diff options
Diffstat (limited to 'graphql2/resolvers/pagers_template.go')
| -rw-r--r-- | graphql2/resolvers/pagers_template.go | 224 |
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 +//} |