Difference between revisions of "DataRetriever"

From GreenVulcano Wiki
Jump to: navigation, search
Line 15: Line 15:
  
  
==Examples of GenericRetriever services==
+
==Examples of GenericRetriever functions==
  
 +
Configuration examples.
 
<syntaxhighlight lang="xml">
 
<syntaxhighlight lang="xml">
 
<RetrieverConfig>
 
<RetrieverConfig>
Line 49: Line 50:
 
     </GenericRetriever>
 
     </GenericRetriever>
 
</RetrieverConfig>
 
</RetrieverConfig>
 +
</syntaxhighlight>
 +
 +
Function description.
 +
{|class="gvtable"
 +
! Function !! Parameters !! Cacheable !! Description
 +
|-
 +
| getCityID || NAME || true || Returns the ID field of the first record of table CITY with field NAME equals to the passed parameter.<br/>The parameter is cacheable so, for the given parameter value, the subsequent call returns the same value.
 +
|-
 +
| getCityName || ID || true || Returns the NAME field of the first record of table CITY with field ID equals to the passed parameter.<br/>The parameter is cacheable so, for the given parameter value, the subsequent call returns the same value.
 +
|-
 +
| getPersonID || NAME,CITY || false || Returns the ID field of a record of table PERSON with field NAME equals to the first passed parameter and with an external reference to a record of table CITY with field NAME equals to the second passed parameter.
 +
|-
 +
| getCardID || NUMBER,ID_OWNER || true || Returns the ID field of the first record of table CREDIT_CARD with field CNUMBER equals to the first passed parameter and the field ID_OWNER equals to the second passed parameter.<br/>The parameter is cacheable so, for the given parameters value, the subsequent call returns the same value.
 +
|-
 +
| getSeqVal || || false || Returns the next sequence value.
 +
|}
 +
 +
Usage examples in XSL transformation. The examples use the calling procedure of Java classes of [http://xml.apache.org/xalan-j/extensions.html#ex-java-namespace Xalan-J XSLT Engine].
 +
<syntaxhighlight lang="xml">
 +
    <xsl:variable name="name" select="/PersonsData/PersonData/Name"/>
 +
    <xsl:variable name="city" select="/PersonsData/PersonData/City"/>
 +
    <xsl:element name="col">
 +
        <xsl:value-of select="java:it.greenvulcano.gvesb.datahandling.utils.GenericRetriever.getData('getPersonID',concat($name,';',$city))"/>
 +
    </xsl:element>
 
</syntaxhighlight>
 
</syntaxhighlight>

Revision as of 18:16, 23 February 2012

The GreenVulcano® ESB element DataRetriever defines a helper function.

It is defined by four parameters:

Attribute Type Description
cacheable optional If true the calculated function value, for the given parameters set, is cached for future access during the service processing.
The cache is cancelled at service end.
Default false.
DataRetriever optional The helper function. Might contain placeholders.
method required Helper function name.
signature optional Comma-separated list of parameters name to be substituted in the function.


Examples of GenericRetriever functions

Configuration examples.

<RetrieverConfig>
    <GenericRetriever class="it.greenvulcano.gvesb.datahandling.utils.GenericRetriever"
                        type="retriever">

        <DataRetriever cacheable="true" method="getCityID" signature="NAME">
            select ID from CITY
            where NAME='@{{NAME}}'
        </DataRetriever>

        <DataRetriever cacheable="true" method="getCityName" signature="ID">
            select NAME from CITY
            where ID=@{{ID}}
        </DataRetriever>

        <DataRetriever method="getPersonID" signature="NAME,CITY">
            select ID from PERSON
            where NAME='@{{NAME}}'
            and ID_CITY=(select ID from CITY where NAME='@{{CITY}}')
        </DataRetriever>

        <DataRetriever cacheable="true" method="getCardID" signature="NUMBER,ID_OWNER">
            select ID from CREDIT_CARD
            where CNUMBER='@{{NUMBER}}'
            and ID_OWNER=@{{ID_OWNER}}
        </DataRetriever>

        <DataRetriever method="getSeqVal">
            select SEQ_PERSON_ID.nextval from dual
        </DataRetriever>
    </GenericRetriever>
</RetrieverConfig>

Function description.

Function Parameters Cacheable Description
getCityID NAME true Returns the ID field of the first record of table CITY with field NAME equals to the passed parameter.
The parameter is cacheable so, for the given parameter value, the subsequent call returns the same value.
getCityName ID true Returns the NAME field of the first record of table CITY with field ID equals to the passed parameter.
The parameter is cacheable so, for the given parameter value, the subsequent call returns the same value.
getPersonID NAME,CITY false Returns the ID field of a record of table PERSON with field NAME equals to the first passed parameter and with an external reference to a record of table CITY with field NAME equals to the second passed parameter.
getCardID NUMBER,ID_OWNER true Returns the ID field of the first record of table CREDIT_CARD with field CNUMBER equals to the first passed parameter and the field ID_OWNER equals to the second passed parameter.
The parameter is cacheable so, for the given parameters value, the subsequent call returns the same value.
getSeqVal false Returns the next sequence value.

Usage examples in XSL transformation. The examples use the calling procedure of Java classes of Xalan-J XSLT Engine.

    <xsl:variable name="name" select="/PersonsData/PersonData/Name"/>
    <xsl:variable name="city" select="/PersonsData/PersonData/City"/>
    <xsl:element name="col">
        <xsl:value-of select="java:it.greenvulcano.gvesb.datahandling.utils.GenericRetriever.getData('getPersonID',concat($name,';',$city))"/>
    </xsl:element>