fastxml 0.9.0

A fast, memory-efficient XML library with XPath and XSD validation support
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
154
155
156
157
158
159

//! Tests for the redesigned `Transformer` entry point.

use std::io::BufReader;

use fastxml::transform::Transformer;

const XML: &str = r#"<root><item id="1">a</item><item id="2">b</item></root>"#;

#[test]
fn in_memory_to_string() {
    let out = Transformer::from(XML)
        .on("//item[@id='2']", |node| {
            node.set_attribute("done", "1");
        })
        .to_string()
        .unwrap();
    assert!(out.contains(r#"done="1""#), "output was: {out}");
    // The untouched item is preserved verbatim.
    assert!(
        out.contains(r#"<item id="1">a</item>"#),
        "output was: {out}"
    );
}

#[test]
fn in_memory_write_to_returns_count() {
    let mut buf = Vec::new();
    let count = Transformer::from(XML)
        .on("//item", |node| {
            node.set_attribute("seen", "1");
        })
        .write_to(&mut buf)
        .unwrap();
    assert_eq!(count, 2);
    let s = String::from_utf8(buf).unwrap();
    assert_eq!(s.matches(r#"seen="1""#).count(), 2, "output was: {s}");
}

#[test]
fn reader_into_bytes() {
    let out = Transformer::from_reader(BufReader::new(XML.as_bytes()))
        .on("//item", |node| {
            node.set_attribute("seen", "1");
        })
        .into_bytes()
        .unwrap();
    let s = String::from_utf8(out).unwrap();
    assert_eq!(s.matches(r#"seen="1""#).count(), 2, "output was: {s}");
}

#[test]
fn reader_write_to_counts_matches() {
    let mut buf = Vec::new();
    let count = Transformer::from_reader(BufReader::new(XML.as_bytes()))
        .on("//item", |node| {
            node.set_attribute("seen", "1");
        })
        .write_to(&mut buf)
        .unwrap();
    assert_eq!(count, 2);
}

#[test]
fn for_each_collects_side_effects() {
    let mut contents = Vec::new();
    Transformer::from(XML)
        .on("//item", |node| {
            contents.push(node.get_content().unwrap_or_default());
        })
        .for_each()
        .unwrap();
    assert_eq!(contents, vec!["a".to_string(), "b".to_string()]);
}

#[test]
fn namespaces_bind_prefix() {
    let xml = r#"<r xmlns:n="urn:x"><n:item>v</n:item></r>"#;
    let mut hits = 0;
    Transformer::from(xml)
        .namespace("n", "urn:x")
        .on("//n:item", |_node| {
            hits += 1;
        })
        .for_each()
        .unwrap();
    assert_eq!(hits, 1);
}

#[test]
fn collect_extracts_values() {
    let ids: Vec<String> = Transformer::from(XML)
        .collect("//item", |node| {
            node.get_attribute("id").unwrap_or_default()
        })
        .unwrap();
    assert_eq!(ids, vec!["1".to_string(), "2".to_string()]);
}

#[test]
fn collect_multi_extracts_tuples() {
    let (ids, contents): (Vec<String>, Vec<String>) = Transformer::from(XML)
        .collect_multi((
            ("//item", |node: &mut fastxml::transform::EditableNode| {
                node.get_attribute("id").unwrap_or_default()
            }),
            ("//item", |node: &mut fastxml::transform::EditableNode| {
                node.get_content().unwrap_or_default()
            }),
        ))
        .unwrap();
    assert_eq!(ids, vec!["1".to_string(), "2".to_string()]);
    assert_eq!(contents, vec!["a".to_string(), "b".to_string()]);
}

#[test]
fn on_with_context_receives_context() {
    let out = Transformer::from(XML)
        .on_with_context("//item", |node, ctx| {
            node.set_attribute("depth", &ctx.depth().to_string());
        })
        .to_string()
        .unwrap();
    assert!(out.contains("depth="), "output was: {out}");
}

#[test]
fn with_root_namespaces_auto_registers() {
    let xml = r#"<r xmlns:n="urn:x"><n:item>v</n:item></r>"#;
    let mut hits = 0;
    Transformer::from(xml)
        .with_root_namespaces()
        .unwrap()
        .on("//n:item", |_node| hits += 1)
        .for_each()
        .unwrap();
    assert_eq!(hits, 1);
}

#[test]
fn reader_rejects_collect() {
    let result = Transformer::from_reader(BufReader::new(XML.as_bytes()))
        .collect("//item", |node| {
            node.get_attribute("id").unwrap_or_default()
        });
    assert!(
        result.is_err(),
        "collect should be unsupported on reader input"
    );
}

#[test]
fn reader_defers_in_memory_only_op_to_terminal() {
    // on_with_context is in-memory only; on reader input the error surfaces
    // at the terminal rather than panicking mid-chain.
    let result = Transformer::from_reader(BufReader::new(XML.as_bytes()))
        .on_with_context("//item", |_node, _ctx| {})
        .to_string();
    assert!(result.is_err());
}