solr/solr-ref-guide/src/working-with-currencies-and-exchange-rates.adoc - lucene-solr - Git at Google

 = Working with Currencies and Exchange Rates
 // Licensed to the Apache Software Foundation (ASF) under one
 // or more contributor license agreements.  See the NOTICE file
 // distributed with this work for additional information
 // regarding copyright ownership.  The ASF licenses this file
 // to you under the Apache License, Version 2.0 (the
 // "License"); you may not use this file except in compliance
 // with the License.  You may obtain a copy of the License at
 //
 //   http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing,
 // software distributed under the License is distributed on an
 // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 // KIND, either express or implied.  See the License for the
 // specific language governing permissions and limitations
 // under the License.

 The `currency` FieldType provides support for monetary values to Solr/Lucene with query-time currency conversion and exchange rates. The following features are supported:

 * Point queries
 * Range queries
 * Function range queries
 * Sorting
 * Currency parsing by either currency code or symbol
 * Symmetric & asymmetric exchange rates (asymmetric exchange rates are useful if there are fees associated with exchanging the currency)
 * Range faceting (using either `facet.range` or `type:range` in `json.facet`) as long as the `start` and `end` values are specified in the same Currency.

 == Configuring Currencies

 .CurrencyField has been Deprecated
 [WARNING]
 ====
 CurrencyField has been deprecated in favor of CurrencyFieldType; all configuration examples below use CurrencyFieldType.
 ====

 The `currency` field type is defined in `schema.xml`. This is the default configuration of this type.

 [source,xml]
 ----
 <fieldType name="currency" class="solr.CurrencyFieldType"
            amountLongSuffix="_l_ns" codeStrSuffix="_s_ns"
            defaultCurrency="USD" currencyConfig="currency.xml" />
 ----

 In this example, we have defined the name and class of the field type, and defined the `defaultCurrency` as "USD", for U.S. Dollars. We have also defined a `currencyConfig` to use a file called "currency.xml". This is a file of exchange rates between our default currency to other currencies. There is an alternate implementation that would allow regular downloading of currency data. See <<Exchange Rates>> below for more.

 Many of the example schemas that ship with Solr include a <<dynamic-fields.adoc#,dynamic field>> that uses this type, such as this example:

 [source,xml]
 ----
     <dynamicField name="*_c"   type="currency" indexed="true"  stored="true"/>
 ----

 This dynamic field would match any field that ends in `_c` and make it a currency typed field.

 At indexing time, money fields can be indexed in a native currency. For example, if a product on an e-commerce site is listed in Euros, indexing the price field as "1000,EUR" will index it appropriately. The price should be separated from the currency by a comma, and the price must be encoded with a floating point value (a decimal point).

 During query processing, range and point queries are both supported.

 === Sub-field Suffixes

 You must specify parameters `amountLongSuffix` and `codeStrSuffix`, corresponding to dynamic fields to be used for the raw amount and the currency dynamic sub-fields, for example:

 [source,xml]
 ----
 <fieldType name="currency" class="solr.CurrencyFieldType"
            amountLongSuffix="_l_ns" codeStrSuffix="_s_ns"
            defaultCurrency="USD" currencyConfig="currency.xml" />
 ----

 In the above example, the raw amount field will use the `"*_l_ns"` dynamic field, which must exist in the schema and use a long field type, i.e., one that extends `LongValueFieldType`.  The currency code field will use the `"*_s_ns"` dynamic field, which must exist in the schema and use a string field type, i.e., one that is or extends `StrField`.

 .Atomic Updates won't work if dynamic sub-fields are stored
 [NOTE]
 ====
 As noted on <<updating-parts-of-documents.adoc#field-storage,Updating Parts of Documents>>, stored dynamic sub-fields will cause indexing to fail when you use Atomic Updates. To avoid this problem, specify `stored="false"` on those dynamic fields.
 ====

 == Exchange Rates

 You configure exchange rates by specifying a provider. Natively, two provider types are supported: `FileExchangeRateProvider` or `OpenExchangeRatesOrgProvider`.

 === FileExchangeRateProvider

 This provider requires you to provide a file of exchange rates. It is the default, meaning that to use this provider you only need to specify the file path and name as a value for `currencyConfig` in the definition for this type.

 There is a sample `currency.xml` file included with Solr, found in the same directory as the `schema.xml` file. Here is a small snippet from this file:

 [source,xml]
 ----
 <currencyConfig version="1.0">
   <rates>
     <!-- Updated from http://www.exchangerate.com/ at 2011-09-27 -->
     <rate from="USD" to="ARS" rate="4.333871" comment="ARGENTINA Peso" />
     <rate from="USD" to="AUD" rate="1.025768" comment="AUSTRALIA Dollar" />
     <rate from="USD" to="EUR" rate="0.743676" comment="European Euro" />
     <rate from="USD" to="CAD" rate="1.030815" comment="CANADA Dollar" />

     <!-- Cross-rates for some common currencies -->
     <rate from="EUR" to="GBP" rate="0.869914" />
     <rate from="EUR" to="NOK" rate="7.800095" />
     <rate from="GBP" to="NOK" rate="8.966508" />

     <!-- Asymmetrical rates -->
     <rate from="EUR" to="USD" rate="0.5" />
   </rates>
 </currencyConfig>
 ----

 === OpenExchangeRatesOrgProvider

 You can configure Solr to download exchange rates from http://www.OpenExchangeRates.Org[OpenExchangeRates.Org], with updates rates between USD and 170 currencies hourly. These rates are symmetrical only.

 In this case, you need to specify the `providerClass` in the definitions for the field type and sign up for an API key. Here is an example:

 [source,xml]
 ----
 <fieldType name="currency" class="solr.CurrencyFieldType"
            amountLongSuffix="_l_ns" codeStrSuffix="_s_ns"
            providerClass="solr.OpenExchangeRatesOrgProvider"
            refreshInterval="60"
            ratesFileLocation="http://www.openexchangerates.org/api/latest.json?app_id=yourPersonalAppIdKey"/>
 ----

 The `refreshInterval` is minutes, so the above example will download the newest rates every 60 minutes. The refresh interval may be increased, but not decreased.
	= Working with Currencies and Exchange Rates
	// Licensed to the Apache Software Foundation (ASF) under one
	// or more contributor license agreements. See the NOTICE file
	// distributed with this work for additional information
	// regarding copyright ownership. The ASF licenses this file
	// to you under the Apache License, Version 2.0 (the
	// "License"); you may not use this file except in compliance
	// with the License. You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing,
	// software distributed under the License is distributed on an
	// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	// KIND, either express or implied. See the License for the
	// specific language governing permissions and limitations
	// under the License.

	The `currency` FieldType provides support for monetary values to Solr/Lucene with query-time currency conversion and exchange rates. The following features are supported:

	* Point queries
	* Range queries
	* Function range queries
	* Sorting
	* Currency parsing by either currency code or symbol
	* Symmetric & asymmetric exchange rates (asymmetric exchange rates are useful if there are fees associated with exchanging the currency)
	* Range faceting (using either `facet.range` or `type:range` in `json.facet`) as long as the `start` and `end` values are specified in the same Currency.

	== Configuring Currencies

	.CurrencyField has been Deprecated
	[WARNING]
	====
	CurrencyField has been deprecated in favor of CurrencyFieldType; all configuration examples below use CurrencyFieldType.
	====

	The `currency` field type is defined in `schema.xml`. This is the default configuration of this type.

	[source,xml]
	----
	<fieldType name="currency" class="solr.CurrencyFieldType"
	amountLongSuffix="_l_ns" codeStrSuffix="_s_ns"
	defaultCurrency="USD" currencyConfig="currency.xml" />
	----

	In this example, we have defined the name and class of the field type, and defined the `defaultCurrency` as "USD", for U.S. Dollars. We have also defined a `currencyConfig` to use a file called "currency.xml". This is a file of exchange rates between our default currency to other currencies. There is an alternate implementation that would allow regular downloading of currency data. See <<Exchange Rates>> below for more.

	Many of the example schemas that ship with Solr include a <<dynamic-fields.adoc#,dynamic field>> that uses this type, such as this example:

	[source,xml]
	----
	<dynamicField name="*_c" type="currency" indexed="true" stored="true"/>
	----

	This dynamic field would match any field that ends in `_c` and make it a currency typed field.

	At indexing time, money fields can be indexed in a native currency. For example, if a product on an e-commerce site is listed in Euros, indexing the price field as "1000,EUR" will index it appropriately. The price should be separated from the currency by a comma, and the price must be encoded with a floating point value (a decimal point).

	During query processing, range and point queries are both supported.

	=== Sub-field Suffixes

	You must specify parameters `amountLongSuffix` and `codeStrSuffix`, corresponding to dynamic fields to be used for the raw amount and the currency dynamic sub-fields, for example:

	[source,xml]
	----
	<fieldType name="currency" class="solr.CurrencyFieldType"
	amountLongSuffix="_l_ns" codeStrSuffix="_s_ns"
	defaultCurrency="USD" currencyConfig="currency.xml" />
	----

	In the above example, the raw amount field will use the `"_l_ns"` dynamic field, which must exist in the schema and use a long field type, i.e., one that extends `LongValueFieldType`. The currency code field will use the `"_s_ns"` dynamic field, which must exist in the schema and use a string field type, i.e., one that is or extends `StrField`.

	.Atomic Updates won't work if dynamic sub-fields are stored
	[NOTE]
	====
	As noted on <<updating-parts-of-documents.adoc#field-storage,Updating Parts of Documents>>, stored dynamic sub-fields will cause indexing to fail when you use Atomic Updates. To avoid this problem, specify `stored="false"` on those dynamic fields.
	====

	== Exchange Rates

	You configure exchange rates by specifying a provider. Natively, two provider types are supported: `FileExchangeRateProvider` or `OpenExchangeRatesOrgProvider`.

	=== FileExchangeRateProvider

	This provider requires you to provide a file of exchange rates. It is the default, meaning that to use this provider you only need to specify the file path and name as a value for `currencyConfig` in the definition for this type.

	There is a sample `currency.xml` file included with Solr, found in the same directory as the `schema.xml` file. Here is a small snippet from this file:

	[source,xml]
	----
	<currencyConfig version="1.0">
	<rates>
	<!-- Updated from http://www.exchangerate.com/ at 2011-09-27 -->
	<rate from="USD" to="ARS" rate="4.333871" comment="ARGENTINA Peso" />
	<rate from="USD" to="AUD" rate="1.025768" comment="AUSTRALIA Dollar" />
	<rate from="USD" to="EUR" rate="0.743676" comment="European Euro" />
	<rate from="USD" to="CAD" rate="1.030815" comment="CANADA Dollar" />

	<!-- Cross-rates for some common currencies -->
	<rate from="EUR" to="GBP" rate="0.869914" />
	<rate from="EUR" to="NOK" rate="7.800095" />
	<rate from="GBP" to="NOK" rate="8.966508" />

	<!-- Asymmetrical rates -->
	<rate from="EUR" to="USD" rate="0.5" />
	</rates>
	</currencyConfig>
	----

	=== OpenExchangeRatesOrgProvider

	You can configure Solr to download exchange rates from http://www.OpenExchangeRates.Org[OpenExchangeRates.Org], with updates rates between USD and 170 currencies hourly. These rates are symmetrical only.

	In this case, you need to specify the `providerClass` in the definitions for the field type and sign up for an API key. Here is an example:

	[source,xml]
	----
	<fieldType name="currency" class="solr.CurrencyFieldType"
	amountLongSuffix="_l_ns" codeStrSuffix="_s_ns"
	providerClass="solr.OpenExchangeRatesOrgProvider"
	refreshInterval="60"
	ratesFileLocation="http://www.openexchangerates.org/api/latest.json?app_id=yourPersonalAppIdKey"/>
	----

	The `refreshInterval` is minutes, so the above example will download the newest rates every 60 minutes. The refresh interval may be increased, but not decreased.