Smart Page List

[0xDing]

Problem

Articulate the problem that this piece of work addresses

We need a smart page list block inspired by macOS' smart folders to improve the experience of organising pages.

Why is this the right time to address this problem?

Time Budget

2 weeks

Solution

• Users can insert Smart Page List blocks via /smartpagelist.
• The user can set the filter conditions by popover and the smart list block will display the pages with the compound conditions as a link list.

Out of Bounds

• Caching of list results is currently not supported for the time being.
• Currently only the parent page is x filter needs to be supported

Rabbitholes

• Do we need to support views other than link lists?

[stackia]

owner @clszzyh

[toadfanszz]

Summary

Smart Page List is a new block to provide an ability for user to search page dynamically.

Core Lifestyle

Parse and Interpret

Filter Strategies is registered dynamically.

const smartPageListInterpreter = new FormulaInterpreter({
  version: "v1",
  lexer: [
    WHITESPACE_TOKEN, 
    AND_TOKEN, 
    OR_TOKEN,
    LParen, RParen // To support the parenthesis.
  ],
  parser: [
    combineExpression,
    parenthesisExpression // To support the parenthesis.
  ],
  interpreter: [
    combineInterpret
  ],
  filterStrategies: [
    parentPageFilter,
    ...
  ],
  ...
})

Usage:

const filterPredicate = smartPageListInterpreter.parse(' ParentPageIs("current page name") OR ParentPageIs("other page name") ')

typeof filterPredicate 

interface ParseResult {
  success: boolean
  codeFragments: CodeFragment[]
}

interface SuccessParseResult extends ParseResult {
  success: true
  predicate: (aPage: PageType) => [true, MatchReasonIfNeed] | [false]
}

interface ErrorParseResult extends ParseResult {
  success: false
  errorMessage: [ErrorMessage, ...ErrorMessage[]]
}

Apply filter

const pageList = currentPages.filter(p => filterPredicate.predicate(p))

Filter is only on the frontend since fat client.

Process result

1. Add result pages to current page's linked page. Refer to Use WinFS-style graph model instead of block tree model #392
2. Add subscription to result pages, if one of them is deleted, then automatic delete it from result area or trigger re-filter.
3. (Maybe) Write cache. See Cache Section.

Filter Strategy

1. parent page is (default)

• Accept page name array.
• Subscribe rename page event, automatic update filter condition.

const parentPageFilter = new SmartPageFilter({
  name: 'parentPageIs',
  events: [{ event: PageRenameEvent, ... }],
  handleParse: () => {},
  handleInterpret: () => {},
  accept: PageNamePopover
})

2. tag is

• Accept tag name array.
• Subscribe rename tag event, automatic update filter condition.

3. creator is

• Accept creator name array
• Subscribe member add / remove event.

4. createdAt is

Combine Strategy

Simple Automatic Merge By Formula

tag is "A" AND tag is "B" equals tag is ("A" AND "B")
parent page is "foo" OR parent page is "bar" equals parent page is ("foo" OR "bar")

1. And

This is the default operator.

Usages:

1. tag is "A" AND tag is "B", support short-circuit
2. tag is ("A" AND "B")

2. Or

Usages:

1. parent page is "foo" OR parent page is "bar", support short-circuit
2. parent page is ("foo" OR "bar"), same as ["foo", "bar"]

Cache Strategy

Backend caching of list results is currently not supported.
Page List is always re-filtered when page is reload.

Persist

SmartPageList is a Prosemirror Node and attrs is saved in data field.

data

{
  "version": "v1",
  "filter": "ParentPageIs(\"current page name\") OR ParentPageIs(\"other page name\")"
}

Result View

interface FilterResult {
  pageId: string
  pageName: string
  index: number
}

1. Page List

Icon + Title

2. Page Card

Display the preview images of each result page in card format.

More menu

1. Sort
2. Limit

Timing of Re-filter

1. Cache is empty

page is first load

2. Global Event

• PageCreate
• PageDelete
• PageRestore
• ...

3. User manual trigger update

Action

Formula

1. Move old formula to legacy-formula, extract core part of formula to formula

Rabbitholes

1. Maybe we should rename Smart Page List to Smart Page if we need to support card view.