Wait until angular finishes $http calls in Selenium webdriver

Wait.java

    /**
     * Sometime it happens while automating the angular app, view gets loaded entirely but performing any action
     * on that view fails the test. This could happen because angular $http calls are still pending in backend.
     * We can have explicit wait in this way to ensure that angular has made all the $http calls.
     * Wait until angular finishes the $http calls while loading the view
     */
    public void waitForAngular() {
        final String javaScriptToLoadAngular =
                "var injector = window.angular.element('body').injector();" + 
                "var $http = injector.get('$http');" + 
                "return ($http.pendingRequests.length === 0)";

        ExpectedCondition<Boolean> pendingHttpCallsCondition = new ExpectedCondition<Boolean>() {
            public Boolean apply(WebDriver driver) {
                return ((JavascriptExecutor) driver).executeScript(javaScriptToLoadAngular).equals(true);
            }
        };
        WebDriverWait wait = new WebDriverWait(driver, 20);
        wait.until(pendingHttpCallsCondition);
    }