B4X Requires Chilkat v11.7.0+
Box: Search Files with Offset Pagination

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. Search within a folder hierarchy. Box search is indexed and may lag recent changes; use returned upload IDs for immediate follow-up requests. Search uses offset pagination, not folder-list markers.
See the Box API guide for setup and the complete workflow.
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Dim success As Boolean = False

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

success = False

'  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.
Dim curl As ChilkatHttpCurl
curl.Initialize("curl")
curl.SetVar("access_token", "BOX_ACCESS_TOKEN")
curl.SetVar("parent_name", "/")
'  Box's fixed root ID is an implementation detail; callers supply names.
curl.SetVar("parent_id", "0")
Dim setupCommand As ChilkatStringBuilder
setupCommand.Initialize
Dim setupReplacements As Int

'  Register findParent; registration sends no request.
setupCommand.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer ACCESS_TOKEN" & Chr(34))
setupReplacements = setupCommand.Replace("ACCESS_TOKEN", curl.GetVar("access_token"))
success = curl.AddFunction("findParent", setupCommand.GetAsString)
If success <> True Then
    Log(curl.LastErrorText)
    Return
End If


'  Register findFolder; registration sends no request.
setupCommand.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/folders/{{parent_id}}/items?limit=1000&fields=id,type,name" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer ACCESS_TOKEN" & Chr(34))
setupReplacements = setupCommand.Replace("ACCESS_TOKEN", curl.GetVar("access_token"))
success = curl.AddFunction("findFolder", setupCommand.GetAsString)
If success <> True Then
    Log(curl.LastErrorText)
    Return
End If


'  Register findFile; registration sends no request.
setupCommand.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/folders/{{folder_id}}/items?limit=1000&fields=id,type,name" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer ACCESS_TOKEN" & Chr(34))
setupReplacements = setupCommand.Replace("ACCESS_TOKEN", curl.GetVar("access_token"))
success = curl.AddFunction("findFile", setupCommand.GetAsString)
If success <> True Then
    Log(curl.LastErrorText)
    Return
End If


'  Register findDestination; registration sends no request.
setupCommand.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer ACCESS_TOKEN" & Chr(34))
setupReplacements = setupCommand.Replace("ACCESS_TOKEN", curl.GetVar("access_token"))
success = curl.AddFunction("findDestination", setupCommand.GetAsString)
If success <> True Then
    Log(curl.LastErrorText)
    Return
End If


'  Register getFileDetails; registration sends no request.
setupCommand.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/files/{{file_id}}?fields=id,sha1,file_version" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer ACCESS_TOKEN" & Chr(34))
setupReplacements = setupCommand.Replace("ACCESS_TOKEN", curl.GetVar("access_token"))
success = curl.AddFunction("getFileDetails", setupCommand.GetAsString)
If success <> True Then
    Log(curl.LastErrorText)
    Return
End If


'  Register getEnterprise; registration sends no request.
setupCommand.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/users/me?fields=enterprise" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer ACCESS_TOKEN" & Chr(34))
setupReplacements = setupCommand.Replace("ACCESS_TOKEN", curl.GetVar("access_token"))
success = curl.AddFunction("getEnterprise", setupCommand.GetAsString)
If success <> True Then
    Log(curl.LastErrorText)
    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.
success = curl.AddOutput2("findParent", "entries", "name", "{{parent_name}}", True, "id", "parent_id")
If success <> True Then
    Log(curl.LastErrorText)
    Return
End If

success = curl.AddOutput2("findFolder", "entries", "name", "{{folder_name}}", True, "id", "folder_id")
If success <> True Then
    Log(curl.LastErrorText)
    Return
End If

success = curl.AddOutput2("findFile", "entries", "name", "{{file_name}}", True, "id", "file_id")
If success <> True Then
    Log(curl.LastErrorText)
    Return
End If

success = curl.AddOutput2("findDestination", "entries", "name", "{{destination_name}}", True, "id", "destination_id")
If success <> True Then
    Log(curl.LastErrorText)
    Return
End If

success = curl.AddOutput("getFileDetails", "file_version.id", "file_version_id")
If success <> True Then
    Log(curl.LastErrorText)
    Return
End If

success = curl.AddOutput("getFileDetails", "sha1", "file_sha1")
If success <> True Then
    Log(curl.LastErrorText)
    Return
End If

success = curl.AddOutput("getEnterprise", "enterprise.id", "enterprise_id")
If success <> True Then
    Log(curl.LastErrorText)
    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.
Dim parentName As String = "/"
Dim folderName As String = "images"
If (curl.GetVar("parent_name") <> parentName) Or ((parentName = "/") And (curl.VarDefined("parent_id") = False)) Then
    curl.SetVar("parent_name", parentName)
    curl.ClearVar("parent_id")
    curl.ClearVar("folder_id")
    curl.ClearVar("file_id")
    curl.ClearVar("file_version_id")
    curl.ClearVar("file_sha1")
    If parentName = "/" Then
        curl.SetVar("parent_id", "0")
    End If

End If

If curl.GetVar("folder_name") <> folderName Then
    curl.SetVar("folder_name", folderName)
    curl.ClearVar("folder_id")
    curl.ClearVar("file_id")
    curl.ClearVar("file_version_id")
    curl.ClearVar("file_sha1")
End If

curl.SetVar("query", "penguins")
Dim page As ChilkatJsonObject
page.Initialize
Dim number As ChilkatStringBuilder
number.Initialize
Dim offset As Int = 0
Dim count As Int
Dim pageLimit As Int
Dim total As Int
Dim i As Int
Dim more As Boolean = True
Do While more = True
    number.Clear
    number.AppendInt(offset)
    curl.SetVar("offset", number.GetAsString)
    curl.ClearTargetOutput("*")
    Dim authorizedCommand1 As ChilkatStringBuilder
    authorizedCommand1.Initialize
    authorizedCommand1.SetString("curl -X GET " & Chr(34) & "https://api.box.com/2.0/search?query={{query}}&type=file&ancestor_folder_ids={{folder_id}}&content_types=name&limit=100&offset={{offset}}" & Chr(34) & " -H " & Chr(34) & "Authorization: Bearer {{access_token}}" & Chr(34))
    Dim headerReplacement1 As Int = authorizedCommand1.Replace("{{access_token}}", curl.GetVar("access_token"))
    success = curl.DoYourThing(authorizedCommand1.GetAsString)
    If (success <> True) Or (curl.StatusCode <> 200) Then
        Log("Box request failed. HTTP status: " & curl.StatusCode)
        Log("Failure reason: " & curl.FailReason)
        Log(curl.ResponseBodyStr)
        Return
    End If

    success = curl.GetResponseJson(page)
    If success <> True Then
        Log(curl.LastErrorText)
        Return
    End If

    count = page.SizeOfArray("entries")
    i = 0
    Do While i < count
        page.I = i
        Log(page.StringOf("entries[i].id") & " " & page.StringOf("entries[i].name"))
        i = i + 1
    Loop
    pageLimit = page.IntOf("limit")
    total = page.IntOf("total_count")
    If pageLimit <= 0 Then
        Log("Missing or invalid search page limit.")
        Return
    End If

    offset = offset + pageLimit
    more = (offset < total) And (count > 0)
    If (more = True) And (offset > 9999) Then
        Log("Search offset limit reached; narrow the query or folder scope.")
        Return
    End If

Loop