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From: Apache Wiki <wikidiffs@apache.org>
To: Apache Wiki <wikidiffs@apache.org>
Date: Wed, 23 Sep 2009 21:54:43 -0000
Message-ID: <20090923215443.3276.53324@eos.apache.org>
Subject: 
 =?utf-8?q?=5BSolr_Wiki=5D_Update_of_=22LocalParams=22_by_naomidushay?=

Dear Wiki user,

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ge notification.

The "LocalParams" page has been changed by naomidushay:
http://wiki.apache.org/solr/LocalParams?action=3Ddiff&rev1=3D6&rev2=3D7

  =3D LocalParams =3D
- LocalParams stands for local parameters... arguments in a Solr request th=
at are localized and specific to a parameter.  They provide a way to add me=
ta-data to certain argument types such as query strings.
+ LocalParams stands for local parameters:  they provide a way to "localize=
" information about a specific argument that is being sent to Solr.  In oth=
er words, LocalParams provide a way to add meta-data to certain argument ty=
pes such as query strings.
  =

- If localparams exist as prefixes to arguments.
+ LocalParams are expressed as prefixes to arguments to be sent to Solr.  F=
or example:
+ =

- Assuming we have the existing query parameter
+ Assume we have the existing query parameter
- {{{q=3Dsolr rocks
+  `q=3Dsolr rocks`
- }}}
- We can prefix this query string with localparams to provide more informat=
ion to the query parser, for example changing the default operator type to =
"AND" and the default field to "title" for the lucene query parser.
+ We can prefix this query string with LocalParams to provide more informat=
ion to the query parser, for example changing the default operator type to =
"AND" and the default field to "title" for the lucene query parser:
- {{{q=3D{!q.op=3DAND df=3Dtitle}solr rocks
+  `q=3D{!q.op=3DAND df=3Dtitle}solr rocks`
- }}}
  =

  =3D=3D=3D Basic Syntax =3D=3D=3D
- An argument with localparams starts with {{{ {! }}}, includes any number =
of {{{key=3Dvalue}}} pairs separated by whitespace, and the localparams end=
 with {{{ } }}} followed by the original argument value.  There may only be=
 one localparams prefix per argument, preventing the need for any escaping =
of the original argument.  Values in the key-value pairs may be quoted via =
single or double quotes, and backslash escaping works within quoted strings.
+ To indicate a LocalParam, the argument is prefixed with curly braces whos=
e contents begin with an exclamation point and include any number of `key=
=3Dvalue` pairs separated by whitespace.  So if the original argument is `f=
oo`, applying LocalParams would look something like `{!k1=3Dv1 k2=3Dv2 k3=
=3Dv3}foo`.
+ =

+ There may only be one LocalParams prefix per argument, preventing the nee=
d for any escaping of the original argument.  Values in the key-value pairs=
 may be quoted via single or double quotes, and backslash escaping works wi=
thin quoted strings.
+ =

+  `q=3D{!type=3Ddismax qf=3D'myfield yourfield'}solr rocks` =

+ is equivalent to =

+  `q=3D{!type=3Ddismax qf=3D"myfield yourfield"}solr rocks`
+ but =

+  `q=3D{!type=3Ddismax qf=3Dmyfield yourfield}solr rocks`
+ will give an error because "yourfield" is expected to be a key=3Dvalue pa=
ir.
+ =

+ example of backslash escaping:
+  `q=3D{!type=3Ddismax qf=3D"title"}2 \+ 2`
  =

  =3D=3D=3D Query type short-form =3D=3D=3D
- If a localparam value appears without a name, it is given the implicit na=
me of "type".  This allows short-form representation for the type of query =
parser to use when parsing a query string.  Thus =

+ If a LocalParams value appears without a name, it is given the implicit n=
ame of "type".  This allows short-form representation for the type of query=
 parser to use when parsing a query string.  Thus =

- {{{q=3D{!dismax qf=3Dmyfield}solr rocks
+  `q=3D{!dismax qf=3Dmyfield}solr rocks`
- }}} is equivalent to =

+ is equivalent to =

- {{{q=3D{!type=3Ddismax qf=3Dmyfield}solr rocks
+  `q=3D{!type=3Ddismax qf=3Dmyfield}solr rocks`
- }}}
  =

  =3D=3D=3D Parameter value =3D=3D=3D
  A special key of "v" within local parameters is an alternate way to speci=
fy the value of that parameter.
- {{{q=3D{!dismax qf=3Dmyfield}solr rocks
+  `q=3D{!dismax qf=3Dmyfield}solr rocks`
- }}} is equivalent to =

+ is equivalent to =

- {{{q=3D{!type=3Ddismax qf=3Dmyfield v=3D'solr rocks'}
+  `q=3D{!type=3Ddismax qf=3Dmyfield v=3D'solr rocks'}`
- }}}
  =

  =3D=3D=3D Parameter dereferencing =3D=3D=3D
  Parameter dereferencing or indirection allows one to use the value of ano=
ther argument rather than specifying it directly.  This can be used to simp=
lify queries, decouple user input from query parameters, or decouple front-=
end GUI parameters from defaults set in solrconfig.xml.
- {{{q=3D{!dismax qf=3Dmyfield}solr rocks
+  `q=3D{!dismax qf=3Dmyfield}solr rocks`
- }}} is equivalent to =

+ is equivalent to =

- {{{q=3D{!type=3Ddismax qf=3Dmyfield v=3D$qq}&qq=3Dsolr rocks
+  `q=3D{!type=3Ddismax qf=3Dmyfield v=3D$qq}&qq=3Dsolr rocks`
- }}}
 =20