+enum { MAX_PREVIEW_LINES = 1000 }; /* Max number of lines to read. */
+
+
+/*
+ Update IA according to the contents of DICT and CREADER.
+ CREADER will be destroyed by this function.
+*/
+void
+update_assistant (struct import_assistant *ia)
+{
+ struct sheet_spec_page *ssp = &ia->sheet_spec;
+
+ struct file *file = &ia->file;
+ struct separators_page *sepp = &ia->separators;
+ int col;
+ int rows = 0;
+ struct ccase *c;
+
+ sepp->column_cnt = dict_get_var_cnt (ssp->dict);
+ sepp->columns = xcalloc (sepp->column_cnt, sizeof (*sepp->columns));
+ for (col = 0; col < sepp->column_cnt ; ++col)
+ {
+ const struct variable *var = dict_get_var (ssp->dict, col);
+ sepp->columns[col].name = xstrdup (var_get_name (var));
+ sepp->columns[col].contents = NULL;
+ }
+
+ for (; (c = casereader_read (ssp->reader)) != NULL; case_unref (c))
+ {
+ rows++;
+ for (col = 0; col < sepp->column_cnt ; ++col)
+ {
+ char *ss;
+ const struct variable *var = dict_get_var (ssp->dict, col);
+
+ sepp->columns[col].contents = xrealloc (sepp->columns[col].contents,
+ sizeof (struct substring) * rows);
+
+ ss = data_out (case_data (c, var), dict_get_encoding (ssp->dict),
+ var_get_print_format (var));
+
+ sepp->columns[col].contents[rows - 1] = ss_cstr (ss);
+ }
+
+ if (rows > MAX_PREVIEW_LINES)
+ {
+ case_unref (c);
+ break;
+ }
+ }
+
+ file->line_cnt = rows;
+ casereader_destroy (ssp->reader);
+ ssp->reader = NULL;
+}
+