Package com.vaadin.client

Class WidgetUtil

  • public class WidgetUtil
extends Object
    Utility methods which are related to client side code only.
    Since:
    1.0

    • Constructor Detail

      • WidgetUtil

        public WidgetUtil()

    • Method Detail

      • refresh

        public static void refresh()
        Refreshes the browser.

      • redirect

        public static void redirect​(String url)
        Redirects the browser to the given url or refreshes the page if url is null
        Parameters:
        url - The url to redirect to or null to refresh

      • getAbsoluteUrl

        public static String getAbsoluteUrl​(String url)
        Resolve a relative URL to an absolute URL based on the current document's location.
        Parameters:
        url - a string with the relative URL to resolve
        Returns:
        the corresponding absolute URL as a string

      • isAbsoluteUrl

        public static boolean isAbsoluteUrl​(String url)
        Detects if an URL is absolute. URLs wihtout schema but starting with double slashes (e.g. //myhost/path} are considered absolute.
        Parameters:
        url - a string with the URL to check
        Returns:
        true if the url is absolute, otherwise false.

      • crazyJsCast

        public static <T> T crazyJsCast​(Object value)
        Anything in, anything out. It's JavaScript after all. This method just makes the Java compiler accept the fact.
        Type Parameters:
        T - the object type
        Parameters:
        value - anything
        Returns:
        the same stuff

      • crazyJsoCast

        public static <T extends com.google.gwt.core.client.JavaScriptObject> T crazyJsoCast​(Object value)
        Anything in, JSO out. It's JavaScript after all. This method just makes the Java compiler accept the fact. The regular crazy cast doesn't work for JSOs since the generics still makes the compiler insert a JSO check.
        Type Parameters:
        T - the object type
        Parameters:
        value - anything
        Returns:
        the same stuff

      • toPrettyJson

        public static String toPrettyJson​(elemental.json.JsonValue json)
        Converts a JSON value to a formatted string.
        Parameters:
        json - the JSON value to stringify
        Returns:
        the JSON string

      • updateAttribute

        public static void updateAttribute​(elemental.dom.Element element,
                                   String attribute,
                                   String value)
        Updates the attribute value for the element to the given value.

        If value is null then attribute is removed, otherwise value is set as its value.

        Parameters:
        element - the DOM element owning attribute
        attribute - the attribute to update
        value - the value to update

      • setJsProperty

        public static void setJsProperty​(Object object,
                                 String name,
                                 Object value)
        Assigns a value as JavaScript property of an object.
        Parameters:
        object - the target object
        name - the property name
        value - the property value

      • getJsProperty

        public static Object getJsProperty​(Object object,
                                   String name)
        Retrieves the value of a JavaScript property.
        Parameters:
        object - the target object
        name - the property name
        Returns:
        the value

      • hasOwnJsProperty

        public static boolean hasOwnJsProperty​(Object object,
                                       String name)
        Checks whether the provided object itself has a JavaScript property with the given name. Inherited properties are not taken into account.
        Parameters:
        object - the target object
        name - the name of the property
        Returns:
        true if the object itself has the named property; false if it doesn't have the property of if the property is inherited
        See Also:
        hasJsProperty(Object, String)

      • hasJsProperty

        public static boolean hasJsProperty​(Object object,
                                    String name)
        Checks whether the provided object has or inherits a JavaScript property with the given name.
        Parameters:
        object - the target object
        name - the name of the property
        Returns:
        true if the object itself has or inherits the named property; false otherwise
        See Also:
        hasOwnJsProperty(Object, String)

      • isUndefined

        public static boolean isUndefined​(Object property)
        Checks if the given value is explicitly undefined. null values returns false.
        Parameters:
        property - the value to be verified
        Returns:
        true is the value is explicitly undefined, false otherwise

      • deleteJsProperty

        public static void deleteJsProperty​(Object object,
                                    String name)
        Removes a JavaScript property from an object.
        Parameters:
        object - the object from which to remove the property
        name - the name of the property to remove

      • createJsonObjectWithoutPrototype

        public static elemental.json.JsonObject createJsonObjectWithoutPrototype()
        Creates a new JsonObject without any JavaScript prototype at all. Not having any prototype is only relevant for objects that are displayed through the browser console.
        Returns:
        a new json object

      • createJsonObject

        public static elemental.json.JsonObject createJsonObject()
        Creates a new JsonObject with the JavaScript prototype.
        Returns:
        a new json object

      • isTrueish

        public static boolean isTrueish​(Object value)
        Gets the boolean value of the provided value based on JavaScript semantics.
        Parameters:
        value - the value to check for truthness
        Returns:
        true if the provided value is trueish according to JavaScript semantics, otherwise false

      • getKeys

        public static String[] getKeys​(Object value)
        Gets all JavaScript property names of the given object. This directly calls Object.keys.
        Parameters:
        value - the value to get keys for
        Returns:
        an array of key names

      • stringify

        public static String stringify​(elemental.json.JsonObject payload)
        When serializing the JsonObject we check the values for dom nodes and throw and exception if one is found as they should not be synced and may create cyclic dependencies.
        Parameters:
        payload - JsonObject to stringify
        Returns:
        json string of given object

      • equals

        public static boolean equals​(Object obj1,
                             Object obj2)
        Checks whether the objects are equal either as Java objects (considering types and Java Object.equals(Object) method) or as JS values.
        Parameters:
        obj1 - an object
        obj2 - an object to be compared with a for deep equality
        Returns:
        true if the arguments are equal to each other and false otherwise
        See Also:
        equalsInJS(Object, Object)

      • equalsInJS

        public static boolean equalsInJS​(Object obj1,
                                 Object obj2)
        Checks whether the objects are equal as JS values.

        This check ignores object types and checks the values via JS ==. E.g. it means that an empty string equals to 0.

        Parameters:
        obj1 - an object
        obj2 - an object to be compared with a for deep equality
        Returns:
        true if the arguments are equal via JS == to each other and false otherwise