Fixes https://github.com/yesodweb/yesod/issues/1771
This is done by adding a function to Yesod
typeclass which can match on any exception
and tell the framework if it should rethrow
or not.
I used an overridable function because it seemed
more flexible then a whitelist.
A user can now for example choose to throw
everything, or catch everything as easily.
add docs
bump
`setDescription` and `setDescriptionI` present a similar API to
`setTitle` and `setTitleI`, but unlike those functions the description
functions are not idempotent - so calling them multiple times inserts
multiple `<meta/>` tags in HTML `<head/>`.
This adds explicitly idempotent versions of those functions which are
handled in a similar way to the title, so that calling them multiple
times has the effect of taking the final value specified.
Because the non-idempotent behaviour of setDescription is not obvious,
this also adds warnings for that behaviour to make it clear what the
effect of multiple calls will be. Unfortunately, setDescriptionIdemp
can't be made a drop-in replacement because developers may have defined
their own layouts which need to take pageDescription into account.
Yesod.Core.Handler.languages checks first for a language set in the
user's session, prepending that value to YesodRequest{reqLangs}, so it
is respected above all else if present.
For context, reqLangs itself also includes the session, but just later
in line:
langs' = catMaybes [ lookup langKey gets -- Query _LANG
, lookup langKey cookies -- Cookie _LANG
, lookupText langKey session -- Session _LANG
] ++ langs -- Accept-Language(s)
In #1720, it was raised that allowing the session (something implicitly
present for any request) to override a query parameter (something
explicitly given on that request) is surprising.
We decided (without knowing what order reqLangs was doing) that query,
cookie, session, accept was best and languages should be changed to do
that. Conveniently, this just makes languages equivalent to reqLangs, so
that is what this patch does.
GHC 8.0 and later come with the `DeriveLift` extension for deriving
instances of `Language.Haskell.TH.Syntax.Lift`. `yesod-core` supports
GHC 8.2 and up, so it is able to make use of this. Not only does
`DeriveLift` make for much shorter code, but it also fixes warnings
that you get when compiling `yesod-core` with GHC 8.10 or later:
```
[20 of 31] Compiling Yesod.Routes.TH.Types ( src/Yesod/Routes/TH/Types.hs, interpreted )
src/Yesod/Routes/TH/Types.hs:34:10: warning: [-Wmissing-methods]
• No explicit implementation for
‘liftTyped’
• In the instance declaration for ‘Lift (ResourceTree t)’
|
34 | instance Lift t => Lift (ResourceTree t) where
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
src/Yesod/Routes/TH/Types.hs:49:10: warning: [-Wmissing-methods]
• No explicit implementation for
‘liftTyped’
• In the instance declaration for ‘Lift (Resource t)’
|
49 | instance Lift t => Lift (Resource t) where
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
src/Yesod/Routes/TH/Types.hs:59:10: warning: [-Wmissing-methods]
• No explicit implementation for
‘liftTyped’
• In the instance declaration for ‘Lift (Piece t)’
|
59 | instance Lift t => Lift (Piece t) where
| ^^^^^^^^^^^^^^^^^^^^^^^^
src/Yesod/Routes/TH/Types.hs:78:10: warning: [-Wmissing-methods]
• No explicit implementation for
‘liftTyped’
• In the instance declaration for ‘Lift (Dispatch t)’
|
78 | instance Lift t => Lift (Dispatch t) where
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
```
This is because `DeriveLift` fills in implementations of `liftTyped`,
a method that was introduced to `Lift` in `template-haskell-2.16.0.0`
(bundled with GHC 8.10).
* Add functions for setting description and OG meta
It's common that a website author will want to add a specific
description and Open Graph image to a given page in their website. These
functions are simple conveniences to add these meta tags to the document
head.
I decided against simply adding all possible meta tags, because not all
of them are useful, and even in the case of Open Graph tags, many of
them should be set only once and they should use the same value for the
entire website. In those cases, it's probably better for the website
author to add those tags in their layout template.
Closes https://github.com/yesodweb/yesod/issues/1659
