stac 0.17.0

Rust library for the SpatioTemporal Asset Catalog (STAC) specification
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153

use crate::{Error, Item, Link, Migrate, Result, Version};
use serde::{Deserialize, Deserializer, Serialize};
use serde_json::{Map, Value};
use stac_derive::{Links, SelfHref};
use std::{ops::Deref, vec::IntoIter};

const ITEM_COLLECTION_TYPE: &str = "FeatureCollection";

fn item_collection_type() -> String {
    ITEM_COLLECTION_TYPE.to_string()
}

fn deserialize_item_collection_type<'de, D>(
    deserializer: D,
) -> std::result::Result<String, D::Error>
where
    D: Deserializer<'de>,
{
    let r#type = String::deserialize(deserializer)?;
    if r#type != ITEM_COLLECTION_TYPE {
        Err(serde::de::Error::invalid_value(
            serde::de::Unexpected::Str(&r#type),
            &ITEM_COLLECTION_TYPE,
        ))
    } else {
        Ok(r#type)
    }
}

/// A [GeoJSON FeatureCollection](https://www.rfc-editor.org/rfc/rfc7946#page-12) of items.
///
/// While not part of the STAC specification, ItemCollections are often used to store many items in a single file.
#[derive(Debug, Serialize, Deserialize, PartialEq, Clone, SelfHref, Links)]
pub struct ItemCollection {
    #[serde(
        default = "item_collection_type",
        deserialize_with = "deserialize_item_collection_type"
    )]
    r#type: String,

    /// The list of [Items](Item).
    ///
    /// The attribute is actually "features", but we rename to "items".
    #[serde(rename = "features", default)]
    pub items: Vec<Item>,

    /// List of link objects to resources and related URLs.
    #[serde(skip_serializing_if = "Vec::is_empty", default)]
    pub links: Vec<Link>,

    /// Additional fields.
    #[serde(flatten)]
    pub additional_fields: Map<String, Value>,

    #[serde(skip)]
    self_href: Option<String>,
}

impl From<Vec<Item>> for ItemCollection {
    fn from(items: Vec<Item>) -> Self {
        ItemCollection {
            r#type: item_collection_type(),
            items,
            links: Vec::new(),
            additional_fields: Map::new(),
            self_href: None,
        }
    }
}

impl FromIterator<Item> for ItemCollection {
    fn from_iter<I: IntoIterator<Item = Item>>(iter: I) -> Self {
        iter.into_iter().collect::<Vec<_>>().into()
    }
}

impl IntoIterator for ItemCollection {
    type IntoIter = IntoIter<Item>;
    type Item = Item;
    fn into_iter(self) -> Self::IntoIter {
        self.items.into_iter()
    }
}

impl Deref for ItemCollection {
    type Target = Vec<Item>;
    fn deref(&self) -> &Self::Target {
        &self.items
    }
}

impl Migrate for ItemCollection {
    fn migrate(mut self, version: &Version) -> Result<Self> {
        let mut items = Vec::with_capacity(self.items.len());
        for item in self.items {
            items.push(item.migrate(version)?);
        }
        self.items = items;
        Ok(self)
    }
}

impl TryFrom<Value> for ItemCollection {
    type Error = Error;

    fn try_from(value: Value) -> Result<Self> {
        match serde_json::from_value::<ItemCollection>(value.clone()) {
            Ok(item_collection) => Ok(item_collection),
            Err(err) => {
                if let Value::Array(array) = value {
                    let mut items = Vec::new();
                    for item in array {
                        items.push(serde_json::from_value(item)?);
                    }
                    Ok(items.into())
                } else {
                    Err(Error::from(err))
                }
            }
        }
    }
}

#[cfg(test)]
mod tests {
    use super::ItemCollection;
    use crate::Item;
    use serde_json::json;

    #[test]
    fn item_collection_from_vec() {
        let items = vec![Item::new("a"), Item::new("b")];
        let _ = ItemCollection::from(items);
    }

    #[test]
    fn item_collection_from_iter() {
        let items = vec![Item::new("a"), Item::new("b")];
        let _ = ItemCollection::from_iter(items);
    }

    #[test]
    fn permissive_deserialization() {
        let _: ItemCollection = serde_json::from_value(json!({})).unwrap();
    }

    #[test]
    fn serialize_type_field() {
        let item_collection = ItemCollection::from(vec![]);
        let value = serde_json::to_value(item_collection).unwrap();
        assert_eq!(value.as_object().unwrap()["type"], "FeatureCollection");
    }
}