iOS UIAutomation UIAElement.isVisible() throwing stale response? - automator

Question

I'm trying to use isVisible() within a loop to create a waitForElement type of a function for my iOS UIAutomation. When I try to use the following code, it fails while waiting for an element when a new screen pops up. The element is clearly there because if I do a delay(2) before tapping the element it works perfectly fine. How is everyone else accomplishing this, because I am at a loss...
Here's the waitForElement code that I am using:
function waitForElement(element, timeout, step) {
if (step == null) {
step = 0.5;
}
if (timeout == null) {
timeout = 10;
}
var stop = timeout/step;
for (var i = 0; i < stop; i++) {
if (element.isVisible()) {
return;
}
target.delay(step);
}
element.logElement();
throw("Not visible");
}

Answer 1

Here is a simple wait_for_element method that could be used:
this.wait_for_element = function(element, preDelay) {
if (!preDelay) {
target.delay(0);
}
else {
target.delay(preDelay);
}
var found = false;
var counter = 0;
while ((!found) && (counter < 60)) {
if (!element.isValid()) {
target.delay(0.5);
counter++;
}
else {
found = true;
target.delay(1);
}
}
}

Answer 2

I tend to stay away from my wait_for_element and look for any activityIndicator objects on screen. I use this method to actual wait for the page to load.
this.wait_for_page_load = function(preDelay) {
if (!preDelay) {
target.delay(0);
}
else {
target.delay(preDelay);
}
var done = false;
var counter = 0;
while ((!done) && (counter < 60)) {
var progressIndicator = UIATarget.localTarget().frontMostApp().windows()[0].activityIndicators()[0];
if (progressIndicator != "[object UIAElementNil]") {
target.delay(0.25);
counter++;
}
else {
done = true;
}
}
target.delay(0.25);
}

Answer 3

Here is a simple and better one using recursion. "return true" is not needed but incase u want it.
waitForElementToDismiss:function(elementToWait,waitTime){ //Using recursion to wait for an element. pass in 0 for waitTime
if(elementToWait && elementToWait.isValid() && elementToWait.isVisible() && (waitTime < 30)){
this.log("Waiting for element to invisible");
target.delay(1);
this.waitForElementToDismiss(elementToWait, waitTime++);
}
if(waitTime >=30){
fail("Possible login failed or too long to login. Took more than "+waitTime +" seconds")
}
return true;
}

Answer 4

Solution
I know this is an old question but here is my solution for a situation where I have to perform a repetitive task against a variable timed event. Since UIAutomation runs on javascript I use a recursive function with an empty while loop that checks the critical control state required before proceeding to the next screen. This way one never has to hard code a delay.
// Local target is the running simulator
var target = UIATarget.localTarget();
// Get the frontmost app running in the target
var app = target.frontMostApp();
// Grab the main window of the application
var window = app.mainWindow();
//Get the array of images on the screen
var allImages = window.images();
var helpButton = window.buttons()[0];
var nextButton = window.buttons()[2];
doSomething();
function doSomething ()
{
//only need to tap button for half the items in array
for (var i=0; i<(allImages.length/2); i++){
helpButton.tap();
}
//loop while my control is NOT enabled
while (!nextButton.isEnabled())
{
//wait
}
//proceed to next screen
nextButton.tap();
//go again
doSomething();
}