# `gno.land/p/moul/pageable`

Pagination for anything that can hand out a window of its items, plus the
Markdown page picker to navigate it.

Implement one method and you get pages, page sizes, reverse order, URL query
parsing and a rendered picker:

```go
type Pageable interface {
	Size() int
	IterateByOffset(offset, count int, cb func(index, value interface{}) bool) bool
}
```

Note the single `IterateByOffset`. Some structures expose separate forward and
reverse iteration; this interface deliberately does not. Direction is carried
by the sign of `count` (offset 0 count 5 gives items 0..4; offset 0 count -5
gives 4..0), and the implementation handles it internally, so the pager has one
code path instead of two.

## Use

```go
pager := pageable.NewPager(source, 10 /* default page size */, false /* reversed */)

page := pager.MustGetPageByPath(path)   // reads ?page= and ?size= from the path
out := ""
for _, item := range page.Items {
	out += "- " + item.Value.(string) + "\n"   // Item is {Index, Value interface{}}
}
out += page.Picker()                    // "1 | **2** | 3 | ..." as Markdown links
```

`GetPageByPath` returns an error instead of panicking; `MustGetPageByPath` is
the Render-side shorthand. `PickerWithPath(path)` preserves the other query
parameters (everything but `page`), which is what you want when the realm has
its own filters in the URL.

`GetPage(n)` and `GetPageWithSize(n, size)` skip URL parsing entirely.

`Page` also carries `TotalItems`, `TotalPages`, `HasPrev` and `HasNext`, so a
realm can render its own navigation instead of using `Picker()`.

## Nothing imports it

The package doc claims two consumers, `p/nt/avl/pager` and
`p/moul/ulist/pager`. Neither holds today: the upstream
[`p/nt/avl/pager`](https://github.com/gnolang/gno/tree/master/examples/gno.land/p/nt/avl/pager)
is a standalone AVL pager that does not import this interface, and
`p/moul/ulist/pager` does not exist in this repository (`p/moul/ulist` ships
`lplist`, not a pager). Grepping this repo, the only files mentioning
`pageable` are its own source and test.

So treat it as a proposed interface with a working reference implementation and
a 410-line test, not as load-bearing code. The package doc comment has been
corrected to say so.

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---

Part of **[moul/gno-contracts](https://github.com/moul/gno-contracts)** — moul's versioned gno.land contracts. See the repository for the full catalog, build/test tooling, and usage.

**Dependency graph:**

![gno.land/p/moul/pageable/v0 dependency graph](https://raw.githubusercontent.com/moul/gno-contracts/main/_assets/gno.land/p/moul/pageable/v0/deps.png)

> ⚠️ **Disclaimer:** provided as-is, without warranty; not security-audited. Full disclaimer: [DISCLAIMER](https://github.com/moul/gno-contracts/blob/main/DISCLAIMER.md).

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