105 lines
2.4 KiB
Go
105 lines
2.4 KiB
Go
package query
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import (
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"context"
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"net/http"
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"go.pkg.cx/middleware"
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)
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// Context keys
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var (
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FilterCtxKey = &middleware.CtxKey{Pkg: "go.pkg.cx/middleware/query", Name: "Filter"}
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)
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// FilterOptions turns a list of option instances into an option
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func FilterOptions[T any](opts ...FilterOption[T]) FilterOption[T] {
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return func(f *filter[T]) {
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for _, opt := range opts {
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opt(f)
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}
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}
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}
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// FilterOption configures filter middleware
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type FilterOption[T any] func(f *filter[T])
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// WithParseFilterFn adds filter parse function to the list
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func WithParseFilterFn[T any](fn func(r *http.Request) (T, error)) FilterOption[T] {
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return func(f *filter[T]) {
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f.parseFilterFns = append(f.parseFilterFns, fn)
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}
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}
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// SetFilterDefault sets filter default value
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func SetFilterDefault[T any](defaultValue T) FilterOption[T] {
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return func(f *filter[T]) {
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f.defaultFilter = defaultValue
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}
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}
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// SetResponseHandler sets filter response handler
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func SetResponseHandler[T any](fn middleware.ResponseHandle) FilterOption[T] {
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return func(f *filter[T]) {
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f.responseHandler = fn
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}
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}
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type filter[T any] struct {
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defaultFilter T
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parseFilterFns []func(r *http.Request) (T, error)
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responseHandler middleware.ResponseHandle
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}
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// Filter returns filter middleware
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func Filter[T any](opts ...FilterOption[T]) func(next http.Handler) http.Handler {
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f := &filter[T]{
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defaultFilter: *new(T),
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parseFilterFns: []func(r *http.Request) (T, error){},
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responseHandler: RespondWithBadRequest,
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}
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for _, opt := range opts {
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opt(f)
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}
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return func(next http.Handler) http.Handler {
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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filter := f.defaultFilter
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var err error
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for _, fn := range f.parseFilterFns {
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if filter, err = fn(r); err == nil {
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break
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}
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}
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if err != nil {
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f.responseHandler(w, r, err)
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return
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}
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ctx := r.Context()
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ctx = context.WithValue(ctx, FilterCtxKey, filter)
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next.ServeHTTP(w, r.WithContext(ctx))
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})
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}
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}
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// FilterFromContext returns filter from context
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func FilterFromContext[T any](ctx context.Context) T {
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if filter, ok := ctx.Value(FilterCtxKey).(T); ok {
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return filter
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}
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return *new(T)
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}
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// FilterFromQuery returns filter string from query params
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func FilterFromQuery(filterParam string) func(r *http.Request) string {
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return func(r *http.Request) string {
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return r.URL.Query().Get(filterParam)
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}
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}
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