tSSIHandler

Function pointer for the SSI tag handler callback. This function will be called each time the HTTPD server detects a tag of the form in files with extensions mentioned in the g_pcSSIExtensions array (currently .shtml, .shtm, .ssi, .xml, .json) where "name" appears as one of the tags supplied to http_set_ssi_handler in the tags array. The returned insert string, which will be appended after the the string "" in file sent back to the client, should be written to pointer pcInsert. iInsertLen contains the size of the buffer pointed to by pcInsert. The iIndex parameter provides the zero-based index of the tag as found in the tags array and identifies the tag that is to be processed. The handler returns the number of characters written to pcInsert excluding any terminating NULL or HTTPD_SSI_TAG_UNKNOWN when tag is not recognized. Note that the behavior of this SSI mechanism is somewhat different from the "normal" SSI processing as found in, for example, the Apache web server. In this case, the inserted text is appended following the SSI tag rather than replacing the tag entirely. This allows for an implementation that does not require significant additional buffering of output data yet which will still offer usable SSI functionality. One downside to this approach is when attempting to use SSI within JavaScript. The SSI tag is structured to resemble an HTML comment but this syntax does not constitute a comment within JavaScript and, hence, leaving the tag in place will result in problems in these cases. In order to avoid these problems, define LWIP_HTTPD_SSI_INCLUDE_TAG as zero in your lwip options file, or use JavaScript style block comments in the form / * # name * / (without the spaces).