Safe Haskell	None

Hakyll.Web.Page.Metadata

Description

Provides various functions to manipulate the metadata fields of a page

Synopsis

Documentation

getField Source

Arguments

:: String	Key
-> Page a	Page
-> String	Value

Get a metadata field. If the field does not exist, the empty string is returned.

getFieldMaybe Source

Arguments

:: String	Key
-> Page a	Page
-> Maybe String	Value, if found

Get a field in a Maybe wrapper

setField Source

Arguments

:: String	Key
-> String	Value
-> Page a	Page to add it to
-> Page a	Resulting page

Version of trySetField which overrides any previous value

trySetField Source

Arguments

:: String	Key
-> String	Value
-> Page a	Page to add it to
-> Page a	Resulting page

Add a metadata field. If the field already exists, it is not overwritten.

setFieldA Source

Arguments

:: Arrow a
=> String	Key
-> a x String	Value arrow
-> a (Page b, x) (Page b)	Resulting arrow

Arrow-based variant of setField. Because of it's type, this function is very usable together with the different require functions.

setFieldPage Source

Arguments

:: String	Key to add the page under
-> Identifier (Page String)	Page to add
-> Compiler (Page a) (Page a)	Page compiler

Set a field of a page to the contents of another page

renderField Source

Arguments

:: String	Key of which the value should be copied
-> String	Key the value should be copied to
-> (String -> String)	Function to apply on the value
-> Page a	Page on which this should be applied
-> Page a	Resulting page

Do something with a metadata value, but keep the old value as well. If the key given is not present in the metadata, nothing will happen. If the source and destination keys are the same, the value will be changed (but you should use changeField for this purpose).

changeField Source

Arguments

:: String	Key to change.
-> (String -> String)	Function to apply on the value.
-> Page a	Page to change
-> Page a	Resulting page

Change a metadata value.

 import Data.Char (toUpper)
 changeField "title" (map toUpper)

Will put the title in UPPERCASE.

copyField Source

Arguments

:: String	Key to copy
-> String	Destination to copy to
-> Page a	Page on which this should be applied
-> Page a	Resulting page

Make a copy of a metadata field (put the value belonging to a certain key under some other key as well)

renderDateField Source

Arguments

:: String	Key in which the rendered date should be placed
-> String	Format to use on the date
-> String	Default value, in case the date cannot be parsed
-> Page a	Page on which this should be applied
-> Page a	Resulting page

When the metadata has a field called published in one of the following formats then this function can render the date.

Sun, 01 Feb 2000 13:00:00 UT (RSS date format)
2000-02-01T13:00:00Z (Atom date format)
February 1, 2000 1:00 PM (PM is usually uppercase)
February 1, 2000 (assumes 12:00 AM for the time)

Alternatively, when the metadata has a field called path in a folder/yyyy-mm-dd-title.extension format (the convention for pages) and no published metadata field set, this function can render the date.

 renderDateField "date" "%B %e, %Y" "Date unknown"

Will render something like January 32, 2010.

renderDateFieldWith Source

Arguments

:: TimeLocale	Output time locale
-> String	Destination key
-> String	Format to use on the date
-> String	Default value
-> Page a	Target page
-> Page a	Resulting page

This is an extended version of renderDateField that allows you to specify a time locale that is used for outputting the date. For more details, see renderDateField.

renderModificationTime Source

Arguments

:: String	Destination key
-> String	Format to use on the time
-> Compiler (Page String) (Page String)	Resulting compiler

Set the modification time as a field in the page

renderModificationTimeWith Source

Arguments

:: TimeLocale	Output time locale
-> String	Destination key
-> String	Format to use on the time
-> Compiler (Page String) (Page String)	Resulting compiler

copyBodyToField Source

Arguments

:: String	Destination key
-> Page String	Target page
-> Page String	Resulting page

Copy the body of a page to a metadata field

copyBodyFromField Source

Arguments

:: String	Source key
-> Page String	Target page
-> Page String	Resulting page

Copy a metadata field to the page body

comparePagesByDate :: Page a -> Page a -> Ordering Source

Compare pages by the date and time parsed as in renderDateField, where LT implies earlier, and GT implies later. For more details, see renderDateField.