Adding a File Field to my System.xml - File Not Uploading

Question

Here's my system.xml field definition:

<fields>
    <upload translate="label">
        <label>Upload Latest</label>
        <comment><![CDATA[This file gives you a more up-to-date BIN database. Please upload one regularly to stay ahead.]]></comment>
        <frontend_type>file</frontend_type>
        <backend_model>adminhtml/system_config_backend_file</backend_model>
        <upload_dir>var/uploads</upload_dir>
        <sort_order>50</sort_order>
        <show_in_default>1</show_in_default>
        <show_in_website>0</show_in_website>
        <show_in_store>0</show_in_store>
    </upload>
</fields>

The field shows successfully, but for some reason, when I browse for a file and click Save Config, it just redirects me to the Dashboard, there's no communication with any models, it literally just loads the dashboard.

How can I debug this issue successfully?

Update
After some additional digging, it appears to accept some files.

The particular file I'm looking to upload is a CSV that is 11.9 Mb. I've tried a small Jpg and it uploads successfully.

Could be to do with Filesize or File Type. How do I specifically enable CSV and increase the File Size limit to 20Mb?

Answer 1

It would be very good to tell magento to allow upload only files with csv type.

In your extension create

class Namespace_Module_Model_System_Config_Backend_Csv extends Mage_Adminhtml_Model_System_Config_Backend_File
{
    protected function _getAllowedExtensions()
    {
        return array('csv');
    }
}

Now in system.xml

<backend_model>namespace_module/system_config_backend_csv</backend_model>

And of course in php.ini increase post_max_size value.

post_max_size = 20M

Answer 2

This is not a problem in magento.

Need to set in your configuration file.

In php.ini set

post_max_size = 20M