HASH to File and File to HASH

[Otto]

Hello friends,
Is there a Harbour function to save a HASH to a file and then read it back in.

Best regards,
Otto

[Antonio Linares]

Dear Otto,

good morning

You have to convert the hash into a JSON string using hb_jsonEncode( hTheHash ) --> cJson then you can save it to disk using hb_memoWrit()

to recover the hash from the file you use hb_memoRead() and then call to hb_jsonDecode( cJson, @hTheHash ), simply declare local hTheHash before

[Otto]

Dear Antonio,
now as I have written down my question, I remembered.
Thank you so much and have a nice day.
Best regards,
Otto

Code: Select all  Expand view

 local hPost
//memowrit( "c:\www\htdocs\booking_new1\room.txt", hb_jsonencode( hPairs ) )
 
hb_jsondecode( memoread( "c:\www\htdocs\booking_new1\room.txt" ), @hPost )

[Otto]

Dear Antonio,
This is real time support from you.
Thank you very much.
There is no better forum and programming community than this.
Best regards,

Otto

[Antonio Linares]

Dear Otto,

thank you

We all together make these forums as good as they are

[Enrico Maria Giordano]

Dear Antonio,
This is real time support from you.
Thank you very much.
There is no better forum and programming community than this.

I totally agree!

[nageswaragunupudi]

I prefer

Code: Select all  Expand view

HB_MEMOWRIT( cFile, HB_ValToExp( hHash ) )
// Reading back
hHash := &( MEMOREAD( cFile ) )
 

There is one problem with HASH --> JSON --> HASH.
Any date values in the original hash are converted to character stings "yyyymmdd". Unless we scan the hash and convert all such values back to date type, the hash can not be used in date calculations.

Please try this simple test to prove the point.

Code: Select all  Expand view

#include "fivewin.ch"

function Main()

   local hHash1, hHash2, cJson, cHash

   SET DATE GERMAN
   SET CENTURY ON

   hHash1 := { "date" => Date() }
   cJson  := hb_jsonEncode( hHash1 )
   hb_jsonDecode( cJson, @hHash2 )
   ? hHash1[ "date" ], ValType( hHash1[ "date" ] ), ;
     hHash2[ "date" ], ValType( hHash2[ "date" ] )

   hHash1   := { "date" => Date() }
   cHash    := hb_ValToExp( hHash1 )
   hHash2   := &cHash
   ? hHash1[ "date" ], ValType( hHash1[ "date" ] ), ;
     hHash2[ "date" ], ValType( hHash2[ "date" ] )

return nil