[FELIX-2815] Difference between "instance" and "provides"

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Component/s: iPOJO
• Labels: documentation felix, ipojo
• Assignee: Clement Escoffier
• Reporter: Andriyko
• Created: 01/Feb/11 04:14
• Updated: 04/Feb/13 12:34
• Resolved: 13/Mar/11 18:07

Description

In the documentation on iPOJO Services:
http://felix.apache.org/site/providing-osgi-services.html#ProvidingOSGiservices-Instancereconfiguration

There is no clear explanation of what is the difference between <provides> and <instance>.
It is not clear why "instance" is needed at all.

Under the "Service Properties" heading on the page, the two are used interchangeably in the examples.

For example, first "property" is configured with <provides>:

<component classname="...FooProviderType1">
<provides>
<property name="foo" field="m_foo" value="Foo"/>
<property name="static" type="java.lang.String" value="this is a static property"/>
</provides>
</component>

and then immediately, with no explanation what-so-ever and <intsance> is used, with a tiny explanation that "The value can be given in the instance configuration":

<instance component="...FooProviderType1">
<property name="foo" value="My New Foo Value"/>
<property name="static" value="My Value For Static"/>
</instance>