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Module Rss

module Rss: sig .. end
The RSS library to read and write RSS 2.0 files.

Reference: RSS 2.0 specification.


Types


type date = Netdate.t 
val string_of_date : ?fmt:string -> date -> string
Format a date/time record as a string according to the format string fmt.
fmt : The format string. It consists of zero or more conversion specifications and ordinary characters. All ordinary characters are kept as such in the final string. A conversion specification consists of the '%' character and one other character. See Netdate.format_to for more details. Default: "%d %b %Y".
type email = string
can be, for example: foo@bar.com (Mr Foo Bar)
type pics_rating = string 
type skip_hours = int list
0 .. 23
type skip_days = int list
0 is Sunday, 1 is Monday, ...
type url = Neturl.url 
type category = {
   cat_name : string; (*A forward-slash-separated string that identifies a hierarchic location in the indicated taxonomy.*)
   cat_domain : url option; (*Identifies a categorization taxonomy.*)
} 
type image = {
   image_url : url; (*The URL of a GIF, JPEG or PNG image that represents the channel.*)
   image_title : string; (*Description of the image, it's used in the ALT attribute of the HTML <img> tag when the channel is rendered in HTML.*)
   image_link : url; (*The URL of the site, when the channel is rendered, the image is a link to the site. (Note, in practice the image_title and image_link should have the same value as the Rss.channel's ch_title and ch_link.)*)
   image_height : int option; (*Height of the image, in pixels.*)
   image_width : int option; (*Width of the image, in pixels.*)
   image_desc : string option; (*Text to be included in the "title" attribute of the link formed around the image in the HTML rendering.*)
} 
type text_input = {
   ti_title : string; (*The label of the Submit button in the text input area.*)
   ti_desc : string; (*Explains the text input area.*)
   ti_name : string; (*The name of the text object in the text input area.*)
   ti_link : url; (*The URL of the CGI script that processes text input requests.*)
} 
type enclosure = {
   encl_url : url; (*URL of the enclosure*)
   encl_length : int; (*size in bytes*)
   encl_type : string; (*MIME type*)
} 
type guid =
| Guid_permalink of url (*A permanent URL pointing to the story.*)
| Guid_name of string (*A string that uniquely identifies the item.*) 
type source = {
   src_name : string;
   src_url : url;
} 
type cloud = {
   cloud_domain : string;
   cloud_port : int;
   cloud_path : string;
   cloud_register_procedure : string;
   cloud_protocol : string;
}
See specification
type 'a item_t = {
   item_title : string option; (*Optional title*)
   item_link : url option; (*Optional link*)
   item_desc : string option; (*Optional description*)
   item_pubdate : date option; (*Date of publication*)
   item_author : email option; (*The email address of the author of the item.*)
   item_categories : category list; (*Categories for the item. See the field Rss.category.*)
   item_comments : url option; (*Url of comments about this item*)
   item_enclosure : enclosure option;
   item_guid : guid option; (*A globally unique identifier for the item.*)
   item_source : source option;
   item_data : 'a option; (*Additional data, since RSS can be extended with namespace-prefixed nodes.*)
}
An item may represent a "story". Its description is a synopsis of the story (or sometimes the full story), and the link points to the full story.
type namespace = string * string
A namespace is a pair (name, url).
type ('a, 'b) channel_t = {
   ch_title : string; (*Mandatory. The name of the channel, for example the title of your web site.*)
   ch_link : url; (*Mandatory. The URL to the HTML website corresponding to the channel.*)
   ch_desc : string; (*Mandatory. A sentence describing the channel.*)
   ch_language : string option; (*Language of the news, e.g. "en". See the W3C language codes.*)
   ch_copyright : string option; (*Copyright notice.*)
   ch_managing_editor : email option; (*Managing editor of the news.*)
   ch_webmaster : email option; (*The address of the webmasterof the site.*)
   ch_pubdate : date option; (*Publication date of the channel.*)
   ch_last_build_date : date option; (*When the channel content changed for the last time.*)
   ch_categories : category list; (*Categories for the channel. See the field Rss.category.*)
   ch_generator : string option; (*The tool used to generate this channel.*)
   ch_cloud : cloud option; (*Allows processes to register with a cloud to be notified of updates to the channel.*)
   ch_docs : url option; (*An url to a RSS format reference.*)
   ch_ttl : int option; (*Time to live, in minutes. It indicates how long a channel can be cached before refreshing from the source.*)
   ch_image : image option;
   ch_rating : pics_rating option; (*The PICS rating for the channel.*)
   ch_text_input : text_input option;
   ch_skip_hours : skip_hours option; (*A hint for aggregators telling them which hours they can skip.*)
   ch_skip_days : skip_days option; (*A hint for aggregators telling them which days they can skip.*)
   ch_items : 'b item_t list;
   ch_data : 'a option; (*Additional data, since RSS can be extended with namespace-prefixed nodes.*)
   ch_namespaces : namespace list;
} 
type item = unit item_t 
type channel = (unit, unit) channel_t

Building items and channels


val item : ?title:string ->
       ?link:url ->
       ?desc:string ->
       ?pubdate:date ->
       ?author:email ->
       ?cats:category list ->
       ?comments:url ->
       ?encl:enclosure ->
       ?guid:guid -> ?source:source -> ?data:'a -> unit -> 'a item_t
item() creates a new item with all fields set to None. Use the optional parameters to set fields.
val channel : title:string ->
       link:url ->
       desc:string ->
       ?language:string ->
       ?copyright:string ->
       ?managing_editor:email ->
       ?webmaster:email ->
       ?pubdate:date ->
       ?last_build_date:date ->
       ?cats:category list ->
       ?generator:string ->
       ?cloud:cloud ->
       ?docs:url ->
       ?ttl:int ->
       ?image:image ->
       ?rating:pics_rating ->
       ?text_input:text_input ->
       ?skip_hours:skip_hours ->
       ?skip_days:skip_days ->
       ?data:'a ->
       ?namespaces:namespace list ->
       'b item_t list -> ('a, 'b) channel_t
channel items creates a new channel containing items. Other fields are set to None unless the corresponding optional parameter is used.
val compare_item : ?comp_data:('a -> 'a -> int) -> 'a item_t -> 'a item_t -> int
val copy_item : 'a item_t -> 'a item_t
val copy_channel : ('a, 'b) channel_t -> ('a, 'b) channel_t

Manipulating channels


val keep_n_items : int -> ('a, 'b) channel_t -> ('a, 'b) channel_t
keep_n_items n ch returns a copy of the channel, keeping only n items maximum.
val sort_items_by_date : 'a item_t list -> 'a item_t list
Sort items by date, older last.
val merge_channels : ('a, 'b) channel_t -> ('a, 'b) channel_t -> ('a, 'b) channel_t
merge_channels c1 c2 merges the given channels in a new channel, sorting items using Rss.sort_items_by_date. Channel information are copied from the first channel c1.

Reading channels


type xmltree =
| E of Xmlm.tag * xmltree list
| D of string
This represents XML trees. Such XML trees are given to functions provided to read additional data from RSS channels and items.
val xml_of_source : Xmlm.source -> xmltree
Read an XML tree from a source.
Raises Failure in case of error.
exception Error of string
Use this exception to indicate an error is functions given to make_opts used to read additional data from prefixed XML nodes.
type ('a, 'b) opts
Options used when reading source.
val make_opts : ?schemes:(string, Neturl.url_syntax) Hashtbl.t ->
       ?base_syntax:Neturl.url_syntax ->
       ?read_channel_data:(xmltree list -> 'a option) ->
       ?read_item_data:(xmltree list -> 'b option) -> unit -> ('a, 'b) opts
See Neturl documentation for schemes and base_syntax options. They are used to parse URLs.
read_channel_data : provides a way to read additional information from the subnodes of the channels. All these subnodes are prefixed by an expanded namespace.
read_item_data : is the equivalent of read_channel_data parameter but is called of each item with its prefixed subnodes.
val default_opts : (unit, unit) opts
val channel_t_of_file : ('a, 'b) opts -> string -> ('a, 'b) channel_t * string list
channel_[t_]of_X returns the parsed channel and a list of encountered errors. Note that only namespaces declared in the root not of the XML tree are added to ch_namespaces field.
Raises Failure if the channel could not be parsed.
val channel_t_of_string : ('a, 'b) opts -> string -> ('a, 'b) channel_t * string list
val channel_t_of_channel : ('a, 'b) opts ->
       Pervasives.in_channel -> ('a, 'b) channel_t * string list
val channel_t_of_xmls : ('a, 'b) opts -> xmltree list -> ('a, 'b) channel_t * string list
Read a channel from XML trees. These trees correspond to nodes under the "channel" XML node of a reguler RSS document.
val channel_of_file : string -> channel * string list
val channel_of_string : string -> channel * string list
val channel_of_channel : Pervasives.in_channel -> channel * string list

Writing channels


type 'a data_printer = 'a -> xmltree list 
val print_channel : ?channel_data_printer:'a data_printer ->
       ?item_data_printer:'b data_printer ->
       ?indent:int ->
       ?date_fmt:string ->
       ?encoding:string -> Format.formatter -> ('a, 'b) channel_t -> unit
val print_file : ?channel_data_printer:'a data_printer ->
       ?item_data_printer:'b data_printer ->
       ?indent:int ->
       ?date_fmt:string ->
       ?encoding:string -> string -> ('a, 'b) channel_t -> unit