From dbc5e0d190ecfb3b047e133294b8d1e6ef451c46 Mon Sep 17 00:00:00 2001 From: "Chris St. Pierre" Date: Tue, 19 Jun 2012 14:17:52 -0400 Subject: added automatch to automatically invoke XMLMatch() on Properties files --- doc/server/plugins/connectors/properties.txt | 110 ++++++++++++++++++++++----- 1 file changed, 89 insertions(+), 21 deletions(-) (limited to 'doc') diff --git a/doc/server/plugins/connectors/properties.txt b/doc/server/plugins/connectors/properties.txt index ca0e9cf63..123959093 100644 --- a/doc/server/plugins/connectors/properties.txt +++ b/doc/server/plugins/connectors/properties.txt @@ -39,37 +39,37 @@ XML tag should be ````. Usage ===== -Specific property files can be referred to in -templates as ``metadata.Properties[]``. The -``xdata`` attribute is an LXML element object. (Documented -`here `_) +Specific property files can be referred to in templates as +``metadata.Properties[]``. The ``xdata`` attribute is an +lxml.etree._Element object. (Documented `here +`_) -Currently, only one access method is defined for this data, ``Match``. -``Match`` parses the Group and Client tags in the file and returns a -list of elements that apply to the client described by a set of -metadata. (See :ref:`server-plugins-structures-bundler-index` for -more details on how Group and Client tags are parsed.) For instance:: +In addition to the ``xdata`` attribute that can be used to access the +raw data, the following access methods are defined: + +* ``Match()`` parses the Group and Client tags in the file and returns + a list of elements that apply to the client described by a set of + metadata. For instance:: {% python ntp_servers = [el.text - for el in metadata.Properties['ntp.xml'].Match(metadata): + for el in metadata.Properties['ntp.xml'].Match(metadata) if el.tag == "Server"] %} -If you need to make persistent changes to properties data, you can use -the ``write`` method of the ``PropertyFile`` class:: +* ``XMLMatch()`` parses the Group and Client tags in the file and + returns an XML document containing only the data that applies to the + client described by a set of metadata. (The Group and Client tags + themselves are also removed, leaving only the tags and data + contained in them.) For instance:: {% python - import lxml.etree - from genshi.template import TemplateError - lxml.etree.SubElement(metadata.Properties['foo.xml'], - "Client", - name=metadata.hostname) - if not metadata.Properties['foo.xml'].write(): - raise TemplateError("Failed to write changes back to foo.xml") + ntp_servers = [el.text + for el in metadata.Properties['ntp.xml'].XMLMatch(metadata).findall("//Server")] + %} -The ``write`` method checks the data in the object against its schema -before writing it; see `Data Structures`_ for details. +See :ref:`server-plugins-structures-bundler-index` for more details on +how Group and Client tags are parsed. As we formulate more common use cases, we will add them to the ``PropertyFile`` class as methods. This will simplify templates. @@ -86,6 +86,58 @@ directly in one of several ways: top-level element. (I.e., everything directly under the ```` tag.) +.. _server-plugins-connectors-properties-automatch: + +Automatch +========= + +You can enable ``XMLMatch()`` for all Property files by setting +``automatch`` to ``true`` in the ``[properties]`` section of +``bcfg2.conf``. This makes ``metadata.Properties`` values +lxml.etree._Element objects that contain only matching data. (This +makes it impossible to do +:ref:`server-plugins-connectors-properties-write-back` as a +side-effect.) + +In Python terms, setting ``automatch=true`` is the same as doing the +following at the top of each template:: + + {% python + for prop in metadata.Properties.values(): + prop = prop.XMLMatch(metadata) + %} + +The example above that describes ``XMLMatch()`` would then become +simply:: + + {% python + ntp_servers = [el.text + for el in metadata.Properties['ntp.xml'].findall("//Server")] + %} + +You can also enable automatch for individual Property files by setting +the attribute ``automatch="true"`` in the top-level ```` tag. + +.. _server-plugins-connectors-properties-write-back: + +Properties Write-Back +===================== + +If you need to make persistent changes to properties data, you can use +the ``write`` method of the ``PropertyFile`` class:: + + {% python + import lxml.etree + from genshi.template import TemplateError + lxml.etree.SubElement(metadata.Properties['foo.xml'], + "Client", + name=metadata.hostname) + if not metadata.Properties['foo.xml'].write(): + raise TemplateError("Failed to write changes back to foo.xml") + +The ``write`` method checks the data in the object against its schema +before writing it; see `Data Structures`_ for details. + .. _server-plugins-connectors-properties-encrypted: Encrypted Properties data @@ -161,3 +213,19 @@ Accessing Properties contents from TGenshi Access contents of ``Properties/auth.xml``:: ${metadata.Properties['auth.xml'].xdata.find('file').find('bcfg2.key').text} + +Configuration +============= + +``bcfg2.conf`` contains several miscellaneous configuration options for the +Properties plugin. Any booleans in the config file accept the values +"1", "yes", "true", and "on" for True, and "0", "no", "false", and +"off" for False. + +It understands the following directives: + +[properties] section +-------------------- + +* ``automatch``: Enable + :ref:`server-plugins-connectors-properties-automatch` -- cgit v1.2.3-1-g7c22