libervia-backend: doc/jp/pubsub.rst comparison

comparison doc/jp/pubsub.rst @ 3041:72583524cfd3

doc (jp): jp commands are now fully documented: rel 232

author	Goffi <goffi@goffi.org>
date	Tue, 01 Oct 2019 22:49:06 +0200
parents
children	cea52c9ddfd9

comparison

equal deleted inserted replaced

-:fee60f17ebac
+:72583524cfd3
+.. _jp-pubsub:
+=========================
+pubsub: PubSub management
+=========================
+PubSub commands are low level command to handle a PubSub Service.
+They are using the generic pubsub arguments
+For most of those commands, :ref:`pubsub_common` commands are used to specify the
+destination item.
+set
+===
+Publish a pubsub item.
+``stdin`` is used to get the raw XML of the payload of the item to publish.
+example
+-------
+Create an item with a custom note XML::
+$ echo '<note xmlns="http://example.net/mynotes">this is a note</note>' | jp pubsub set -n "notes"
+get
+===
+Retrieve items from specified node. Default output is prettified and highlighted XML.
+example
+-------
+Retrieve the last 5 notes from our custom notes node::
+$ jp pubsub get -n notes -m 5
+delete
+======
+Delete an item from a node. If ``-N, --notify`` is specified, subscribers will be notified
+of the item retraction.
+By default a confirmation is requested before deletion is requested to the PubSub service,
+but you can override this behaviour by using ``-f, --force`` option.
+example
+-------
+Delete item with id ``123456`` from a node::
+$ jp pubsub delete -n test_node -i 123456
+edit
+====
+Edit the raw XML of an item payload using your local editor (the one set in ``$EDITOR``).
+If you don't change anything or publish an empty blog post, the edition will be cancelled.
+:ref:`draft_common` commands can be used.
+example
+-------
+Edit the last note in our custom node::
+$ jp pubsub edit -n notes -L
+subscribe
+=========
+Subscribe to a node.
+Subscription is used to get notifications from the node in case of new/updated item or
+deletion.
+example
+-------
+Subscribe to an information blog::
+$ jp pubsub subscribe -n informations -s pubsub.example.net
+unsubscribe
+===========
+Unsubscribe from a node.
+example
+-------
+Unsubscribe from an information blog::
+$ jp pubsub unsubscribe -n informations -s pubsub.example.net
+subscriptions
+=============
+Retrieve subscriptions for all nodes on a service.
+``-n NODE, --node NODE`` can be used to request subscriptions for a specific node (e.g. if
+it has subscription with multiple subIDs).
+example
+-------
+Retrieve all subscriptions on a pubsub service::
+$ jp pubsub subscriptions -s pubsub@example.net
+affiliations
+=============
+Retrieve affiliations for all nodes at a service.
+``-n NODE, --node NODE`` can be used to request affiliation for a specific node.
+examples
+--------
+Retrieve all affiliations at a pubsub service::
+$ jp pubsub affiliations -s pubsub@example.net
+Retrieve affiliation for the ``notes`` node::
+$ jp pubsub affiliations -s pubsub@example.net -n notes
+search
+======
+Search items corresponding to one or more filter(s).
+``search`` will check all items (or some of them according to options used) from one or
+several nodes (several nodes can be checked if recursion is used, see below). For each
+item the given filters will be checked, and all corresponding items will be returned.
+This is a resource intensive method (both for server and client), use with caution, and
+use MAM to do searching when suitable.
+filters
+-------
+To do a search you one or more filters. Filters are checked in the order in which they are
+specified. You can use 4 kinds of filters:
+``-t TEXT, --text TEXT``
+do a full-text search. If *TEXT* is appearing anywhere in the item (including in XML
+tags or arguments), the item is selected
+``-r EXPRESSION, --regex EXPRESSION``
+do a regular expression search. `Python standard re module`_ is used internally, so you
+can use its syntax.
+``-x XPATH, --xpath XPATH``
+use an `XPath version 1.0`_ expression to filter the query. You can have a look at
+`Wikipedia XPath page`_ for a user friendly introduction.
+``-P PYTHON_CODE, --python PYTHON_CODE``
+use a Python expression to do a test. The expression must return a boolean (``True`` to
+keep item, ``False`` otherwise). From within the Python expression 3 variables are
+defined: ``item`` which contain the raw item as a string, and ``item_xml`` which is the
+parsed XML as an lxml ``etree.Element`` and ``etree`` which is the ``lxml.etree`` module.
+.. _Python standard re module: https://docs.python.org/3.7/library/re.html
+.. _XPath version 1.0: https://www.w3.org/TR/1999/REC-xpath-19991116/
+.. _Wikipedia XPath page: https://en.wikipedia.org/wiki/XPath
+filter modifiers
+----------------
+Before each filter you can specify one or more filter modifiers. A modifier will change
+filter behaviour, it's a flag which can be used either without argument (then it will
+activate the flag), or with an explicit boolean value (i.e. ``true`` or ``false``).
+The available filters are:
+``-C [BOOLEAN], --ignore-case [BOOLEAN]``
+(don't) ignore case. Filters are normally case sensitive, this modifier change this
+behaviour.
+``-I [BOOLEAN], --invert [BOOLEAN]``
+(don't) invert effect of following filters. This is applying a logical ``NOT`` to the
+filter. This means that instead of keeping item matching the filter, it will keep the
+items which are **not** matching the filter.
+``-A [BOOLEAN], --dot-all [BOOLEAN]``
+(don't) use `DOTALL`_ option for regex. This filter only makes sense before a
+``--regex`` expression.
+``-k [BOOLEAN], --only-matching [BOOLEAN]``
+(don't) keep only the matching part of the item. Normally the whole item is returned,
+with this flag, only the part matching the filters are kept.
+.. _DOTALL: https://docs.python.org/3.7/library/re.html#re.DOTALL
+actions
+-------
+Once filters are set, you may indicate what do to with the found items. By default they
+are printed, but you can also use an other jp command, or even an external tool.
+The following actions are available:
+``print`` (default)
+pretty print the found items.
+``exec``
+use the given jp command on each found item. Everything after the ``exec`` is used to
+indicate the command and arguments to use (you must not specify ``jp``, use the command
+directly). The service, node and item will be set to match the found item.
+``external``
+pipe the raw XML of each item to the given command. Everything after the ``external``
+action is used to indicate the command and arguments to use.
+recursive search
+----------------
+By default, only items in the given node will be filtered, but if you specify a recursion
+depth > 0 (using ``-D MAX_DEPTH, --max-depth MAX_DEPTH``), every node linked in item will
+be checked too, then node linked in linked item and so on until depth level is reached.
+For instance, if you want to find all comments of a blog node containing an http(s) link,
+you can do that::
+$ jp pubsub search -n urn:xmpp:microblog:0 -s user@example.net -D 1 -r 'https?://'
+examples
+--------
+Finding all items containing the text "something interesting" in personal blog::
+$ jp pubsub search -n urn:xmpp:microblog:0 -M -1 -t "something interesting"
+Find which blog items in the last 20 have a body with less than 200 characters (note that
+body can be either ``<title>`` or ``<content>``, see `XEP-0277`_ for details). Here we use
+a python expression on the text of the body to count the number of characters::
+$ jp pubsub search -n urn:xmpp:microblog:0 -M 20 --python "len((item_xml.find('.//{http://www.w3.org/2005/Atom}content[@type=\"text\"]') or item_xml.find('.//{http://www.w3.org/2005/Atom}title[@type=\"text\"]')).text) < 200"
+Find items published by ``toto@example.net`` among last 30 on a blog node, and use
+``pubsub blog`` command to retrieve id and title. We use ``-N`` to specify the ``pubsub``
+namespace which is used in the XPath expression, then we use ``exec`` to run ``blog get -k
+title -k id`` on found items::
+$ jp pubsub search -n some_blog_node -s pubsub.example.net -M 30 -N pubsub http://jabber.org/protocol/pubsub -x '/pubsub:item[starts-with(@publisher, "toto@example.net")]' exec blog get -k title -k id
+Find items which have **NOT** a title among last 30 items in our personal blog. As
+explained in `XEP-0277`_ Atom's ``<title>`` is always used (even if there is only a body
+and no title), so we actually look for items without ``<content>``. We do that with an
+XPath looking for this ``atom:content`` element, then we use the ``-I [BOOLEAN], --invert
+[BOOLEAN]`` to filter out elements which match.::
+$ jp pubsub search -n urn:xmpp:microblog:0 -M 30 -I -x //atom:content -N atom http://www.w3.org/2005/Atom
+Display authors names from last 10 items and their comments, using the ``-k [BOOLEAN],
+--only-matching [BOOLEAN]`` modifier to only display the data we need. We use ``-D 1`` to
+do a recursive search of level 1, which will also look into comments nodes (using last 10
+items there too)::
+$ jp pubsub search -n urn:xmpp:microblog:0 -M 10 --only-matching -x //atom:author/atom:name -N atom http://www.w3.org/2005/Atom -D 1
+.. _XEP-0277: https://xmpp.org/extensions/xep-0277.html
+transform
+=========
+Modify items using an external command.
+``transform`` will retrieve requested items, and will send each of them to the standard
+input (stdin) of the specified command. The output of the command will be used, it can be
+3 things:
+- a raw XML of the modified item, in which case the item will be republished
+- the string ``SKIP``, in which case the item will be ignored
+- the string ``DELETE``, in which case the item will be retracted
+By default a dry run is done, which means that no item is modified or deleted. To actually
+do the transformation, you have to use ``--apply`` argument.
+If you have to modify the ``publisher`` of an item, you need specific privileges. The
+``--admin`` allows you do to that, but it must be supported by your PubSub service
+(currently only ``SàT PubSub`` supports this non standard feature).
+To modify all items of a node, use the ``-A, --all`` option. This will use `RSM`_
+repetitively until all items are treated. Of course that means that your PubSub service
+must support RSM. The items being republished, they will reappear on top of your node,
+that's why it is recommended to use ``--order-by creation`` option when supported by the
+service, to keep consistent order and avoid transforming the same items several times.
+If the command you're using exit with a non zero code, the process will stop. Use ``-I,
+--ignore_errors`` if you want to continue transformation even if an non zero code is
+returned.
+.. _RSM: https://xmpp.org/extensions/xep-0059.html
+example
+-------
+Imagine that you want to replace all occurrences of "sàt" by "Salut à Toi" in your personal blog. You first create a Python script like this:
+.. sourcecode:: python
+#!/usr/bin/env python3
+import sys
+item_raw = sys.stdin.read()
+if not "sàt" in item_raw:
+print("SKIP")
+else:
+print(item_raw.replace("sàt", "Salut à Toi"))
+And save it a some location, e.g. ``~/expand_sat.py`` (don't forget to make is executable
+with ``chmod +x ~/expand_sat.py``).
+To be sure it's safe, you can first do a dry-run and check the result::
+$ jp pubsub transform -n urn:xmpp:microblog:0 -A -o creation ~/expand_sat.py
+Once you have checked that you have the expected behaviour, you can apply the
+transformations::
+$ jp pubsub transform -n urn:xmpp:microblog:0 -A -o creation --apply ~/expand_sat.py
+And that's it. You can use the same technique for more complex transformations, including
+modifying the XML (with Python, you can easily do that with standard
+``xml.etree.ElementTree`` module or with ``lxml.etree``).
+uri
+===
+Build an XMPP URI linking to a PubSub node or item.
+example
+-------
+Build a link to personal blog::
+$ jp pubsub uri -n urn:xmpp:microblog:0
+node
+====
+Subcommands for node management. Please check :ref:`jp-pubsub_node`.
+hook
+====
+Subcommands for hooks management. Please check :ref:`jp-pubsub_hook`.

Mercurial > libervia-backend

comparison doc/jp/pubsub.rst @ 3041:72583524cfd3