Android NFC: Smart Poster NDEF Record with concatenated "URI" and "Text" Contents -


i have developed multi-purpose nfc app, capable of reading , writing different types of tags , in different types of formats, including external type, rtd text, , rtd uri. there is, however, problem parsing , reading "tnf_well_known" smart poster contents. more specifically, , begin problem have, used well-known "nfc tagwriter" app on android create simple contact content. contact contains name, e.g., "police", , phone number, e.g., "911". when trying read same content using yet popular app called "nfc taginfo", able read smart poster, showing supposed show:

well-known: urn:nfc:wkt:sp (smart poster)

  1. well-known: urn:nfc:wkt:u (uri) identifier: 0x05 ("tel:") "911"
  2. well-known: urn:nfc:wkt:u (text) encoding: utf-8 language: en "police"

on other hand, not able achieve same. here code came attempt decode aforementioned content:

first extract ndef message(s) , corresponding ndef record(s):

 // use ndefmessage[] getndefmessages(intent) method extract ndef message(s)   ndefmessage[] ndefmessages = getndefmessages(intent);  for(int = 0; < ndefmessages.length; i++) {      ndefrecords = ndefmessages[i].getrecords();      (int j = 0; j < ndefrecords.length; j++) {           // ndef record parsing snippet comes here!         if (ndefrecords[j].gettnf() == ndefrecord.tnf_well_known) {             // if tnf indicates "well-known" type,            // determine type using "type" field               if (arrays.equals(ndefrecords[j].gettype(),  ndefrecord.rtd_smart_poster)) {                 // first try decode content                payload = new string(ndefrecords[j].getpayload(), 1, ndefrecords[j].getpayload().length - 1, charset.forname("utf-8"));                log.i(tag, "content: " + payload);                 // second try decode content                log.i(tag, "content: " + ndefrecords[j].touri());            }          }        }     }

when looking @ logcat output, first log.i prints:

u911q   tenpolice

while second prints:

tel:911

it appears me nfc tagwriter app creates nested ndef record, in 1 uri type , 1 text type concatenated. trying figure out how content decoded successfully. first attempt removes payload header , decodes remaining part of ndef record payload. clearly, first part contains "tel:911" content , second part contains "police", "en" indicates language. second attempt uses ndefrecord class' touri() helper method, according api documentation able extract rtd uris. wondering in order extract nested records, decode one, convert byte[] array , remove payload, re-iterated yet decoding. though, approach looks inefficient. so, know other experts suggest on how approach problem.

[update] following short snippet compose smart poster ndef record interested:

ndefrecord urindefrecord = ndefrecord.createuri(uri.parse((string) o[0])); //rtd_uri ndefrecord textndefrecord = createtextrecord((string) o[1], locale.us, true); //rtd_text ndefrecord[] recs = new ndefrecord[]{urindefrecord, textndefrecord}; ndefmessage smartposterpcontentmessage = new ndefmessage(recs); byte[] bytes = smartposterpcontentmessage.tobytearray(); ndefrecord newrec = new ndefrecord((short) 0x01, ndefrecord.rtd_smart_poster, null, bytes); ndefmessagewriter(new ndefmessage(newrec));

in above snippet, "ndefmessagewriter" uses thread communicate tag , write content it.

as correctly found out smart poster record contains text record , uri record payload. have these records decode smart poster records payload (btw. if had googled "smart poster record" have come smart poster record type definition specification, grab here).

you found out sp record contains ndef message, decode record's payload ndef message:

ndefmessage spcontentmsg = new ndefmessage(sprecord.getpayload());

now have ndef message which, per specification, contains @ least 1 uri record , other optional records (e.g. 1 descriptive text record each language):

ndefrecord[] spcontentrecs = spcontentmsg.getrecords(); (ndefrecord rec : spcontentrecs) {     if (rec.gettnf() == ndefrecord.tnf_well_known) {        if (arrays.equals(rec.gettype(),  ndefrecord.rtd_uri)) {            //        } else if (arrays.equals(rec.gettype(),  ndefrecord.rtd_text)) {            //        }      }    } }

btw, of nfc forum's specifications written , easy follow (particularly various ndef , rtd related specifications).


Comments

Post a Comment

Popular posts from this blog

get url and add instance to a model with prefilled foreign key :django admin -

Image
i have page in each contest shown in row. each row contains contest id , link other model names have foreign key contest. news model: class news(models.model): title = models.charfield(max_length=50, null=true) description = models.textfield() time = models.timefield( default= datetime.datetime.now().time()) contest = models.foreignkey(contest) i want use admin adding , changing these models. want when user clicks on 'news' has foreign key contest id=1, shows list of news value foreign key. use {% instance in instances %} <tr class="{% cycle 'row1' 'row2' %}"> <td>{{ instance.title }}</td> <td>{{ instance.starttime }}</td> <td>{{ instance.timespan }}</td> <td>{{ instance.date }}</td> <td><a href="/adm...
Read more

android - Keyboard hides my half of edit-text and button below it even in scroll view -

i having trouble keyboard covers edit-text , half of button in scroll view. here's layout , please tell me how should resolve problem. many questions on topic none of them s working me. <?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:background="@drawable/bg" android:layout_height="match_parent"> <scrollview android:layout_width="match_parent" android:fillviewport="true" android:layout_height="match_parent"> <relativelayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical"> <linearlayout android:layout_width="match_parent" android:layout_height="w...
Read more

css - Make div keyboard-scrollable in jQuery Mobile? -

from can tell, although jquery-mobile-powered pages can contain divs overflow set scroll or auto, , these divs can scrolled one-screen bar or mouse wheel, cannot scrolled using arrow keys, page-up/page-down, or home/end. instead, official "page" div (with data-role="page") absorbs input. perhaps other divs can't acquire focus, i'm not sure. is there way around this? edit: jsfiddle of simple example: https://jsfiddle.net/qogz0shx/ <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.4/jquery.min.js"></script> <script src="https://ajax.googleapis.com/ajax/libs/jquerymobile/1.4.5/jquery.mobile.min.js"> </script> <link rel="stylesheet" href="https://code.jquery.com/mobile/1.4.5/jquery.mobile-1.4.5.css"/> <style> #outer { overflow:scroll; height: 50vh; width: 50vw; } #inner { height: 500vh; width: 500vw; } ...
Read more