PowerBuilder Requires Chilkat v11.7.0+
Box: Reuse HttpCurl and Invalidate Cached IDs

Run the reusable setup once per HttpCurl object, then select names and execute the operation. The setup is repeated here only to make this published example independently runnable. Perform three operations with one configured object: cold file lookup, warm download without lookups, then another download to a different local path after clearing only file state. Functions and output rules are registered only once; their variables are evaluated when used.
See the Box API guide for setup and the complete workflow.
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integer li_rc
long li_Success
oleobject loo_Curl
oleobject loo_SetupCommand
long li_SetupReplacements
string ls_ParentName
string ls_FolderName
string ls_FileName
oleobject loo_AuthorizedCommand1
long li_HeaderReplacement1
oleobject loo_WarmPlan
oleobject loo_AuthorizedCommand2
long li_HeaderReplacement2
oleobject loo_AuthorizedCommand3
long li_HeaderReplacement3
oleobject loo_AuthorizedCommand4
long li_HeaderReplacement4
oleobject loo_AuthorizedCommand5
long li_HeaderReplacement5

li_Success = 0

//  Requires Chilkat 11.7.0 or later and a previously unlocked Chilkat bundle.
//  See Global Unlock Sample.
//  Guide: Box API Guide.

li_Success = 0

//  BEGIN ONE-TIME SETUP
//  This block is repeated so each published example can run on its own.
//  In an application, run the setup example once and pass the SAME curl object
//  to operation code below. Do not recreate it for every operation.
//  See Reusable Box HttpCurl Setup.
loo_Curl = create oleobject
li_rc = loo_Curl.ConnectToNewObject("Chilkat.HttpCurl")
if li_rc < 0 then
    destroy loo_Curl
    MessageBox("Error","Connecting to COM object failed")
    return
end if
loo_Curl.SetVar("access_token","BOX_ACCESS_TOKEN")
loo_Curl.SetVar("parent_name","/")
//  Box's fixed root ID is an implementation detail; callers supply names.
loo_Curl.SetVar("parent_id","0")
loo_SetupCommand = create oleobject
li_rc = loo_SetupCommand.ConnectToNewObject("Chilkat.StringBuilder")

//  Register findParent; registration sends no request.
loo_SetupCommand.SetString("curl -X GET ~"https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name~" -H ~"Authorization: Bearer ACCESS_TOKEN~"")
li_SetupReplacements = loo_SetupCommand.Replace("ACCESS_TOKEN",loo_Curl.GetVar("access_token"))
li_Success = loo_Curl.AddFunction("findParent",loo_SetupCommand.GetAsString())
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    return
end if

//  Register findFolder; registration sends no request.
loo_SetupCommand.SetString("curl -X GET ~"https://api.box.com/2.0/folders/{{parent_id}}/items?limit=1000&fields=id,type,name~" -H ~"Authorization: Bearer ACCESS_TOKEN~"")
li_SetupReplacements = loo_SetupCommand.Replace("ACCESS_TOKEN",loo_Curl.GetVar("access_token"))
li_Success = loo_Curl.AddFunction("findFolder",loo_SetupCommand.GetAsString())
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    return
end if

//  Register findFile; registration sends no request.
loo_SetupCommand.SetString("curl -X GET ~"https://api.box.com/2.0/folders/{{folder_id}}/items?limit=1000&fields=id,type,name~" -H ~"Authorization: Bearer ACCESS_TOKEN~"")
li_SetupReplacements = loo_SetupCommand.Replace("ACCESS_TOKEN",loo_Curl.GetVar("access_token"))
li_Success = loo_Curl.AddFunction("findFile",loo_SetupCommand.GetAsString())
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    return
end if

//  Register findDestination; registration sends no request.
loo_SetupCommand.SetString("curl -X GET ~"https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name~" -H ~"Authorization: Bearer ACCESS_TOKEN~"")
li_SetupReplacements = loo_SetupCommand.Replace("ACCESS_TOKEN",loo_Curl.GetVar("access_token"))
li_Success = loo_Curl.AddFunction("findDestination",loo_SetupCommand.GetAsString())
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    return
end if

//  Register getFileDetails; registration sends no request.
loo_SetupCommand.SetString("curl -X GET ~"https://api.box.com/2.0/files/{{file_id}}?fields=id,sha1,file_version~" -H ~"Authorization: Bearer ACCESS_TOKEN~"")
li_SetupReplacements = loo_SetupCommand.Replace("ACCESS_TOKEN",loo_Curl.GetVar("access_token"))
li_Success = loo_Curl.AddFunction("getFileDetails",loo_SetupCommand.GetAsString())
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    return
end if

//  Register getEnterprise; registration sends no request.
loo_SetupCommand.SetString("curl -X GET ~"https://api.box.com/2.0/users/me?fields=enterprise~" -H ~"Authorization: Bearer ACCESS_TOKEN~"")
li_SetupReplacements = loo_SetupCommand.Replace("ACCESS_TOKEN",loo_Curl.GetVar("access_token"))
li_Success = loo_Curl.AddFunction("getEnterprise",loo_SetupCommand.GetAsString())
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    return
end if

//  Register output rules once. Chilkat 11.7.0 evaluates {{name}} variables
//  when extracting each output, using the current value at that time.
li_Success = loo_Curl.AddOutput2("findParent","entries","name","{{parent_name}}",1,"id","parent_id")
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    return
end if

li_Success = loo_Curl.AddOutput2("findFolder","entries","name","{{folder_name}}",1,"id","folder_id")
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    return
end if

li_Success = loo_Curl.AddOutput2("findFile","entries","name","{{file_name}}",1,"id","file_id")
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    return
end if

li_Success = loo_Curl.AddOutput2("findDestination","entries","name","{{destination_name}}",1,"id","destination_id")
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    return
end if

li_Success = loo_Curl.AddOutput("getFileDetails","file_version.id","file_version_id")
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    return
end if

li_Success = loo_Curl.AddOutput("getFileDetails","sha1","file_sha1")
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    return
end if

li_Success = loo_Curl.AddOutput("getEnterprise","enterprise.id","enterprise_id")
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    return
end if

//  END ONE-TIME SETUP
//  The name lookups below assume each listing fits in one page (1000 items).
//  Parent and destination names select root children; folder_name selects a child
//  of parent_name. "/" selects the root parent. These are not arbitrary paths.

//  BEGIN OPERATION -- keep the configured object when reusing it.
//  Inputs are names. Retain cached IDs when the selected names have not changed.
ls_ParentName = "/"
ls_FolderName = "images"
ls_FileName = "penguins.jpg"
if (loo_Curl.GetVar("parent_name") <> ls_ParentName) OR ((ls_ParentName = "/") AND (loo_Curl.VarDefined("parent_id") = 0)) then
    loo_Curl.SetVar("parent_name",ls_ParentName)
    loo_Curl.ClearVar("parent_id")
    loo_Curl.ClearVar("folder_id")
    loo_Curl.ClearVar("file_id")
    loo_Curl.ClearVar("file_version_id")
    loo_Curl.ClearVar("file_sha1")
    if ls_ParentName = "/" then
        loo_Curl.SetVar("parent_id","0")
    end if

end if

if loo_Curl.GetVar("folder_name") <> ls_FolderName then
    loo_Curl.SetVar("folder_name",ls_FolderName)
    loo_Curl.ClearVar("folder_id")
    loo_Curl.ClearVar("file_id")
    loo_Curl.ClearVar("file_version_id")
    loo_Curl.ClearVar("file_sha1")
end if

if loo_Curl.GetVar("file_name") <> ls_FileName then
    loo_Curl.SetVar("file_name",ls_FileName)
    loo_Curl.ClearVar("file_id")
    loo_Curl.ClearVar("file_version_id")
    loo_Curl.ClearVar("file_sha1")
end if

loo_Curl.SetVar("local_path","qa_output/penguins.jpg")
//  Operation 1: get information by name. This resolves folder_id and file_id.
loo_Curl.ClearTargetOutput("*")
loo_AuthorizedCommand1 = create oleobject
li_rc = loo_AuthorizedCommand1.ConnectToNewObject("Chilkat.StringBuilder")

loo_AuthorizedCommand1.SetString("curl -X GET ~"https://api.box.com/2.0/files/{{file_id}}?fields=id,name~" -H ~"Authorization: Bearer {{access_token}}~"")
li_HeaderReplacement1 = loo_AuthorizedCommand1.Replace("{{access_token}}",loo_Curl.GetVar("access_token"))
li_Success = loo_Curl.DoYourThing(loo_AuthorizedCommand1.GetAsString())
if (li_Success <> 1) OR (loo_Curl.StatusCode <> 200) then
    Write-Debug "Box request failed. HTTP status: " + string(loo_Curl.StatusCode)
    Write-Debug "Failure reason: " + string(loo_Curl.FailReason)
    Write-Debug loo_Curl.ResponseBodyStr
    destroy loo_Curl
    destroy loo_SetupCommand
    destroy loo_AuthorizedCommand1
    return
end if

//  Operation 2: keep the same object and IDs. Only the final download is needed.
loo_WarmPlan = create oleobject
li_rc = loo_WarmPlan.ConnectToNewObject("Chilkat.JsonObject")

loo_WarmPlan.EmitCompact = 0
loo_AuthorizedCommand2 = create oleobject
li_rc = loo_AuthorizedCommand2.ConnectToNewObject("Chilkat.StringBuilder")

loo_AuthorizedCommand2.SetString("curl -X GET ~"https://api.box.com/2.0/files/{{file_id}}/content~" -H ~"Authorization: Bearer {{access_token}}~" -L -o ~"{{local_path}}~"")
li_HeaderReplacement2 = loo_AuthorizedCommand2.Replace("{{access_token}}",loo_Curl.GetVar("access_token"))
li_Success = loo_Curl.ExaminePlan(loo_AuthorizedCommand2.GetAsString(),loo_WarmPlan)
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    destroy loo_AuthorizedCommand1
    destroy loo_WarmPlan
    destroy loo_AuthorizedCommand2
    return
end if

Write-Debug loo_WarmPlan.Emit()
loo_Curl.ClearTargetOutput("*")
loo_AuthorizedCommand3 = create oleobject
li_rc = loo_AuthorizedCommand3.ConnectToNewObject("Chilkat.StringBuilder")

loo_AuthorizedCommand3.SetString("curl -X GET ~"https://api.box.com/2.0/files/{{file_id}}/content~" -H ~"Authorization: Bearer {{access_token}}~" -L -o ~"{{local_path}}~"")
li_HeaderReplacement3 = loo_AuthorizedCommand3.Replace("{{access_token}}",loo_Curl.GetVar("access_token"))
li_Success = loo_Curl.DoYourThing(loo_AuthorizedCommand3.GetAsString())
if (li_Success <> 1) OR (loo_Curl.StatusCode <> 200) then
    Write-Debug "Box request failed. HTTP status: " + string(loo_Curl.StatusCode)
    Write-Debug "Failure reason: " + string(loo_Curl.FailReason)
    Write-Debug loo_Curl.ResponseBodyStr
    destroy loo_Curl
    destroy loo_SetupCommand
    destroy loo_AuthorizedCommand1
    destroy loo_WarmPlan
    destroy loo_AuthorizedCommand2
    destroy loo_AuthorizedCommand3
    return
end if

//  Operation 3: explicitly invalidate file state, retaining the known folder.
//  Here we select the same name so this demonstration needs only one real file.
//  Substitute another filename to switch files in this folder.
//  The existing output rule reads the current file_name; do not register it again.
loo_Curl.ClearVar("file_id")
loo_Curl.ClearVar("file_version_id")
loo_Curl.ClearVar("file_sha1")
loo_Curl.SetVar("file_name","penguins.jpg")
loo_Curl.SetVar("local_path","qa_output/penguins-copy.jpg")
loo_AuthorizedCommand4 = create oleobject
li_rc = loo_AuthorizedCommand4.ConnectToNewObject("Chilkat.StringBuilder")

loo_AuthorizedCommand4.SetString("curl -X GET ~"https://api.box.com/2.0/files/{{file_id}}/content~" -H ~"Authorization: Bearer {{access_token}}~" -L -o ~"{{local_path}}~"")
li_HeaderReplacement4 = loo_AuthorizedCommand4.Replace("{{access_token}}",loo_Curl.GetVar("access_token"))
li_Success = loo_Curl.ExaminePlan(loo_AuthorizedCommand4.GetAsString(),loo_WarmPlan)
if li_Success <> 1 then
    Write-Debug loo_Curl.LastErrorText
    destroy loo_Curl
    destroy loo_SetupCommand
    destroy loo_AuthorizedCommand1
    destroy loo_WarmPlan
    destroy loo_AuthorizedCommand2
    destroy loo_AuthorizedCommand3
    destroy loo_AuthorizedCommand4
    return
end if

Write-Debug loo_WarmPlan.Emit()
loo_Curl.ClearTargetOutput("*")
loo_AuthorizedCommand5 = create oleobject
li_rc = loo_AuthorizedCommand5.ConnectToNewObject("Chilkat.StringBuilder")

loo_AuthorizedCommand5.SetString("curl -X GET ~"https://api.box.com/2.0/files/{{file_id}}/content~" -H ~"Authorization: Bearer {{access_token}}~" -L -o ~"{{local_path}}~"")
li_HeaderReplacement5 = loo_AuthorizedCommand5.Replace("{{access_token}}",loo_Curl.GetVar("access_token"))
li_Success = loo_Curl.DoYourThing(loo_AuthorizedCommand5.GetAsString())
if (li_Success <> 1) OR (loo_Curl.StatusCode <> 200) then
    Write-Debug "Box request failed. HTTP status: " + string(loo_Curl.StatusCode)
    Write-Debug "Failure reason: " + string(loo_Curl.FailReason)
    Write-Debug loo_Curl.ResponseBodyStr
    destroy loo_Curl
    destroy loo_SetupCommand
    destroy loo_AuthorizedCommand1
    destroy loo_WarmPlan
    destroy loo_AuthorizedCommand2
    destroy loo_AuthorizedCommand3
    destroy loo_AuthorizedCommand4
    destroy loo_AuthorizedCommand5
    return
end if

//  Changing parent_name invalidates parent_id, folder_id, and file state.
//  Changing folder_name invalidates folder_id and file state.
//  Changing destination_name invalidates destination_id.


destroy loo_Curl
destroy loo_SetupCommand
destroy loo_AuthorizedCommand1
destroy loo_WarmPlan
destroy loo_AuthorizedCommand2
destroy loo_AuthorizedCommand3
destroy loo_AuthorizedCommand4
destroy loo_AuthorizedCommand5