====== File Upload ========

The question type "File Upload" allows participants to upload a file to the survey server during the interview.

**Important:** The amount of memory per survey project is limited. Depending on their content and file type, uploaded images require a lot of storage space.

**Important:** If participants upload large files (>500 KB), it may take a while after clicking "Next" until the file is transferred and the next page is loaded.


===== Download Files =====

The uploaded files can be downloaded under **Collected Data** -> **Uploaded Files**. Either individually or bundled by question. The file name contains the number (CASE) of the data set in each case.

===== Show Image =====

If the uploaded file is an image, you can use it in the current interview. The filename prefix ''%%upload://%%'' allows access to the uploaded files.

For the display, you still need the file name that SoSci Survey assigned when uploading the file. You can retrieve this from the dataset using ''[[:en:create:functions:value]]''. Together with the necessary HTML code, the display could then look like this. In the example, the question for "Upload file" has the identifier UP01.

<code php>
html('
    <div>
        <img src="upload://'.value('UP01x02').'" style="max-width: 100%">
    </div>
');
</code>

**Note:** If participants upload large files, this can also lead to long loading times when the files are later integrated.