Mediating URLs to make a prettier API!

[davissean]

Scenario - you have a simple API with GET requests that aren't very RESTful.

e.g.

GET /something/blah/dogs/id/123/breed/dalmation

and you want to convert it to

GET /dogs/123?breed=dalmation

A simple way to implement this uses two Apigee policies.

Firstly, an Extract Variables policy can use a regular expression to obtain the variables we want.

ExtractPathVariables.xml

<ExtractVariables name="ExtractPathVariables">
   <DisplayName>Extract URL variables</DisplayName>
   <Source>request</Source>
   <URIPath>
      <Pattern ignoreCase="true">/dogs/{dogId}</Pattern>
   </URIPath>
   <QueryParam name="breed">
	<Pattern ignoreCase="true">{dogBreed}</Pattern>
   </QueryParam>
   <VariablePrefix>urirequest</VariablePrefix>
   <IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
</ExtractVariables>

Next we can create the new URL. There are two options.

We can use an Assign Message policy if we have very simple logic.

AssignNewUrl.xml

<AssignMessage name="AssignNewUrl">
    <AssignTo createNew="false" type="request">request</AssignTo>
    <Set>
	<Path>/something/blah/dogs/id/{urirequest.dogId}/breed/{urirequest.dogBreed}</Path>	
    </Set>
    <IgnoreUnresolvedVariables>false</IgnoreUnresolvedVariables>
</AssignMessage>

If our logic is more complex, we can use a Javascript policy.

//some logic here to work out the url
/* ... */
var baseUrl = context.getVariable("https://httpbin.org");
var dogId = context.getVariable("urirequest.dogId");
var dogBreed = context.getVariable("urirequest.dogBreed");


//set the url
context.setVariable("target.url", baseUrl + "/something/blah/dogs/id/" + dogId + "/breed/" + dogBreed);

[ozanseymen]

Do we need to set target.copy.pathsuffix to false?