xesite/vendor/github.com/Xe/jsonfeed/jsonfeed.go

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2017-05-20 22:43:42 +00:00
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/
/*
Package jsonfeed is a set of types and convenience functions for reading and
parsing JSON Feed version 1 as defined here: https://jsonfeed.org/version/1
*/
package jsonfeed
import (
"encoding/json"
"io"
"time"
)
// CurrentVersion will point to the current specification of JSON feed
// that this package implements.
const CurrentVersion = "https://jsonfeed.org/version/1"
// Item is a single article or link in a JSON Feed.
type Item struct {
// ID is unique for that item for that feed over time. If an item
// is ever updated, the id should be unchanged. New items should
// never use a previously-used id. If an id is presented as a number
// or other type, a JSON Feed reader must coerce it to a string.
// Ideally, the id is the full URL of the resource described by the
// item, since URLs make great unique identifiers.
ID string `json:"id"`
// URL is the URL of the resource described by the item. Its the
// permalink. This may be the same as the id — but should be present
// regardless.
URL string `json:"url,omitempty"`
// ExternalURL is the URL of a page elsewhere. This is especially
// useful for linkblogs. If url links to where youre talking about
// a thing, then this links to the thing youre talking about.
ExternalURL string `json:"external_url,omitempty"`
// Title (optional, string) is plain text. Microblog items in
// particular may omit titles.
Title string `json:"title,omitempty"`
// ContentHTML and ContentText are each optional strings — but one
// or both must be present. This is the HTML or plain text of the
// item. Important: the only place HTML is allowed in this format
// is in content_html. A Twitter-like service might use content_text,
// while a blog might use content_html. Use whichever makes sense
// for your resource. (It doesnt even have to be the same for each
// item in a feed.)
ContentHTML string `json:"content_html,omitempty"`
ContentText string `json:"content_text,omitempty"`
// Summary is a plain text sentence or two describing the item.
// This might be presented in a timeline, for instance, where a
// detail view would display all of ContentHTML or ContentText.
Summary string `json:"summary,omitempty"`
// Image is the URL of the main image for the item. This image
// may also appear in the content_html — if so, its a hint to
// the feed reader that this is the main, featured image. Feed
// readers may use the image as a preview (probably resized as
// a thumbnail and placed in a timeline).
Image string `json:"image,omitempty"`
// BannerImage is the URL of an image to use as a banner. Some
// blogging systems (such as Medium) display a different banner
// image chosen to go with each post, but that image wouldnt
// otherwise appear in the content_html. A feed reader with a
// detail view may choose to show this banner image at the top
// of the detail view, possibly with the title overlaid.
BannerImage string `json:"banner_image,omitempty"`
// DatePublished specifies the date of this Item's publication.
DatePublished time.Time `json:"date_published,omitempty"`
// DateModified specifies the date of this Item's last modification
// (if applicable)
DateModified time.Time `json:"date_modified,omitempty"`
// Author has the same structure as the top-level author. If not
// specified in an item, then the top-level author, if present,
// is the author of the item.
Author *Author `json:"author,omitempty"`
// Tags can have any plain text values you want. Tags tend to be
// just one word, but they may be anything. Note: they are not
// the equivalent of Twitter hashtags. Some blogging systems and
// other feed formats call these categories.
Tags []string `json:"tags,omitempty"`
// Attachments (optional, array) lists related resources. Podcasts,
// for instance, would include an attachment thats an audio or
// video file.
Attachments []Attachment `json:"attachments,omitempty"`
}
// Author specifies the feed author. The author object has several members.
// These are all optional, but if you provide an author object, then at
// least one is required.
type Author struct {
// Name is the author's name.
Name string `json:"name,omitempty"`
// URL is the URL of a site owned by the author. It could be a
// blog, micro-blog, Twitter account, and so on. Ideally the linked-to
// page provides a way to contact the author, but thats not
// required. The URL could be a mailto: link, though we suspect
// that will be rare.
URL string `json:"url,omitempty"`
// Avatar is the URL for an image for the author. As with icon,
// it should be square and relatively large — such as 512 x 512 —
// and should use transparency where appropriate, since it may
// be rendered on a non-white background.
Avatar string `json:"avatar,omitempty"`
}
// Hub describes endpoints that can be used to subscribe to real-time
// notifications from the publisher of this feed. Each object has a type
// and url, both of which are required.
type Hub struct {
Type string `json:"type"`
URL string `json:"url"`
}
// Attachment is a related resource to an Item. If the Feed describes a
// podcast, this would refer to the episodes of said podcast.
type Attachment struct {
// URL specifies the location of the attachment.
URL string `json:"url"`
// MIMEType specifies the type of the attachment, such as "audio/mpeg".
MIMEType string `json:"mime_type"`
// Title is a name for the attachment. Important: if there are multiple
// attachments, and two or more have the exact same title (when title
// is present), then they are considered as alternate representations
// of the same thing. In this way a podcaster, for instance, might
// provide an audio recording in different formats.
Title string `json:"title,omitifempty"`
// SizeInBytes specifies the attachment filesize in bytes.
SizeInBytes int64 `json:"size_in_bytes,omitempty"`
// DurationInSeconds specifies how long the attachment takes to listen
// to or watch.
DurationInSeconds int64 `json:"duration_in_seconds,omitempty"`
}
// Feed is a list that may change over time, and the individual items in the
// list may change.
//
// Think of a blog or microblog, Twitter or Facebook timeline, set of commits
// to a repository, or even a server log. These are all lists, and each could
// be described by a Feed.
//
// A JSON Feed starts with some info at the top: it says where the Feed comes
// from, and may say who created it and so on.
type Feed struct {
// Version is the URL of the version of the format the Feed uses.
Version string `json:"version"`
// Title is the name of the Feed, which will often correspond to the
// name of the website (blog, for instance), though not necessarily.
Title string `json:"title"`
// HomePageURL is the URL of the resource that the Feed describes.
// This resource may or may not actually be a “home” page, but it
// should be an HTML page. If a Feed is published on the public web,
// this should be considered as required. But it may not make sense
// in the case of a file created on a desktop computer, when that
// file is not shared or is shared only privately.
//
// This field is strongly reccomended, but not required.
HomePageURL string `json:"home_page_url,omitempty"`
// FeedURL is the URL of the Feed, and serves as the unique identifier
// for the Feed. As with home_page_url, this should be considered
// required for Feeds on the public web.
//
// This field is strongly reccomended, but not required.
FeedURL string `json:"Feed_url,omitempty"`
// Description provides more detail, beyond the title, on what the Feed
// is about. A Feed reader may display this text.
Description string `json:"description,omitempty"`
// UserComment is a description of the purpose of the Feed. This is for
// the use of people looking at the raw JSON, and should be ignored by
// Feed readers.
UserComment string `json:"user_comment,omitempty"`
// NextURL is the URL of a Feed that provides the next n items, where
// n is determined by the publisher. This allows for pagination, but
// with the expectation that reader software is not required to use it
// and probably wont use it very often. next_url must not be the same
// as Feed_url, and it must not be the same as a previous next_url
// (to avoid infinite loops).
NextURL string `json:"next_url,omitempty"`
// Icon is the URL of an image for the Feed suitable to be used in a
// timeline, much the way an avatar might be used. It should be square
// and relatively large — such as 512 x 512 — so that it can be scaled-down
// and so that it can look good on retina displays. It should use transparency
// where appropriate, since it may be rendered on a non-white background.
Icon string `json:"icon,omitempty"`
// Favicon is the URL of an image for the Feed suitable to be used in a
// source list. It should be square and relatively small, but not smaller
// than 64 x 64 (so that it can look good on retina displays). As with icon,
// this image should use transparency where appropriate, since it may be
// rendered on a non-white background.
Favicon string `json:"favicon,omitempty"`
// Author specifies the Feed author.
Author Author `json:"author,omitempty"`
// Expired specifies if the Feed will never update again. A Feed for a
// temporary event, such as an instance of the Olympics, could expire.
// If the value is true, then its expired. Any other value, or the
// absence of expired, means the Feed may continue to update.
Expired bool `json:"expired,omitempty"`
// Hubs describes endpoints that can be used to subscribe to real-time
// notifications from the publisher of this Feed.
Hubs []Hub `json:"hubs,omitempty"`
// Items is the list of Items in this Feed.
Items []Item `json:"items"`
}
// Parse reads a JSON feed object out of a reader.
func Parse(r io.Reader) (Feed, error) {
var feed Feed
decoder := json.NewDecoder(r)
if err := decoder.Decode(&feed); err != nil {
return Feed{}, err
}
return feed, nil
}