Implemented element finding using various strategies.

src/webdriver.nim

@@ -9,14 +9,32 @@ type
     driver: WebDriver
     id*: string
 
+  Element* = object
+    session: Session
+    id*: string
+
+  LocationStrategy* = enum
+    CssSelector, LinkTextSelector, PartialLinkTextSelector, TagNameSelector,
+    XPathSelector
+
   WebDriverException* = object of Exception
 
   ProtocolException* = object of WebDriverException
 
+proc toKeyword(strategy: LocationStrategy): string =
+  case strategy
+  of CssSelector: "css selector"
+  of LinkTextSelector: "link text"
+  of PartialLinkTextSelector: "partial link text"
+  of TagNameSelector: "tag name"
+  of XPathSelector: "xpath"
+
 proc newWebDriver*(url: string = "http://localhost:4444"): WebDriver =
   WebDriver(url: url.parseUri, client: newHttpClient())
 
 proc createSession*(self: WebDriver): Session =
+  ## Creates a new browsing session.
+
   # Check the readiness of the Web Driver.
   let resp = self.client.getContent($(self.url / "status"))
   let obj = parseJson(resp)
@@ -39,6 +57,7 @@ proc createSession*(self: WebDriver): Session =
   return Session(id: sessionObj["value"]["sessionId"].getStr(), driver: self)
 
 proc navigate*(self: Session, url: string) =
+  ## Instructs the session to navigate to the specified URL.
   let reqUrl = $(self.driver.url / "session" / self.id / "url")
   let obj = %*{"url": url}
   let resp = self.driver.client.postContent(reqUrl, $obj)
@@ -48,6 +67,7 @@ proc navigate*(self: Session, url: string) =
     raise newException(WebDriverException, $respObj)
 
 proc getPageSource*(self: Session): string =
+  ## Retrieves the specified session's page source.
   let reqUrl = $(self.driver.url / "session" / self.id / "source")
   let resp = self.driver.client.getContent(reqUrl)
 
@@ -57,9 +77,34 @@ proc getPageSource*(self: Session): string =
 
   return respObj{"value"}.getStr()
 
+proc findElement*(self: Session, selector: string,
+                  strategy = CssSelector): Element =
+  let reqUrl = $(self.driver.url / "session" / self.id / "element")
+  let reqObj = %*{"using": toKeyword(strategy), "value": selector}
+  let resp = self.driver.client.postContent(reqUrl, $reqObj)
+
+  let respObj = parseJson(resp)
+  if respObj{"value"}.isNil:
+    raise newException(WebDriverException, $respObj)
+
+  for key, value in respObj["value"].getFields().pairs():
+    return Element(id: value.getStr(), session: self)
+
+proc getText*(self: Element): string =
+  let reqUrl = $(self.session.driver.url / "session" / self.session.id /
+                 "element" / self.id / "text")
+  let resp = self.session.driver.client.getContent(reqUrl)
+  let respObj = parseJson(resp)
+  if respObj{"value"}.isNil:
+    raise newException(WebDriverException, $respObj)
+
+  return respObj["value"].getStr()
+
 when isMainModule:
   let webDriver = newWebDriver()
   let session = webDriver.createSession()
-  echo(session)
-  session.navigate("https://picheta.me")
-  echo(session.getPageSource())
+  let amazonUrl = "https://www.amazon.co.uk/Nintendo-Classic-Mini-" &
+                  "Entertainment-System/dp/B073BVHY3F"
+  session.navigate(amazonUrl)
+
+  echo session.findElement("#priceblock_ourprice").getText()