# type mismatch error is shown while passing “tName” in stringbody **URL:** \ **Category:** Gatling (Open-Source)\ **Created:** [February 8, 2017, 2:09pm UTC](https://community.gatling.io/t/type-mismatch-error-is-shown-while-passing-tname-in-stringbody/3543 "2017-02-08T14:09:59Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Peter](https://avatars.discourse-cdn.com/v4/letter/p/278dde/32.png) [@Peter](https://community.gatling.io/u/Peter)\ **Post date:** [February 8, 2017, 2:09pm UTC](https://community.gatling.io/t/type-mismatch-error-is-shown-while-passing-tname-in-stringbody/3543/1 "2017-02-08T14:09:59Z")
```auto val tName = System.getProperty("tName", "asdflkjh") ``` I am planning to make `"tName"` dynamic but it prints `"$tName"` in output instead of “asdflkjh”.`.body(StringBody("""{"objectId":${assetid},"objectType":"m-asset","name1": "$tName","accountId":4,"userId":5}"""))` If I use `'session=>s'` in stringBody it throws below error `.body(StringBody(session=>s"""{"objectId":${assetid},"objectType":"m-asset","name1": "$tName","accountId":4,"userId":5}"""))` **//////////////////////ERROR: ////////////////////////////////** ```auto 3894 [main] ERROR io.gatling.compiler.ZincCompiler$ - type mismatch; found : String("${ThumbIdList}") required: ?{def apply: ?} Note that implicit conversions are not applicable because they are ambiguous: both method augmentString in object Predef of type (x: String)scala.collection.immutable.StringOps and method stringToExpression in object Predef of type [T](string: String)(implicit evidence$1: scala.reflect.ClassTag[T])io.gatling.core.session.Expression[T] are possible conversion functions from String("${ThumbIdList}") to ?{def apply: ?} 3894 [main] ERROR io.gatling.compiler.ZincCompiler$ - .foreach("${ThumbIdList}", "thumbid") { 3894 [main] ERROR io.gatling.compiler.ZincCompiler$ - ^ 3914 [main] ERROR io.gatling.compiler.ZincCompiler$ - D:\myTags.scala:110: type mismatch; found : String("thumbid") required: ?{def apply: ?} Note that implicit conversions are not applicable because they are ambiguous: both method augmentString in object Predef of type (x: String)scala.collection.immutable.StringOps and method stringToExpression in object Predef of type [T](string: String)(implicit evidence$1: scala.reflect.ClassTag[T])io.gatling.core.session.Expression[T] are possible conversion functions from String("thumbid") to ?{def apply: ?} 3914 [main] ERROR io.gatling.compiler.ZincCompiler$ - .foreach("${ThumbIdList}", "thumbid") { 3924 [main] ERROR io.gatling.compiler.ZincCompiler$ - ^ 4004 [main] ERROR io.gatling.compiler.ZincCompiler$ - D:\myTags.scala:98: not found: value assetid 4004 [main] ERROR io.gatling.compiler.ZincCompiler$ - .body(StringBody(session=>s"""{"objectId":${assetid},"objectType":"m-asset","name1": "$tName","accountId":4,"userId":5}""")) 4004 [main] ERROR io.gatling.compiler.ZincCompiler$ - ^ 4054 [main] ERROR io.gatling.compiler.ZincCompiler$ - three errors found 4054 [main] DEBUG io.gatling.compiler.ZincCompiler$ - Compilation failed (CompilerInterface) ``` **///////////// Script Starts here ///////////** ```auto import scala.concurrent.duration._ import io.gatling.core.Predef._ import io.gatling.http.Predef._ import io.gatling.jdbc.Predef._ class myTags extends Simulation { val testServerUrl = System.getProperty("testServerUrl", "https:someurl") val username = System.getProperty("username", "ma") val password = System.getProperty("password", "ma") val userCount = Integer.getInteger("userCount", 1).toInt val accountname = System.getProperty("accountname", "ma1") val tName = System.getProperty("tName", "asdflkjh") val httpProtocol = http .baseURL(testServerUrl) val headers_6 = Map( "Accept" -> "application/json, text/plain, */*", "Cache-Control" -> "no-cache", "If-Modified-Since" -> "Mon, 26 Jul 1997 05:00:00 GMT", "Pragma" -> "no-cache", "X-Requested-With" -> "XMLHttpRequest") val headers_52 = Map( "Accept" -> "application/json, text/plain, */*", "Accept-Encoding" -> "gzip, deflate, br", "Cache-Control" -> "no-cache", "Origin" -> testServerUrl, "Pragma" -> "no-cache", "X-Requested-With" -> "XMLHttpRequest", "Content-Type" -> "application/json;charset=UTF-8", "Connection" -> "keep-alive", "User-Agent" -> "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Safari/537.36") val scn = scenario("Add") .exec(http("Fetch") .get("/someurl2") .headers(headers_6) .check(jsonPath("$.resources[*].ids").findAll.saveAs("IdList")) .check(jsonPath("$.resources[*].thumbIds").findAll.saveAs("ThumbIdList"))) .foreach("${IdList}", "assetid") { exec(http("Load_Details") .get("/mmm/images/loader.svg") .resources( http("C1_request") .get("/mmm/ast/${assetid}/c1") .headers(headers_6), http("T1_request") .get("/mmm/ast/${assetid}/t1") .headers(headers_6), http("A1_request") .post("/mmm/actions") .headers(headers_52) .body(StringBody("""{"objects":[{"id":${assetid},"resource":"m-asset"}]}""")), http("R1_request") .get("/mmm/variants%3BresourceType=m-asset") .headers(headers_6), http("S1_request") .get("/mmm/ast/${assetid}/keyframes") .headers(headers_6))) .exec(http("Add Tags") .post("/mmm/objs/${assetid}/tags") .headers(headers_52) // The PROBLEM IS Here. I want to pass "$tName" dynamically .body(StringBody("""{"objectId":${assetid},"objectType":"m-asset","name1": "$tName","accountId":4,"userId":5}""")) ) } .foreach("${ThumbIdList}", "thumbid") { doIf(session => session("thumbid").as[String] != "-1") { exec(http("Set_Keyframes") .get("/mmm/keyframes/${thumbid};width=185;height=103") ) } } setUp(scn.inject(atOnceUsers(userCount))).protocols(httpProtocol) } ``` ---
**Author:** ![notdryft](https://dub1.discourse-cdn.com/flex013/user_avatar/community.gatling.io/notdryft/32/1103_2.png) [@notdryft](https://community.gatling.io/u/notdryft)\ **Post date:** [February 8, 2017, 2:39pm UTC](https://community.gatling.io/t/type-mismatch-error-is-shown-while-passing-tname-in-stringbody/3543/2 "2017-02-08T14:39:21Z")
You have a conflict between Gatling’s Expression Language (used with a ${}), and Scala’s String Interpolation (also ${} and $, completed with the s"" macro). There is a way to use both, but this is a bit tricky: - Prefix the string with s - Escape Gatling’s Expression Language such that it won’t be interpreted by Scala as an interpolation Typically, double the $ that are Gatling’s EL you don’t want to be interpolated, as such: ```auto StringBody(s"""{"objectId":$${assetid},"objectType":"m-asset","name1": "$tName","accountId":4,"userId":5}""") ``` ---
**Author:** ![Peter](https://avatars.discourse-cdn.com/v4/letter/p/278dde/32.png) [@Peter](https://community.gatling.io/u/Peter)\ **Post date:** [February 9, 2017, 5:05am UTC](https://community.gatling.io/t/type-mismatch-error-is-shown-while-passing-tname-in-stringbody/3543/3 "2017-02-09T05:05:04Z")
**Thanks a TON Guillaume Corré** for such a nice explanation. It worked. Thanks 🙂