(Visual FoxPro) Cloudfare DNS over HTTPS

Cloudflare offers a DNS over HTTPS resolver at: https://cloudflare-dns.com/dns-query

This example demonstrates how to do a DNS lookup for a domain using Cloudfare's HTTPS resolver.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loHttp
LOCAL lcUrl
LOCAL lcJsonResp
LOCAL loJson
LOCAL lnStatus
LOCAL lnTC
LOCAL lnRD
LOCAL lnRA
LOCAL lnAD
LOCAL lnCD
LOCAL i
LOCAL lnCount_i
LOCAL lcName
LOCAL lnType
LOCAL lnTTL
LOCAL lcData
LOCAL lcIpAddr

* This example requires the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Http')
loHttp = CreateObject('Chilkat.Http')

* Send the following CURL request:   curl -H 'accept: application/dns-json' 'https://cloudflare-dns.com/dns-query?name=chilkat.io&type=A'

loHttp.Accept = "application/dns-json"

lcUrl = "https://cloudflare-dns.com/dns-query?name=chilkat.io&type=A"

lcJsonResp = loHttp.QuickGetStr(lcUrl)
IF (loHttp.LastMethodSuccess <> 1) THEN
    ? loHttp.LastErrorText
    RELEASE loHttp
    CANCEL
ENDIF

? "Response Status Code: " + STR(loHttp.LastStatus)

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJson = CreateObject('Chilkat.JsonObject')
loJson.Load(lcJsonResp)
loJson.EmitCompact = 0
? loJson.Emit()

IF (loHttp.LastStatus <> 200) THEN
    ? "Failed."
    RELEASE loHttp
    RELEASE loJson
    CANCEL
ENDIF

* Sample output...
* (See the parsing code below..)
* 

* {
*   "Status": 0,
*   "TC": false,
*   "RD": true,
*   "RA": true,
*   "AD": false,
*   "CD": false,
*   "Question": [
*     {
*       "name": "chilkat.io.",
*       "type": 1
*     }
*   ],
*   "Answer": [
*     {
*       "name": "chilkat.io.",
*       "type": 1,
*       "TTL": 900,
*       "data": "52.25.83.238"
*     }
*   ]
* }

* Use this online tool to generate parsing code from sample JSON: 
* Generate Parsing Code from JSON

lnStatus = loJson.IntOf("Status")
lnTC = loJson.BoolOf("TC")
lnRD = loJson.BoolOf("RD")
lnRA = loJson.BoolOf("RA")
lnAD = loJson.BoolOf("AD")
lnCD = loJson.BoolOf("CD")
i = 0
lnCount_i = loJson.SizeOfArray("Question")
DO WHILE i < lnCount_i
    loJson.I = i
    lcName = loJson.StringOf("Question[i].name")
    lnType = loJson.IntOf("Question[i].type")
    i = i + 1
ENDDO
i = 0
lnCount_i = loJson.SizeOfArray("Answer")
* The domain name resolves to 1 or more IP addresses..
DO WHILE i < lnCount_i
    loJson.I = i
    lcName = loJson.StringOf("Answer[i].name")
    lnType = loJson.IntOf("Answer[i].type")
    lnTTL = loJson.IntOf("Answer[i].TTL")
    lcIpAddr = loJson.StringOf("Answer[i].data")

    ? "IP Address: " + lcIpAddr
    i = i + 1
ENDDO

RELEASE loHttp
RELEASE loJson