Lua Requires Chilkat v11.7.0+

Box: Reuse HttpCurl and Invalidate Cached IDs

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. 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.

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.jpg")
-- Operation 1: get information by name. This resolves folder_id and file_id.
curl:clear_target_output("*")
local authorizedCommand1 = chilkat.StringBuilder.new()
authorizedCommand1:set_string("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}?fields=id,name\" -H \"Authorization: Bearer {{access_token}}\"")
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

-- Operation 2: keep the same object and IDs. Only the final download is needed.
local warmPlan = chilkat.JsonObject.new()
warmPlan.emit_compact = false
local authorizedCommand2 = chilkat.StringBuilder.new()
authorizedCommand2:set_string("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}/content\" -H \"Authorization: Bearer {{access_token}}\" -L -o \"{{local_path}}\"")
local headerReplacement2 = authorizedCommand2:replace("{{access_token}}", curl:get_var("access_token"))
success = curl:examine_plan(authorizedCommand2:get_as_string(), warmPlan)
if not success then
    print(curl.last_error_text)
    return
end

print(warmPlan:emit())
curl:clear_target_output("*")
local authorizedCommand3 = chilkat.StringBuilder.new()
authorizedCommand3:set_string("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}/content\" -H \"Authorization: Bearer {{access_token}}\" -L -o \"{{local_path}}\"")
local headerReplacement3 = authorizedCommand3:replace("{{access_token}}", curl:get_var("access_token"))
success = curl:do_your_thing(authorizedCommand3: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

-- 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.
curl:clear_var("file_id")
curl:clear_var("file_version_id")
curl:clear_var("file_sha1")
curl:set_var("file_name", "penguins.jpg")
curl:set_var("local_path", "qa_output/penguins-copy.jpg")
local authorizedCommand4 = chilkat.StringBuilder.new()
authorizedCommand4:set_string("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}/content\" -H \"Authorization: Bearer {{access_token}}\" -L -o \"{{local_path}}\"")
local headerReplacement4 = authorizedCommand4:replace("{{access_token}}", curl:get_var("access_token"))
success = curl:examine_plan(authorizedCommand4:get_as_string(), warmPlan)
if not success then
    print(curl.last_error_text)
    return
end

print(warmPlan:emit())
curl:clear_target_output("*")
local authorizedCommand5 = chilkat.StringBuilder.new()
authorizedCommand5:set_string("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}/content\" -H \"Authorization: Bearer {{access_token}}\" -L -o \"{{local_path}}\"")
local headerReplacement5 = authorizedCommand5:replace("{{access_token}}", curl:get_var("access_token"))
success = curl:do_your_thing(authorizedCommand5: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

-- 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.