Unable to fetch uri variable from request url using Extract variable or assign message policy

[#1]

My requirement is quite simple.I am sending a request url 'http://apitechbasics-test.apigee.net/conditionalroutingwithdynamicendpoint' which is my proxy endpoint url .I will add one variable to request url 'http://apitechbasics-test.apigee.net/conditionalroutingwithdynamicendpoint/13' ,the value '13' needs to picked up by 'extractvariable' or 'assignmessage' policy and prepare target request based this value.Desired target url is 'http://www.thomas-bayer.com/sqlrest/CUSTOMER/13'.

I have used below policies at the Target endpoint request flow and tried to call backend .My requirement is clear ,but I am not able to create complete code for this .

Here is the desinged code.

API proxy:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?> <APIProxy revision="1" name="ConditionalRoutingwithDynamicEndpoint"> <Basepaths>/conditionalroutingwithdynamicendpoint</Basepaths> <ConfigurationVersion majorVersion="4" minorVersion="0"/> <CreatedAt>1477473512324</CreatedAt> <CreatedBy>nvraghavendra254@gmail.com</CreatedBy> <Description/> <DisplayName>ConditionalRoutingwithDynamicEndpoint</DisplayName> <LastModifiedAt>1477487807086</LastModifiedAt> <LastModifiedBy>nvraghavendra254@gmail.com</LastModifiedBy> <Policies> <Policy>Assign-Message-1</Policy> <Policy>GetZipCode</Policy> </Policies> <ProxyEndpoints> <ProxyEndpoint>default</ProxyEndpoint> </ProxyEndpoints> <Resources> <Resource>jsc://JavaScript-1.js</Resource> </Resources> <Spec/> <TargetServers/> <TargetEndpoints> <TargetEndpoint>default</TargetEndpoint> </TargetEndpoints> <validate>false</validate> </APIProxy>

Extract variable:GetZipCode

<?xml version="1.0" encoding="UTF-8" standalone="yes"?> <ExtractVariables async="false" continueOnError="true" enabled="true" name="GetZipCode"> <DisplayName>GetZipCode</DisplayName> <!--<Pattern ignoreCase="true">/a/{pathSeg}</Pattern>--> <URIPath> <Pattern ignoreCase="true">/{pathSeg}</Pattern> </URIPath> <!-- Uncomment for extraction from header --> <!--<Header name="ZIP">--> <!-- <Pattern ignoreCase="true">{zipcode}</Pattern>--> <!--</Header>--> <Source>request</Source> <VariablePrefix>getcityforecastbyzip</VariablePrefix> </ExtractVariables>

Assign message:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?> <AssignMessage async="false" continueOnError="false" enabled="true" name="Assign-Message-1"> <DisplayName>Assign Message-1</DisplayName> <Properties/> <Copy source="request"> <Headers/> <QueryParams/> <FormParams/> <Payload/> <Verb/> <StatusCode/> <ReasonPhrase/> <Path/> </Copy> <AssignVariable> <Name>target.url</Name> <Value>http://apitechbasics-test.apigee.net/conditionalroutingwithdynamicendpoint/{id}</Value> </AssignVariable> <IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables> <AssignTo createNew="false" transport="http" type="request"/> </AssignMessage>

My implementation might be wrong ,please suggest me the appropriate way to acheive my requirement.

[nmallesh · Accepted solution]

Hi @veeraraghavendra,

• Scenario 1 - Assuming the base path be '/'

<Pattern ignoreCase="true">/conditionalroutingwithdynamicendpoint/{zipcode}</Pattern>

• Scenario 2 - Assuming the base path be '/conditionalroutingwithdynamicendpoint'

<Pattern ignoreCase="true">/{zipcode}</Pattern>

Extract Variable Policy - Assuming Scenario 2 - the uri param is extracted to a flow variable called zipcode

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ExtractVariables async="false" continueOnError="true" enabled="true" name="GetZipCode"> 
<DisplayName>GetZipCode</DisplayName>
<URIPath name="zipcode">
<Pattern ignoreCase="true">/{zipcode}</Pattern> 

</URIPath> 

<IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables> 

</ExtractVariables>

Javascript Policy - Assign target.url

//get zipcode value already extracted
var zipcode=context.getVariable("zipcode");

//frame target_url
var target_url="http://www.thomas-bayer.com/sqlrest/CUSTOMER/"+zipcode;

//assign to target.url flow variable
context.setVariable("target.url",target_url);

Following is the issue with Assign Message Policy you have used -

<Ref> tag is used to specify the source variable.

http://apitechbasics-test.apigee.net/conditionalroutingwithdynamicendpoint/{id} as a whole,having not found as a variable fails to assign the value.

<Value> tag is used to specify the value directly, no substitution occurs here. Hence, http://apitechbasics-test.apigee.net/conditionalroutingwithdynamicendpoint/{id} is directly set as target.url and {id} is not replaced

<AssignVariable>
<Name>target.url</Name>
<Value>http://apitechbasics-test.apigee.net/conditionalroutingwithdynamicendpoint/{id}</Value> 
<Ref>http://apitechbasics-test.apigee.net/conditionalroutingwithdynamicendpoint/{id}</Ref>
</AssignVariable>

Hope this works, thank you!

[#3]

Thanks for your help,let me try this way

[#4]

Hi Nisha,

Many thanks for helping me on this .It is working now ,

Thanks Again

[anilsr]

@Nisha Mallesh , Great answer, Just FYI, use code button in editor to beautify code instead of table border.

[nmallesh]

@Anil Sagar Thanks, Yes I have started using them, in my latest posts.