This resolves some surprising behaviour when reading other pages' content from shortcodes. Before this commit, that behaviour was undefined. Note that this has never been an issue from regular templates.
It will still not be possible to get **the current shortcode's page's rendered content**. That would have impressed Einstein.
The new and well defined rules are:
* `.Page.Content` from a shortcode will be empty. The related `.Page.Truncated` `.Page.Summary`, `.Page.WordCount`, `.Page.ReadingTime`, `.Page.Plain` and `.Page.PlainWords` will also have empty values.
* For _other pages_ (retrieved via `.Page.Site.GetPage`, `.Site.Pages` etc.) the `.Content` is there to use as you please as long as you don't have infinite content recursion in your shortcode/content setup. See below.
* `.Page.TableOfContents` is good to go (but does not support shortcodes in headlines; this is unchanged)
If you get into a situation of infinite recursion, the `.Content` will be empty. Run `hugo -v` for more information.
Fixes#4632Fixes#4653Fixes#4655
As an example:
```html
{{ $pages := .Site.RegularPages | lang.Merge $frSite.RegularPages | lang.Merge $enSite.RegularPages }}
```
Will "fill in the gaps" in the current site with, from left to right, content from the French site, and lastly the English.
Fixes#4463
This commit expands the Resource interface with 3 new methods:
* Name
* Title
* Params
All of these can be set in the Page front matter. `Name` will get its default value from the base filename, and is the value used in the ByPrefix and GetByPrefix lookup methods.
Fixes#4244
The Param method currently assumes that its argument is a single,
distinct, top-level key to look up in the Params map. This enhances the
Param method; it will now also attempt to see if the key can be
interpreted as a nested chain of keys to look up in Params.
Fixes#2598
The custom sort functions used from the templates had some subtle data race- and related issues,
especially when used in the single page template.
This commit fixes this by making copies and protect the read and writes with a RWMutex.
The results are cached (it will typically be invoked *number of pages* times with exactly the same data).
This is, not surprisingly, also faster:
```
benchmark old ns/op new ns/op delta
BenchmarkSortByWeightAndReverse 14228 491 -96.55%
benchmark old allocs new allocs delta
BenchmarkSortByWeightAndReverse 1 0 -100.00%
benchmark old bytes new bytes delta
BenchmarkSortByWeightAndReverse 32 0 -100.00%
```
Fixes#1293
`GroupBy` is modified to allow it to receive a method name argument for
example `Type` as its first argument. It is only allowed to call with
a method which takes no arguments and returns a result or a pair of
a result and an error.
The functions discussed at #443 are also added
- `ByPublishDate`: Order contents by `PublishDate` front matter variable
- `GroupByPublishDate(format, order)`: Group contents by `PublishDate`
front matter variable formatted in string like `GroupByDate`
- `GroupByParam(key, order)`: Group contents by `Param` front matter
variable specified by `key` argument
- `GroupByParamDate(key, format, order)`: Group contents by `Param`
front matter variable specified by `key` argument and formatted in
string like `GroupByDate`. It's effective against `time.Time` type
front matter variable
