• caseInsensitive

• encoding

• userInfo

• detectParsingErrors

Examples

All examples below can be found in the included specs.

Initialization

let xml = XMLHash.parse(xmlToParse)

Alternatively, if you're parsing a large XML file and need the best performance, you may wish to configure the parsing to be processed lazily. Lazy processing avoids loading the entire XML document into memory, so it could be preferable for performance reasons. See the error handling for one caveat regarding lazy loading.

let xml = XMLHash.config {
              config in
              config.shouldProcessLazily = true
          }.parse(xmlToParse)

The above approach uses the config method, but there is also a lazy method directly off of XMLHash.

let xml = XMLHash.lazy(xmlToParse)

Single Element Lookup

Given:

<root>
  <header>
    <title>Foo</title>
  </header>
  ...
</root>

Will return "Foo".

xml["root"]["header"]["title"].element?.text

Multiple Elements Lookup

Given:

<root>
  ...
  <catalog>
    <book><author>Bob</author></book>
    <book><author>John</author></book>
    <book><author>Mark</author></book>
  </catalog>
  ...
</root>

The below will return "John".

xml["root"]["catalog"]["book"][1]["author"].element?.text

Attributes Usage

Given:

<root>
  ...
  <catalog>
    <book id="1"><author>Bob</author></book>
    <book id="123"><author>John</author></book>
    <book id="456"><author>Mark</author></book>
  </catalog>
  ...
</root>

The below will return "123".

xml["root"]["catalog"]["book"][1].element?.attribute(by: "id")?.text

Alternatively, you can look up an element with specific attributes. The below will return "John".

xml["root"]["catalog"]["book"].withAttribute("id", "123")["author"].element?.text

Returning All Elements At Current Level

Given:

<root>
  ...
  <catalog>
    <book><genre>Fiction</genre></book>
    <book><genre>Non-fiction</genre></book>
    <book><genre>Technical</genre></book>
  </catalog>
  ...
</root>

The all method will iterate over all nodes at the indexed level. The code below will return "Fiction, Non-fiction, Technical".

", ".join(xml["root"]["catalog"]["book"].all.map { elem in
    elem["genre"].element!.text!
})

You can also iterate over the all method:

for elem in xml["root"]["catalog"]["book"].all {
    print(elem["genre"].element!.text!)
}

Returning All Child Elements At Current Level

Given:

<root>
  <catalog>
    <book>
      <genre>Fiction</genre>
      <title>Book</title>
      <date>1/1/2015</date>
    </book>
  </catalog>
</root>

The below will print "root", "catalog", "book", "genre", "title", and "date" (note the children method).

func enumerate(indexer: XMLIndexer) {
    for child in indexer.children {
        print(child.element!.name)
        enumerate(child)
    }
}
enumerate(indexer: xml)

Filtering elements

Given:

<root>
  <catalog>
    <book id="bk101">
      <author>Gambardella, Matthew</author>
      <title>XML Developer's Guide</title>
      <genre>Computer</genre><price>44.95</price>
      <publish_date>2000-10-01</publish_date>
    </book>
    <book id="bk102">
      <author>Ralls, Kim</author>
      <title>Midnight Rain</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-12-16</publish_date>
    </book>
    <book id="bk103">
      <author>Corets, Eva</author>
      <title>Maeve Ascendant</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-11-17</publish_date>
    </book>
  </catalog>
</root>

The following will return "Midnight Rain". Filtering can be by any part of the XMLElement class or by index as well.

let subIndexer = xml!["root"]["catalog"]["book"]
    .filterAll { elem, _ in elem.attribute(by: "id")!.text == "bk102" }
    .filterChildren { _, index in index >= 1 && index <= 3 }
print(subIndexer.children[0].element?.text)

Error Handling

Using Do-Catch with Errors:

do {
    try xml!.byKey("root").byKey("what").byKey("header").byKey("foo")
} catch let error as IndexingError {
    // error is an IndexingError instance that you can deal with
}

Or using the existing indexing functionality:

switch xml["root"]["what"]["header"]["foo"] {
case .element(let elem):
    // everything is good, code away!
case .xmlError(let error):
    // error is an IndexingError instance that you can deal with
}

Note that error handling as shown above will not work with lazy loaded XML. The lazy parsing doesn't actually occur until the element or all method are called - as a result, there isn't any way to know prior to asking for an element if it exists or not.

XML Deserialization Into Objects

Even more often, you'll want to deserialize an XML tree into an array of custom types. This is where XMLObjectDeserialization comes into play.

Given:

<root>
  <books>
    <book isbn="0000000001">
      <title>Book A</title>
      <price>12.5</price>
      <year>2015</year>
      <categories>
        <category>C1</category>
        <category>C2</category>
      </categories>
    </book>
    <book isbn="0000000002">
      <title>Book B</title>
      <price>10</price>
      <year>1988</year>
      <categories>
        <category>C2</category>
        <category>C3</category>
      </categories>
    </book>
    <book isbn="0000000003">
      <title>Book C</title>
      <price>8.33</price>
      <year>1990</year>
      <amount>10</amount>
      <categories>
        <category>C1</category>
        <category>C3</category>
      </categories>
    </book>
  </books>
</root>

with Book struct implementing XMLObjectDeserialization:

struct Book: XMLObjectDeserialization {
    let title: String
    let price: Double
    let year: Int
    let amount: Int?
    let isbn: Int
    let category: [String]
static func deserialize(_ node: XMLIndexer) throws -> Book {
        return try Book(
            title: node["title"].value(),
            price: node["price"].value(),
            year: node["year"].value(),
            amount: node["amount"].value(),
            isbn: node.value(ofAttribute: "isbn"),
            category : node["categories"]["category"].value()
        )
    }
}

The below will return an array of Book structs:

let books: [Book] = try xml["root"]["books"]["book"].value()

!Types Conversion

You can convert any XML to your custom type by implementing XMLObjectDeserialization for any non-leaf node (e.g. in the example above).

For leaf nodes (e.g.