Xpath Package for Golang, Supports HTML, XML, JSON Document Query

XPath

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

Implementation

htmlquery - an XPath query package for HTML document

xmlquery - an XPath query package for XML document.

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.

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

(a/b) : Selects all matches nodes as grouping set.

Node Axes

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()'.

Expressions

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()`	✓
`matches()`	✓
`name()`	✓
`namespace-uri()`	✓
`normalize-space()`	✓
`not()`	✓
`number()`	✓
`position()`	✓
`replace()`	✓
`reverse()`	✓
`round()`	✓
`starts-with()`	✓
`string()`	✓
`string-length()`	✓
`substring()`	✓
`substring-after()`	✓
`substring-before()`	✓
`sum()`	✓
`system-property()`	✗
`translate()`	✓
`true()`	✓
`unparsed-entity-url()`	✗

Author: Antchfx
Source Code: https://github.com/antchfx/xpath
License: MIT license

#go #golang #html #xml