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pocketbase/daos/record_expand.go
2024-02-25 21:06:43 +02:00

314 lines
9.0 KiB
Go

package daos
import (
"errors"
"fmt"
"log"
"regexp"
"strings"
"github.com/pocketbase/dbx"
"github.com/pocketbase/pocketbase/models"
"github.com/pocketbase/pocketbase/models/schema"
"github.com/pocketbase/pocketbase/tools/dbutils"
"github.com/pocketbase/pocketbase/tools/list"
"github.com/pocketbase/pocketbase/tools/security"
"github.com/pocketbase/pocketbase/tools/types"
)
// MaxExpandDepth specifies the max allowed nested expand depth path.
//
// @todo Consider eventually reusing resolvers.maxNestedRels
const MaxExpandDepth = 6
// ExpandFetchFunc defines the function that is used to fetch the expanded relation records.
type ExpandFetchFunc func(relCollection *models.Collection, relIds []string) ([]*models.Record, error)
// ExpandRecord expands the relations of a single Record model.
//
// If optFetchFunc is not set, then a default function will be used
// that returns all relation records.
//
// Returns a map with the failed expand parameters and their errors.
func (dao *Dao) ExpandRecord(record *models.Record, expands []string, optFetchFunc ExpandFetchFunc) map[string]error {
return dao.ExpandRecords([]*models.Record{record}, expands, optFetchFunc)
}
// ExpandRecords expands the relations of the provided Record models list.
//
// If optFetchFunc is not set, then a default function will be used
// that returns all relation records.
//
// Returns a map with the failed expand parameters and their errors.
func (dao *Dao) ExpandRecords(records []*models.Record, expands []string, optFetchFunc ExpandFetchFunc) map[string]error {
normalized := normalizeExpands(expands)
failed := map[string]error{}
for _, expand := range normalized {
if err := dao.expandRecords(records, expand, optFetchFunc, 1); err != nil {
failed[expand] = err
}
}
return failed
}
// Deprecated
var indirectExpandRegexOld = regexp.MustCompile(`^(\w+)\((\w+)\)$`)
var indirectExpandRegex = regexp.MustCompile(`^(\w+)_via_(\w+)$`)
// notes:
// - if fetchFunc is nil, dao.FindRecordsByIds will be used
// - all records are expected to be from the same collection
// - if MaxExpandDepth is reached, the function returns nil ignoring the remaining expand path
func (dao *Dao) expandRecords(records []*models.Record, expandPath string, fetchFunc ExpandFetchFunc, recursionLevel int) error {
if fetchFunc == nil {
// load a default fetchFunc
fetchFunc = func(relCollection *models.Collection, relIds []string) ([]*models.Record, error) {
return dao.FindRecordsByIds(relCollection.Id, relIds)
}
}
if expandPath == "" || recursionLevel > MaxExpandDepth || len(records) == 0 {
return nil
}
mainCollection := records[0].Collection()
var relField *schema.SchemaField
var relFieldOptions *schema.RelationOptions
var relCollection *models.Collection
parts := strings.SplitN(expandPath, ".", 2)
var matches []string
// @todo remove the old syntax support
if strings.Contains(parts[0], "(") {
matches = indirectExpandRegexOld.FindStringSubmatch(parts[0])
if len(matches) == 3 {
log.Printf(
"%s expand format is deprecated and will be removed in the future. Consider replacing it with %s_via_%s.\n",
matches[0],
matches[1],
matches[2],
)
}
} else {
matches = indirectExpandRegex.FindStringSubmatch(parts[0])
}
if len(matches) == 3 {
indirectRel, _ := dao.FindCollectionByNameOrId(matches[1])
if indirectRel == nil {
return fmt.Errorf("couldn't find back-related collection %q", matches[1])
}
indirectRelField := indirectRel.Schema.GetFieldByName(matches[2])
if indirectRelField == nil || indirectRelField.Type != schema.FieldTypeRelation {
return fmt.Errorf("couldn't find back-relation field %q in collection %q", matches[2], indirectRel.Name)
}
indirectRelField.InitOptions()
indirectRelFieldOptions, _ := indirectRelField.Options.(*schema.RelationOptions)
if indirectRelFieldOptions == nil || indirectRelFieldOptions.CollectionId != mainCollection.Id {
return fmt.Errorf("invalid back-relation field path %q", parts[0])
}
// add the related id(s) as a dynamic relation field value to
// allow further expand checks at later stage in a more unified manner
prepErr := func() error {
q := dao.DB().Select("id").
From(indirectRel.Name).
Limit(1000) // the limit is arbitrary chosen and may change in the future
if indirectRelFieldOptions.IsMultiple() {
q.AndWhere(dbx.Exists(dbx.NewExp(fmt.Sprintf(
"SELECT 1 FROM %s je WHERE je.value = {:id}",
dbutils.JsonEach(indirectRelField.Name),
))))
} else {
q.AndWhere(dbx.NewExp("[[" + indirectRelField.Name + "]] = {:id}"))
}
pq := q.Build().Prepare()
for _, record := range records {
var relIds []string
err := pq.Bind(dbx.Params{"id": record.Id}).Column(&relIds)
if err != nil {
return errors.Join(err, pq.Close())
}
if len(relIds) > 0 {
record.Set(parts[0], relIds)
}
}
return pq.Close()
}()
if prepErr != nil {
return prepErr
}
relFieldOptions = &schema.RelationOptions{
MaxSelect: nil,
CollectionId: indirectRel.Id,
}
if dbutils.HasSingleColumnUniqueIndex(indirectRelField.Name, indirectRel.Indexes) {
relFieldOptions.MaxSelect = types.Pointer(1)
}
// indirect/back relation
relField = &schema.SchemaField{
Id: "_" + parts[0] + security.PseudorandomString(3),
Type: schema.FieldTypeRelation,
Name: parts[0],
Options: relFieldOptions,
}
relCollection = indirectRel
} else {
// direct relation
relField = mainCollection.Schema.GetFieldByName(parts[0])
if relField == nil || relField.Type != schema.FieldTypeRelation {
return fmt.Errorf("Couldn't find relation field %q in collection %q.", parts[0], mainCollection.Name)
}
relField.InitOptions()
relFieldOptions, _ = relField.Options.(*schema.RelationOptions)
if relFieldOptions == nil {
return fmt.Errorf("Couldn't initialize the options of relation field %q.", parts[0])
}
relCollection, _ = dao.FindCollectionByNameOrId(relFieldOptions.CollectionId)
if relCollection == nil {
return fmt.Errorf("Couldn't find related collection %q.", relFieldOptions.CollectionId)
}
}
// ---------------------------------------------------------------
// extract the id of the relations to expand
relIds := make([]string, 0, len(records))
for _, record := range records {
relIds = append(relIds, record.GetStringSlice(relField.Name)...)
}
// fetch rels
rels, relsErr := fetchFunc(relCollection, relIds)
if relsErr != nil {
return relsErr
}
// expand nested fields
if len(parts) > 1 {
err := dao.expandRecords(rels, parts[1], fetchFunc, recursionLevel+1)
if err != nil {
return err
}
}
// reindex with the rel id
indexedRels := make(map[string]*models.Record, len(rels))
for _, rel := range rels {
indexedRels[rel.GetId()] = rel
}
for _, model := range records {
relIds := model.GetStringSlice(relField.Name)
validRels := make([]*models.Record, 0, len(relIds))
for _, id := range relIds {
if rel, ok := indexedRels[id]; ok {
validRels = append(validRels, rel)
}
}
if len(validRels) == 0 {
continue // no valid relations
}
expandData := model.Expand()
// normalize access to the previously expanded rel records (if any)
var oldExpandedRels []*models.Record
switch v := expandData[relField.Name].(type) {
case nil:
// no old expands
case *models.Record:
oldExpandedRels = []*models.Record{v}
case []*models.Record:
oldExpandedRels = v
}
// merge expands
for _, oldExpandedRel := range oldExpandedRels {
// find a matching rel record
for _, rel := range validRels {
if rel.Id != oldExpandedRel.Id {
continue
}
rel.MergeExpand(oldExpandedRel.Expand())
}
}
// update the expanded data
if relFieldOptions.MaxSelect != nil && *relFieldOptions.MaxSelect <= 1 {
expandData[relField.Name] = validRels[0]
} else {
expandData[relField.Name] = validRels
}
model.SetExpand(expandData)
}
return nil
}
// normalizeExpands normalizes expand strings and merges self containing paths
// (eg. ["a.b.c", "a.b", " test ", " ", "test"] -> ["a.b.c", "test"]).
func normalizeExpands(paths []string) []string {
// normalize paths
normalized := make([]string, 0, len(paths))
for _, p := range paths {
p = strings.ReplaceAll(p, " ", "") // replace spaces
p = strings.Trim(p, ".") // trim incomplete paths
if p != "" {
normalized = append(normalized, p)
}
}
// merge containing paths
result := make([]string, 0, len(normalized))
for i, p1 := range normalized {
var skip bool
for j, p2 := range normalized {
if i == j {
continue
}
if strings.HasPrefix(p2, p1+".") {
// skip because there is more detailed expand path
skip = true
break
}
}
if !skip {
result = append(result, p1)
}
}
return list.ToUniqueStringSlice(result)
}
func isRelFieldUnique(collection *models.Collection, fieldName string) bool {
for _, idx := range collection.Indexes {
parsed := dbutils.ParseIndex(idx)
if parsed.Unique && len(parsed.Columns) == 1 && strings.EqualFold(parsed.Columns[0].Name, fieldName) {
return true
}
}
return false
}