Required and scored predicates

[mhluongo]

And, it happened. We need a way to require, exclude, prefer, or not prefer based on predicates. The current plan is to add two additional fields to the get-or-create POST call. We're co-opting some terms from search engines here-

{
    "browser_name":"phantomjs",
    "require": ["and",
        ["session_tag", "starbucks"],
        ["not", ["node_tag", "starbucks"]],
        ["browser", "chrome"]
    ],
    "score": [
        ["2", ["node_tag", "starbucks"]],
        ["1", ["or", ["node_tag", "walmart"], ["session-tag", "starbucks"]]]
    ]
}

Basically, there are a few built-in domain predicates (session_tag, node_tag, browser, reserved, id) and the basic connectives.

Fun!

[mhluongo]

@chris-martin can you post the new example with the object-literal rows?

[chris-martin]

{
    "require": {
        "and": [
            {"session-tag": "starbucks"},
            {"not": {"node-tag": "starbucks"}},
            {"browser": "chrome"}
        ]
    },
    "score": [
        {
            "weight": "2",
            "require": {"node-tag": "starbucks"}
        },
        {
            "weight": "1",
            "require": {
                "or": [
                    {"node-tag": "walmart"},
                    {"session-tag": "starbucks"}
                ]
            }
        }
    ]
}

[mhluongo]

How did we decide we wanted to tackle this? Are you still going to take the initial req parsing / eval?

[chris-martin]

I'm doing that right now

[chris-martin]

Meh, going back to this

{
    "require": ["and", [
        ["session-tag", "starbucks"],
        ["not", ["node-tag", "starbucks"]],
        ["browser-name", "chrome"]
    ]],
    "score": [
        {
            "weight": "2",
            "require": ["node-tag", "starbucks"]
        },
        {
            "weight": "1",
            "require": ["or", [
                ["node-tag", "walmart"],
                ["session-tag", "starbucks"]
            ]]
        }
    ]
}

Changed browser to browser-name for consistency.

[chris-martin]

Slightly off-topic, but a discussion that spun out of this...

A breakdown of all of the properties that should be stored in redis about a session.

Mutable

• tags
• reserved

Immutable

• id
• node-id
• browser-name

Pulled from the webdriver

• current-url
• capabilities