Shared dependency – real example

Example of oik-lib shared dependency showing shared libraries loaded for oik-bwtrace admin pages a3 [ style=dotted ]; c3->b3 [ style=dotted ]; 3->1 [dir=back ]; 3->2 [dir=back]; 3 -> c3; 3 -> f; f -> e [ style=dotted]; a1 [ label=”oik_boot” style=dashed ]; b [label=”bwtrace” style=dashed ]; d [label=”bobbfunc”]; e [label=”bobbforms”]; f [ label=”oik-admin” ]; a2 [ style=dashed label=”oik_boot”]; b2 [style=dashed label=”bwtrace”]; d2 [style=dashed label=”bobbfunc” ]; e2 [ style=dashed label=”bobbforms” ]; f2 [ style=dashed label=”oik-admin” ]; 1 -> a1 [dir=none style=invis]; 1 -> b [style=invis]; e -> d [ style=dotted]; 1 -> f [ style=invis]; 2 -> a2 [dir=none style=invis]; 2 -> b2 [style=invis]; e2 -> d2 [ style=invis]; 2 -> f2 [ style=invis]; f2 -> e2 [ style=invis]; subgraph cluster_3 { style=filled color=gray95; 3; a3; b3; c3; } subgraph cluster_1 { style=filled; color=lightgrey; 1; a1; b; d; e; f; rankdir=”TB”;} subgraph cluster_2 { 2; a2; b2; d2; e2; f2; rankdir=”TB”; color=gray97; style=filled;} [/bw_graphviz] –>

Scenario

• oik-lib is running as a Must-Use (MU) plugin
• oik and oik-bwtrace are both activated
• oik-bwtrace is not operating in Must-Use (MU) mode
• the bwtrace library is not loaded by wp-config.php
• Admin user visits Settings > oik trace options

Shared library loading

• oik-lib MU plugin loads the oik-lib library and invokes oik_lib_boot()
• oik_lib_boot() loads “oik_boot” and “bwtrace” libraries
• When the plugins are loaded each of them registers their filter function responding to oik_query_libs filter to indicate which libraries they offer. The priorities are such that oik trumps oik-lib and oik-bwtrace; ie. oik’s libraries are listed first
• When oik-bwtrace requires the oik-admin library, this is therefore served from the oik plugin

If the oik plugin was not activated then the library files would be served from oik-bwtrace.