mirror of
https://github.com/gryf/pentadactyl-pm.git
synced 2025-12-20 16:07:59 +01:00
150 lines
2.8 KiB
Plaintext
150 lines
2.8 KiB
Plaintext
A terse introduction to E4X
|
|
Public Domain
|
|
|
|
The inline XML literals in this code are part of E4X, a standard
|
|
XML processing interface for ECMAScript. In addition to syntax
|
|
for XML literals, E4X provides a new kind of native object,
|
|
"xml", and a syntax, similar to XPath, for accessing and
|
|
modifying the tree. Here is a brief synopsis of the kind of
|
|
usage you'll see herein:
|
|
|
|
> let xml =
|
|
<foo bar="baz" baz="qux">
|
|
<bar>
|
|
<baz id="1"/>
|
|
</bar>
|
|
<baz id="2"/>
|
|
</foo>;
|
|
|
|
// Select all bar elements of the root foo element
|
|
> xml.bar
|
|
<bar><baz id="1"/></bar>
|
|
|
|
// Select all baz elements anywhere beneath the root
|
|
> xml..baz
|
|
<baz id="1"/>
|
|
<baz id="2"/>
|
|
|
|
// Select all of the immediate children of the root
|
|
> xml.*
|
|
<bar><baz id="1"/></bar>
|
|
<baz id="2"/>
|
|
|
|
// Select the bar attribute of the root node
|
|
> xml.@bar
|
|
baz
|
|
|
|
// Select all id attributes in the tree
|
|
> xml..@id
|
|
1
|
|
2
|
|
|
|
// Select all attributes of the root node
|
|
> xml.@*
|
|
baz
|
|
quz
|
|
|
|
// Add a quux elemend beneath the first baz
|
|
> xml..baz[0] += <quux/>
|
|
<baz id="1"/>
|
|
<quux/>
|
|
> xml
|
|
<foo bar="baz" baz="qux">
|
|
<bar>
|
|
<baz id="1"/>
|
|
<quux/>
|
|
</bar>
|
|
<baz id="2"/>
|
|
</foo>
|
|
|
|
// and beneath the second
|
|
> xml.baz[1] = <quux id="1"/>
|
|
> xml
|
|
<foo bar="baz" baz="qux">
|
|
<bar>
|
|
<baz id="1"/>
|
|
<quux/>
|
|
</bar>
|
|
<baz id="2"/>
|
|
<quux id="1"/>
|
|
</foo>
|
|
|
|
// Replace bar's subtree with a foo element
|
|
> xml.bar.* = <foo id="1"/>
|
|
> xml
|
|
<foo bar="baz" baz="qux">
|
|
<bar>
|
|
<foo id="1"/>
|
|
</bar>
|
|
<baz id="2"/>
|
|
<quux id="1"/>
|
|
</foo>
|
|
|
|
// Add a bar below bar
|
|
> xml.bar.* += <bar id="1"/>
|
|
<foo id="1"/>
|
|
<bar id="1"/>
|
|
> xml
|
|
<foo bar="baz" baz="qux">
|
|
<bar>
|
|
<foo id="1"/>
|
|
<bar id="1"/>
|
|
</bar>
|
|
<baz id="2"/>
|
|
<quux id="1"/>
|
|
</foo>
|
|
|
|
// Adding a quux attribute to the root
|
|
> xml.@quux = "foo"
|
|
foo
|
|
> xml
|
|
<foo bar="baz" baz="qux" quux="foo">
|
|
<bar>
|
|
<foo id="1"/>
|
|
<bar id="1"/>
|
|
</bar>
|
|
<baz id="2"/>
|
|
<quux id="1"/>
|
|
</foo>
|
|
|
|
> xml.bar.@id = "0"
|
|
> xml..foo[0] = "Foo"
|
|
Foo
|
|
> xml..bar[1] = "Bar"
|
|
Bar
|
|
> xml
|
|
js> xml
|
|
<foo bar="baz" baz="qux" quux="foo" id="0">
|
|
<bar id="0">
|
|
<foo id="1">Foo</foo>
|
|
<bar id="1">Bar</bar>
|
|
</bar>
|
|
<baz id="2"/>
|
|
<quux id="1"/>
|
|
</foo>
|
|
|
|
// Selecting all bar elements where id="1"
|
|
> xml..bar.(@id == 1)
|
|
Bar
|
|
|
|
// Literals:
|
|
// XMLList literal. No root node.
|
|
> <>Foo<br/>Baz</>
|
|
Foo
|
|
<br/>
|
|
Baz
|
|
|
|
// Interpolation.
|
|
> let x = "<foo/>"
|
|
> <foo bar={x}>{x + "<?>"}</foo>
|
|
<foo/><?>
|
|
> <foo bar={x}>{x + "<?>"}</foo>.toXMLString()
|
|
<foo bar="<foo/>"><foo/><?></foo>
|
|
|
|
> let x = <foo/>
|
|
> <foo bar={x}>{x}</foo>.toXMLString()
|
|
<foo bar="">
|
|
<foo/>
|
|
</foo>
|
|
|