third_party/nix/src/libutil/xml-writer.cc


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

#include <assert.h>

#include "xml-writer.hh"


namespace nix {
    

XMLWriter::XMLWriter(bool indent, std::ostream & output)
    : output(output), indent(indent)
{
    output << "<?xml version='1.0' encoding='utf-8'?>" << std::endl;
    closed = false;
}


XMLWriter::~XMLWriter()
{
    close();
}


void XMLWriter::close()
{
    if (closed) return;
    while (!pendingElems.empty()) closeElement();
    closed = true;
}


void XMLWriter::indent_(size_t depth)
{
    if (!indent) return;
    output << string(depth * 2, ' ');
}


void XMLWriter::openElement(const string & name,
    const XMLAttrs & attrs)
{
    assert(!closed);
    indent_(pendingElems.size());
    output << "<" << name;
    writeAttrs(attrs);
    output << ">";
    if (indent) output << std::endl;
    pendingElems.push_back(name);
}


void XMLWriter::closeElement()
{
    assert(!pendingElems.empty());
    indent_(pendingElems.size() - 1);
    output << "</" << pendingElems.back() << ">";
    if (indent) output << std::endl;
    pendingElems.pop_back();
    if (pendingElems.empty()) closed = true;
}


void XMLWriter::writeEmptyElement(const string & name,
    const XMLAttrs & attrs)
{
    assert(!closed);
    indent_(pendingElems.size());
    output << "<" << name;
    writeAttrs(attrs);
    output << " />";
    if (indent) output << std::endl;
}


void XMLWriter::writeAttrs(const XMLAttrs & attrs)
{
    for (auto & i : attrs) {
        output << " " << i.first << "=\"";
        for (size_t j = 0; j < i.second.size(); ++j) {
            char c = i.second[j];
            if (c == '"') output << "&quot;";
            else if (c == '<') output << "&lt;";
            else if (c == '>') output << "&gt;";
            else if (c == '&') output << "&amp;";
            /* Escape newlines to prevent attribute normalisation (see
               XML spec, section 3.3.3. */
            else if (c == '\n') output << "&#xA;";
            else output << c;
        }
        output << "\"";
    }
}


}