
Checks if a document (specified by the URL address) is supported by the client device, i.e. if the specified document can be displayed.
| Name | Description | Type | Use | 
|---|---|---|---|
| url | An URL to the file. Use "undefined" to indicate that the mimeType(from the "options" object below) should be
            checked. | string | required | 
| options | Configuration passed to the function call. It must contain either urlormimeTypeparameter. | object | optional | 
| callbacks | Passed to verify whether there is an external application that can open that particular file type. | undefined | required | 
The canOpen method's options object looks like in
      the following example.
{ mimeType, preview, timeout, authenticationType, username, password }| Name | Description | Type | Use | 
|---|---|---|---|
| mimeType | A MIME type to be checked. If this property is specified, the urlmust be null or not defined. | string | optional | 
| preview | If set to true, the API will check if a preview of that file type is possible (instead of looking for an external application). This property is supported on iOS only and its default value is "false". | boolean | optional | 
| timeout | A server response timeout (in seconds). It is used only if http(s)-based URL address has been specified. The default value of this property is "60". | integer | optional | 
| authenticationType | Specifies the function's behavior when HTTP basic authentication is requested. The setting's default value is "AUTHENTICATION_ANONYMOUS". Other possible settings are listed in the Constants section of the DocumentViewer article. | string | optional | 
| username | An optional username used when HTTP basic authentication is requested. The value is
            passed only if authenticationTypeis set to
            "AUTHENTICATION_CUSTOM_CREDENTIALS". | string | optional | 
| password | An optional passoword used when HTTP basic authentication is requested. The value is
            passed only if authenticationTypeis set to
            "AUTHENTICATION_CUSTOM_CREDENTIALS". | string | optional | 
The canOpen method's callbacks object can be
      structured as follows:
{
  onResult: function(result) {...},
  onFailure: function(error) {...}
}The table below lists all callbacks supported by the method.
| Name | Description | Return type | 
|---|---|---|
| onResult | Called when the function finishes without an error. The resultparameter passed in this callback is a boolean value specifying
            whether the file can be opened or not. | undefined | 
| onFailure | Called when an error occurs. The  | undefined |