This commit adds support for theme composition and inheritance in Hugo.
With this, it helps thinking about a theme as a set of ordered components:
```toml
theme = ["my-shortcodes", "base-theme", "hyde"]
```
The theme definition example above in `config.toml` creates a theme with the 3 components with presedence from left to right.
So, Hugo will, for any given file, data entry etc., look first in the project, and then in `my-shortcode`, `base-theme` and lastly `hyde`.
Hugo uses two different algorithms to merge the filesystems, depending on the file type:
* For `i18n` and `data` files, Hugo merges deeply using the translation id and data key inside the files.
* For `static`, `layouts` (templates) and `archetypes` files, these are merged on file level. So the left-most file will be chosen.
The name used in the `theme` definition above must match a folder in `/your-site/themes`, e.g. `/your-site/themes/my-shortcodes`. There are plans to improve on this and get a URL scheme so this can be resolved automatically.
Also note that a component that is part of a theme can have its own configuration file, e.g. `config.toml`. There are currently some restrictions to what a theme component can configure:
* `params` (global and per language)
* `menu` (global and per language)
* `outputformats` and `mediatypes`
The same rules apply here: The left-most param/menu etc. with the same ID will win. There are some hidden and experimental namespace support in the above, which we will work to improve in the future, but theme authors are encouraged to create their own namespaces to avoid naming conflicts.
A final note: Themes/components can also have a `theme` definition in their `config.toml` and similar, which is the "inheritance" part of this commit's title. This is currently not supported by the Hugo theme site. We will have to wait for some "auto dependency" feature to be implemented for that to happen, but this can be a powerful feature if you want to create your own theme-variant based on others.
Fixes#4460Fixes#4450
This allows a `config.toml` (or `yaml`, ´yml`, or `json`) in the theme to set:
1) `params` (but cannot override params in project. Will also get its own "namespace", i.e. `{{ .Site.Params.mytheme.my_param }}` will be the same as `{{ .Site.Params.my_param }}` providing that the main project does not define a param with that key.
2) `menu` -- but cannot redefine/add menus in the project. Must create its own menus with its own identifiers.
3) `languages` -- only `params` and `menu`. Same rules as above.
4) **new** `outputFormats`
5) **new** `mediaTypes`
This should help with the "theme portability" issue and people having to copy and paste lots of setting into their projects.
Fixes#4490
Note that this looks like overkill for just the logger, and that is correct,
but this will make sense once we start with the template handling etc.
Updates #2701
There are currently several Params and case related issues floating around in Hugo.
This is very confusing for users and one of the most common support questions on the forum.
And while there have been done some great leg work in Viper etc., this is of limited value since this and similar doesn't work:
`Params.myCamelCasedParam`
Hugo has control over all the template method invocations, and can take care of all the lower-casing of the map lookup keys.
But that doesn't help with direct template lookups of type `Site.Params.TWITTER_CONFIG.USER_ID`.
This commit solves that by doing some carefully crafted modifications of the templates' AST -- lowercasing the params keys.
This is low-level work, but it's not like the template API wil change -- and this is important enough to defend such "bit fiddling".
Tests are added for all the template engines: Go templates, Ace and Amber.
Fixes#2615Fixes#1129Fixes#2590
There are currently several Params and case related issues floating around in Hugo.
This is very confusing for users and one of the most common support questions on the forum.
And while there have been done some great leg work in Viper etc., this is of limited value since this and similar doesn't work:
`Params.myCamelCasedParam`
Hugo has control over all the template method invocations, and can take care of all the lower-casing of the map lookup keys.
But that doesn't help with direct template lookups of type `Site.Params.TWITTER_CONFIG.USER_ID`.
This commit solves that by doing some carefully crafted modifications of the templates' AST -- lowercasing the params keys.
This is low-level work, but it's not like the template API wil change -- and this is important enough to defend such "bit fiddling".
Tests are added for all the template engines: Go templates, Ace and Amber.
Fixes#2615Fixes#1129Fixes#2590
