[Solr Wiki] Update of "DataImportHandler" by ShalinMangar

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The "DataImportHandler" page has been changed by ShalinMangar.
The comment on this change is: Adding note on stopTransform flag.
http://wiki.apache.org/solr/DataImportHandler?action=diff&rev1=218&rev2=219

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   * '''`newerThan`''' : A date param . Use the format (`yyyy-MM-dd HH:mm:ss`) . It can also be a datemath string eg: ('NOW-3DAYS'). The single quote is necessary . Or it can be a valid variableresolver format like (${var.name})
   * '''`olderThan`''' : A date param . Same rules as above
   * '''`rootEntity`''' :It must be false for this (Unless you wish to just index filenames) An entity directly under the <document> is a root entity. That means that for each row emitted by the root entity one document is created in Solr/Lucene. But as in this case we do not wish to make one document per file. We wish to make one document per row emitted by the following entity 'x'. Because the entity 'f' has rootEntity=false the entity directly under it becomes a root entity automatically and each row emitted by that becomes a document.
+  3E>
-  * '''`dataSource`''' :If you use Solr1.3 It must be set to "null" because this does not use any DataSource. No need to specify that in Solr1.4 .It just means that we won't create a DataSource instance. (In most of the cases there is only one !DataSource (A !JdbcDataSource) and all entities just use them. In case of !FileListEntityProcessor a !DataSource is not necessary.)
- 
- example:
- {{{
- <dataConfig>
-     <dataSource type="FileDataSource" />
-     <document>
-         <entity name="f" processor="FileListEntityProcessor" baseDir="/some/path/to/files" fileName=".*xml" newerThan="'NOW-3DAYS'" recursive="true" rootEntity="false" dataSource="null">
-             <entity name="x" processor="XPathEntityProcessor" forEach="/the/record/xpath" url="${f.fileAbsolutePath}">
-                 <field column="full_name" xpath="/field/xpath"/>
-             </entity>
-         </entity>
-     </document>
- </dataConfig>
- }}}
- Do not miss the `rootEntity` attribute. The implicit fields generated by the !FileListEntityProcessor are `fileAbsolutePath, fileSize, fileLastModified, fileName` and these are available for use within the entity X as shown above. It should be noted that !FileListEntityProcessor returns a list of pathnames and that the subsequent entity must use the !FileDataSource to fetch the files content.
- 
- === CachedSqlEntityProcessor ===
- <<Anchor(cached)>>
- 
- This is an extension of the !SqlEntityProcessor.  This !EntityProcessor helps reduce the no: of DB queries executed by caching the rows. It does not help to use it in the root most entity because only one sql is run for the entity.
- 
- Example 1.
- {{{
- <entity name="x" query="select * from x">
-     <entity name="y" query="select * from y where xid=${x.id}" processor="CachedSqlEntityProcessor">
-     </entity>
- <entity>
- }}}
- 
- The usage is exactly same as the other one. When a query is run the results are stored and if the same query is run again it is fetched from the cache and returned
- 
- Example 2:
- {{{
- <entity name="x" query="select * from x">
-     <entity name="y" query="select * from y" processor="CachedSqlEntityProcessor"  where="xid=x.id">
-     </entity>
- <entity>
- }}}
- 
- The difference with the previous one is the 'where' attribute. In this case the query fetches all the rows from the table and stores all the rows in the cache. The magic is in the 'where' value. The cache stores the values with the 'xid' value in 'y' as the key. The value for 'x.id' is evaluated every time the entity has to be run and the value is looked up in the cache an the rows are returned.
- 
- In the where the lhs (the part before '=') is the column in y and the rhs (the part after '=') is the value to be computed for looking up the cache.
- 
- === PlainTextEntityProcessor ===
- <<Anchor(plaintext)>>
- <!> [[Solr1.4]]
- 
- This !EntityProcessor reads all content from the data source into an single implicit field called 'plainText'. The content is not parsed in any way, however you may add transformers to manipulate the data within 'plainText' as needed or to create other additional fields.
- 
- example:
- {{{
- <entity processor="PlainTextEntityProcessor" name="x" url="http://abc.com/a.txt" dataSource="data-source-name">
-    <!-- copies the text to a field called 'text' in Solr-->
-   <field column="plainText" name="text"/>
- </entity>
- }}}
- 
- Ensure that the dataSource is of type !DataSource<Reader> (!FileDataSource, URL!DataSource)
- 
- === LineEntityProcessor ===
- <<Anchor(LineEntityProcessor)>>
  <!> [[Solr1.4]]
  
  This !EntityProcessor reads all content from the data source on a line by line basis, a field called 'rawLine' is returned for each line read. The content is not parsed in any way, however you may add transformers to manipulate the data within 'rawLine' or to create other additional fields.
@@ -884, +823 @@

   * '''`encoding`''': (optional) If the files are to be read in an encoding that is not same as the platform encoding
  
  === FieldReaderDataSource ===
+ <!> [[Solr1.4]]>>
+ <!> [[Solr1.4]]
+ 
+ This !EntityProcessor reads all content from the data source on a line by line basis, a field called 'rawLine' is returned for each line read. The content is not parsed in any way, however you may add transformers to manipulate the data within 'rawLine' or to create other additional fields.
+ 
+ The lines read can be filtered by two regular expressions '''acceptLineRegex''' and '''omitLineRegex'''.
+ This entities additional attributes are:
+  * '''`url`''' : a required attribute that specifies the location of the input file in a way that is compatible with the configured datasource. If this value is relative and you are using !FileDataSource or URL!DataSource, it assumed to be relative to '''baseLoc'''.
+  * '''`acceptLineRegex`''' :an optional attribute that if present discards any line which does not match the regExp.
+  * '''`omitLineRegex`''' : an optional attribute that is applied after any acceptLineRegex and discards any line which matches this regExp.
+ example:
+ {{{
+ <entity name="jc"
+         processor="LineEntityProcessor"
+         acceptLineRegex="^.*\.xml$"
+         omitLineRegex="/obsolete"
+         url="file:///Volumes/ts/files.lis"
+         rootEntity="false"
+         dataSource="myURIreader1"
+         transformer="RegexTransformer,DateFormatTransformer"
+         >
+    ...
+ }}}
+ While there are use cases where you might need to create a solr document per line read from a file, it is expected that in most cases that the lines read will consist of a pathname which is in turn consumed by another !EntityProcessor
+ such as X!PathEntityProcessor.
+ 
+ == DataSource ==
+ <<Anchor(datasource)>>
+ A class can extend `org.apache.solr.handler.dataimport.DataSource` . [[http://svn.apache.org/viewvc/lucene/solr/trunk/contrib/dataimporthandler/src/main/java/org/apache/solr/handler/dataimport/DataSource.java?view=markup|See source]]
+ 
+ and can be used as a !DataSource. It must be configured in the dataSource definition
+ {{{
+ <dataSource type="com.foo.FooDataSource" prop1="hello"/>
+ }}}
+ and it can be used in the entities like a standard one
+ 
+ === JdbcdataSource ===
+ This is the default. See the  [[#jdbcdatasource|example]] . The signature is as follows
+ {{{
+ public class JdbcDataSource extends DataSource<Iterator<Map<String, Object>>>
+ }}}
+ It is designed to iterate rows in DB one by one. A row is represented as a Map.
+ 
+ === URLDataSource ===
+ <!> [[Solr1.4]]
+ This datasource is often used with X!PathEntityProcessor to fetch content from an underlying file:// or http:// location. See the documentation [[#httpds|here]] . The signature is as follows
+ {{{
+ public class URLDataSource extends DataSource<Reader>
+ }}}
+ 
+ === HttpDataSource ===
+ <!> Http!DataSource is being deprecated in favour of URL!DataSource in [[Solr1.4]]. There is no change in functionality between URL!DataSource and !Http!DataSource, only a name change.
+ 
+ === FileDataSource ===
+ This can be used like an URL!DataSource but used to fetch content from files on disk. The only difference from URL!DataSource, when accessing disk files, is how a pathname is specified. The signature is as follows
+ {{{
+ public class FileDataSource extends DataSource<Reader>
+ }}}
+ 
+ The attributes are:
+  * '''`basePath`''': (optional) The base path relative to which the value is evaluated if it is not absolute
+  * '''`encoding`''': (optional) If the files are to be read in an encoding that is not same as the platform encoding
+ 
+ === FieldReaderDataSource ===
  <!> [[Solr1.4]]
  
  This can be used like an URL!DataSource . The signature is as follows
@@ -924, +927 @@

   * '''`$docBoost`''' : Boost the current doc. The value can be a number or the toString of a number
   * '''`$deleteDocById`''' : Delete a doc from Solr with this id. The value hast to be the unniqueKey value of the document <!> [[Solr1.4]]
   * '''`$deleteDocByQuery`''' :Delete docs from Solr by this query. The value must be a Solr Query <!> [[Solr1.4]]
+  * '''`$stopTransform`''' : Stops further transformation of the row. No other Transformers in the chain will be executed if this boolean flag is added to the row  <!> [[Solr1.4]]
  
  
  == Adding datasource in solrconfig.xml ==