/
generator.go
89 lines (73 loc) · 1.77 KB
/
generator.go
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package filter
type IGenerator interface {
Initialize(string) error
Finalize(*Filter) error
Push([]byte)
Set([]byte)
Payload() []byte
WithCriterion(Criterion) error
OrCriterion(Criterion) error
WithField(string) error
GroupByField(string) error
AggregateByField(Aggregation, string) error
SetOption(string, interface{}) error
GetValues() []interface{}
Reset()
}
type Generator struct {
IGenerator
payload []byte
}
func Render(generator IGenerator, collectionName string, filter *Filter) ([]byte, error) {
if err := generator.Initialize(collectionName); err != nil {
return nil, err
}
// add options
for key, value := range filter.Options {
if err := generator.SetOption(key, value); err != nil {
return nil, err
}
}
// add fields
for _, fieldName := range filter.Fields {
if filter.IdentityField != `` && fieldName == `id` {
fieldName = filter.IdentityField
}
if err := generator.WithField(fieldName); err != nil {
return nil, err
}
}
// add criteria
for _, criterion := range filter.Criteria {
if filter.IdentityField != `` && criterion.Field == `id` {
criterion.Field = filter.IdentityField
}
if err := generator.WithCriterion(criterion); err != nil {
return nil, err
}
}
// finalize the payload
if err := generator.Finalize(filter); err != nil {
return nil, err
}
// return the payload
return generator.Payload(), nil
}
func (self *Generator) Set(data []byte) {
self.payload = data
}
func (self *Generator) Push(data []byte) {
if self.payload == nil {
self.payload = make([]byte, 0)
}
self.payload = append(self.payload, data...)
}
func (self *Generator) Reset() {
self.payload = nil
}
func (self *Generator) Payload() []byte {
return self.payload
}
func (self *Generator) Finalize(_ *Filter) error {
return nil
}