Multiple dependent modules under same package - Magento -

i developing magento extension(s) lot of confusions. magento extension(me) in respect should a)export orders, b)import products, c)update shipping etc. common of them have common 'jobs' table used track of sub-modules mentioned above.

that means me has have model, sql, helper etc communicate 'jobs' table. note a) b) , c) may optionally installed users. confused should done develop a, b , c-

therefore, build a), b) , c) separately within same package (i.e. namespace me)? if yes, how many admin modules should have? 1 in common? can use common class?

any suggestion appreciated.

if build 4 moudles:

1. export orders
2. import products
3. update shipping
4. custom data access

depends

you can force user install custom data access module adding following in module 1,2 , 3 module xml files under app/modules/etc remember change "custom_data" ever use module 4

<depends>     <custom_data /> </depends> 

helper

you can deal interactions either extending core module files in other extensions or common data need through helper. can define helper in module's config.xml in section.

<helpers>     <custom_data>         <class>custom_data_helper</class>     </custom_data> </helpers> 

packaging release

you can define dependency when packaging extension release. dependency when user goes install main package instructed install dependency.