surrealpatch/db/lives.go
2017-11-16 20:53:39 +00:00

138 lines
2.8 KiB
Go

// Copyright © 2016 Abcum Ltd
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package db
import (
"context"
"github.com/abcum/surreal/sql"
"github.com/abcum/surreal/util/data"
)
// Lives checks if any table views are specified for
// this table, and executes them in name order.
func (d *document) lives(ctx context.Context, when method) (err error) {
// If this document has not changed
// then there is no need to update
// any registered live queries.
if !d.changed() {
return nil
}
// Get the foreign read-only tables
// specified for this table, and
// update values which have changed.
lvs, err := d.getLV()
if err != nil {
return err
}
if len(lvs) > 0 {
for _, lv := range lvs {
var ok bool
var con *socket
var doc *data.Doc
if con, ok = sockets[lv.FB]; ok {
ctx = con.ctx()
// Check whether this live query has the
// necessary permissions to view this
// document, or continue to the next query.
ok, err = d.grant(ctx, when)
if err != nil {
continue
} else if !ok {
continue
}
// Check whether this document matches the
// filter conditions for the live query and
// if not, then continue to the next query.
ok, err = d.check(ctx, lv.Cond)
if err != nil {
continue
} else if !ok {
continue
}
switch lv.Diff {
// If the live query has specified to only
// receive diff changes, then there will be
// no project fields for this query.
case true:
doc = d.diff()
// If the query has project fields which it
// wants to receive, then let's fetch thses
// fields, and return them to the socket.
case false:
for _, v := range lv.Expr {
if _, ok := v.Expr.(*sql.All); ok {
doc = d.current
break
}
}
if doc == nil {
doc = data.New()
}
for _, e := range lv.Expr {
switch v := e.Expr.(type) {
case *sql.All:
break
default:
v, err := d.i.e.fetch(ctx, v, d.current)
if err != nil {
continue
}
doc.Set(v, e.Field)
}
}
}
switch when {
case _CREATE:
con.queue(lv.ID, "CREATE", doc.Data())
case _UPDATE:
con.queue(lv.ID, "UPDATE", doc.Data())
case _DELETE:
con.queue(lv.ID, "DELETE", d.id)
}
}
}
}
return
}