# SpiderMan

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**SpiderMan,a fast high-level web crawling & scraping framework for Elixir.**

Inspired by [Crawly](https://github.com/elixir-crawly/crawly)(Elixir) and [Scrapy](https://github.com/scrapy/scrapy)(Python).

## Usage

This example show how to crawly data from
[elixir-jobs](https://elixirjobs.net/) website by use SpiderMan.

### Use in livebook

Import notebook from URL: [`elixirjobs.livemd`](./notebooks/elixirjobs.livemd)

### Use in script or mix project

```elixir
Mix.install([
  {:spider_man, "~> 0.4"},
  {:floki, "~> 0.31"},
  {:nimble_csv, "~> 1.1"}
])

defmodule SpiderList.ElixirJobs do
  @moduledoc false
  use SpiderMan
  require Logger
  alias SpiderMan.Response

  @base_url "https://elixirjobs.net/"

  def run do
    SpiderMan.run_until_zero(__MODULE__, [], 3_000)
  end

  @impl true
  def settings do
    requester_options = [
      base_url: @base_url,
      middlewares: [
        {SpiderMan.Middleware.UserAgent,
         [
           "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36",
           "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.114 Safari/537.36",
           "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.82 Safari/537.36",
           "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4389.82 Safari/537.36",
           "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4389.82 Safari/537.36",
           "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36"
         ]},
        {Tesla.Middleware.Headers,
         [
           {"referer", @base_url},
           {"accept",
            "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9"},
           {"accept-encoding", "gzip, deflate"},
           {"accept-language", "zh-CN,zh;q=0.9,zh-TW;q=0.8,en;q=0.7"}
         ]},
        Tesla.Middleware.DecompressResponse
      ]
    ]

    [
      downloader_options: [requester: {SpiderMan.Requester.Finch, requester_options}],
      spider_options: [pipelines: []],
      item_processor_options: [
        storage: [
          {SpiderMan.Storage.ETS, "./data/jobs.ets"},
          {SpiderMan.Storage.CSV,
           file: "./data/jobs.csv",
           headers: [
             :link,
             :title,
             :sub_title,
             :date,
             :workplace,
             :type
           ]}
        ]
      ]
    ]
  end

  @impl true
  def init(state) do
    build_request(@base_url)
    |> set_flag(:first_page)
    |> then(&SpiderMan.insert_request(__MODULE__, &1))

    state
  end

  @impl true
  def handle_response(%Response{env: env, flag: :first_page}, _context) do
    total_page =
      Regex.run(~r/Showing page 1 of (\d+)/, env.body, capture: :all_but_first)
      |> hd()
      |> String.to_integer()

    Logger.info("total: #{total_page}")

    requests =
      Enum.map(2..total_page, fn n ->
        build_request("/?page=#{n}")
        |> set_flag({:list_page, n})
      end)

    handle_list_page(env.body, 1)
    |> Map.put(:requests, requests)
  end

  def handle_response(%Response{env: env, flag: {:list_page, n}}, _context) do
    handle_list_page(env.body, n)
  end

  defp handle_list_page(body, n) do
    Logger.info("processing page #{n}")
    {:ok, document} = Floki.parse_document(body)

    jobs =
      Floki.find(document, ".offers-index")
      |> hd()
      |> Floki.children(include_text: false)
      |> Enum.filter(&match?({"a", _, _}, &1))

    items =
      Enum.map(jobs, fn job ->
        title = Floki.find(job, ".title strong") |> Floki.text() |> String.trim()
        sub_title = Floki.find(job, ".title small") |> Floki.text() |> String.trim()
        link = Floki.attribute(job, "a", "href") |> hd()

        [_, date, _, workplace, _, type] =
          Floki.find(job, ".control .tag")
          |> Enum.map(&(&1 |> Floki.text() |> String.trim()))

        build_item(
          link,
          %{
            link: @base_url <> String.slice(link, 1..-1),
            title: title,
            sub_title: sub_title,
            date: date,
            workplace: workplace,
            type: type
          }
        )
      end)

    %{items: items}
  end
end

SpiderList.ElixirJobs.run()
```

copy this script and save to `elixir_jobs.exs` and then start by command:
```shell
elixir elixir_jobs.exs
```

## Copyright and License

Copyright (c) 2021 feng19

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at [http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0)

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.