The main motivation of this commit is to add a `page.Page` interface to replace the very file-oriented `hugolib.Page` struct.
This is all a preparation step for issue #5074, "pages from other data sources".
But this also fixes a set of annoying limitations, especially related to custom output formats, and shortcodes.
Most notable changes:
* The inner content of shortcodes using the `{{%` as the outer-most delimiter will now be sent to the content renderer, e.g. Blackfriday.
This means that any markdown will partake in the global ToC and footnote context etc.
* The Custom Output formats are now "fully virtualized". This removes many of the current limitations.
* The taxonomy list type now has a reference to the `Page` object.
This improves the taxonomy template `.Title` situation and make common template constructs much simpler.
See #5074Fixes#5763Fixes#5758Fixes#5090Fixes#5204Fixes#4695Fixes#5607Fixes#5707Fixes#5719Fixes#3113Fixes#5706Fixes#5767Fixes#5723Fixes#5769Fixes#5770Fixes#5771Fixes#5759Fixes#5776Fixes#5777Fixes#5778
Before this commit, due to a bug in Go's `text/template` package, this would print different output for typed nil interface values:
```
{{ if .AuthenticatedUser }}User is authenticated!{{ else }}{{ end }}
{{ if not .AuthenticatedUser }}{{ else }}}User is authenticated!{{ end }}
```
This commit works around this by wrapping every `if` and `with` with a custom `getif` template func with truth logic that matches `not`, `and` and `or`.
Those 3 template funcs from Go's stdlib are now pulled into Hugo's source tree and adjusted to support custom zero values, e.g. types that implement `IsZero`.
This means that you can now do:
```
{{ with .Date }}{{ . }}{{ end }}
```
And it would work as expected.
Fixes#5738
Before this commit `where` would produce an error and bail building the
site. Now, `where` simply skips an element of a collection and does not
add it to the final result.
Closes#5637Closes#5416
This means that the current `.Site` and ´.Hugo` is available as a globals, so you can do `site.IsServer`, `hugo.Version` etc.
Fixes#5470Fixes#5467Fixes#5503
In the newly consolidated file cache implementation, we forgot that we also look in the theme(s) for assets (SCSS transformations etc.), which is not good for Netlify and the demo sites.
Fixes#5460
This commits reworks how file caching is performed in Hugo. Now there is only one way, and it can be configured.
This is the default configuration:
```toml
[caches]
[caches.getjson]
dir = ":cacheDir"
maxAge = -1
[caches.getcsv]
dir = ":cacheDir"
maxAge = -1
[caches.images]
dir = ":resourceDir/_gen"
maxAge = -1
[caches.assets]
dir = ":resourceDir/_gen"
maxAge = -1
```
You can override any of these cache setting in your own `config.toml`.
The placeholders explained:
`:cacheDir`: This is the value of the `cacheDir` config option if set (can also be set via OS env variable `HUGO_CACHEDIR`). It will fall back to `/opt/build/cache/hugo_cache/` on Netlify, or a `hugo_cache` directory below the OS temp dir for the others.
`:resourceDir`: This is the value of the `resourceDir` config option.
`maxAge` is the time in seconds before a cache entry will be evicted, -1 means forever and 0 effectively turns that particular cache off.
This means that if you run your builds on Netlify, all caches configured with `:cacheDir` will be saved and restored on the next build. For other CI vendors, please read their documentation. For an CircleCI example, see 6c3960a8f4/.circleci/config.ymlFixes#5404
When run under gccgo, the test looks for the name that gccgo gives to
a thunk method. This name is not normally visible, but can be seen
when using reflect.FuncForPC as this code does. That name changed in
https://golang.org/cl/89555. Change the test to work with both the
old name "$thunk0" and the new name "thunk0".
Fixesgolang/go#28669
This commit also pulls down the log level for a set of WARN statements to INFO. There should be no ERRORs or WARNINGs in a regular Hugo build. That is the story about the Boy Who Cried Wolf.
Since the WARN log is now more visible, this commit also improves on some of them, most notable the "layout not found", which now would look something like this:
```bash
WARN 2018/11/02 09:02:18 Found no layout for "home", language "en", output format "CSS": create a template below /layouts with one of these filenames: index.en.css.css, home.en.css.css, list.en.css.css, index.css.css, home.css.css, list.css.css, index.en.css, home.en.css, list.en.css, index.css, home.css, list.css, _default/index.en.css.css, _default/home.en.css.css, _default/list.en.css.css, _default/index.css.css, _default/home.css.css, _default/list.css.css, _default/index.en.css, _default/home.en.css, _default/list.en.css, _default/index.css, _default/home.css, _default/list.css
```
Fixes#5203
Long identifiers will give errors on the format:
```bash
_default/single.html:5:14: executing "main" at <.ThisIsAVeryLongTitl...>: can't evaluate field ThisIsAVeryLongTitle
```
Hugo use this value to match the "base template or not", so we need to strip the "...".
Fixes#5346
`*json.UnmarshalTypeError` and `*json.SyntaxError` has a byte `Offset`, so use that.
This commit also reworks/simplifies the errror line matching logic. This also makes the file reading unbuffered, but that should be fine in this error case.
See #5324
