Repository : http://git.fedorahosted.org/cgit/docs/anaconda-addon-development-guide.git

On branch : master

commit d9903bc20fe0b576b226a298944d2ceb05a9c6cc Author: David Shea dshea@redhat.com Date: Sat Feb 15 12:56:06 2014 -0500

Document AddonData.handle_header

en-US/Anaconda_Addon_Development_Guide.xml | 88 ++++++++++++++++++++++------ 1 files changed, 69 insertions(+), 19 deletions(-)

diff --git a/en-US/Anaconda_Addon_Development_Guide.xml b/en-US/Anaconda_Addon_Development_Guide.xml index 5651847..715fedf 100644 --- a/en-US/Anaconda_Addon_Development_Guide.xml +++ b/en-US/Anaconda_Addon_Development_Guide.xml @@ -561,7 +561,7 @@ for parsing and storing data from the kickstart file. The part of a kickstart file containing data for an addon has the following format:

- <programlisting>%addon ADDON_NAME + <programlisting>%addon ADDON_NAME [arguments] first line second line ... @@ -572,22 +572,27 @@ second line the beginning of addon section while <emphasis>%end</emphasis> marks its end. In place of the string <emphasis>ADDON_NAME</emphasis> there should be a name of a real addon (like - <emphasis>org_fedora_hello_world</emphasis> in our case). The content - between the two lines starting with the percent sign is passed to an - instance of the addon's class inherited from the - <classname>AddonData</classname> class. To make the code as simple as + <emphasis>org_fedora_hello_world</emphasis> in our case). Any additional + <emphasis>arguments</emphasis> on the addon line will be passed as a + list to an instance of the addon's class inherited from the + <classname>AddonData</classname> class. The content between the two + lines starting with the percent sign is passed to the instance of the + addon's class one line at a time. To make the code as simple as possible, the &HWADDON; will just squash the lines passed in a kickstart file to a single line separating the original lines with a space. We know that our addon needs a class inherited from the - <classname>AddonData</classname> with a method handling lines from a - kickstart <emphasis>%addon</emphasis> section. A quick look into the - <filename>pyanaconda/addons.py</filename> file tells that the name of - such method is <methodname>handle_line</methodname> and it takes the - line as the only argument. Let's have a look at the code implementing - what we have covered so far. + <classname>AddonData</classname> with a method handling the + <emphasis>%addon</emphasis> argument list and with a method handling + lines inside a kickstart <emphasis>%addon</emphasis> section. A quick + look into the <filename>pyanaconda/addons.py</filename> shows these + two methods: <methodname>handle_header</methodname> takes a list of + arguments and the current line numbers (for error reporting), and + <methodname>handle_line</methodname> takes a single line of content. + Let's have a look at the code implementing what we have covered so far. </para>

<programlisting>from pyanaconda.addons import AddonData +from pykickstart.options import KSOptionParser

# export HelloWorldData class to prevent Anaconda's collect method from taking # AddonData class instead of the HelloWorldData class @@ -613,6 +618,32 @@ class HelloWorldData(AddonData):

AddonData.__init__(self, name) self.text = "" + self.reverse = False + + def handle_header(self, lineno, args): + """ + The handle_header method is called to parse additional arguments in the + %addon section line. + + :param lineno: the current linenumber in the kickstart file + :type lineno: int + :param args: any additional arguments after %addon &lt;name&gt; + :type args: list + """ + + op = KSOptionParser() + op.add_option("--reverse", action="store_true", default=False, + dest="reverse", help="Reverse the display of the addon text") + (opts, extra) = op.parse_args(args=args, lineno=lineno) + + # Reject any additoinal arguments. Since AddonData.handle_header + # rejects any arguments, we can use it to create an error message + # and raise an exception. + if extra: + AddonData.handle_header(self, lineno, extra) + + # Store the result of the option parsing + self.reverse = opts.reverse

def handle_line(self, line): """ @@ -643,11 +674,19 @@ class HelloWorldData(AddonData): Then there is a definition of the <classname>HelloWorldData</classname> class inherited from the <classname>AddonData</classname> class with its <methodname>__init__</methodname> method calling the parent's - <methodname>__init__</methodname> method and initializing the attribute - <property>self.text</property> to an empty string. This attribute is - populated in the <methodname>handle_line</methodname> method which just - strips the lines (removes white space characters at the beginning and the - end) and appends them to it. + <methodname>__init__</methodname> method and initializing the attributes + <property>self.text</property> to an empty string and + <property>self.reverse</property> to False. + <property>self.reverse</property> is populated in the + <methodname>handle_header</methodname> method, and + <property>self.text</property> is populated in the + <methodname>handle_line</methodname> method. + <methodname>handle_header</methodname> uses an instance of the + <classname>KSOptionParser</classname> class provided by pykickstart to + parse the additional arguments on the <emphasis>%addon</emphasis> line, + and <methodname>handle_line</methodname> strips the content lines + (removes white space characters at the beginning and the end) and + appends them to <property>self.text</property>. </para>

<para> @@ -740,12 +779,18 @@ HELLO_FILE_PATH = "/root/hello_world_addon_output.txt"</programlisting>

<programlisting> def __str__(self): """ - What should end up between %addon and %end lines in the resulting - kickstart file, i.e. string representation of the stored data. + What should end up in the resulting kickstart file, i.e. the %addon + section containing string representation of the stored data.

"""

- return self.text</programlisting> + addon_str = "%%addon %s" % self.name + + if self.reverse: + addon_str += "--reverse" + + addon_str += "\n%s\n%%end" % self.text + return addon_str</programlisting>

<para> By adding this method method we have everything that is needed for a @@ -1136,6 +1181,11 @@ class HelloWorldSpoke(NormalSpoke): """

text = self.data.addons.org_fedora_hello_world.text + + # If --reverse was specified in the kickstart, reverse the text + if self.data.addons.org_fedora_hello_world.reverse: + text = text[::-1] + if text: return _("Text set: %s") % text else: