https://github.com/LeeLeahy2/SdCardServer README file

SD Card Server Library Copyright (C) 2022 Lee Leahy GNU GPL v3.0

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License v3.0 as published by the Free Software Foundation.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/gpl.html

The SD Card Server library provides routines to add a link to a web page that lists the files on the SD card. Each link on this page displays the file modify date, name and its size. Clicking on one of these links causes the file to be downloaded from the SD card to the computer running the browser.

The constructor initializes an SdCardServer object.

SdCardServer (sd, sdCardPresent, url, serverHeaderText);

sd: Address of an SdFat object associated with the SD card. *(SdFat )

sdCardPresent: Routine address to determine if the SD card is present and available for use.

url: Zero terminated string containing the URL relative to the local website. The URL needs to end in a trailing slash (/). This web page will list the files on the SD card. *(const char )

serverHeaderText: Zero terminated string containing the server name that is added as an optional html header. *(const char )

None.

mySdCardServer = SdCardServer (*sdFat, sdCardPresent, "/SD/");

Determine if the SD card is present and ready for use. This routine exists in the code calling the SdCardServer library.

SD_CARD_PRESENT();

None.

Zero (0) if the SD card is not present. Non-zero if the SD card is present.

sdCardPresent();

Create a website for the SD card. Call this routine if a website does not already exist. If a website already exists then use sdCardListingWebPageLink to add a link (HTML anchor) to an existing web page. If instead of the main web site the SD card listing page is desired then set the redirect value to true.

mySdCardServer.sdCardWebSite(server, redirect);

server: Address of an AsyncWebServer object *(AsyncWebServer ) redirect: Redirect the main web page to the SD card listing page if set true

None.

mySdCardServer.sdCardWebSite = sdCardWebSite (&asyncWebServer);

Add a link (HTML anchor) to an existing web page. The link points to the SD card listing web page.

mySdCardServer.sdCardListingWebPageLink(buffer, maxLen, linkText, options);

buffer: Address of a zero terminated string to be concatenated with the SD card listing link *(uint8_t )

maxLen: Maximum length of the next portion of the HTML response (int)

linkText: Text to display for the link *(const char )

options: Address of a zero terminated string containing the options, use NULL if no options specified *(const char )

None.

bytesAddedToBuffer = mySdCardServer.sdCardListingWebPageLink (buffer, maxlen, "SD Card Files", "target=\"_blank\"");

Display the SD card listing web page if the requested URL matches the URL passed to the SdCardServer constructor. Start the SD card file download if the requested URL starts with the URL passed to the sdCardServer constructor and the file is found on the SD card.

This routine is designed to be called from the server.onNotFound event routine.

mySdCardServer.isSdCardWebPage(request);

request: Address of the AsyncWebServerRequest object *(AsyncWebServerRequest )

Zero (0) if the requested URL does not match the URL passed to the SdCardServer constructor. Non-zero if the URL matches and the page is displayed.

if (mySdCardServer.isSdCardWebPage(request))
    return;
...
// URL not found
request->send(404);

Add the request not found event. This event handles the SD card requests for listing and file download.

Call this routine if and only if the AsyncWebServer.onNotFound event handler is not delared by the code calling SdCardServer. The call is made after the the AsyncWebServer is initialized.

mySdCardServer.onNotFound(server);

server: Address of an AsyncWebServer object *(AsyncWebServer )

None.

mySdCardServer.onNotFound(server);