To follow on from Bruce’s section on Therion header overrides in his Map Definitions thread it seems a good idea to split overrides off into a separate topic..

Survey and map definitions also give you control over the title that appears on the drawing.

It can be complicated, but I once figured it out, and made this bit of code to put in layouts used for plan outputs.  I prefer to allow Therion to decide the output title based on the information I have entered in surveys, maps and selections, but sometimes an override is required.  Note that Therion assumes a survey or map title is the same as its id, unless you specify -title “name” to override the id.  My preference is to always give surveys or maps likely to be a primary selection for output a title that I would like to see on a finished pdf output (and use a concise id).

The code, as below, only has effect if due to the users choices, Therion cannot deduce a unique name for the output.

   #PLAN Cave Map Details

  #--------------------

  # Define Map title overrides   

    code tex-map

   % Output map title as determined by Therion 5.3 is stored in cavename.

   % It will be empty if there are multiple maps selected for any one projection

   % AND there are multiple source surveys identified in the thconfig file

   % ie Therion can not infer a unique title from the input data given.

   % This code allows you to define an output map title {cavename} if it happens to be empty

  \edef\temp{\the\cavename}        % cavename from Therion  

  \edef\nostring{}                 % empty string

  \ifx\temp\nostring             % test if cavename is empty

        % if empty reassign cavename to describe selected maps as a group

                                \cavename={Project Area Caves}

  \else % if not empty keep the value set by therion, or assign an override cavename here

  \fi

endcode 

I have been using this in my layouts to give me multiple lines on my map titles with the added ability to adjust the font size.  Size[30 or whatever size you need]

medskip can be changed to bigskip or smallskip to alter the spacing between the lines of text.

###############THERION OVERIDES##############

##Override Therion Map Header Data###

#------------------------------------------------------

code tex-map

\cavename={\size[20] Tom Taylors Cave\medskip \size[30] How Stean Gorge\medskip \size[30]North Yorkshire}

endcode

The override below is to change the Therion default team, cave length, cave depth data on the map output. Used in this case because a short surface survey needed to be shown on the map but the data was skewing the actual cave length and depth.

##Override cave length and depth to remove surface leg data##

#------------------------------------------------------------------------------------

code tex-map

    \topoteam{BSD}

    \cavelength{164m}

   \cavedepth{12m}

#endcode

Both these overrides I borrowed from one of Andrews configs in the BCA data archive which I find a great resource. No point reinventing the wheel, even if I could.

Nick