.. include:: ../abbreviations.txt

.. _asn1_data_reading_formatting:

ASN.1 data reading formatting
=============================

To permit use of API with ease, read data from smartcard through :js:func:`Token.readFile` is parsed in |JSON|. Indeed,
since Data Groups and other files described in ICAO specifications are in |ASN.1|, their content represents precise and
structured data. Thus, following javascript codes are possible:

.. code-block:: javascript

	// read DG 1 and log issuing state
	myToken.readFile(ICAO.FILE_ID.DG_1).then(function(data){
		console.log("issuing state: " + data.content.issuingState);
	});
	>> issuing state: UTO


.. code-block:: javascript

	// read EF.COM and log tag of present DGs
	myToken.readFile(ICAO.FILE_ID.EF_COM).then(function(data){
		console.log("present DGs tag: " + data.content.dataGroupTagList);
	});
	>> present DGs tag: 97,117,99,118,101,102,103,104,105,107,108,109,111


Generally, guidelines of *International Telecommunication Union X.697* (ITU-T X.697) specifications are followed to
convert ASN.1 into JSON. However, due to a lack of information or technical choice, some *specificities* are described
in this document.

.. toctree::
    :hidden:

    ASN1_JSON_rules
    ASN1_specificities