Updating MPP File

I know you can't create an MPP file, but can you save to an existing one?

Microsoft project can’t write to MPX anymore (since Project 98) but you guys don’t seem to properly support MPP file write. This is ridiculous, how are we suppose to do an intelligent system if we can read MPP but can’t Update it?

Look at how ridiculous this is:

1 - We generate an MPX file
2 - To work with it Our customer then have to save it to MPP since project will not save to MPX
3 - our software need to add to the file so
3.1 - we Read the MPP
3.2 - but have to write back to an MPX because you can’t write to MPP
4- our customer need to reconvert it back to MPP.

Does this make any sense to you guys in the real world??

Dear desjardinsy,

What you think about projects in XML format? MS Project can read and write it. Project saved in XML doesn’t have lacks of MPX format. Can it be a solution for you?

well anything would be better than this.

What I find difficult to understand is that you seem to have no problem reading MPP files, which means you already have the file format properly mapped in your software, what is so difficult in writting back to it? Is that a licensing issue?

Dear desjardinsy,

I’ll try to explain.
MPP file is a set of properties. Properties which used for describing calendars, tasks, resources are documented and can be read and written back to the MPP file. But it’s a tiny part of whole MPP file.
It’s not possible to read part of any MS Office files, change it and write back without rewriting whole file (MS Office programs rewrite whole files too so it’s not only our problem).
As a result if I read all known (documented) properties and create new MPP file with it then MS Project will never read such file.