HOWTO: Retrieve and Insert HTML Into Memo Field

• Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0, 5.0a, 6.0

SUMMARY

The sample program below will connect to an Internet or intranet Web page and bring back the HTML code and store it into a memo field of a FoxPro table.

MORE INFORMATION

Save the sample program below into a Visual FoxPro program file. Use the following syntax to run the program:

   DO readurl.prg WITH "http://www.microsoft.com" 

   * READURL.PRG - return the HTML for a specified URL in HURL.MEMO
   *
   * passed: URLName, in the form "http://www.microsoft.com"
   *
   * returns: length of HTML file
   *
   * usage:
   *
   *      m.urllength = readurl("http://www.microsoft.com")
   *
   *
   * notes:
   * 1 - IE does not need to be running to use this, but must be installed,
   * as the program uses an option that gets information from the registry
   *
   * 2 - the URL name apparently MUST be passed in the form shown above.
   *

   PARAMETERS UrlName

   DECLARE INTEGER InternetOpen IN wininet.DLL STRING sAgent, ;
         INTEGER lAccessType, STRING sProxyName, ;
         STRING sProxyBypass, INTEGER lFlags

   DECLARE INTEGER InternetOpenUrl IN wininet.DLL ;
      INTEGER hInternetSession, STRING sUrl, STRING sHeaders, ;
      INTEGER lHeadersLength, INTEGER lFlags, INTEGER lContext

   DECLARE INTEGER InternetReadFile IN wininet.DLL INTEGER hfile, ;
         STRING @sBuffer, INTEGER lNumberofBytesToRead, INTEGER @lBytesRead

   DECLARE short InternetCloseHandle IN wininet.DLL INTEGER hInst

   #DEFINE INTERNET_OPEN_TYPE_PRECONFIG 0
   #DEFINE INTERNET_OPEN_TYPE_DIRECT 1
   #DEFINE INTERNET_OPEN_TYPE_PROXY 3
   #DEFINE SYNCHRONOUS 0
   #DEFINE INTERNET_FLAG_RELOAD 2147483648
   #DEFINE CR CHR(13)


   IF NOT FILE("hurl.dbf")
         CREATE TABLE hurl (MEMO M)
   ELSE
         USE hurl
   ENDIF
   APPEND BLANK

   * what application is using Internet services?
   sAgent = "VPF 5.0"

   hInternetSession = InternetOpen(sAgent, INTERNET_OPEN_TYPE_PRECONFIG, ;
         '', '', SYNCHRONOUS)

   * debugging line - uncomment to see session handle
   * WAIT WINDOW "Internet session handle: " + LTRIM(STR(hInternetSession))

   IF hInternetSession = 0
         WAIT WINDOW "Internet session cannot be established" TIME 2
         RETURN 0
   ENDIF

   hUrlFile = InternetOpenUrl(hInternetSession, UrlName, '', ;
         0, INTERNET_FLAG_RELOAD, 0)

   * debugging line - uncomment to see URL handle
   * WAIT WINDOW "URL Handle: " + LTRIM(STR(hUrlFile))

   IF hUrlFile = 0
         WAIT WINDOW "URL cannot be opened"
         RETURN 0
   ENDIF

   DO WHILE .T.
         * set aside a big buffer
         sReadBuffer = SPACE(32767)
         lBytesRead = 0
         m.OK = InternetReadFile(hUrlFile, @sReadBuffer, ;
            LEN(sReadBuffer), @lBytesRead)

         * debugging code - uncomment if necessary
         *WAIT WINDOW "hURLFile: " + LTRIM(STR(hURLFile)) + CR + ;
         *                  "lBytesRead: " + LTRIM(STR(lBytesRead)) + CR ;
         *                  + "m.OK      : " + LTRIM(STR(m.OK))

         REPLACE hurl.MEMO WITH sReadBuffer ADDITIVE

         * uncomment to watch the changes to the memo file
         * MODIFY MEMO hurl.memo

         * error trap - either a read failure or read past eof()
         IF m.OK = 0 OR lBytesRead = 0
            EXIT
         ENDIF
   ENDDO

   * close all the handles we opened
   =InternetCloseHandle(hUrlFile)
   =InternetCloseHandle(hInternetSession)

   * return the number of bytes read
   RETURN LEN(hurl.memo) 

REFERENCES

"Visual Basic and the Win32 Internet SDK" by James Braun (September 1996 MSDN)

Additional query words:

Keywords : kbnokeyword kbVFp300 kbVFp500 kbVFp600 kbInetDev
Version :
Platform :
Issue type : kbhowto