OCaml library for JSONfeed parsing and creation
anil.recoil.org
1(*---------------------------------------------------------------------------
2 Copyright (c) 2024 Anil Madhavapeddy. All rights reserved.
3 SPDX-License-Identifier: ISC
4 ---------------------------------------------------------------------------*)
5
6module Unknown = struct
7 type t = Jsont.json
8
9 let empty = Jsont.Object ([], Jsont.Meta.none)
10 let is_empty = function Jsont.Object ([], _) -> true | _ -> false
11end
12
13type content = [ `Html of string | `Text of string | `Both of string * string ]
14
15type t = {
16 id : string;
17 content : content;
18 url : string option;
19 external_url : string option;
20 title : string option;
21 summary : string option;
22 image : string option;
23 banner_image : string option;
24 date_published : Ptime.t option;
25 date_modified : Ptime.t option;
26 authors : Author.t list option;
27 tags : string list option;
28 language : string option;
29 attachments : Attachment.t list option;
30 references : Reference.t list option;
31 unknown : Unknown.t;
32}
33
34let create ~id ~content ?url ?external_url ?title ?summary ?image ?banner_image
35 ?date_published ?date_modified ?authors ?tags ?language ?attachments
36 ?references ?(unknown = Unknown.empty) () =
37 {
38 id;
39 content;
40 url;
41 external_url;
42 title;
43 summary;
44 image;
45 banner_image;
46 date_published;
47 date_modified;
48 authors;
49 tags;
50 language;
51 attachments;
52 references;
53 unknown;
54 }
55
56let id t = t.id
57let content t = t.content
58let url t = t.url
59let external_url t = t.external_url
60let title t = t.title
61let summary t = t.summary
62let image t = t.image
63let banner_image t = t.banner_image
64let date_published t = t.date_published
65let date_modified t = t.date_modified
66let authors t = t.authors
67let tags t = t.tags
68let language t = t.language
69let attachments t = t.attachments
70let references t = t.references
71let unknown t = t.unknown
72
73let content_html t =
74 match t.content with
75 | `Html html -> Some html
76 | `Text _ -> None
77 | `Both (html, _) -> Some html
78
79let content_text t =
80 match t.content with
81 | `Html _ -> None
82 | `Text text -> Some text
83 | `Both (_, text) -> Some text
84
85let equal a b = a.id = b.id
86let compare a b = Option.compare Ptime.compare a.date_published b.date_published
87
88let pp ppf t =
89 match (t.date_published, t.title) with
90 | Some date, Some title ->
91 let (y, m, d), _ = Ptime.to_date_time date in
92 Format.fprintf ppf "[%04d-%02d-%02d] %s (%s)" y m d title t.id
93 | Some date, None ->
94 let (y, m, d), _ = Ptime.to_date_time date in
95 Format.fprintf ppf "[%04d-%02d-%02d] %s" y m d t.id
96 | None, Some title -> Format.fprintf ppf "%s (%s)" title t.id
97 | None, None -> Format.fprintf ppf "%s" t.id
98
99let pp_summary ppf t =
100 Format.fprintf ppf "%s" (Option.value ~default:t.id t.title)
101
102(* Jsont type *)
103
104let jsont =
105 let kind = "Item" in
106 let doc = "A JSON Feed item" in
107
108 (* Helper to construct item from JSON fields *)
109 let make_from_json id content_html content_text url external_url title summary
110 image banner_image date_published date_modified authors tags language
111 attachments references _extensions unknown =
112 (* Determine content from content_html and content_text *)
113 let content =
114 match (content_html, content_text) with
115 | Some html, Some text -> `Both (html, text)
116 | Some html, None -> `Html html
117 | None, Some text -> `Text text
118 | None, None ->
119 Jsont.Error.msg Jsont.Meta.none
120 "Item must have at least one of content_html or content_text"
121 in
122 {
123 id;
124 content;
125 url;
126 external_url;
127 title;
128 summary;
129 image;
130 banner_image;
131 date_published;
132 date_modified;
133 authors;
134 tags;
135 language;
136 attachments;
137 references;
138 unknown;
139 }
140 in
141
142 Jsont.Object.map ~kind ~doc make_from_json
143 |> Jsont.Object.mem "id" Jsont.string ~enc:id
144 |> Jsont.Object.opt_mem "content_html" Jsont.string ~enc:content_html
145 |> Jsont.Object.opt_mem "content_text" Jsont.string ~enc:content_text
146 |> Jsont.Object.opt_mem "url" Jsont.string ~enc:url
147 |> Jsont.Object.opt_mem "external_url" Jsont.string ~enc:external_url
148 |> Jsont.Object.opt_mem "title" Jsont.string ~enc:title
149 |> Jsont.Object.opt_mem "summary" Jsont.string ~enc:summary
150 |> Jsont.Object.opt_mem "image" Jsont.string ~enc:image
151 |> Jsont.Object.opt_mem "banner_image" Jsont.string ~enc:banner_image
152 |> Jsont.Object.opt_mem "date_published" Rfc3339.jsont ~enc:date_published
153 |> Jsont.Object.opt_mem "date_modified" Rfc3339.jsont ~enc:date_modified
154 |> Jsont.Object.opt_mem "authors" (Jsont.list Author.jsont) ~enc:authors
155 |> Jsont.Object.opt_mem "tags" (Jsont.list Jsont.string) ~enc:tags
156 |> Jsont.Object.opt_mem "language" Jsont.string ~enc:language
157 |> Jsont.Object.opt_mem "attachments"
158 (Jsont.list Attachment.jsont)
159 ~enc:attachments
160 |> Jsont.Object.opt_mem "_references"
161 (Jsont.list Reference.jsont)
162 ~enc:references
163 |> Jsont.Object.opt_mem "_extensions" Jsont.json_object ~enc:(fun _t -> None)
164 |> Jsont.Object.keep_unknown Jsont.json_mems ~enc:unknown
165 |> Jsont.Object.finish