[bitbake-devel] [PATCH] Documentation: Add examples to User Manual, Metadata chapter

[Rifenbark, Scott M]

Applied with a bit of rewording and whitespace correction for the example.  Change needs to be merged to the bitbake repo.

Scott

>-----Original Message-----
>From: bitbake-devel-bounces at lists.openembedded.org [mailto:bitbake-
>devel-bounces at lists.openembedded.org] On Behalf Of Robert P. J. Day
>Sent: Wednesday, July 09, 2014 5:04 AM
>To: BitBake developer list
>Subject: [bitbake-devel] [PATCH] Documentation: Add examples to User
>Manual, Metadata chapter
>
>
>Signed-off-by: Robert P. J. Day <rpjday at crashcourse.ca>
>
>---
>
>  as long as i've understood everything correctly, this is just throwing in some
>physical examples of a couple concepts.
>
>diff --git a/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml
>b/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml
>index a9f5072..423d9a4 100644
>--- a/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml
>+++ b/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml
>@@ -285,6 +285,16 @@
>                 The flags are immediately set to "abc" and "123", respectively.
>                 The <filename>a</filename> flag becomes "abc456".
>             </para>
>+
>+            <para>
>+                Note that there is no need to pre-define variable flags; you
>+                can simply start using them.  One extremely common application
>+                is to attach some brief documentation to a BitBake variable as
>+                follows:
>+                <literallayout class='monospaced'>
>+    CACHE[doc] = "The directory holding the cache of the metadata."
>+                </literallayout>
>+            </para>
>         </section>
>
>         <section id='inline-python-variable-expansion'>
>@@ -298,7 +308,19 @@
>      DATE = "${@time.strftime('%Y%m%d',time.gmtime())}"
>                 </literallayout>
>                 This example results in the <filename>DATE</filename>
>-                variable becoming the current date.
>+                variable being set to the current date.
>+            </para>
>+
>+            <para>
>+                Probably the most common use of this feature is to extract
>+                the value of variables from BitBake's internal data dictionary,
>+                <filename>d</filename>. The following lines
>+                select the values of, respectively, a package name and its
>+                version number:
>+                <literallayout class='monospaced'>
>+    PN = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE'),d)[0] or
>'defaultpkgname'}"
>+    PV = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE'),d)[1] or
>'1.0'}"
>+                </literallayout>
>             </para>
>         </section>
>
>
>--
>
>===========================================================
>=============
>Robert P. J. Day                                 Ottawa, Ontario, CANADA
>                        http://crashcourse.ca
>
>Twitter:                                       http://twitter.com/rpjday
>LinkedIn:                               http://ca.linkedin.com/in/rpjday
>===========================================================
>=============
>--
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