Usage example ‐ Amazon (UK) Product Monitoring - huginn/huginn GitHub Wiki

Brief

This is an example of using the Huginn automation system to monitor the price of printer ink cartridges on the Amazon website.

Use Case:

You want to keep track of the price of a specific printer ink cartridge on Amazon UK and receive notifications when the price drops below a certain threshold.

Components

• Website Agent: Periodically checks price and color information, and stores the results as events.
• Email Agent: Sends notifications when events are received.
• Trigger Agent: Monitors price events and triggers new events when the price falls below a threshold.
• Formatter Agent: Formats event output to generate more user-friendly messages.

Applicable to other websites

• US website: Update links and currency symbols, as well as color spellings
• German website: Update links, replace "£" with "EUR "

JSON

{
    "schema_version": 1,
    "name": "Amazon Toner",
    "description": "No description provided",
    "source_url": false,
    "guid": "937f937533d4a490a02781381a763bf3",
    "tag_fg_color": "#ffffff",
    "tag_bg_color": "#5bc0de",
    "icon": "gear",
    "exported_at": "2016-10-03T16:58:25Z",
    "agents": [
        {
            "type": "Agents::EmailAgent",
            "name": "Amazon Toner Email Agent",
            "disabled": false,
            "guid": "230a06d95b01efcbd24f4f7b332506dc",
            "options": {
                "subject": "Amazon Toner On Sale",
                "headline": "",
                "expected_receive_period_in_days": "90",
                "body": "{{body_text}}"
            },
            "propagate_immediately": true
        },
        {
            "type": "Agents::WebsiteAgent",
            "name": "Amazon Toner Website Agent",
            "disabled": false,
            "guid": "2c1ea904fea73164ac69fe5ba657a5db",
            "options": {
                "expected_update_period_in_days": "90",
                "url": [
                    "https://www.amazon.co.uk/..."
                ],
                "type": "html",
                "mode": "on_change",
                "extract": {
                    "body_text": {
                        "xpath": "//*[@id=\"priceblock_ourprice\"]",
                        "value": "substring-after(.,\"£\")"
                    },
                    "url": {
                        "xpath": "//link[@rel='canonical']/@href",
                        "value": "."
                    },
                    "color": {
                        "xpath": "//*[@id=\"variation_color_name\"]/div/span",
                        "value": "normalize-space(.)"
                    }
                }
            },
            "schedule": "every_1h",
            "keep_events_for": 0,
            "propagate_immediately": true
        },
        {
            "type": "Agents::WebsiteAgent",
            "name": "Amazon Toner Website Agent Yellow",
            "disabled": false,
            "guid": "e7e4f3cfde6a14cbf8e7ec6ab6570772",
            "options": {
                "expected_update_period_in_days": "90",
                "url": [
                    "https://www.amazon.co.uk/..."
                ],
                "type": "html",
                "mode": "on_change",
                "extract": {
                    "body_text": {
                        "xpath": "//*[@id=\"priceblock_ourprice\"]",
                        "value": "substring-after(.,\"£\")"
                    },
                    "url": {
                        "xpath": "//link[@rel='canonical']/@href",
                        "value": "."
                    },
                    "color": {
                        "xpath": "//*[@id=\"prodDetails\"]/div/div[1]/div/div[2]/div/div/table/tbody/tr[5]/td[2]",
                        "value": "normalize-space(.)"
                    }
                }
            },
            "schedule": "every_1h",
            "keep_events_for": 0,
            "propagate_immediately": true
        },
        {
            "type": "Agents::TriggerAgent",
            "name": "Amazon Toner Trigger Agent",
            "disabled": false,
            "guid": "eaf805c6260c26c948bf291608e2ceb5",
            "options": {
                "expected_receive_period_in_days": "1",
                "keep_event": "false",
                "rules": [
                    {
                        "type": "field<value",
                        "value": "99",
                        "path": "body_text"
                    }
                ],
                "message": "{{agent}} toner on sale for {{body_text}}. <a href=\"{{url}}\">{{url}}</a>"
            },
            "keep_events_for": 0,
            "propagate_immediately": true
        },
        {
            "type": "Agents::EventFormattingAgent",
            "name": "Amazon Toner Formatting",
            "disabled": false,
            "guid": "f3b7087e155ec7d9c4a5898d06f33615",
            "options": {
                "instructions": {
                    "message": "Amazon Toner On Sale",
                    "agent": "{{color}}",
                    "subject": "{{body_text}}",
                    "body_text": "{{body_text}}",
                    "url": "{{url}}"
                },
                "matchers": [

                ],
                "mode": "clean"
            },
            "keep_events_for": 0,
            "propagate_immediately": true
        }
    ],
    "links": [
        {
            "source": 1,
            "receiver": 4
        },
        {
            "source": 2,
            "receiver": 4
        },
        {
            "source": 3,
            "receiver": 0
        },
        {
            "source": 4,
            "receiver": 3
        }
    ],
    "control_links": [

    ]
}