[gnome-db] export to csv

[Andrea Zagli <azagli libero it>]

- i think that could be useful an additional parameter (or an option)  
to gda_data_model_export_to_file that allow to make the first line of   
the file the list of fields name; so i prepared the patch attached  
named fields_name_header.patch

- i don't know if so for every database, but when the field is of type  
date (or time or timestamp) and it is null postgresql wants in csv  
file a zero-lenght string; so i prepared another patch (in attach  
named null_date.patch) (it makes use of the two functions that i send  
2 days ago)


PS: i don't know if it is the right way to send you/make a patch...

diff --git a/libgda/gda-data-model.c b/libgda/gda-data-model.c
index 70ffd79..2c9ac5e 100644
--- a/libgda/gda-data-model.c
+++ b/libgda/gda-data-model.c
@@ -1050,10 +1050,13 @@ gda_data_model_export_to_string (GdaDataModel *model, GdaDataModelIOFormat forma
 	}
 
 	case GDA_DATA_MODEL_IO_TEXT_SEPARATED: {
+		gchar *retval;
 		gchar sep = ',';
 		gchar quote = '"';
 		gboolean field_quote = TRUE;
 
+		g_return_val_if_fail (GDA_IS_DATA_MODEL (model), NULL);
+
 		if (options) {
 			GdaHolder *holder;
 
@@ -1094,25 +1097,61 @@ gda_data_model_export_to_string (GdaDataModel *model, GdaDataModelIOFormat forma
 				else 
 					g_warning (_("The '%s' parameter must hold a boolean value, ignored."), "FIELD_QUOTE");
 			}
+
+			holder = gda_set_get_holder (options, "FIELDS_NAME");
+			if (holder) {
+				const GValue *value;
+				value = gda_holder_get_value (holder);
+				if (value && (G_VALUE_TYPE (value) == G_TYPE_BOOLEAN))
+					{
+						gint col;
+						gint *rcols;
+						gint rnb_cols;
+
+						if (cols)
+							{
+								rcols = (gint *)cols;
+								rnb_cols = nb_cols;
+							}
+						else
+							{
+								gint i;
+
+								rnb_cols = gda_data_model_get_n_columns (model);
+								rcols = g_new (gint, rnb_cols);
+								for (i = 0; i < rnb_cols; i++)
+									rcols[i] = i;
+							}
+
+						retval = g_strdup ("");
+						for (col = 0; col < rnb_cols; col++)
+							{
+								retval = g_strconcat (retval, g_strdup_printf ("%c", quote), gda_data_model_get_column_name (model, rcols[col]), g_strdup_printf ("%c", quote), g_strdup_printf ("%c", sep), NULL);
+							}
+						if (g_strcmp0 (retval, "") != 0)
+							{
+								retval[strlen (retval) - 1] = '\n';
+							}
+					}
+				else
+					g_warning (_("The '%s' parameter must hold a boolean value, ignored."), "FIELDS_NAME");
+			}
 		}
 
+		if (!retval) retval = g_strdup ("");
 		if (cols)
-			return export_to_text_separated (model, cols, nb_cols, rows, nb_rows, sep, quote, field_quote);
+			retval = g_strconcat (retval, export_to_text_separated (model, cols, nb_cols, rows, nb_rows, sep, quote, field_quote), NULL);
 		else {
-			gchar *retval;
 			gint *rcols, rnb_cols, i;
 			
-			g_return_val_if_fail (GDA_IS_DATA_MODEL (model), NULL);
-			
 			rnb_cols = gda_data_model_get_n_columns (model);
 			rcols = g_new (gint, rnb_cols);
 			for (i = 0; i < rnb_cols; i++)
 				rcols[i] = i;
-			retval = export_to_text_separated (model, rcols, rnb_cols, rows, nb_rows, sep, quote, field_quote);
-			g_free (rcols);
-			
-			return retval;
+			retval = g_strconcat (retval, export_to_text_separated (model, rcols, rnb_cols, rows, nb_rows, sep, quote, field_quote), NULL);
+			g_free (rcols);			
 		}
+		return retval;
 	}
 
 	default:

diff --git a/libgda/gda-data-model.c b/libgda/gda-data-model.c
index 70ffd79..ad4a746 100644
--- a/libgda/gda-data-model.c
+++ b/libgda/gda-data-model.c
@@ -1229,18 +1268,52 @@ export_to_text_separated (GdaDataModel *model, const gint *cols, gint nb_cols, c
 			else {
 				gchar *tmp;
 				gsize len, size;
-				
-				tmp = gda_value_stringify (value);
-				len = strlen (tmp);
-				size = 2 * len + 3;
-				txt = g_new (gchar, size);
-
-				len = csv_write2 (txt, size, tmp, len, quote);
-				txt [len] = 0;
-				if (!field_quotes) {
-					txt [len - 1] = 0;
-					memmove (txt, txt+1, len);
+				GdaColumn *gdacol;
+				GType colgtype;
+
+				tmp = NULL;
+
+				gdacol = gda_data_model_describe_column (model, cols[c]);
+				colgtype = gda_column_get_g_type (gdacol);
+				if (colgtype == GDA_TYPE_TIMESTAMP
+			        || colgtype == G_TYPE_DATE
+			        || colgtype == GDA_TYPE_TIME) {
+			    	if (!gda_value_is_null (value)) {
+			    		if (gda_value_isa (value, GDA_TYPE_TIMESTAMP)) {
+			    			const GdaTimestamp *tt;
+			    			tt = (const GdaTimestamp *)gda_value_get_timestamp (value);
+			    			if (gda_timestamp_valid (tt)) {
+								tmp = gda_value_stringify (value);
+			    			}
+			    		} else if (gda_value_isa (value, G_TYPE_DATE)) {
+			    			tmp = gda_value_stringify (value);
+						} else if (gda_value_isa (value, GDA_TYPE_TIME)) {
+			    			const GdaTime *tt;
+			    			tt = (const GdaTime *)gda_value_get_time (value);
+			    			if (gda_time_valid (tt)) {
+								tmp = gda_value_stringify (value);
+			    			}
+			    		}
+			    	}
+				}
+			    else {
+			    	tmp = gda_value_stringify (value);
+			    }
+
+				if (tmp != NULL) {
+					len = strlen (tmp);
+					size = 2 * len + 3;
+					txt = g_new (gchar, size);
+
+					len = csv_write2 (txt, size, tmp, len, quote);
+					txt [len] = 0;
+					if (!field_quotes) {
+						txt [len - 1] = 0;
+						memmove (txt, txt+1, len);
+					}
 				}
+				else
+					txt = g_strdup ("");
 			}
 			if (c > 0)
 				str = g_string_append_c (str, sep);