx::Context;
 use crate::dbs::Options;
 use crate::dbs::Runtime;
 use crate::dbs::Statement;
 use crate::dbs::Transaction;
 use crate::doc::Document;
 use crate::err::Error;
+use crate::sql::value::Value;
+use std::ops::Deref;
 
 impl<'a> Document<'a> {
 	pub async fn event(
 		&self,
-		_ctx: &Runtime,
-		_opt: &Options,
-		_txn: &Transaction,
+		ctx: &Runtime,
+		opt: &Options,
+		txn: &Transaction,
 		_stm: &Statement,
 	) -> Result<(), Error> {
+		// Check events
+		if !opt.events {
+			return Ok(());
+		}
+		// Check if forced
+		if !opt.force && !self.changed() {
+			return Ok(());
+		}
+		// Get the record id
+		let rid = self.id.as_ref().unwrap();
+		// Get all event statements
+		let evs = txn.clone().lock().await.all_ev(opt.ns(), opt.db(), &rid.tb).await?;
+		// Loop through all event statements
+		for ev in evs.iter() {
+			// Get the event action
+			let met = if self.initial.is_none() {
+				Value::from("CREATE")
+			} else if self.current.is_none() {
+				Value::from("DELETE")
+			} else {
+				Value::from("UPDATE")
+			};
+			// Configure the context
+			let mut ctx = Context::new(ctx);
+			ctx.add_value("event".into(), met);
+			ctx.add_value("value".into(), self.current.deref().clone());
+			ctx.add_value("after".into(), self.current.deref().clone());
+			ctx.add_value("before".into(), self.initial.deref().clone());
+			let ctx = ctx.freeze();
+			// Ensure event queries run
+			let opt = &opt.perms(false);
+			// Process conditional clause
+			let val = ev.when.compute(&ctx, opt, txn, Some(&self.current)).await?;
+			// Execute event if value is truthy
+			if val.is_truthy() {
+				for v in ev.then.iter() {
+					v.compute(&ctx, opt, txn, Some(&self.current)).await?;
+				}
+			}
+		}
+		// Carry on
 		Ok(())
 	}
 }