Cleanup attributeo definition with simple macro for exception catching

semperos · Oct 10, 2012 · 421cdcb · 421cdcb
1 parent ef0a6f7
commit 421cdcb
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Showing 2 changed files with 19 additions and 22 deletions.
diff --git a/src/webdriver_logic/core.clj b/src/webdriver_logic/core.clj
@@ -2,13 +2,11 @@
   (:refer-clojure :exclude [==])
   (:use clojure.core.logic
         [webdriver-logic.state :only [*driver* *html-tags* *html-attributes*]]
-        [webdriver-logic.util :only [fresh? ground?]]
+        [webdriver-logic.util :only [fresh? ground? careful-attribute]]
         [clojure.pprint :only [pprint]])
   (:require [clojure.test :as test]
             [clj-webdriver.core :as wd]
-            [webdriver-logic.state :as st])
-  (:import [org.openqa.selenium InvalidElementStateException]
-           [org.openqa.selenium.remote ErrorHandler$UnknownServerException]))
+            [webdriver-logic.state :as st]))
 
 (defmacro s
   "Deterministic test. Deterministic predicates are predicates that must succeed exactly once and, for well behaved predicates, leave no choicepoints.
@@ -107,35 +105,23 @@
         (and (ground? gelem)
              (ground? gattr)) (unify a
                                      [elem attr value]
-                                     [gelem gattr (try
-                                                    (wd/attribute gelem gattr)
-                                                    (catch InvalidElementStateException _ nil)
-                                                    (catch ErrorHandler$UnknownServerException _ nil))])
+                                     [gelem gattr (careful-attribute gelem gattr)])
         (ground? gelem) (to-stream
                          (for [attribute *html-attributes*]
                            (unify a
                                   [elem attr value]
-                                  [gelem attribute (try
-                                                     (wd/attribute gelem attribute)
-                                                     (catch InvalidElementStateException e nil)
-                                                     (catch ErrorHandler$UnknownServerException _ nil))])))
+                                  [gelem attribute (careful-attribute gelem attribute)])))
         (ground? gattr) (to-stream
                          (for [element (all-elements)]
                            (unify a
                                   [elem attr value]
-                                  [element gattr (try
-                                                   (wd/attribute element gattr)
-                                                   (catch InvalidElementStateException e nil)
-                                                   (catch ErrorHandler$UnknownServerException _ nil))])))
+                                  [element gattr (careful-attribute element gattr)])))
         :default (to-stream
                   (for [element (all-elements)
                         attribute *html-attributes*]
                     (unify a
                            [elem attr value]
-                           [element attribute (try
-                                                (wd/attribute element attribute)
-                                                (catch InvalidElementStateException e nil)
-                                                (catch ErrorHandler$UnknownServerException _ nil))])))))))
+                           [element attribute (careful-attribute element attribute)])))))))
 
 (defn childo
   "A relation where `child-elem` is a child element of the `parent-elem` element on the current page."

diff --git a/src/webdriver_logic/util.clj b/src/webdriver_logic/util.clj
@@ -1,6 +1,9 @@
 (ns ^{:doc "Utilties atop third-party dependendies."}
   webdriver-logic.util
-  (:use [clojure.core.logic :only [lvar?]]))
+  (:use [clojure.core.logic :only [lvar?]])
+  (:require [clj-webdriver.core :as wd])
+  (:import [org.openqa.selenium InvalidElementStateException]
+           [org.openqa.selenium.remote ErrorHandler$UnknownServerException]))
 
 (defn fresh?
   "Returns true, if `x' is fresh.
@@ -12,4 +15,12 @@
   "Returns true, if `x' is ground.
   `x' must have been `walk'ed before!"
   [x]
-  (not (lvar? x)))
+  (not (lvar? x)))
+
+(defmacro careful-attribute
+  "Wrap calls to wd/attribute in try and catch standard exceptions"
+  [elem attr]
+  `(try
+     (wd/attribute ~elem ~attr)
+     (catch InvalidElementStateException _# nil)
+     (catch ErrorHandler$UnknownServerException _# nil)))