# SAXMap
[](https://hex.pm/packages/sax_map)
Converts an XML String or an XML file stream to a Map.
Benefit from [Saxy](https://hex.pm/packages/saxy)'s SAX mode, this library has a good conversion efficiency.
## Installation
```elixir
def deps do
[
{:sax_map, "~> 1.4"}
]
end
```
## Example
```elixir
iex(1)> xml = """
...(1)> <?xml version="1.0" encoding="UTF-8"?>
...(1)> <thread>
...(1)> <title>Hello</title>
...(1)> <items>
...(1)> <item>item1</item>
...(1)> <item>item2</item>
...(1)> </items>
...(1)> </thread>
...(1)> """
iex(2)> SAXMap.from_string(xml)
{:ok,
%{
"thread" => %{"items" => %{"item" => ["item1", "item2"]}, "title" => "Hello"}
}}
```
By default `SAXMap.from_string` will ignore all attributes of elements in the result, if you want to merge the attributes as the child elements, please use `ignore_attribute` option to achieve this:
```
xml = """
<thread version="1">
<title color="red" font="16">Hello</title>
<items size="3">
<item font="12">item1</item>
<item font="12">item2</item>
<item font="12">item3</item>
</items>
</thread>
"""
SAXMap.from_string(xml, ignore_attribute: false)
{:ok,
%{
"thread" => %{
"content" => %{
"items" => %{
"content" => %{
"item" => [
%{"content" => "item1", "font" => "12"},
%{"content" => "item2", "font" => "12"},
%{"content" => "item3", "font" => "12"}
]
},
"size" => "3"
},
"title" => %{"color" => "red", "content" => "Hello", "font" => "16"}
},
"version" => "1"
}
}}
SAXMap.from_string(xml, ignore_attribute: {false, "@"})
{:ok,
%{
"thread" => %{
"@version" => "1",
"content" => %{
"items" => %{
"@size" => "3",
"content" => %{
"item" => [
%{"@font" => "12", "content" => "item1"},
%{"@font" => "12", "content" => "item2"},
%{"@font" => "12", "content" => "item3"}
]
}
},
"title" => %{"@color" => "red", "@font" => "16", "content" => "Hello"}
}
}
}}
```
**Please note**: The `ignore_attribute: false` equals `ignore_attribute: {false, ""}`, in this case, the child elements will be automatically naming with `"content"` as the key of the key-value pair to distinct this key-value pair is from XML text content or attribute. Currently, the `"content"` naming is a reserved keyword, please be careful to distinguish it from the XML node name when transfer an XML to a Map be with XML attributes.
## Benchmark
Only for your reference, all credit goes to [Saxy](https://hex.pm/packages/saxy), the details of benchmark can be found in the `bench` directory of the repository.
Run:
```bash
mix run xml_to_map.exs
```
Output:
```bash
Operating System: macOS
CPU Information: Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
Number of Available Cores: 16
Available memory: 32 GB
Elixir 1.12.2
Erlang 24.0.4
Benchmark suite executing with the following configuration:
warmup: 2 s
time: 10 s
memory time: 2 s
parallel: 1
inputs: none specified
Estimated total run time: 42 s
Benchmarking SAXMap.from_string ignore attribute...
Benchmarking SAXMap.from_string with attribute...
Benchmarking XmlToMap.naive_map...
Name ips average deviation median 99th %
SAXMap.from_string ignore attribute 105.03 K 9.52 μs ±129.42% 9 μs 33 μs
SAXMap.from_string with attribute 96.74 K 10.34 μs ±110.08% 9 μs 35 μs
XmlToMap.naive_map 26.31 K 38.01 μs ±46.21% 33 μs 105 μs
Comparison:
SAXMap.from_string ignore attribute 105.03 K
SAXMap.from_string with attribute 96.74 K - 1.09x slower +0.82 μs
XmlToMap.naive_map 26.31 K - 3.99x slower +28.49 μs
Memory usage statistics:
Name Memory usage
SAXMap.from_string ignore attribute 14.61 KB
SAXMap.from_string with attribute 16.69 KB - 1.14x memory usage +2.08 KB
XmlToMap.naive_map 40.90 KB - 2.80x memory usage +26.29 KB
**All measurements for memory usage were the same**
```
