imag/doc/src/02010-linking.md

## Linking from an store entry {#sec:thestore:linking}

In @sec:thestore:fileformat:header:imag it was already defined that there MUST
BE a section "imag" in the header. This section can be used to link to
"internal" and "external" content, whereas "internal content" refers to entries
which are stored in the very same store as the entry which links.
The term "external content" means content which is not stored in the
store, but elsewhere on the filesystem or the network (thus, an URL is valid
external content).

Entries can be referenced from the content part. For example, if the content
part is written in Markdown, the user is able to link content within the
Markdown text.
These links could be either links to internal content or external content.

### Linking to internal content {#sec:thestore:linking:internal}

Links to internal content are stored in the Array "imag.links = []".
Each entry in this array MUST BE a String which is an absolute path to a store
entry (@sec:thestore:links).

As links from within the content part of a module is not cross-compatible over
modules, each module SHOULD store the links which are in the content
part also in the "imag.links" Array. This way, other modules can read the links
without having knowledge about how to parse the content part of an entry.

### Linking to external content {#sec:thestore:linking:external}

Each Entry can store _one link to external content at most_.

This link is stored in the header field "imag.content.uri"
(@sec:thestore:fileformat:header:imag).
A key "imag.content.file" COULD be used for a local mirror of the content which
is referenced by "imag.content.uri".