A StringTemplate is a String with "holes" in it. This is a port of the Java StringTemplate library written by Terrence Parr. (http://www.stringtemplate.org).
This library implements the basic 3.1 grammar, lacking group files (though not groups themselves), Regions, and Interfaces. The goal is not to blindly copy the StringTemplate API, but rather to take its central ideas and implement them in a Haskellish manner. Indentation and wrapping, for example, are implemented through the HughesPJ Pretty Printing library. Calling toPPDoc on a StringTemplate yields a Doc with appropriate paragraph-fill wrapping that can be rendered in the usual fashion.
This library extends the current StringTemplate grammar by allowing the application of alternating attributes to anonymous as well as regular templates, including therefore sets of alternating attributes.
Basic instances are provided of the StringTemplateShows and ToSElem class.
Any type deriving ToSElem can be passed automatically as a StringTemplate
attribute. This package can be installed with syb-with-class bindings
that provide a ToSElem instance for anything deriving
Data.Generics.SYB.WithClass.Basics.Data. When defining an instance of
ToSElem that can take a format parameter, you should first define an
instance of StringTemplateShows, and then define an instance of ToSElem
toSElem = stShowsToSE.
- data StringTemplate a
- type STGroup a = String -> StFirst (StringTemplate a)
- class ToSElem a where
- class Show a => StringTemplateShows a where
- stShowsToSE :: (StringTemplateShows a, Stringable b) => a -> SElem b
- class Monoid a => Stringable a where
- class Stringable b => SEType b a where
- newSTMP :: Stringable a => String -> StringTemplate a
- newAngleSTMP :: Stringable a => String -> StringTemplate a
- getStringTemplate :: Stringable a => String -> STGroup a -> Maybe (StringTemplate a)
- getStringTemplate' :: Stringable a => String -> STGroup a -> Maybe (StringTemplate a)
- toString :: StringTemplate String -> String
- toPPDoc :: StringTemplate Doc -> Doc
- render :: Stringable a => StringTemplate a -> a
- dumpAttribs :: Stringable a => StringTemplate a
- setAttribute :: (ToSElem a, Stringable b) => String -> a -> StringTemplate b -> StringTemplate b
- (|=) :: Monad m => a -> m a1 -> m (a, a1)
- setManyAttrib :: (ToSElem a, Stringable b) => [(String, a)] -> StringTemplate b -> StringTemplate b
- withContext :: (ToSElem a, Stringable b) => StringTemplate b -> a -> StringTemplate b
- optInsertTmpl :: [(String, String)] -> StringTemplate a -> StringTemplate a
- optInsertGroup :: [(String, String)] -> STGroup a -> STGroup a
- setEncoder :: Stringable a => (String -> String) -> StringTemplate a -> StringTemplate a
- setEncoderGroup :: Stringable a => (String -> String) -> STGroup a -> STGroup a
- groupStringTemplates :: [(String, StringTemplate a)] -> STGroup a
- addSuperGroup :: STGroup a -> STGroup a -> STGroup a
- addSubGroup :: STGroup a -> STGroup a -> STGroup a
- mergeSTGroups :: STGroup a -> STGroup a -> STGroup a
- directoryGroup :: Stringable a => FilePath -> IO (STGroup a)
- unsafeVolatileDirectoryGroup :: Stringable a => String -> Int -> IO (STGroup a)
- directoryGroupLazy :: Stringable a => FilePath -> IO (STGroup a)
- nullGroup :: Stringable a => STGroup a
A String with "holes" in it. StringTemplates may be composed of any
Stringable type, which at the moment includes
Strings, which are actually of type
ShowS. When a StringTemplate is composed of a type, its internals are
as well, so it is, so to speak "turtles all the way down."
A function that generates StringTemplates. This is conceptually a query function into a "group" of StringTemplates.
The ToSElem class should be instantiated for all types that can be inserted as attributes into a StringTemplate.
The StringTemplateShows class should be instantiated for all types that are directly displayed in a StringTemplate, but take an optional format string. Each such type must have an appropriate ToSElem method defined as well.
_ a -> stringTemplateShow a
This method should be used to create ToSElem instances for types defining a custom formatted show function.
The Stringable class should be instantiated with care. Generally, the provided instances should be enough for anything.
mconcatMap m k = foldr (mappend . k) mempty m
(mconcat .) . intersperse
Parses a String to produce a StringTemplate, with '$'s as delimiters. It is constructed with a stub group that cannot look up other templates.
Parses a String to produce a StringTemplate, delimited by angle brackets. It is constructed with a stub group that cannot look up other templates.
Queries an String Template Group and returns Just the appropriate StringTemplate if it exists, otherwise, Nothing.
getStringTemplate but never inlined, so appropriate for use
with volatile template groups.
Renders a StringTemplate to a
Generic render function for a StringTemplate of any type.
A special template that simply dumps the values of all the attributes set in it.
This may be made available to any template as a function by adding it to its group.
myNewGroup = addSuperGroup myGroup $ groupStringTemplates [(dumpAttribs, dumpAttribs)]
Yields a StringTemplate with the appropriate attribute set. If the attribute already exists, it is appended to a list.
Yields a StringTemplate with the appropriate attributes set. If any attribute already exists, it is appended to a list.
Replaces the attributes of a StringTemplate with those described in the second argument. If the argument does not yield a set of named attributes but only a single one, that attribute is named, as a default, "it".
Adds a set of global options to a single template
Adds a set of global options to a group
Sets an encoding function of a template that all values are
rendered with. For example one useful encoder would be
Text.Html.stringToHtmlString. All attributes will be encoded once and only once.
Sets an encoding function of a group that all values are rendered with in each enclosed template
Given a list of named of StringTemplates, returns a group which generates them such that they can call one another.
Adds a supergroup to any StringTemplate group such that templates from the original group are now able to call ones from the supergroup as well.
Adds a "subgroup" to any StringTemplate group such that templates from the original group now have template calls "shadowed" by the subgroup.
Merges two groups into a single group. This function is left-biased, prefering bindings from the first group when there is a conflict.
Given a path, returns a group which generates all files in said directory which have the proper "st" extension. This function is strict, with all files read once. As it performs file IO, expect it to throw the usual exceptions.
Given an integral amount of seconds and a path, returns a group generating all files in said directory with the proper "st" extension, cached for that amount of seconds. IO errors are "swallowed" by this so that exceptions don't arise in unexpected places. This violates referential transparency, but can be very useful in developing templates for any sort of server application. It should be swapped out for production purposes. The dumpAttribs template is added to the returned group by default, as it should prove useful for debugging and developing templates.
Given a path, returns a group which generates all files in said directory which have the proper "st" extension. This function is lazy in the same way that readFile is lazy, with all files read on demand, but no more than once. As it performs file IO, expect it to throw the usual exceptions. And, as it is lazy, expect these exceptions in unexpected places.