Lua Requires Chilkat v11.7.0+

Box: Resolve a File Version by Name and Verify the Download

See more Box Examples

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. One target request requires file_id and file_version_id. The engine uses AddOutput2 for name lookups and AddOutput for version/SHA-1 metadata, then downloads that version to local_path and verifies its digest.

See the Box API guide for setup and the complete workflow.

Lua

local chilkat = require("chilkat")

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

local 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.
local curl = chilkat.HttpCurl.new()
curl:set_var("access_token", "BOX_ACCESS_TOKEN")
curl:set_var("parent_name", "/")
-- Box's fixed root ID is an implementation detail; callers supply names.
curl:set_var("parent_id", "0")
local setupCommand = chilkat.StringBuilder.new()

-- Register findParent; registration sends no request.
setupCommand:set_string("curl -X GET \"https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name\" -H \"Authorization: Bearer ACCESS_TOKEN\"")
local setupReplacements = setupCommand:replace("ACCESS_TOKEN", curl:get_var("access_token"))
success = curl:add_function("findParent", setupCommand:get_as_string())
if not success then
    print(curl.last_error_text)
    return
end

-- Register findFolder; registration sends no request.
setupCommand:set_string("curl -X GET \"https://api.box.com/2.0/folders/{{parent_id}}/items?limit=1000&fields=id,type,name\" -H \"Authorization: Bearer ACCESS_TOKEN\"")
setupReplacements = setupCommand:replace("ACCESS_TOKEN", curl:get_var("access_token"))
success = curl:add_function("findFolder", setupCommand:get_as_string())
if not success then
    print(curl.last_error_text)
    return
end

-- Register findFile; registration sends no request.
setupCommand:set_string("curl -X GET \"https://api.box.com/2.0/folders/{{folder_id}}/items?limit=1000&fields=id,type,name\" -H \"Authorization: Bearer ACCESS_TOKEN\"")
setupReplacements = setupCommand:replace("ACCESS_TOKEN", curl:get_var("access_token"))
success = curl:add_function("findFile", setupCommand:get_as_string())
if not success then
    print(curl.last_error_text)
    return
end

-- Register findDestination; registration sends no request.
setupCommand:set_string("curl -X GET \"https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name\" -H \"Authorization: Bearer ACCESS_TOKEN\"")
setupReplacements = setupCommand:replace("ACCESS_TOKEN", curl:get_var("access_token"))
success = curl:add_function("findDestination", setupCommand:get_as_string())
if not success then
    print(curl.last_error_text)
    return
end

-- Register getFileDetails; registration sends no request.
setupCommand:set_string("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}?fields=id,sha1,file_version\" -H \"Authorization: Bearer ACCESS_TOKEN\"")
setupReplacements = setupCommand:replace("ACCESS_TOKEN", curl:get_var("access_token"))
success = curl:add_function("getFileDetails", setupCommand:get_as_string())
if not success then
    print(curl.last_error_text)
    return
end

-- Register getEnterprise; registration sends no request.
setupCommand:set_string("curl -X GET \"https://api.box.com/2.0/users/me?fields=enterprise\" -H \"Authorization: Bearer ACCESS_TOKEN\"")
setupReplacements = setupCommand:replace("ACCESS_TOKEN", curl:get_var("access_token"))
success = curl:add_function("getEnterprise", setupCommand:get_as_string())
if not success then
    print(curl.last_error_text)
    return
end

-- Register output rules once. Chilkat 11.7.0 evaluates {{name}} variables
-- when extracting each output, using the current value at that time.
success = curl:add_output2("findParent", "entries", "name", "{{parent_name}}", true, "id", "parent_id")
if not success then
    print(curl.last_error_text)
    return
end

success = curl:add_output2("findFolder", "entries", "name", "{{folder_name}}", true, "id", "folder_id")
if not success then
    print(curl.last_error_text)
    return
end

success = curl:add_output2("findFile", "entries", "name", "{{file_name}}", true, "id", "file_id")
if not success then
    print(curl.last_error_text)
    return
end

success = curl:add_output2("findDestination", "entries", "name", "{{destination_name}}", true, "id", "destination_id")
if not success then
    print(curl.last_error_text)
    return
end

success = curl:add_output("getFileDetails", "file_version.id", "file_version_id")
if not success then
    print(curl.last_error_text)
    return
end

success = curl:add_output("getFileDetails", "sha1", "file_sha1")
if not success then
    print(curl.last_error_text)
    return
end

success = curl:add_output("getEnterprise", "enterprise.id", "enterprise_id")
if not success then
    print(curl.last_error_text)
    return
end

-- 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.
local parentName = "/"
local folderName = "images"
local fileName = "penguins.jpg"
if (curl:get_var("parent_name") ~= parentName) or ((parentName == "/") and (not curl:var_defined("parent_id"))) then
    curl:set_var("parent_name", parentName)
    curl:clear_var("parent_id")
    curl:clear_var("folder_id")
    curl:clear_var("file_id")
    curl:clear_var("file_version_id")
    curl:clear_var("file_sha1")
    if parentName == "/" then
        curl:set_var("parent_id", "0")
    end
end

if curl:get_var("folder_name") ~= folderName then
    curl:set_var("folder_name", folderName)
    curl:clear_var("folder_id")
    curl:clear_var("file_id")
    curl:clear_var("file_version_id")
    curl:clear_var("file_sha1")
end

if curl:get_var("file_name") ~= fileName then
    curl:set_var("file_name", fileName)
    curl:clear_var("file_id")
    curl:clear_var("file_version_id")
    curl:clear_var("file_sha1")
end

curl:set_var("local_path", "qa_output/penguins-verified.jpg")
-- file_version_id is also unknown, so getFileDetails becomes a prerequisite.
-- Its AddOutput mappings cache both the selected version and its SHA-1.
curl:clear_target_output("*")
local authorizedCommand1 = chilkat.StringBuilder.new()
authorizedCommand1:set_string("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}/content?version={{file_version_id}}\" -H \"Authorization: Bearer {{access_token}}\" -L -o \"{{local_path}}\"")
local headerReplacement1 = authorizedCommand1:replace("{{access_token}}", curl:get_var("access_token"))
success = curl:do_your_thing(authorizedCommand1:get_as_string())
if (not success) or (curl.status_code ~= 200) then
    print("Box request failed. HTTP status: " .. curl.status_code)
    print("Failure reason: " .. curl.fail_reason)
    print(curl.response_body_str)
    return
end

local digest = chilkat.Crypt2.new()
digest.hash_algorithm = "sha1"
digest.encoding_mode = "hex_lower"
local actualSha1 = digest:hash_file_enc(curl:get_var("local_path"))
if not digest.last_method_success then
    print(digest.last_error_text)
    return
end

if actualSha1 ~= curl:get_var("file_sha1") then
    print("Downloaded content did not match the selected version's SHA-1.")
    return
end

print("Version-specific download verified.")