...
When
...
processing
...
the
...
configuration
...
file
...
, Weave provides a couple of processing instructions that may help to make your life a little easier. They are include and set. These instructions provide a means to alter the configuration items before they are processed.
include
When the include processing instruction is used, the contents of the file specified are read and inserted into the configuration tree at the location where the include tag was specified.
| Code Block | ||||||
|---|---|---|---|---|---|---|
| ||||||
<?xml version="1.0" encoding="UTF-8"?>
<config xmlns="urn:com.cohga.server.config#1.0"...
<?include client_main.xml?>
</config>
{code}
the {{ |
the client_main.xml
...
file
...
could
...
contain
...
| Code Block | ||||||
|---|---|---|---|---|---|---|
| ||||||
<?xml version="1.0" encoding="UTF-8"?>
<config xmlns="urn:com.cohga.server.config#1.0" xmlns:client="urn:com.cohga.html.client#1.0">
<client:config id="main">
<default>true</default>
<debug>false</debug>
<theme>grey</theme>
...
</client:config>
</config>
{code}
|
One
...
other
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thing
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to
...
note
...
about
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that
...
last
...
example
...
is
...
that
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the
...
included
...
client_main.xml
...
file
...
uses
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two
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config
...
tags,
...
but
...
these
...
are
...
different
...
tags
...
because
...
they
...
have
...
different
...
namespaces.
...
The
...
include
...
processing
...
instruction
...
can
...
be
...
particularly
...
useful
...
when
...
moving
...
a
...
development
...
configuration
...
to
...
a
...
production
...
server.
...
The
...
development
...
and
...
production
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servers
...
can
...
have
...
a
...
different
...
version
...
of
...
the
...
included
...
file(s)
...
but
...
with
...
the
...
main
...
configuration
...
file
...
remaining
...
the
...
same
...
between
...
the
...
two
...
systems.
...
It
...
could
...
also
...
be
...
used
...
when
...
repeated
...
elements
...
are
...
required.
...
For
...
example,
...
definitions
...
of
...
connection
...
pools,
...
and
...
the
...
same
...
file
...
used
...
with
...
multiple
...
include
...
instructions.
...
The
...
name
...
of
...
the
...
include
...
file
...
can
...
be
...
just
...
the
...
file
...
name
...
in
...
which
...
case
...
the
...
file
...
is
...
searched
...
for
...
in
...
the
...
same
...
directory
...
as
...
the
...
config.xml
...
file
...
However
...
it
...
could
...
also
...
be
...
a
...
fully
...
qualified
...
file
...
name
...
which
...
specifies
...
an
...
exact
...
location
...
for
...
the
...
file
...
or
...
it
...
can
...
also
...
reference
...
a
...
URL,
...
allowing
...
for
...
the
...
contents
...
to
...
be
...
fetched
...
from
...
another
...
server.
...
If
...
the
...
include
...
reference
...
points
...
to
...
a
...
file
...
then
...
the
...
system
...
will
...
also
...
monitor
...
the
...
included
...
files
...
for
...
changes.
...
set
The set instruction can supplement the include instruction by providing support for variable substitution within the configuration file.
A variation on the previous example can be used when only the hostname needs to change between the development and production servers, so this time config.xml could contain
| Code Block | ||||||
|---|---|---|---|---|---|---|
| ||||||
<?xml version="1.0" encoding="UTF-8"?>
<config xmlns="urn:com.cohga.server.config#1.0"...
<jdbc:dataSource id="datasource.main">
<driver>oracle.jdbc.driver.OracleDriver</driver>
<url><![CDATA[jdbc:oracle:thin:@${HOSTNAME}:1521:GIS]]></url>
<username>reader</username>
<password>0hn0w3rdun</password>
<pool:pool>
<maxActive>15</maxActive>
<minIdle>2</minIdle>
<maxIdle>2</maxIdle>
<testOnBorrow>true</testOnBorrow>
<timeBetweenEvictionRunsMillis>60000</timeBetweenEvictionRunsMillis>
<minEvictableIdleTimeMillis>1200000</minEvictableIdleTimeMillis>
<whenExhaustedAction>grow</whenExhaustedAction>
</pool:pool>
</jdbc:dataSource>
</config>
{code}
|
Then
...
the
...
datasource.xml
...
file
...
on
...
the
...
development
...
server
...
could
...
contain
...
| Code Block | ||||||
|---|---|---|---|---|---|---|
| ||||||
<?set HOSTNAME=development.example.com?>
{code}
|
and
...
the
...
datasource.xml
...
file
...
on
...
the
...
production
...
server
...
could
...
contain
...
| Code Block | ||||||
|---|---|---|---|---|---|---|
| ||||||
<?set HOSTNAME=production.example.com?>
{code}
The {{ |
The ${HOSTNAME
...
}
...
portion
...
of
...
config.xml
...
would
...
be
...
replaced
...
with
...
the
...
appropriate
...
hostname.
...
Also,
...
note
...
that
...
the
...
value
...
substituted
...
is
...
taken
...
verbatim
...
as
...
everything
...
following
...
the
...
=
...
up
...
to
...
the
...
?>
...
,
...
which
...
includes
...
white
...
space
...
and
...
case
...
is
...
important.
...
Of
...
course
...
set
...
can
...
also
...
be
...
used
...
to
...
locate
...
commonly
...
referenced
...
items
...
in
...
a
...
single
...
location
...
at
...
the
...
start
...
of
...
the
...
config.xml
...
file
...
to
...
allow
...
them
...
to
...
be
...
easily
...
changed
...
later.
...
For
...
example
...
passwords
...
that
...
are
...
updated
...
every
...
month
...
or
...
defaults
...
for
...
functions
...
such
...
as
...
connection
...
timeouts.
...
Externally defined values
In addition to the set processing instruction, the value for a substitution variable can also come from system properties or from a property as defined during the startup of the Java Virtual Machine (JVM option). ${property_name} notation can then be used to substitute the values in place.