R: XML Source

XMLSource {tm} | R Documentation

## XML Source

### Description

Create an XML source.

### Usage

    XMLSource(x, parser, reader)

### Arguments

`x` | a character giving a uniform resource identifier.
`parser` | a function accepting an XML tree (as delivered by `xmlTreeParse` in package XML) as input and returning a list of XML elements.
`reader` | a function capable of turning XML elements as returned by `parser` into a subclass of `TextDocument`.

### Value

An object inheriting from `XMLSource`, `SimpleSource`, and `Source`.

### See Also

`Source` for basic information on the source infrastructure employed by package tm.

Vignette 'Extensions: How to Handle Custom File Formats', and `readXML`.

### Examples

    ## An implementation for readGmane is provided as an example in ?readXML
    example(readXML)

    ## Construct a source for a Gmane mailing list RSS feed.
    GmaneSource <-
    function(x)
        XMLSource(x,
                  function(tree) {
                      nodes <- XML::xmlChildren(XML::xmlRoot(tree))
                      nodes[names(nodes) == "item"]
                  },
                  readGmane)
    ## Not run: gs <- GmaneSource("http://rss.gmane.org/gmane.comp.lang.r.general")
    elem <- getElem(stepNext(gs))
    (gmane <- readGmane(elem, language = "en", id = "id1"))
    meta(gmane)
    ## End(Not run)

[Package tm version 0.7-1 Index]