XML parse driver

A WeeWX driver to read data from an XML file.

Description

The XML parse driver extension allows WeeWX to poll an XML format file for data. The driver maps data from XML elements and attributes to WeeWX loop packet fields and emits loop packets at a user configurable rate.

Pre-Requisites

The XML parse driver extension requires:

WeeWX v3.0.0 or greater

Installation

The XML parse driver extension can be installed manually or automatically using the wee_extension utility. The preferred method of installation is through the use of wee_extension.

Note: Symbolic names are used below to refer to some file location on the WeeWX system. These symbolic names allow a common name to be used to refer to a directory that may be different from system to system. The following symbolic names are used below:

$DOWNLOAD_ROOT. The path to the directory containing the downloaded XML parse driver extension.
$BIN_ROOT. The path to the directory where WeeWX executables are located. This directory varies depending on WeeWX installation method. Refer to where to find things in the WeeWX User's Guide for further information.

Installation using the wee_extension utility

Download the latest XML parse driver extension from the XML parse driver extension releases page into a directory accessible from the WeeWX machine.
```
$ wget -P $DOWNLOAD_ROOT https://github.com/gjr80/weewx-xmlparse/releases/download/v0.1.0/xmlparse-0.1.0.tar.gz
```
where $DOWNLOAD_ROOT is the path to the directory where the XML parse driver extension is to be downloaded.

Stop WeeWX:

$ sudo /etc/init.d/weewx stop

$ sudo service weewx stop

$ sudo systemctl stop weewx

Install the XML parse driver extension downloaded at step 1 using the wee_extension utility:

$ wee_extension --install=$DOWNLOAD_ROOT/xmlparse-0.1.0.tar.gz

This will result in output similar to the following:

Request to install '/var/tmp/xmlparse-0.1.0.tar.gz'
Extracting from tar archive /var/tmp/xmlparse-0.1.0.tar.gz
Saving installer file to /home/weewx/bin/user/installer/xmlparse
Saved configuration dictionary. Backup copy at /home/weewx/weewx.conf.20180828124410
Finished installing extension '/var/tmp/xmlparse-0.1.0.tar.gz'

Select the XML parse driver and do a basic driver configuration:

$ sudo /home/weewx/bin/wee_config --reconfigure

$ sudo /usr/share/weewx/wee_config --reconfigure

Edit weewx.conf and complete the required mappings in [XML] [[sensor_map]] section. Refer to Sensor maps in the XML parse driver wiki for details on how to enter sensor and unit maps. In additon, there are short form notes on the sensor and unit maps in the comments at the start of the xmlparse.py file.
Run WeeWX directly and confirm that loop packets and archive records are being generated and the data is appears valid:
```
$ sudo /home/weewx/bin/weewxd /home/weewx/weewx.conf
```
or
```
$ sudo /usr/share/weewx/weewxd /etc/weewx/weewx.conf
```
Note: The above commands include the appropriate paths for a default setup.py and package WeeWX installs accordingly. If you have modified the WeeWX install locations it may be necessary to prefix weewxd and weewx.conf with different paths.

You should now see something like below with a series of loop packets (indicated by LOOP: preceding each line) every poll_interval seconds and archive records (indicated by REC: preceding each line) every archive interval seconds:
```
Some sample LOOP: and REC: output
```
The above indicates that the XML file is being read, valid data is being extracted, loop packets are being emitted by the driver and WeeWX is constructing archive records from the accumulated loop data.
If all appears correct when run directly you can stop WeeWX by entering Ctl-Z in the terminal and you can now start WeeWX as a daemon:
```
$ sudo /etc/init.d/weewx start
```
or
```
$ sudo service weewx start
```
or
```
$ sudo systemctl start weewx
```
The WeeWX log should be monitored to verify archive records are being saved.

Manual installation

Download the latest XML parse driver extension from the XML parse driver extension releases page into a directory accessible from the WeeWX machine.
```
$ wget -P $DOWNLOAD_ROOT https://github.com/gjr80/weewx-xmlparse/releases/download/v0.1.0/xmlparse-0.1.0.tar.gz
```
where $DOWNLOAD_ROOT is the path to the directory where the XML parse driver extension is to be downloaded.

Stop WeeWX:

$ sudo /etc/init.d/weewx stop

$ sudo service weewx stop

$ sudo systemctl stop weewx

Unpack the extension as follows:
```
$ tar xvfz xmlparse-0.1.0.tar.gz
```

Copy files from within the resulting directory as follows:

$ cp xmlparse/bin/user/xmlparse.py /home/weewx/bin/user

$ cp xmlparse/bin/user/xmlparse.py /usr/share/weewx/user

Select the XML parse driver and do a basic driver configuration:

$ sudo /home/weewx/bin/wee_config --reconfigure

$ sudo /usr/share/weewx/wee_config --reconfigure

Edit weewx.conf and complete the required mappings in [XML] [[sensor_map]] section. Refer to Sensor maps in the XML parse driver wiki for details on how to enter sensor and unit maps. In additon, there are short form notes on the sensor and unit maps in the comments at the start of the xmlparse.py file.
Run WeeWX directly and confirm that loop packets and archive records are being generated and the data is appears valid:
```
$ sudo /home/weewx/bin/weewxd /home/weewx/weewx.conf
```
or
```
$ sudo /usr/share/weewx/weewxd /etc/weewx/weewx.conf
```
Note: The above commands include the appropriate paths for a default setup.py and package WeeWX installs accordingly. If you have modified the WeeWX install locations it may be necessary to prefix weewxd and weewx.conf with different paths.

You should now see something like below with a series of loop packets (indicated by LOOP: preceding each line) every poll_interval seconds and archive records (indicated by REC: preceding each line) every archive interval seconds:
```
Some sample LOOP: and REC: output
```
The above indicates that the XML file is being read, valid data is being extracted, loop packets are being emitted by the driver and WeeWX is constructing archive records from the accumulated loop data.
If all appears correct when run directly you can stop WeeWX by entering Ctl-Z in the terminal and you can now start WeeWX as a daemon:
```
$ sudo /etc/init.d/weewx start
```
or
```
$ sudo service weewx start
```
or
```
$ sudo systemctl start weewx
```
The WeeWX log should be monitored to verify archive records are being saved.

Support

General support issues may be raised in the Google Groups weewx-user forum . Specific bugs in the XML parse driver extension code should be the subject of a new issue raised via the XML parse driver extension issues page.

Licensing

The XML parse driver extension is licensed under the GNU Public License v3.

gjr80/weewx-xmlparse