I'd like to make a custom lasered label from a user's input on a website. I have a template dxf file and I'd like to replace placeholder text with the user input. My problem is the dxf file format is very unreadable in its text format. Is there any way to make sense of the numeric data? If not are there any other formats (svg, etc) that would be easier to work with?
EDIT: The reason I've found it unreadable in terms of text is that the program (Solidworks) converted the text to curves.) At this point I'm trying to figure out how to prevent that.
AutoDesk was nice enough to document DXF syntax in great detail. Spend a couple hours understanding the documentation from the link below, and I think you will find it quite easy to parse and edit using code.
To just replace some placeholder text, it should be just as simple as reading the DXF file into a string (a dxf file is no different than a txt file), performing a text replace operation and saving it back to file. Just make sure that your placeholder text is very unique and is not contained in any of the key words in the document below (otherwise your DXF file will get corrupted). Something like "PlaceHolderText" will do the trick.
http://images.autodesk.com/adsk/files/autocad_2012_pdf_dxf-reference_enu.pdf
Edit: More Info
I do a lot of work with AutoDesk Inventor which is in direct competition with SolidWorks, so they are effectively the same tool. We were faced with a similar problem of needing to place text onto sheet metal flat pattern DXFs that came out of Inventor in order to identify the part, but Inventor simply could not do it (see, exactly the same!). One of our developers had the idea to place a very precise geometry punch onto the flat pattern. After the DXF was generated he wrote some code that parsed the DXF file and replaced the geometry with a text entity. More specifically we used a triangle with sides having each length defined to something like the 7th decimal place. You can then use one of the vertices of the triangle to position the text, including rotation. This process would be automatic, so once you write the code with the help of the document above (which won't take the long), it will just work. If your engraver can handle text the way you want it, I'd say this is a very good solution. We generate hundreds of parts every day using this code. Hope this helps.