hugo/common/collections/collections.go
Bjørn Erik Pedersen e27fd4c1b8 tpl/collections: Add collections.Append
Before this commit you would typically use `.Scratch.Add` to manually create slices in a loop.

With variable overwrite in Go 1.11, we can do better. This commit adds the `append` template func.

A made-up example:

```bash
{{ $p1 := index .Site.RegularPages 0 }}{{ $p2 := index .Site.RegularPages 1 }}
{{ $pages := slice }}
{{ if true }}
  {{ $pages = $pages | append $p2 $p1 }}
{{ end }}
```

Note that with 2 slices as arguments, the two examples below will give the same result:

```bash
{{ $s1 := slice "a" "b" | append (slice "c" "d") }}
{{ $s2 := slice "a" "b" | append "c" "d" }}
```

Both of the above will give `[]string{a, b, c, d}`.

This commit also improves the type handling in the `slice` template function. Now `slice "a" "b"` will give a `[]string` slice. The old behaviour was to return a `[]interface{}`.

Fixes #5190
2018-09-14 10:12:08 +02:00

28 lines
1.1 KiB
Go

// Copyright 2018 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache 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://www.apache.org/licenses/LICENSE-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 collections contains common Hugo functionality related to collection
// handling.
package collections
// Grouper defines a very generic way to group items by a given key.
type Grouper interface {
Group(key interface{}, items interface{}) (interface{}, error)
}
// Slicer definse a very generic way to create a typed slice. This is used
// in collections.Slice template func to get types such as Pages, PageGroups etc.
// instead of the less useful []interface{}.
type Slicer interface {
Slice(items interface{}) (interface{}, error)
}