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-rw-r--r--graphql2/resolvers/pagers_template.go224
1 files changed, 224 insertions, 0 deletions
diff --git a/graphql2/resolvers/pagers_template.go b/graphql2/resolvers/pagers_template.go
new file mode 100644
index 00000000..0ca7de75
--- /dev/null
+++ b/graphql2/resolvers/pagers_template.go
@@ -0,0 +1,224 @@
+package resolvers
+
+import (
+ "fmt"
+ "github.com/cheekybits/genny/generic"
+)
+
+type NodeType generic.Type
+type EdgeType generic.Type
+
+type NodeTypeEdger func(value NodeType, offset int) Edge
+
+func NodeTypePaginate(source []NodeType, edger NodeTypeEdger, input ConnectionInput) ([]EdgeType, PageInfo, error) {
+ var result []EdgeType
+ var pageInfo PageInfo
+
+ offset := 0
+
+ if input.After != nil {
+ for i, value := range source {
+ edge := edger(value, i)
+ if edge.GetCursor() == *input.After {
+ // remove all previous element including the "after" one
+ source = source[i+1:]
+ offset = i + 1
+ break
+ }
+ }
+ }
+
+ if input.Before != nil {
+ for i, value := range source {
+ edge := edger(value, i+offset)
+
+ if edge.GetCursor() == *input.Before {
+ // remove all after element including the "before" one
+ break
+ }
+
+ result = append(result, edge.(EdgeType))
+ }
+ } else {
+ result = make([]EdgeType, len(source))
+
+ for i, value := range source {
+ result[i] = edger(value, i+offset).(EdgeType)
+ }
+ }
+
+ if input.First != nil {
+ if *input.First < 0 {
+ return nil, PageInfo{}, fmt.Errorf("first less than zero")
+ }
+
+ if len(result) > *input.First {
+ // Slice result to be of length first by removing edges from the end
+ result = result[:*input.First]
+ pageInfo.HasNextPage = true
+ }
+ }
+
+ if input.Last != nil {
+ if *input.Last < 0 {
+ return nil, PageInfo{}, fmt.Errorf("last less than zero")
+ }
+
+ if len(result) > *input.Last {
+ // Slice result to be of length last by removing edges from the start
+ result = result[len(result)-*input.Last:]
+ pageInfo.HasPreviousPage = true
+ }
+ }
+
+ return result, pageInfo, nil
+}
+
+// Apply the before/after cursor params to the source and return an array of edges
+//func ApplyCursorToEdges(source []interface{}, edger Edger, input ConnectionInput) []Edge {
+// var result []Edge
+//
+// if input.After != nil {
+// for i, value := range source {
+// edge := edger(value)
+// if edge.Cursor() == *input.After {
+// // remove all previous element including the "after" one
+// source = source[i+1:]
+// break
+// }
+// }
+// }
+//
+// if input.Before != nil {
+// for _, value := range source {
+// edge := edger(value)
+//
+// if edge.Cursor() == *input.Before {
+// // remove all after element including the "before" one
+// break
+// }
+//
+// result = append(result, edge)
+// }
+// } else {
+// result = make([]Edge, len(source))
+//
+// for i, value := range source {
+// result[i] = edger(value)
+// }
+// }
+//
+// return result
+//}
+
+// Apply the first/last cursor params to the edges
+//func EdgesToReturn(edges []Edge, input ConnectionInput) ([]Edge, PageInfo, error) {
+// hasPreviousPage := false
+// hasNextPage := false
+//
+// if input.First != nil {
+// if *input.First < 0 {
+// return nil, nil, fmt.Errorf("first less than zero")
+// }
+//
+// if len(edges) > *input.First {
+// // Slice result to be of length first by removing edges from the end
+// edges = edges[:*input.First]
+// hasNextPage = true
+// }
+// }
+//
+// if input.Last != nil {
+// if *input.Last < 0 {
+// return nil, nil, fmt.Errorf("last less than zero")
+// }
+//
+// if len(edges) > *input.Last {
+// // Slice result to be of length last by removing edges from the start
+// edges = edges[len(edges)-*input.Last:]
+// hasPreviousPage = true
+// }
+// }
+//
+// pageInfo := PageInfo{
+// HasNextPage: hasNextPage,
+// HasPreviousPage: hasPreviousPage,
+// }
+//
+// return edges, pageInfo, nil
+//}
+
+//func EdgesToReturn(allEdges []Edge, before *cursor, after *cursor, first *int, last *int) ([]Edge, error) {
+// result := ApplyCursorToEdges(allEdges, before, after)
+//
+// if first != nil {
+// if *first < 0 {
+// return nil, fmt.Errorf("first less than zero")
+// }
+//
+// if len(result) > *first {
+// // Slice result to be of length first by removing edges from the end
+// result = result[:*first]
+// }
+// }
+//
+// if last != nil {
+// if *last < 0 {
+// return nil, fmt.Errorf("last less than zero")
+// }
+//
+// if len(result) > *last {
+// // Slice result to be of length last by removing edges from the start
+// result = result[len(result)-*last:]
+// }
+// }
+//
+// return result, nil
+//}
+
+//func ApplyCursorToEdges(allEdges []Edge, before *cursor, after *cursor) []Edge {
+// result := allEdges
+//
+// if after != nil {
+// for i, edge := range result {
+// if edge.Cursor() == *after {
+// // remove all previous element including the "after" one
+// result = result[i+1:]
+// break
+// }
+// }
+// }
+//
+// if before != nil {
+// for i, edge := range result {
+// if edge.Cursor() == *before {
+// // remove all after element including the "before" one
+// result = result[:i]
+// }
+// }
+// }
+//
+// return result
+//}
+
+//func HasPreviousPage(allEdges []Edge, before *cursor, after *cursor, last *int) bool {
+// if last != nil {
+// edges := ApplyCursorToEdges(allEdges, before, after)
+// return len(edges) > *last
+// }
+//
+// // TODO: handle "after", but according to the spec it's ok to return false
+//
+// return false
+//}
+//
+//func HasNextPage(allEdges []Edge, before *cursor, after *cursor, first *int) bool {
+// if first != nil {
+// edges := ApplyCursorToEdges(allEdges, before, after)
+// return len(edges) > *first
+// }
+//
+// // TODO: handle "before", but according to the spec it's ok to return false
+//
+// return false
+//}