iOS Predicate text is not finding element but working with Xpath in appium java - appium

Question

I am new to iOS automation testing through appium Java. I wrote this code to include predicate text. for some reason the xpath works fine but when I use predicate text I get no such element exception
Iam using Eclipse,maven appium 1.7.2 and I'm using the ioS simulator
My appium server is on the latest version
protected IOSDriver<IOSElement> driver = null;
DesiredCapabilities dc = new DesiredCapabilities();
#BeforeMethod
public void setUp() throws MalformedURLException {
dc.setCapability("deviceName", "iPhone X");
dc.setCapability("platformName", "iOS");
dc.setCapability("app", "xxx.app";
dc.setCapability("platformVersion", "12.2");
dc.setCapability("automationName", "XCUITest");
dc.setCapability("useNewWDA", true);
dc.setCapability("fullReset", false);
dc.setCapability("appiumVersion", "1.7.2");
//dc.setCapability("automationName", "XCUITest");
driver = new iOSDriver<>(new URL("http://localhost:4723/wd/hub"), dc);
driver.setLogLevel(Level.INFO);
}
#Test
public void testUntitled() throws InterruptedException {
driver.findElement(By.xpath("//XCUIElementTypeButton[#name='Allow']")).click();
Thread.sleep(10000);
String selector= "type == 'XCUIElementTypeTextField' AND value ==
'Email'";
driver.findElement(MobileBy.iOSNsPredicateString(selector)).sendKeys("gjghhj"); driver.findElement(By.xpath("//XCUIElementTypeTextField[#value='Email']")).sendKeys("dssss");
}
I am expecting it to detect the email field through iOS predicate text
I'm getting below exception pls help
org.openqa.selenium.NoSuchElementException: An element could not be located on the page using the given search parameters.
*** Element info: {Using=-ios predicate string, value=type == 'XCUIElementTypeTextField' AND value == 'Email'}
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.openqa.selenium.remote.http.W3CHttpResponseCodec.createException(W3CHttpResponseCodec.java:187)
at org.openqa.selenium.remote.http.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:122)
at org.openqa.selenium.remote.http.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:49)
at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:158)
at io.appium.java_client.remote.AppiumCommandExecutor.execute(AppiumCommandExecutor.java:239)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:552)
at io.appium.java_client.DefaultGenericMobileDriver.execute(DefaultGenericMobileDriver.java:41)
at io.appium.java_client.AppiumDriver.execute(AppiumDriver.java:1)
at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:323)
at io.appium.java_client.DefaultGenericMobileDriver.findElement(DefaultGenericMobileDriver.java:61)
at io.appium.java_client.AppiumDriver.findElement(AppiumDriver.java:1)
at io.appium.java_client.MobileBy.findElement(MobileBy.java:61)
at io.appium.java_client.MobileBy$ByIosNsPredicate.findElement(MobileBy.java:458)
at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:315)
at io.appium.java_client.DefaultGenericMobileDriver.findElement(DefaultGenericMobileDriver.java:57)
at io.appium.java_client.AppiumDriver.findElement(AppiumDriver.java:1)
at com.gtl.probatio.tests.iosLeap.testUntitled(iosLeap.java:54)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:124)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:583)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:719)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:989)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109)
at org.testng.TestRunner.privateRun(TestRunner.java:648)
at org.testng.TestRunner.run(TestRunner.java:505)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:455)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:450)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:415)
at org.testng.SuiteRunner.run(SuiteRunner.java:364)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:84)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1208)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1137)
at org.testng.TestNG.runSuites(TestNG.java:1049)
at org.testng.TestNG.run(TestNG.java:1017)
at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:115)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:251)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:77)

Answer 1

Your predicate is probably incorrect. Consider using name instead of value
String selector= "type == 'XCUIElementTypeTextField' AND name == 'Email'";
P.S.
You shall not use Thread.sleep(); when you do not know exact time of waiting. Try this utility function:
public void waitForExistence(final String predicate) {
for (int attempt = 0; attempt < 10; attempt++) {
try {
driver.findElementByIosNsPredicate(predicate);
break;
} catch (Exception e) {
driver.manage().timeouts().implicitlyWait(1, TimeUnit.SECONDS);
}
}
}

Answer 2

If you are using page factory below code will work fine, just replace "Your Text" with your search criteria.
#iOSXCUITFindBy(iOSNsPredicate = "type == 'XCUIElementTypeStaticText' AND name CONTAINS[c] 'Your Text'")
public WebElement myElementUsingiOSNsPredicate;
public void clickOnMyiOSText()
{
myElementUsingiOSNsPredicate.click();
}

Answer 3

Give a try on classChain.(https://github.com/facebookarchive/WebDriverAgent/wiki/Class-Chain-Queries-Construction-Rules).
MobileBy.iOSClassChain("**/XCUIElementTypeTextField[`value=='Email'`]")