Task Management

get_task_status()

Get current task status:

require 'legnext_sdk'

# Configure API client
Legnext.configure do |config|
  config.api_key['x-api-key'] = ENV['LEGNEXT_API_KEY']
  config.host = 'api.legnext.ai'
  config.base_path = '/api'
end

task_api = Legnext::TaskManagementApi.new

begin
  job_id = 'job-123'
  task = task_api.get_task_status(job_id)

  puts "Status: #{task.status}"
  puts "Progress: #{task.progress}%"

  if task.status == 'completed'
    puts "Result: #{task.output}"
  end

rescue Legnext::ApiError => e
  puts "Error: #{e.message}"
end

Polling for Completion

Wait for task completion with polling:

def wait_for_completion(task_api, job_id, timeout_seconds = 300, poll_interval_seconds = 3)
  start_time = Time.now
  timeout = timeout_seconds

  loop do
    task = task_api.get_task_status(job_id)

    puts "Current status: #{task.status}"

    if task.status == 'completed'
      puts "Task completed successfully!"
      puts "Output: #{task.output}"
      return task
    elsif task.status == 'failed'
      raise "Task failed: #{task.error}"
    end

    # Check timeout
    elapsed = Time.now - start_time
    if elapsed > timeout
      raise "Task timeout after #{timeout_seconds} seconds"
    end

    # Wait before next poll
    sleep poll_interval_seconds
  end
end

Usage:

task_api = Legnext::TaskManagementApi.new
job_id = 'job-123'

begin
  result = wait_for_completion(task_api, job_id, 300, 3)
  puts "Final result: #{result}"
rescue StandardError => e
  puts "Error: #{e.message}"
end

Complete Example with Error Handling

require 'legnext_sdk'

# Configure API client
Legnext.configure do |config|
  config.api_key['x-api-key'] = ENV['LEGNEXT_API_KEY']
  config.host = 'api.legnext.ai'
  config.base_path = '/api'
end

def wait_for_completion(task_api, job_id, timeout_seconds = 300, poll_interval_seconds = 3)
  start_time = Time.now
  timeout = timeout_seconds

  loop do
    task = task_api.get_task_status(job_id)

    if task.status == 'completed'
      return task
    elsif task.status == 'failed'
      raise "Task failed: #{task.error}"
    end

    elapsed = Time.now - start_time
    if elapsed > timeout
      raise "Task timeout after #{timeout_seconds} seconds"
    end

    sleep poll_interval_seconds
  end
end

def generate_image_with_polling
  image_api = Legnext::ImageGenerationApi.new
  task_api = Legnext::TaskManagementApi.new

  # Step 1: Start generation
  request = Legnext::DiffusionRequest.new(
    text: 'a beautiful sunset over mountains'
  )

  response = image_api.generate_image(request)
  job_id = response.job_id

  puts "Job started: #{job_id}"

  # Step 2: Poll for completion
  result = wait_for_completion(task_api, job_id, 600, 3)

  # Step 3: Get final result
  if result.output && result.output.image_urls
    puts "Image URLs: #{result.output.image_urls}"
  end

rescue Legnext::ApiError => e
  handle_api_error(e)
rescue StandardError => e
  puts "Error: #{e.message}"
end

def handle_api_error(error)
  case error.code
  when 400
    puts "Validation error: #{error.response_body}"
  when 401
    puts "Authentication error: Invalid API key"
  when 404
    puts "Resource not found: #{error.response_body}"
  when 429
    puts "Rate limit exceeded. Please retry later."
  when 500, 502, 503
    puts "Server error: #{error.response_body}"
  else
    puts "API error (#{error.code}): #{error.response_body}"
  end
end

generate_image_with_polling

Error Handling

HTTP Error Handling:

begin
  task = task_api.get_task_status(job_id)

rescue Legnext::ApiError => e
  case e.code
  when 400
    puts "Validation error: Check request parameters"
  when 401
    puts "Authentication error: Invalid API key"
  when 404
    puts "Resource not found: Check job ID exists"
  when 429
    puts "Rate limit exceeded. Please retry later."
  when 500, 502, 503
    puts "Server error. Please retry with backoff."
  else
    puts "API error (#{e.code}): #{e.message}"
  end
  puts "Response body: #{e.response_body}"
end

Common HTTP Status Codes:

Status Code	Description	Action
400	Invalid request parameters	Check request body format
401	Invalid API key	Verify API key is correct
404	Resource not found	Check job ID exists
429	Rate limit exceeded	Wait and retry with backoff
500/502/503	Server error	Retry with exponential backoff

Retry Logic with Exponential Backoff:

def call_with_retry(image_api, request, max_retries = 3)
  retries = 0

  begin
    image_api.generate_image(request)

  rescue Legnext::ApiError => e
    if e.code == 429 && retries < max_retries
      # Rate limited - wait and retry
      retries += 1
      sleep 5
      retry
    elsif e.code >= 500 && retries < max_retries
      # Server error - exponential backoff
      retries += 1
      delay = 2**retries
      sleep delay
      retry if retries < max_retries
      raise
    else
      # Other errors - don't retry
      raise
    end
  end
end

# Usage
image_api = Legnext::ImageGenerationApi.new
request = Legnext::DiffusionRequest.new(text: 'a beautiful landscape')

begin
  response = call_with_retry(image_api, request, 3)
  puts "Job ID: #{response.job_id}"
rescue Legnext::ApiError => e
  puts "Failed after retries: #{e.message}"
end

Concurrent Operations with Threads

For processing multiple tasks concurrently:

require 'thread'

def generate_multiple_images
  Legnext.configure do |config|
    config.api_key['x-api-key'] = ENV['LEGNEXT_API_KEY']
    config.host = 'api.legnext.ai'
    config.base_path = '/api'
  end

  image_api = Legnext::ImageGenerationApi.new
  task_api = Legnext::TaskManagementApi.new

  prompts = ['sunset', 'mountains', 'ocean']
  threads = []
  results = Queue.new

  prompts.each do |prompt|
    threads << Thread.new do
      begin
        # Start generation
        request = Legnext::DiffusionRequest.new(text: prompt)
        response = image_api.generate_image(request)
        job_id = response.job_id

        # Wait for completion
        result = wait_for_completion(task_api, job_id, 600, 3)

        if result.output && result.output.image_urls && !result.output.image_urls.empty?
          results << { prompt: prompt, url: result.output.image_urls[0] }
        end

      rescue StandardError => e
        results << { prompt: prompt, error: e.message }
      end
    end
  end

  # Wait for all threads
  threads.each(&:join)

  # Collect results
  all_results = []
  all_results << results.pop until results.empty?

  all_results.each do |result|
    if result[:error]
      puts "Error for '#{result[:prompt]}': #{result[:error]}"
    else
      puts "Image '#{result[:prompt]}': #{result[:url]}"
    end
  end
end

generate_multiple_images

Progress Callbacks

def wait_for_completion_with_progress(task_api, job_id, timeout_seconds = 300, poll_interval_seconds = 3, &block)
  start_time = Time.now
  timeout = timeout_seconds

  loop do
    task = task_api.get_task_status(job_id)

    # Call progress callback
    if block_given?
      progress = task.progress || 0
      status = task.status || 'unknown'
      yield(progress, status)
    end

    if task.status == 'completed'
      return task
    elsif task.status == 'failed'
      raise "Task failed: #{task.error}"
    end

    elapsed = Time.now - start_time
    if elapsed > timeout
      raise "Task timeout after #{timeout_seconds} seconds"
    end

    sleep poll_interval_seconds
  end
end

# Usage
task_api = Legnext::TaskManagementApi.new
job_id = 'job-123'

result = wait_for_completion_with_progress(task_api, job_id, 600, 3) do |progress, status|
  puts "Progress: #{progress}% - Status: #{status}"
end

Using Fibers for Cooperative Multitasking

require 'fiber'

def create_image_fiber(image_api, task_api, prompt)
  Fiber.new do
    # Start generation
    request = Legnext::DiffusionRequest.new(text: prompt)
    response = image_api.generate_image(request)
    job_id = response.job_id

    Fiber.yield job_id

    # Poll for completion
    loop do
      task = task_api.get_task_status(job_id)

      if task.status == 'completed'
        Fiber.yield task.output
        break
      elsif task.status == 'failed'
        raise "Task failed: #{task.error}"
      end

      Fiber.yield :pending
      sleep 3
    end
  end
end

# Usage
Legnext.configure do |config|
  config.api_key['x-api-key'] = ENV['LEGNEXT_API_KEY']
  config.host = 'api.legnext.ai'
  config.base_path = '/api'
end

image_api = Legnext::ImageGenerationApi.new
task_api = Legnext::TaskManagementApi.new

fiber = create_image_fiber(image_api, task_api, 'a beautiful landscape')

job_id = fiber.resume
puts "Job started: #{job_id}"

loop do
  result = fiber.resume
  break unless fiber.alive?

  if result == :pending
    puts "Still processing..."
  elsif result
    puts "Result: #{result}"
  end
end

Overview

Client Libraries

get_task_status()

Polling for Completion

Complete Example with Error Handling

Error Handling

Concurrent Operations with Threads

Progress Callbacks

Using Fibers for Cooperative Multitasking

Learn More

Overview

Client Libraries

​get_task_status()

​Polling for Completion

​Complete Example with Error Handling

​Error Handling

​Concurrent Operations with Threads

​Progress Callbacks

​Using Fibers for Cooperative Multitasking

​Learn More

get_task_status()

Polling for Completion

Complete Example with Error Handling

Error Handling

Concurrent Operations with Threads

Progress Callbacks

Using Fibers for Cooperative Multitasking

Learn More