XPath
XPath is Go package provides selecting nodes from XML, HTML or other documents using XPath expression.
Implementation
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htmlquery - an XPath query package for HTML document
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xmlquery - an XPath query package for XML document.
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jsonquery - an XPath query package for JSON document
Supported Features
The basic XPath patterns.
The basic XPath patterns cover 90% of the cases that most stylesheets will need.
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node : Selects all child elements with nodeName of node.
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* : Selects all child elements.
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@attr : Selects the attribute attr.
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@* : Selects all attributes.
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node() : Matches an org.w3c.dom.Node.
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text() : Matches a org.w3c.dom.Text node.
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comment() : Matches a comment.
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. : Selects the current node.
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.. : Selects the parent of current node.
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/ : Selects the document node.
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a[expr] : Select only those nodes matching a which also satisfy the expression expr.
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a[n] : Selects the nth matching node matching a When a filter's expression is a number, XPath selects based on position.
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a/b : For each node matching a, add the nodes matching b to the result.
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a//b : For each node matching a, add the descendant nodes matching b to the result.
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//b : Returns elements in the entire document matching b.
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a|b : All nodes matching a or b, union operation(not boolean or).
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(a, b, c) : Evaluates each of its operands and concatenates the resulting sequences, in order, into a single result sequence
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(a/b) : Selects all matches nodes as grouping set.
Node Axes
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child::* : The child axis selects children of the current node.
child::node(): Selects all the children of the context node.child::text(): Selects all text node children of the context node.
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descendant::* : The descendant axis selects descendants of the current node. It is equivalent to '//'.
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descendant-or-self::* : Selects descendants including the current node.
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attribute::* : Selects attributes of the current element. It is equivalent to @*
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following-sibling::* : Selects nodes after the current node.
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preceding-sibling::* : Selects nodes before the current node.
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following::* : Selects the first matching node following in document order, excluding descendants.
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preceding::* : Selects the first matching node preceding in document order, excluding ancestors.
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parent::* : Selects the parent if it matches. The '..' pattern from the core is equivalent to 'parent::node()'.
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ancestor::* : Selects matching ancestors.
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ancestor-or-self::* : Selects ancestors including the current node.
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self::* : Selects the current node. '.' is equivalent to 'self::node()'.
Expressions
The gxpath supported three types: number, boolean, string.
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path : Selects nodes based on the path.
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a = b : Standard comparisons.
a = b : True if a equals b.a != b : True if a is not equal to b.a < b : True if a is less than b.a <= b : True if a is less than or equal to b.a > b : True if a is greater than b.a >= b : True if a is greater than or equal to b.
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a + b : Arithmetic expressions.
- a Unary minusa + b : Additiona - b : Subtractiona * b : Multiplicationa div b : Divisiona mod b : Modulus (division remainder)
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a or b : Boolean or operation.
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a and b : Boolean and operation.
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(expr) : Parenthesized expressions.
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fun(arg1, ..., argn) : Function calls:
| Function | Supported |
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boolean() | ✓ |
ceiling() | ✓ |
choose() | ✗ |
concat() | ✓ |
contains() | ✓ |
count() | ✓ |
current() | ✗ |
document() | ✗ |
element-available() | ✗ |
ends-with() | ✓ |
false() | ✓ |
floor() | ✓ |
format-number() | ✗ |
function-available() | ✗ |
generate-id() | ✗ |
id() | ✗ |
key() | ✗ |
lang() | ✗ |
last() | ✓ |
local-name() | ✓ |
lower-case()1 | ✓ |
matches() | ✓ |
name() | ✓ |
namespace-uri() | ✓ |
normalize-space() | ✓ |
not() | ✓ |
number() | ✓ |
position() | ✓ |
replace() | ✓ |
reverse() | ✓ |
round() | ✓ |
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