12 Matching Annotations
  1. Feb 2023
    1. <table><tbody><tr class="evn"><td> XPath </td><td> JSONPath </td><td> Description </td></tr> <tr class="odd"><td> / </td><td> $ </td><td class="lft">the root object/element </td></tr> <tr class="evn"><td> . </td><td> @ </td><td class="lft">the current object/element </td></tr> <tr class="odd"><td> / </td><td> . or [] </td><td class="lft">child operator </td></tr> <tr class="evn"><td> .. </td><td> n/a </td><td class="lft">parent operator </td></tr> <tr class="odd"><td> // </td><td> .. </td><td class="lft">recursive descent. JSONPath borrows this syntax from E4X. </td></tr> <tr class="evn"><td> * </td><td> * </td><td class="lft">wildcard. All objects/elements regardless their names. </td></tr> <tr class="odd"><td> @ </td><td> n/a </td><td class="lft">attribute access. JSON structures don't have attributes. </td></tr> <tr class="evn"><td> [] </td><td> [] </td><td class="lft">subscript operator. XPath uses it to iterate over element collections and for predicates. In Javascript and JSON it is the native array operator. </td></tr> <tr class="odd"><td> | </td><td> [,] </td><td class="lft">Union operator in XPath results in a combination of node sets. JSONPath allows alternate names or array indices as a set. </td></tr> <tr class="evn"><td> n/a </td><td> [start:end:step] </td><td class="lft">array slice operator borrowed from ES4. </td></tr> <tr class="odd"><td> [] </td><td> ?() </td><td class="lft">applies a filter (script) expression. </td></tr> <tr class="evn"><td> n/a </td><td> () </td><td class="lft">script expression, using the underlying script engine. </td></tr> <tr class="odd"><td> () </td><td> n/a </td><td class="lft">grouping in Xpath </td></tr></tbody></table>
  2. Sep 2022
  3. Jan 2022
    1. although if you are using XMLDOM with JavaScript you can code something like var n1 = uXmlDoc.selectSingleNode("//bookstore/book[1]/title/@lang"); and n1.text will give you the value "eng"
      • TEST, value: "selected".text
    2. @KorayTugay, No, the first expression selects, doesn't "return" -- a set of nodes, and this set of nodes is not a string. A node is not a string -- a node is a node in a tree. An XML document is a tree of nodes. lang="eng" is just one of many textual representations of an attribute node that has a name "lang", doesn't belong to a namespace, and has a string value the string "eng" – Dimitre Novatchev Oct 22 '14 at
      • OK: select, not value
    1. //Parent[@id='1']/Children/child/@name will only output the name attribute of the 4 child nodes belonging to the Parent specified by its predicate [@id=1]. You'll then need to change the predicate to [@id=2] to get the set of child nodes for the next Parent. However, if you ignore the Parent node altogether and use: //child/@name you can select name attribute of all child nodes in one go.
      • OK, select ALL
    2. //Parent[@id='1']/Children/child/@name Your original child[@name] means an element child which has an attribute name. You want child/@name.
      • OK: /@name
    3. So far I have this XPath string: //Parent[@id='1']/Children/child[@name]
      • [@name] NO SELECCIONA, sino que FILTRA!
      • ver respuesta "382"
  4. Mar 2021
    1. The document.evaluate() method evaluates an XPATH query/expression. So you can pass XPATH expressions there, traverse into the HTML document and locate the desired element.
  5. Aug 2019
    1. Case in point: take this css selector: h1.header > a[rel~="author"] Its shortest functional XPath equivalent would be //h1[contains(" "+normalize-space(@class)+" "," header ")]/a[contains(" "+normalize-space(@rel)+" "," author ")] …which is both much harder to read and write. If you wrote this XPath instead: //h1[@class="header"]/a[@rel="author"] …you would incorrectly have missed markup like <h1 class="article header"><a rel="author external" href="/mike">...</a></h1>
    2. CSS syntax is awesome for two reasons: It is an order of magnitude faster and less resource intensive than the more complex XPath. When what you want to find can be found with a css selector, a corresponding XPath query doing the same would most of the time be much longer and harder to read.
  6. Apr 2016
    1. Interestingly, it uses multiple methods to locate the annotation within the cited page: absolute character count, text to search for, and XPath notation.

      That's done to accommodate sites who's DOM changes either over time or during user interaction (single page apps, etc).

      This blog post explains the current approach and thinking behind it in Hypothes.is: https://hypothes.is/blog/fuzzy-anchoring/