XPath

XPath is Go package provides selecting nodes from XML, HTML or other documents using XPath expression.

Implementation

The basic XPath patterns cover 90% of the cases that most stylesheets will need.

node : Selects all child elements with nodeName of node.
* : Selects all child elements.
@attr : Selects the attribute attr.
@* : Selects all attributes.
node() : Matches an org.w3c.dom.Node.
text() : Matches a org.w3c.dom.Text node.
comment() : Matches a comment.
. : Selects the current node.
.. : Selects the parent of current node.
/ : Selects the document node.
a[expr] : Select only those nodes matching a which also satisfy the expression expr.
a[n] : Selects the nth matching node matching a When a filter's expression is a number, XPath selects based on position.
a/b : For each node matching a, add the nodes matching b to the result.
a//b : For each node matching a, add the descendant nodes matching b to the result.
//b : Returns elements in the entire document matching b.
a, b : All nodes matching a or b, union operation(not boolean or).
(a, b, c) : Evaluates each of its operands and concatenates the resulting sequences, in order, into a single result sequence

child::* : The child axis selects children of the current node.
descendant::* : The descendant axis selects descendants of the current node. It is equivalent to '//'.
descendant-or-self::* : Selects descendants including the current node.
attribute::* : Selects attributes of the current element. It is equivalent to @*
following-sibling::* : Selects nodes after the current node.
preceding-sibling::* : Selects nodes before the current node.
following::* : Selects the first matching node following in document order, excluding descendants.
preceding::* : Selects the first matching node preceding in document order, excluding ancestors.
parent::* : Selects the parent if it matches. The '..' pattern from the core is equivalent to 'parent::node()'.
ancestor::* : Selects matching ancestors.
ancestor-or-self::* : Selects ancestors including the current node.
self::* : Selects the current node. '.' is equivalent to 'self::node()'.

The gxpath supported three types: number, boolean, string.

path : Selects nodes based on the path.
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.
a + b : Arithmetic expressions.
- - a Unary minus
- a + b Add
- a - b Substract
- a * b Multiply
- a div b Divide
- a mod b Floating point mod, like Java.
a or b : Boolean or operation.
a and b : Boolean and operation.
(expr) : Parenthesized expressions.
fun(arg1, ..., argn) : Function calls:, Function, Supported, ---, ---, 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(), ✓, name(), ✓, namespace-uri(), ✓, normalize-space(), ✓, not(), ✓, number(), ✓, position(), ✓, replace(), ✓, round(), ✓, starts-with(), ✓, string(), ✓, string-length(), ✓, substring(), ✓, substring-after(), ✓, substring-before(), ✓, sum(), ✓, system-property(), ✗, translate(), ✓, true(), ✓, unparsed-entity-url(), ✗, Changelogs
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2019-03-19

optimize XPath , operation performance. #33. Tips: suggest split into multiple subquery if you have a lot of , operations.

2019-01-29

2018-12-07