hugo/hugolib/pageSort.go

96 lines
2.3 KiB
Go

// Copyright © 2014 Steve Francia <spf@spf13.com>.
//
// Licensed under the Simple Public License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://opensource.org/licenses/Simple-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package hugolib
import (
"sort"
)
/*
* Implementation of a custom sorter for Pages
*/
// A type to implement the sort interface for Pages
type PageSorter struct {
pages Pages
by PageBy
}
// Closure used in the Sort.Less method.
type PageBy func(p1, p2 *Page) bool
func (by PageBy) Sort(pages Pages) {
ps := &PageSorter{
pages: pages,
by: by, // The Sort method's receiver is the function (closure) that defines the sort order.
}
sort.Sort(ps)
}
var DefaultPageSort = func(p1, p2 *Page) bool {
if p1.Weight == p2.Weight {
return p1.Date.Unix() > p2.Date.Unix()
} else {
return p1.Weight < p2.Weight
}
}
func (ps *PageSorter) Len() int { return len(ps.pages) }
func (ps *PageSorter) Swap(i, j int) { ps.pages[i], ps.pages[j] = ps.pages[j], ps.pages[i] }
// Less is part of sort.Interface. It is implemented by calling the "by" closure in the sorter.
func (ps *PageSorter) Less(i, j int) bool { return ps.by(ps.pages[i], ps.pages[j]) }
func (p Pages) Sort() {
PageBy(DefaultPageSort).Sort(p)
}
func (p Pages) Limit(n int) Pages {
if len(p) < n {
return p[0:n]
} else {
return p
}
}
func (p Pages) ByWeight() Pages {
PageBy(DefaultPageSort).Sort(p)
return p
}
func (p Pages) ByDate() Pages {
date := func(p1, p2 *Page) bool {
return p1.Date.Unix() < p2.Date.Unix()
}
PageBy(date).Sort(p)
return p
}
func (p Pages) ByLength() Pages {
length := func(p1, p2 *Page) bool {
return len(p1.Content) < len(p2.Content)
}
PageBy(length).Sort(p)
return p
}
func (p Pages) Reverse() Pages {
for i, j := 0, len(p)-1; i < j; i, j = i+1, j-1 {
p[i], p[j] = p[j], p[i]
}
return p
}