Add Coffeescript version of waitfor.js.

examples/waitfor.coffee

@@ -0,0 +1,40 @@
+###
+ Wait until the test condition is true or a timeout occurs. Useful for waiting
+ on a server response or for a ui change (fadeIn, etc.) to occur.
+
+ @param testFx javascript condition that evaluates to a boolean,
+ it can be passed in as a string (e.g.: "1 == 1" or "$('#bar').is(':visible')" or
+ as a callback function.
+ @param message a message describing e.g. the ui change
+ @param timeOutMillis the max amount of time to wait. If not specified, 3 sec is used.
+###
+waitFor = (testFx, message, maxtimeOutMillis = 3000) ->
+    start = new Date().getTime()
+    condition = false
+    while (new Date().getTime() - start) < maxtimeOutMillis
+        phantom.sleep(250)
+        if typeof(testFx) is "string"
+            condition = eval testFx
+        else
+            condition = testFx()
+        if condition
+            break
+    if not condition
+        console.log "Timeout: " + message
+        phantom.exit 1
+    else
+        console.log message
+        console.log "+++ waitUntil finished in " + (new Date().getTime() - start) + " millis."
+
+# example use:
+if not phantom.state
+    # load a twitter page
+    phantom.state = "loaded"
+    phantom.open "http://twitter.com/#!/senchainc"
+else
+    # click the "sign in" link
+    $(".signin-link").click()
+
+    # wait for the sign in dialog to pop up
+    waitFor (-> $("#signin-dropdown").is ":visible"), "The sign-in dialog should be visible"
+    phantom.exit()