How can I import non-unicode text file by Feeds module? My drupal version is : 7.5x

I want to import an csv or txt file that have non-unicode (iransystem) encoding.

After import this file to Drupal (persian character with iransystem encoding) my characters show correctly in my site. So these texts are imported successfully. But when I want to filter results of those fields by Views (exposed filter), I can not see any result by filtering views fields (search in fields by views exposed filter).

I want to import non-utf8 or unicode persian text files into Drupal and filter those fields by Views exposed filter (search on non-unicode characters).

For example I imported A Persian or arabian word into a field of Drupal. This passage shows correctly to me, but when I search type this passage in exposed A Persian or arabian word text in Drupal page and paste on search field of Drupal Views, I can see results correctly.
I can only provide high-level guidance here, but you need to use the Feeds Tamper module, which allows you to alter data between when it is read from the source, and then passed to Feeds.

However, I don't think there is an existing tamper plugin that can handle your situation; you will have to create your own.

There are two patches in the issue queue that may provide guidance:


https://www.drupal.org/node/1817516
https://www.drupal.org/node/2263119 (disclosure, I wrote this one)


You can take one of those two patches, and update them to use your character set instead of the ones in the patch.

For example, in this patch, you would need to update

+function feeds_tamper_utf8_encode_callback($result, $item_key, $element_key, &amp;$field, $settings, $source) {
+  $field = drupal_convert_to_utf8($field, 'ISO-8859-1');
+}


to use your encoding name instead of 'ISO-8859-1'.