APath
一、node
| expression | description |
| node | select all children nodes of this node |
| / | select from root node |
| // | select the document node from the current matched node,regardless of their position |
| . | select current node |
| .. | select the parent node of current node |
| @ | select properties |
二、predicate
| expression | implication |
| /bookstore/book[1] | select the first book element belongs to bookstore |
| /bookstore/book[last()] | select the lastbook element belongs to bookstore |
| /bookstore/book[position()<3] | select the first two book elements belongs to bookstore |
| //title[@lang] | choose elements of title with lang property |
三、wildcard
| expression | description | usage | specification |
| * | match any node | xpath("/div/*") | select all children nodes under div node |
| @* | match nodes with any property | xpath("/div[@*]") | select all node with properties |
| node() | match nodes of any type | xpath("//div[@class=\"tb_cls\"]").node() | select all div tags which class property is tb_cls |
四、multiple path selection
| usage | specification |
| xpath("//book/title*|*//book/price") | select all title elements and price elements of book |
| xpath("//title|//price") | select all title elements and price elements in the document |
五、xpath axis
| expression | description | usage | illustration |
| ancestor | select all ancestor nodes of current node | xpath("//div[@id=\"123\"]/ancestor::*") | select all ancestor nodes that tags name is div and id property is 123 |
| ancestor-or-self | select all ancestor node of current node and itself | xpath("//div[@id=\"123\"]/ancestor-or-self::*") | select all ancestor nodes and itself that tags name is div and id property is 123 |
| attribute | select all attributs of current node | xpath("//div[@id=\"123\"]/attribute::class") | select class attribute name that tags name is div and id property is 123 |
| child | select all child nodes of current node | xpath("//div[@id=\"123\"]/child::book") | select all child book nodes that tags name is div and id property is 123 |
| descendant | ... | xpath("./descendant::*") | ... |
| following | ... | xpath("./following::*") | ... |
| parent | ... | xpath("./parent::*") | ... |
| preceding | ... | xpath("//div[@id=\"123\"]/preceding::*") | ... |
| preceding-sibling | ... | xpath("//div[@id=\"123\"]/preceding-sibling::*") | ... |
| self | ... | xpath("./self::*") | ... |
六、operators
| expression | description | usage | illustration |
| + | ... | ... | ... |
| - | ... | ... | ... |
| * | ... | ... | ... |
| div | ... | ... | ... |
| = | ... | ... | ... |
| != | ... | ... | ... |
| < | ... | ... | ... |
| <= | ... | ... | ... |
|
> |
... | ... | ... |
| >= | ... | ... | ... |
| or | ... | ... | ... |
| and | ... | ... | ... |
| mod | ... | ... | ... |
七、functions
| expression | description | usage | illustration |
| starts-with() | ... | xpath("//div[starts-with(@id,\"ma\")]") | ... |
| contains() | ... | xpath("//div[contains(@id,\"ma\")]") | ... |
| and | ... | xpath("//div[contains(@id,\"ma\")] and contains(@id,\"in\")") | ... |
| text() | ... | xpath("//div[contains(text(),\"ma\")]") | ... |
