SELECT

Selector Functions

Name Spec Data Types Value Description
css requied [String, Object] CSS Selector GET, POST, PUT, HEAD, OPTIONS, DELETE
xpath requied [String] XPath 2 Name of the form to target
regex requied [String] Regex (Java) Parameters to pass
headers optional [Array of Strings] Headers to pass to the request
cookies optional [Array of Strings] Cookies to pass to the request
response optional [Array of Strings] Cookies to pass to the request
snapshot optional [Object] Generates a graphical snapshot of a web page’s / selected content

Selectors support two types of of parameters Implicit and Explicit. Implicit parameters are a shorthand that allows us to pass parameter without explicity specifing that is a selector and they can be used when no addional options are needed to be passed to the Selector function.

Following expressions are syntactically different but semantically equivalent.

   CSS Version
       
       css("#title")
       css({"selector" : "#title"})

   XPATH Version

       xpath("//a")
       xpath({"selector" : "//a"})

Selector chaining

Selectors can be chained to provide fine grained selections or to simplify the expression. During selector chaining we can use any type of a selector.

  SELECT 
      css("#selector")
        .css(".sub-selector")
          .css(".another-selector") as ColumnA

    FROM  http://www.delven.io/test/index-01.html 


  SELECT 
      css("#selector")
        .xpath(".//a")
          .regex("(.+?))") as ColumnA

    FROM  http://www.delven.io/test/index-01.html

Examples

CSS Selector

In Delve, css selectors are patterns used to select the element(s) you want to interact with.

Selector Example Description Reference
.class .intro Selects all elements with class=“intro”
#id #firstname Selects the element with id=“firstname” ID selectors
[attribute=value] [redonly=true] Selects all elements with redonly=“true” 
  <span id="id1" class="class-one intro" redonly="true">Here's a span with some text.</span>
  <span id="id2" class="class-two intro">Here's a span with some text.</span>

Selector by CSS classname

  SELECT  css(".class-one") FROM  http://www.delven.io/test/index-01.html

Selector by CSS id

  SELECT  css("#id1")  FROM  http://www.delven.io/test/index-01.html

Selector by CSS attribute

  SELECT  css("[readonly=true]") FROM  http://www.delven.io/test/index-01.html

XPath Selector

  SELECT  xpath("//a") as links  FROM  http://www.delven.io/test/index-01.html

Regex Selector

  SELECT  reges("(.+?)") as links  FROM  http://www.delven.io/test/index-01.html

Snapshot Selector

Generates a graphical snapshot of a web page’s content. This selector implies the dynamic document retrieval option. Snapshot accepts two properties.

Name Spec Data Types Value Default Description
width optional [Numeric] 1…N 1024 Width of the image to generate, in pixels.
height optional [Numeric] 1…N Proportonal Height of the image to generate, in pixels.
format optional [String] PNG,TIF,JPG PNG Image format to use 
  SELECT  snapshot({"width":1024, "height":1024, "format":"jpg"}}) as pic
     FROM  http://www.delven.io/test/index-01.html

Response Selector

Return complete response

  SELECT  response()
     FROM  http://www.delven.io/test/index-01.html

Cookies Selector

Return cookies associated with the request

Name Spec Data Types Value Default Description
name optional [Array of Strings] Cookie Name All Get cookies by names 
  SELECT  cookies(["cookieA", "cookieB"])
     FROM  http://www.delven.io/test/index-01.html

Response data

 {
   "name"  : "The name of the cookie",
   "value" : "The value of the cookie"
 }

Headers Selector Headers

View the headers returned

Name Spec Data Types Value Default Description
name optional [Array of Strings] Name All Name of the header 
  SELECT  headers(["headerA", "Header"])
     FROM  http://www.delven.io/test/index-01.html

Response data

 {
   "name"  : "The name of the header",
   "value" : "The value of the header"
 }

Selector Extensions W3 CSS selectors Rules

Delven adds number of css selector extensions

Name Example Description
:value a:value Select value of selected element
:first a:first Selects the first matched element
:last a:last Selects the last matched element

[//] https://code.tutsplus.com/tutorials/the-30-css-selectors-you-must-memorize--net-16048 [//] https://api.jquery.com/category/selectors/