For my country the following applies:
* Must have residency permit, permanent or temporary with intent to be permanent
* Must pass residency exam (tests language, law, etc.)
* Must be living in country for 8 years minimum
* Must have independent source of income that isn't social welfare or unemployment benefits
* Sufficient knowledge of local language
* Must not have been convicted of a crime
* Must pledge to the democratic order laid out by the constitution
* Annulling or otherwise revoking your previous citizenship