--- title: "リンクカード" description: "1 つのリンクをブロックとして描きます。リンク先のタイトル、それを説明する文、画像、掲載サイトを、渡された値から描き、自分では何も読み込みません。" url: "https://tanrei.chnotchy.com/ja/components/link-card/" last_updated: 2026-10-23T21:17:12.000Z --- # リンクカード > 1 つのリンクをブロックとして描きます。リンク先のタイトル、それを説明する文、画像、掲載サイトを、渡された値から描き、自分では何も読み込みません。 ## 概要 リンクカードは、リンク先をそれ自体ひとまとまりのものとして見せます。タイトル、それを説明する文、あれば画像、そして掲載サイトです。全体で 1 つのリンクです。ブロック全体を押すことができ、中の一部だけを押すことはできません。 - 文の中でどこかへ導く語句は[リンク](https://tanrei.chnotchy.com/ja/components/link/)です。 - プロダクト側のコンテンツをまとめ、全体でどこかへ導くものは、リンク先を持つ[カード](https://tanrei.chnotchy.com/ja/components/card/)です。 - 独自のボタン（保存、共有、閉じる）を持つプレビューは、リンクとそれらのボタンを収めたカードです。 **このコンポーネントは何も取得しません。** 渡された値を描くだけで、`href` について、リンク先にも、プロキシにも、どのサービスにも問い合わせません。行うリクエストは、渡された画像とサイトのアイコンに対するものだけです。サイトが値を得る方法は[値の用意](https://tanrei.chnotchy.com/ja/components/link-card/#%E5%80%A4%E3%81%AE%E7%94%A8%E6%84%8F)で説明します。 Web では、プロダクト側の `` を囲む `` です。この要素はシャドウルートを持たないので、カードはスクリプトが動く前からリンクとして働きます。ほかのプラットフォームはまだ実装していません。 ### 使い方 **Web** ```html トークンで設計する わずかなダイヤルから、システム全体ができるまで。 Example Journal example.com 外部リンク ``` **React** ```tsx import { LinkCard } from '@tanrei/react'; import '@tanrei/web/icons.css'; import '@tanrei/web/link-card.css'; ``` このマークアップを手で書く必要はありません。`@tanrei/web/links` の `linkCardToHtml()` と `linkCardToNodes()` が値から書き出すので、カードは最初の描画の時点で、スクリプトが無効でも、完全な形で表示されます。 ### スクリプトで組み立てるカード `` を含まない `` は、属性から `` を組み立てます。値はどれもテキストとして書き込まれ、マークアップとして解釈されることはありません。 ```html ``` タイトルの属性は `headline` です。HTML の `title` を使うと、カード全体にツールチップが出てしまうためです。この形はスクリプトが動いてから描かれます。コンテンツのページでは、ビルド時にマークアップを書き出してください。 ## 仕様 - Category: Navigation - Level: base - Listing: default - Page: https://tanrei.chnotchy.com/components/link-card/ - Spec: https://github.com/chnotchy/tanrei/blob/main/specs/link-card.spec.json ### Availability | Design system | Has it | Notes | | --- | --- | --- | | Tanrei (`tanrei`) | Yes | — | | Cupertino (Apple HIG-inspired) (`cupertino`) | Yes | — | | M3 Expressive-like (Material 3 Expressive-inspired) (`m3-expressive-like`) | Yes | — | | M3-like (Material 3-inspired) (`m3-like`) | Yes | — | ### Platforms - Web: the element ``, registered by importing `@tanrei/web` (or only its own module, `@tanrei/web/components/link-card`). - React: `LinkCard` from `@tanrei/react`. | Platform | Name | Status | | --- | --- | --- | | Web | `tanrei-link-card` | lagging | | SwiftUI | `TanreiLinkCard` | planned | | Jetpack Compose | `TanreiLinkCard` | planned | | Flutter | `TanreiLinkCard` | planned | | React Native | `LinkCard` | planned | Names a platform gives in its own idiom: | Spec | Web | SwiftUI | Jetpack Compose | Flutter | React Native | | --- | --- | --- | --- | --- | --- | | `href` (prop) | `href` | `destination` | `href` | `href` | `href` | | `targetLabel` (prop) | `targetLabel` | `targetLabel` | `targetLabel` | `targetSemanticLabel` | `targetLabel` | | `externalLabel` (prop) | `externalLabel` | `externalLabel` | `externalLabel` | `externalSemanticLabel` | `externalLabel` | | `title` (prop) | `headline` | `title` | `title` | `title` | `title` | | `imageAlt` (prop) | `imageAlt` | `imageDescription` | `imageDescription` | `imageSemanticLabel` | `imageAccessibilityLabel` | | `click` (event) | `click` | `action` | `onClick` | `onPressed` | `onPress` | Statuses: `planned` — In the inventory. Nothing shippable exists yet. `lagging` — An implementation of an earlier spec exists; it has not caught up with the current one. `alpha` — Implemented with tests. The API may still change. `beta` — Feature complete and at parity. Only fixes are expected. `stable` — Covered by semantic versioning. `deprecated` — Still shipped; scheduled for removal. ### Anatomy - `container`: The shape that holds everything, clips it to its corners and carries hover, focus and press. It is the link: one element, pressed as a whole. - `outline` (optional): The edge of the outlined look, drawn above the picture. - `title`: The destination's title, at a heading's weight, on a few lines at most. The card's accessible name. Where there is none, the address stands in its place. - `description` (optional): A sentence or two about the destination, quieter than the title, on a few lines at most. - `site` (optional): The line that says where the card leads: the site's icon, its name, the host and the mark, in that order. The host is computed from the destination's address and is never cut. - `site-icon` (optional): The site's small icon, a picture the card is given. Decorative. - `host` (optional): The host of the destination's address, as the card reads it from href: the one part of the card that no given value can change. - `mark` (optional): The one glyph at the end of the site line that says where following the card takes the person: open_in_new for a destination that opens a new context, arrow_outward for one that leaves the site and opens where the person is. Never both. Decorative; what it means is said in words. - `media` (optional): The box of the destination's picture: beside the text at the end edge of a wide card, above the text in a narrow one. The picture covers it and is cropped by it. Decorative unless the product says what it shows. - `focus-ring`: The indicator shown for keyboard focus, around the whole card. ### Props | Prop | Type | Default | Web attribute | Description | | --- | --- | --- | --- | --- | | `href` | `string` | `""` | `href` | The destination: an address as the platform's links take one (a URL; on the web a path or a fragment as well). It is also the one thing the card reads the host from (LKC-8). A link card without a destination is not a link and is not drawn as a card (LKC-27). | | `target` | `enum`: `same`, `new` | `"same"` | `target` | Where the destination opens. same: where the person is — the same tab on the web, the app's own handling of the address elsewhere. new: a new context — a new tab or window on the web, outside the current screen elsewhere — which the card marks with the glyph open_in_new at the end of its site line and says through targetLabel (LKC-23). | | `targetLabel` | `string` | `""` | `target-label` | What assistive technology reads at the end of the card's description while target is new ("opens in a new tab"). Tanrei ships no words of its own, so the product gives them in its language. Required while target is new; ignored otherwise. | | `external` | `enum`: `auto`, `on`, `off` | `"auto"` | `external` | Whether the destination is on another site than the one the person is on: the same prop, with the same values and the same rule, as the Link's (LNK-30). auto: the card decides as the Link does, where the platform can tell. on: it is external, whatever the address. off: it is not. An external card that opens where the person is draws the arrow at the end of its site line and says so through externalLabel (LKC-24). It changes nothing else: the host is drawn whether the destination is external or not. | | `externalLabel` | `string` | `""` | `external-label` | What assistive technology reads at the end of the card's description while the destination is external and target is same ("external link"), in the product's language. Empty, the words the product has set once for every external link are read, as for the Link (LNK-34). Ignored while target is new. | | `title` | `string` | `""` | — | The destination's title: what the page calls itself. Plain text; it is the card's accessible name. Drawn on at most two lines by default. Empty, the address is drawn in its place (LKC-5). | | `description` | `string` | `""` | `description` | A sentence or two about the destination. Plain text; it is the first part of the card's description for assistive technology. Drawn on at most two lines by default; empty, nothing is drawn for it. | | `image` | `string` | `""` | `image` | The address of a picture that stands for the destination. It is drawn beside the text in a wide card and above it in a narrow one, cropped to its box. The card asks for this address and for nothing else about the destination (LKC-14); a site should keep the picture among its own files rather than name the destination's. Empty, or failing to load, the card is drawn without a picture. | | `imageAlt` | `string` | `""` | `image-alt` | What the picture shows, in the product's language, where that is worth saying. Empty — the usual case — the picture is decoration: the title and the description already say where the card leads. Never drawn; read as part of the description (LKC-25). | | `siteName` | `string` | `""` | `site-name` | What the destination's site calls itself ("Example Journal"). Plain text, drawn before the host on the site line and cut first when the line is short. It never replaces the host, and it is not drawn where it only repeats it (LKC-7). | | `siteIcon` | `string` | `""` | `site-icon` | The address of the destination site's small icon, given to the card and never looked up by it: the same value, resolved the same way, as the Link's site icon. Drawn at the start of the site line; empty or failing to load, nothing is drawn in its place. | | `variant` | `enum`: `outlined`, `filled` | `"outlined"` | `variant` | How the card is set apart. outlined: the surface inside one hairline, for running text and the page's own surface. filled: a tone of the surface and no edge, where one more line would crowd. It changes colors and the edge only. A design system may add values. | ### Events | Event | Description | | --- | --- | | `click` | The card was activated by pointer, touch, Enter or assistive technology. It is emitted before the destination opens; a product that takes the navigation itself (a client-side router) cancels it (LKC-22). | ### States `enabled`, `hovered`, `focused`, `pressed` ### Accessibility - Role: `link` - Labeling: The card is one link. Its name is the title (the address where there is none), and nothing is added to the name. Its description is, in order, the description, the picture's alternative text where the product gives one, the site's name, the host and last — while target is new — targetLabel, or — while the destination is external and target is same — externalLabel or the product's words for every external link. The picture, the site icon, the dot and the marks are decorative. A title that is cut on the screen is exposed whole. - Minimum target size: yes | Keys | Action | | --- | --- | | Tab | Moves focus to the card: one stop, whatever it shows. | | Enter | Follows the link. Space does what it does on any link (on the web it scrolls the page). | - A link card is told as a link by being one bounded block that answers the pointer and the keyboard as a whole, not by an underline or a color: it is not a phrase inside a sentence, where WCAG 1.4.1 asks for more than color. In forced colors the title takes the platform's link color and both looks have an edge (LKC-30). - The host is for everyone. A reader who cannot see the site line hears the host in the description, computed from the address exactly as the drawn one is (LKC-8, LKC-25); a destination cannot hide where it leads from either. - Text that is cut (LKC-4, LKC-6) is a preview of a page, not content of this one: all of it reaches assistive technology, and the whole of it is one press away. Do not put text a reader must have into a link card. - The picture is decoration by default, because the title already names the destination; give imageAlt only where the picture says something the text does not. A picture that fails or has not arrived exposes nothing. - Nothing inside a link card is a control. A preview with its own buttons (save, share, dismiss) is a Card that holds a Link and those buttons, not a link card. - The card keeps its focus ring clear of the picture: the ring is drawn outside the container, so a picture of any color cannot hide it. - Text must remain readable at 200% text size: the card has no fixed height, counts lines rather than points, and moves its picture above the text when the text needs the room (LKC-29). - Contrast in the default system: the title is the surface's text color and the description and the site line the secondary text color, on fills of the surface ladder — pairs the token invariants hold at 4.5:1 (7:1 in the high-contrast schemes). The outlined look's edge is decorative: the card is found by its text. - No visited state (LKC-26). - How a state looks is a value decision of the active design system (a state-layer mix in Tanrei, a dim or no hover at all elsewhere). The link card reads the state's tokens and never computes the effect itself. - Web: the card is the product's own anchor in the document, wrapped by an element with no shadow root, so it is a link before any script runs and for whatever reads the page as built. Once defined, the element names the anchor by the title's element and describes it by the others (aria-labelledby, aria-describedby with ids it writes); before that the anchor is named by all of its text in reading order, which says the same things in one breath. ### Behaviour Requirements in EARS form, each with its stable id. - **LKC-1** WHILE href is a destination THE link card SHALL be the platform's own link to it (the web's anchor element in the document itself, not in a shadow root; SwiftUI's Link; on Compose, Flutter and React Native an element with the platform's link semantics whose address is opened by the platform's opener), so that whatever the platform gives a link — on the web its context menu, opening in a new tab or window, copying and dragging its address, the address shown before it is followed, a crawler and a search index that read it, and a link that works before any script has run — is the platform's, and not the link card's to draw or to take over; it SHALL be exactly one focusable element with the link role, and everything it draws SHALL be the presentational content of that one element. - **LKC-2** THE link card SHALL lay itself out as a block in the flow of its container: it SHALL take the whole inline size the container gives it, with its start edge on the start edge of the text around it, SHALL bring no outer space of its own (PRS-15: the space between it and its neighbours is its container's), SHALL never be wider than its container, and SHALL be exactly as tall as what it holds, with no height of its own. It SHALL draw a container with corners comp.link-card.container.shape, filled with the container color of its variant (comp.link-card.outlined.container.color for outlined, comp.link-card.filled.container.color for filled), SHALL clip everything it draws to that shape, SHALL draw the outline of its variant (comp.link-card.outlined.outline.color, comp.link-card.filled.outline.color) comp.link-card.outline.width wide inside the container's size and above the picture, and SHALL draw no elevation. - **LKC-3** THE link card SHALL draw its text in a body padded by comp.link-card.container.padding on every side: from top to bottom the title (LKC-4, LKC-5); the description where there is one (LKC-6), comp.link-card.title.gap below the title; and the site line where there is one (LKC-7), comp.link-card.site.gap below the text above it. A part that is not drawn SHALL take no room and leave no gap, and the body SHALL place its text at the start edge in every layout. - **LKC-4** THE link card SHALL draw title in comp.link-card.title.typescale and in the title color of its variant and state (comp.link-card.outlined.title.color for outlined, comp.link-card.filled.title.color for filled), on at most comp.link-card.title.max-lines lines: a longer title SHALL be cut at the end of its last drawn line, where its own direction ends, with an ellipsis, and a run with no place to break that is longer than the line SHALL break inside the run rather than overflow. THE link card SHALL draw no underline under the title, SHALL expose the whole title to assistive technology whatever part of it is drawn, and SHALL NOT expose it as a heading. THE link card SHALL set the title's letter-spacing by the script of its text, as every title is set (PRS-20): no negative letter-spacing WHERE its language is Chinese, Japanese or Korean, and none WHERE its script joins its letters or stacks marks on them. - **LKC-5** WHILE title is empty or only white space THE link card SHALL draw the address of href, as it was given, in the title's place and style — as one left-to-right run that may break anywhere, held to the same number of lines — SHALL be named by that address, and in debug builds SHALL report that a link card has no title. - **LKC-6** WHILE description is not empty THE link card SHALL draw it in comp.link-card.description.typescale and in the description color of its variant and state (comp.link-card.outlined.description.color for outlined, comp.link-card.filled.description.color for filled), on at most comp.link-card.description.max-lines lines, cut as LKC-4 cuts the title, and SHALL expose the whole of it; WHILE description is empty or only white space it SHALL draw nothing for it. - **LKC-7** WHERE the link card has a host (LKC-8), a site name or a mark (LKC-23, LKC-24) THE link card SHALL draw a site line in comp.link-card.site.typescale and in the site color of its variant and state (comp.link-card.outlined.site.color for outlined, comp.link-card.filled.site.color for filled), holding in reading order the site icon (LKC-10), the site's name, the host and the mark, comp.link-card.site.item-gap apart and each centred on the height of the line's first row; WHERE both the site's name and the host are drawn it SHALL draw a middle dot between them, kept from assistive technology. THE link card SHALL draw siteName as the site's name, on one line, and SHALL NOT draw it WHILE it is empty or says only what the host says (the same characters without regard to case, with or without a leading "www."). WHERE the line is too narrow THE site's name SHALL give way first — cut at its own end with an ellipsis, and left out together with the dot where not even its first character and an ellipsis fit — and THE host SHALL never be cut, shortened or ended with an ellipsis: a host longer than the line SHALL run onto further lines, breaking after a dot and, where one label is longer than the line, inside it, with the mark after its last character. - **LKC-8** THE link card SHALL compute the host it draws from href and from nothing else: the host name the platform's address parser reads from href, in lower case, followed by a colon and the port where href names a port that is not its scheme's own; never a user name or a password written before the host, never a path, a query or a fragment; and never anything taken from title, description, siteName or any other value it is given. No prop SHALL set, replace or hide the host. WHILE href has no host of its own — a path, a fragment, an address relative to the page, a scheme that has none — THE link card SHALL draw no host. - **LKC-9** WHERE a label of the host is the ASCII form of an internationalised name (it begins with "xn--") THE link card SHALL draw the whole host in its Unicode form only WHILE every such label of it (a) decodes, and encodes back to exactly the label it was; (b) holds nothing but letters, combining marks, the digits 0 to 9 and the hyphen; (c) has all of its letters in one script, or in one of the sets a single writing system uses together — Latin with Han, Hiragana and Katakana; Latin with Han and Hangul; Latin with Han and Bopomofo — where the Latin of each set is the ASCII letters a to z alone, so that a Latin letter with a mark beside Han keeps the ASCII form; and (d) is not written wholly in Cyrillic or wholly in Greek under a last label that is ASCII. In every other case THE link card SHALL draw the whole host in the ASCII form the address parser gives, never a part of it in each form. THE link card SHALL draw the host as one left-to-right run, isolated from the text beside it, with its labels in the address's own order, in every layout direction. A platform that cannot decode a label or cannot tell the script of a character SHALL draw the ASCII form always, and state that in its README. - **LKC-10** WHILE siteIcon is not empty and its picture has not failed THE link card SHALL keep, at the start of the site line, a square box comp.link-card.site.icon.size a side, and once the picture has loaded SHALL draw it there, scaled to fit inside the box with its proportions kept, clipped to corners comp.link-card.site.icon.shape, and kept from assistive technology. WHILE siteIcon is empty, or IF its picture cannot be loaded, THE link card SHALL draw no icon, no glyph in its place and no box, SHALL NOT ask for it again by itself, and for a failure SHALL report the address in debug builds. - **LKC-11** WHILE image is not empty and its picture has not failed THE link card SHALL draw a picture box (LKC-12 says where and how large) filled with comp.link-card.media.container.color, and once the picture has loaded SHALL draw it over the whole box, scaled so that it covers the box with its proportions kept and its centre on the box's centre, clipped by the box and by the card's corners where the box meets them. THE link card SHALL NOT mirror, tint or otherwise change the picture in any layout direction, scheme or state. WHILE image is empty THE link card SHALL draw no picture box and ask for nothing. - **LKC-12** WHILE the link card has a picture box and its own inline size is at least comp.link-card.layout.beside-min-width multiplied by the scale of the text THE link card SHALL draw the box beside the body, at the card's end edge, comp.link-card.media.width wide and as tall as the card, whose height is the body's; WHILE it is narrower THE link card SHALL draw the box above the body, across the card's whole inline size, as tall as that size divided by comp.link-card.media.aspect-ratio. THE link card SHALL choose between the two from its own inline size alone, never from the window's, and WHEN that size crosses the boundary SHALL draw the other layout at once, without a motion, keeping its focus and its state. - **LKC-13** WHILE image is not empty and its picture has not yet loaded THE link card SHALL draw the picture box at its final size, so that nothing changes place when the picture arrives; WHEN the picture has loaded THE link card SHALL draw it at once, without a motion; IF the picture cannot be loaded THE link card SHALL be drawn as a link card without a picture, SHALL draw no broken-picture mark, no alternative text and no address in the picture's place, SHALL NOT ask for the picture again by itself, and in debug builds SHALL report the address that failed. WHEN image changes THE link card SHALL draw the box of LKC-11 until the new picture has loaded. - **LKC-14** THE link card SHALL NOT ask the network, a cache, a proxy or any service for href, for the page at href, or for anything it could learn from that page — its title, its description, its picture, its icon — at any time: until a person activates it, nothing it does reaches the destination, and it SHALL draw only what it was given. The only addresses THE link card SHALL ask for are image and siteIcon, each as a picture: WHERE the platform lets a request withhold the page it comes from THE link card SHALL withhold it (the web: no referrer); WHERE the platform can put a request off THE link card SHALL ask only once the card is near what is shown; and it SHALL draw what arrives as a picture and nothing else — never as a document, a frame, markup, or anything that can run or lay out content of its own. IF image or siteIcon names a script to run, or something the platform cannot read as the address of a picture, THE link card SHALL treat that value as empty and in debug builds report it; and in debug builds it SHALL report an image or a siteIcon that is asked of another party than the one the page or the app itself comes from, because every reader would then tell that party what they are reading (LNK-35). - **LKC-15** THE link card SHALL draw and expose title, description, siteName and imageAlt as plain text: a character that would begin markup elsewhere is drawn as the character it is, and nothing in them is parsed, linked, styled or run. Before drawing and exposing each of them THE link card SHALL read a line break or a tab as one space, SHALL drop every other control character, and SHALL drop the characters that embed, override or isolate the direction of text (U+202A to U+202E and U+2066 to U+2069), so that no value can reorder itself or the text beside it; it SHALL keep every other character, the marks that only state a direction and the joiners a script needs included. - **LKC-16** WHILE hovered, keyboard-focused or pressed THE link card SHALL render its container, outline, title, description, site line and opacity from the component tokens of the highest-precedence active state, with precedence pressed over focused over hovered; focus gained by pointer or touch SHALL NOT select the focused state. THE link card SHALL draw the answer to a state behind its text and SHALL NOT draw it over the picture or the site icon, which take the card's opacity and are otherwise drawn as at rest. - **LKC-17** WHEN the link card receives keyboard focus THE link card SHALL show the focus ring without animation — the system's focus indicator around the whole card, sys.focus.offset from the container and following its corners, sys.focus.outer-width wide in the color role focus-ring, with the inner stroke of sys.focus.inner-width where the system has one; focus gained by pointer or touch SHALL NOT show it. - **LKC-18** WHEN the link card is pressed by pointer, touch or Enter THE link card SHALL show the pressed state without delay and SHALL keep it visible for at least sys.motion.duration.press-hold, even when the press ends sooner. - **LKC-19** WHILE pressed THE link card SHALL answer as sys.behavior.pressed-feedback names: overlay applies the pressed tokens to the whole container at once; ripple grows the pressed state layer from the point of contact (from the center for keyboard activation); dim applies the pressed opacity to the whole control and draws no state layer; none draws no answer to the press. Under ripple and dim only the container color stays with the state under the press; title, description, site line, outline, opacity and shape still come from the pressed tokens. Under none every part stays with the state under the press. The ripple grows over comp.link-card.motion.feedback-duration with comp.link-card.motion.state-easing, fades over comp.link-card.motion.state-duration with comp.link-card.motion.state-easing once the press has ended and press-hold has passed, and appears whole where motion is reduced. - **LKC-20** THE link card SHALL ease its container corners by sys.shape.corner-smoothing (0 is a quarter circle, 0.6 the iOS continuous corner; a platform with only the OS curve draws it for any amount above 0) and show its keyboard focus as sys.behavior.focus-style names (ring or glow); a platform that cannot draw a choice SHALL fall back to the first value and state that in its README. - **LKC-21** WHERE the visual size of the link card is below the minimum target THE link card SHALL extend its hit area on both axes to sys.target.touch for touch input and sys.target.pointer for fine pointers, without changing its visual size; a platform that cannot tell the input type SHALL use sys.target.touch. - **LKC-22** WHEN the user activates the link card by pointer, touch or Enter THE link card SHALL emit click exactly once and then open href where target names, unless the product cancelled that click, in which case it SHALL open nothing: the product's own router has taken the navigation. It SHALL NOT hold the navigation back for sys.motion.duration.press-hold. THE link card SHALL NOT be activated by Space, which on the web scrolls the page as it does on any link, and SHALL NOT show the pressed state for it; WHERE the platform gives its links other keys or gestures (on the web a modified or a middle click that opens a new tab, on Apple platforms a long press that previews) THE link card SHALL leave them to the platform. - **LKC-23** WHILE target is new THE link card SHALL open href in a new context — on the web a new tab or window that is given no handle to the page that opened it; on the other platforms outside the screen the person is on, as the platform's opener decides — and SHALL draw the glyph open_in_new of the system's icon set at the end of the site line (LKC-7), in a box as large as the font size of that line's text, in the site color of its variant and state, through the icon helper, which mirrors it in a right-to-left layout because the icon set marks its name, and hidden from assistive technology; a link card with neither a host nor a site name draws a site line that holds the mark alone. No prop SHALL hide the mark or force it. THE link card SHALL expose targetLabel as part of its description (LKC-25), and WHILE targetLabel is empty SHALL still render and in debug builds report that a link that opens a new context does not say so. WHILE target is same THE link card SHALL draw no such mark and SHALL ignore targetLabel. - **LKC-24** THE link card SHALL treat its destination as external exactly as the Link does (LNK-30) and SHALL have no rule of its own for it: as its external prop names — on, off, or under auto exactly when the platform can tell that href is on another site than the one the person is on, from the same declaration of the product's own site that the Link reads. WHILE the destination is external and target is same THE link card SHALL draw the glyph arrow_outward of the system's icon set in the place and manner of LKC-23's mark, kept from assistive technology, and SHALL expose externalLabel — or, WHILE externalLabel is empty, the words the product has set once for every external link (LNK-34) — as the last part of its description (LKC-25); WHILE target is new THE link card SHALL draw LKC-23's mark alone, never two, and expose targetLabel and not externalLabel. Being external SHALL change nothing else: not the host, which is drawn for a destination on the product's own site as well, not where the destination opens, and nothing about how any address is requested. - **LKC-25** THE link card SHALL expose the title — or, WHILE title is empty, the address (LKC-5) — as its accessible name and add nothing to it. THE link card SHALL expose as its description, in this order and leaving out what it does not have: the description, the alternative text of the picture (imageAlt), the site's name where it is drawn, the host as it is drawn, and last targetLabel WHILE target is new, or the words of LKC-24 WHILE the destination is external and target is same. THE picture SHALL be kept from assistive technology as a picture in every case — imageAlt, where the product gives it, is read as part of the description — and the site icon, the middle dot and every mark SHALL be kept from it. - **LKC-26** THE link card SHALL draw no state for a destination already visited: its colors say what it is and what state it is in, and are the same before and after it has been followed. - **LKC-27** IF href is empty or only white space, or names a script to run rather than a place to go (the web's javascript: scheme), or cannot be read as an address by the platform, THE link card SHALL NOT be a link and SHALL NOT be drawn as a card: it SHALL draw its title, where it has one, as plain text in the style of the text around it and nothing else — no container, no description, no picture, no site line, no state — SHALL expose no role, SHALL NOT be focusable, SHALL emit nothing and ask for nothing, and in debug builds report it. WHEN target names a value the link card does not define THE link card SHALL behave as same, WHEN external names one it SHALL treat it as auto, and WHEN variant names a value the active design system does not have it SHALL render with the default variant's tokens; in debug builds it SHALL report the unknown value. - **LKC-28** WHEN the colors of the link card change between states THE link card SHALL animate the change over comp.link-card.motion.state-duration with comp.link-card.motion.state-easing, and SHALL change them at once where motion is reduced. - **LKC-29** WHILE the text size is enlarged THE link card SHALL grow its title, its description, its site line and the mark with it, SHALL keep its paddings, gaps, edge, the site icon's box and comp.link-card.media.width, SHALL keep counting lines by comp.link-card.title.max-lines and comp.link-card.description.max-lines, and SHALL grow in height; it SHALL set no fixed height, SHALL draw the picture above the text sooner (LKC-12), and SHALL need no sideways scrolling of what holds it at a width of 320 points with text at 200 %. - **LKC-30** WHERE the platform draws with a person's own forced colors (the web's forced-colors mode, and a platform's equivalent where it has one) THE link card SHALL draw an edge comp.link-card.outline.width wide in the platform's text color in both looks, so that a look whose fill the mode removes is still a bounded block; SHALL draw its title in the platform's link color and its description and site line in the platform's text color; SHALL draw its focus ring in the platform's highlight color; SHALL draw no fill in the picture box; and SHALL leave the picture and the site icon as they are. - **LKC-31** THE link card SHALL take its layout direction from where it is used — the direction of the nearest ancestor that sets one, and the platform's own where none does — and SHALL have no direction setting of its own; WHEN that direction changes while the link card is shown THE link card SHALL draw itself for the new direction at once, without a motion of its own, keeping its focus. - **LKC-32** WHERE the layout direction is right-to-left THE link card SHALL apply its paddings by logical start and end and mirror its layout: the picture beside the text stands at the left, the text begins at the right, and the site line runs from the right — icon, site's name, host, mark. Top and bottom SHALL NOT change. THE link card SHALL NOT mirror the picture or the site icon, SHALL NOT mirror a glyph itself (the icon helper mirrors a mark whose name the icon set marks, inside its own box), SHALL keep the host a left-to-right run (LKC-9), and SHALL grow a ripple from the point of contact as in left-to-right. - **LKC-33** THE link card SHALL lay out its title, its description and its site's name as text of their own direction, each isolated from the others and from the text around the card: each takes the base direction of its first strong character, or the layout direction where it has none, so that a left-to-right name, a number with its unit and a version keep their own order in a right-to-left layout and reorder nothing beside them; THE link card SHALL still place each and align its lines by the layout direction, not by the text's own, and SHALL cut each where its own direction ends (LKC-4). - **LKC-34** WHEN href, title, description, image, imageAlt, siteName, siteIcon, target, targetLabel, external, externalLabel or variant changes while the link card is shown THE link card SHALL draw and expose the new value at once, without a motion, keeping its focus, and SHALL NOT announce the change by itself. - **LKC-35** THE link card SHALL hold no interactive element — no button, no second link, no field, nothing else that takes focus — and SHALL offer no place to put one: its parts are the values it is given. A platform whose link card is drawn on the product's own elements (the web) SHALL report in debug builds an interactive element found inside it, and SHALL keep the card one link. - **LKC-36** WHERE the platform shows a page before its script has run, or without it (the web), THE link card SHALL already be drawn whole and at rest from what is in the document — its container, its text, its site line, its picture box and the layout of LKC-12 — SHALL be a link that can be followed, and SHALL move nothing when its script arrives. Script SHALL add only what the document cannot hold: the answer to a press beyond a plain state change, the host computed anew from href (LKC-8, LKC-9), the cleaning of LKC-15 for values given by script, the name and the description as LKC-25 divides them, the failures of LKC-10 and LKC-13, and every debug report. ### Tokens As written in the token documents (DTCG): an alias in braces names the token it takes its value from, which each design system resolves. On the web each token is a CSS custom property: `--tanrei` and the name after `tanrei`, joined by hyphens (`tanrei.comp.link-card.…` → `--tanrei-comp-link-card-…`). #### `tanrei.comp.link-card` | Token | Type | Value | | --- | --- | --- | | `comp.link-card.container.shape` | `dimension` | `{tanrei.sys.shape.corner.medium}` | | `comp.link-card.container.padding` | `dimension` | `{tanrei.sys.space.space200}` | | `comp.link-card.outline.width` | `dimension` | `{tanrei.sys.border.hairline}` | | `comp.link-card.outlined.container.color` | `color` | `{tanrei.sys.color.surface}` | | `comp.link-card.outlined.outline.color` | `color` | `{tanrei.sys.color.outline-variant}` | | `comp.link-card.outlined.title.color` | `color` | `{tanrei.sys.color.on-surface}` | | `comp.link-card.outlined.description.color` | `color` | `{tanrei.sys.color.on-surface-variant}` | | `comp.link-card.outlined.site.color` | `color` | `{tanrei.sys.color.on-surface-variant}` | | `comp.link-card.outlined.state-layer.color` | `color` | `{tanrei.comp.link-card.outlined.title.color}` | | `comp.link-card.filled.container.color` | `color` | `{tanrei.sys.color.surface-container-highest}` | | `comp.link-card.filled.outline.color` | `color` | `{"colorSpace":"srgb","components":[0,0,0],"alpha":0,"hex":"#000000"}` | | `comp.link-card.filled.title.color` | `color` | `{tanrei.sys.color.on-surface}` | | `comp.link-card.filled.description.color` | `color` | `{tanrei.sys.color.on-surface-variant}` | | `comp.link-card.filled.site.color` | `color` | `{tanrei.sys.color.on-surface-variant}` | | `comp.link-card.filled.state-layer.color` | `color` | `{tanrei.comp.link-card.filled.title.color}` | | `comp.link-card.title.typescale` | `typography` | `{tanrei.sys.typescale.heading-5}` | | `comp.link-card.title.max-lines` | `number` | `2` | | `comp.link-card.title.gap` | `dimension` | `{tanrei.sys.space.space50}` | | `comp.link-card.description.typescale` | `typography` | `{tanrei.sys.typescale.body}` | | `comp.link-card.description.max-lines` | `number` | `2` | | `comp.link-card.site.typescale` | `typography` | `{tanrei.sys.typescale.body-small}` | | `comp.link-card.site.gap` | `dimension` | `{tanrei.sys.space.space100}` | | `comp.link-card.site.item-gap` | `dimension` | `{tanrei.sys.space.space75}` | | `comp.link-card.site.icon.size` | `dimension` | `{tanrei.sys.icon.extra-small}` | | `comp.link-card.site.icon.shape` | `dimension` | `{tanrei.sys.shape.corner.extra-small}` | | `comp.link-card.media.width` | `dimension` | `192px` | | `comp.link-card.media.aspect-ratio` | `number` | `1.9` | | `comp.link-card.media.container.color` | `color` | `{tanrei.sys.color.surface-container-high}` | | `comp.link-card.layout.beside-min-width` | `dimension` | `480px` | | `comp.link-card.motion.state-duration` | `duration` | `{tanrei.sys.motion.role.state.large}` | | `comp.link-card.motion.state-easing` | `cubicBezier` | `{tanrei.sys.motion.easing.state}` | | `comp.link-card.motion.feedback-duration` | `duration` | `{tanrei.sys.motion.role.feedback}` | Per-state tokens, valued by the design system's pattern rules (not written by hand): - `comp.link-card...` for the variants `outlined`, `filled`, the states `hovered`, `focused`, `pressed` and the properties `container.color`, `outline.color`, `title.color`, `description.color`, `site.color`, `state-layer.color`. - `comp.link-card..` for the states `hovered`, `focused`, `pressed` and the properties `opacity`. ## ガイドライン ### 渡すもの | 値 | 属性 | 描かれ方 | | --- | --- | --- | | `href` | `href` | リンク先。テキストの下のホストは、これだけから読み取ります。 | | `title` | `headline` | タイトル。最大 2 行。カードのアクセシブルネームです。 | | `description` | `description` | 1、2 文の説明。最大 2 行。 | | `image`、`imageAlt` | `image`、`image-alt` | 枠いっぱいに、中央を基準に切り抜いて描く画像。`imageAlt` は読み上げられますが、描かれません。 | | `siteName` | `site-name` | サイトが名乗る名前。ホストの前に描きます。 | | `siteIcon` | `site-icon` | サイトの小さなアイコン。サイトの行の先頭に描きます。 | | `target`、`targetLabel` | `target`、`target-label` | `new` は新しいタブで開き、その印を描きます。言葉も渡してください。 | | `external`、`externalLabel` | `external`、`external-label` | `auto`（既定）、`on`、`off`。リンクと同じです。 | | `variant` | `variant` | `outlined`（既定）または `filled`。 | ### どこへ導くか カードのほかの部分はすべて、リンク先が自分について述べた内容です。リンク先は何とでも名乗れます。そこで、1 つのパーツだけはリンク先に決めさせません。 - ホストは `href` から計算します。どの値でも、設定することも、置き換えることも、隠すこともできません。マークアップに書かれたホストが違っていれば、要素が定義された時点で置き換えられ、デバッグビルドがそれを報告します。 - サイト名はホストの前に置かれ、ホストの代わりにはなりません。ホストを繰り返すだけの名前は描かれません。 - ホストは切り詰められません。行が短いときは、まずサイト名が譲ります。行より長いホストは折り返します。 - 国際化ドメイン名のホストは、安全なときだけ本来の文字で表示します。該当するラベルがそれぞれ 1 つの文字体系、または日本語・韓国語・中国語が一緒に使う文字体系だけで書かれている場合です。借りてきた 1 文字が混ざったラテン文字の名前や、ASCII の末尾を持つキリル文字・ギリシャ文字だけの語は、`xn--` の形のままです。 - ホストは、カードの説明の一部として支援技術にも読み上げられます。 カードはリンク先の真偽を判定しません。それでも、ページは自分を偽って説明できます。説明の横のホストが、読み手にとっての確認手段です。同じ文字体系の中のよく似た文字は検出しません。 ### パーツが欠けているとき | 渡されたもの | 描かれるもの | | --- | --- | | 画像なし、または読み込めない画像 | 画像の枠のない同じカード。代わりのものは何も描きません。 | | 説明なし | タイトルとサイトの行。 | | タイトルだけ | タイトルと、アドレスから得たホスト。 | | アドレスだけ | タイトルの位置にアドレス。タイトルを渡してください。ない場合はデバッグビルドが報告します。 | | 自分のサイトのパス（`/guides/`） | ホストがないので、サイトの行もありません。タイトルと 1 文です。 | | リンク先なし、またはリンク先がスクリプト | リンクではなく、カードとしても描かれません。タイトルをただのテキストとして描きます。 | ### レイアウト - カードはブロックです。コンテナが与える幅いっぱいに広がり、高さは中身で決まります。周囲に自分の余白を持ちません。 - 幅が 480 以上なら、画像はテキストの横、末尾側の端に置かれます。それより狭ければ、テキストの上に置かれます。カードはウィンドウの幅ではなく自分の幅で判断し、この境界は文字サイズに合わせて大きくなります。 - 要素はサイズコンテナなので、レイアウトから幅を受け取る必要があります。フレックスの行やグリッドのセルの中では、幅を指定してください。 - 長文の中では、図と同じくブロックです。文の中に置くことはありません。 ### 新しいタブと別のサイト - `target="new"` は、サイトの行の末尾に `open_in_new` を描きます。`target-label`（「新しいタブで開きます」）を渡してください。印だけでは読み上げられません。 - 別のサイトへ、いまいる場所で開くリンク先には `arrow_outward` を描きます。外部かどうかはリンクの規則で決まります。`external="auto"` は、アドレスをページのオリジンと `setSiteOrigins()` に照らして判断します。言葉は `external-label`、または `setExternalLabel()` で一度だけ設定したものです。 - 印が 2 つ並ぶことはありません。新しいタブが優先されます。 Tanrei は言葉を同梱しません。プロダクトの言語で渡してください。 ### 値の用意 カードは渡されたものを描きます。リンク先を読むのは、ページが読まれているときではなく、**サイトをビルドするとき**にしてください。 そのための Node モジュールが `@tanrei/web/links/node` です。`resolveLinkData()` は、サイトをビルドするマシンでページを 1 度だけ読み、カードが受け取る形で値を返します。 ```js import { linkCardToHtml, resolveLinkData } from '@tanrei/web/links/node'; const result = await resolveLinkData(href, { site: ['docs.example.com'], lock: 'link-data.lock.json', pictureDirectory: 'public/link-pictures' }); const html = result.ok ? linkCardToHtml(result.data) : `${href}`; ``` - 読み取った内容は、コミットするファイル `link-data.lock.json` に保存されます。ビルドはこのファイルを読み、ネットワークには触れません。`tanrei-links update` で更新すると、変更は人がレビューできる差分になります。 - 画像は、自分の画像処理で改めてエンコードしたうえで、サイト自身のファイルとして保存されます。読み手のブラウザーは、いま見ているサイトにしか問い合わせません。 - このヘルパーは公開された `https` のアドレスだけを読み、リダイレクトのたびに確認し、時間とサイズに上限を設け、どのフィールドもテキストとして扱います。 - 読み取りに失敗したアドレスからはカードを作れません。通常のリンクを描いてください。 詳しくは、パッケージの README の「Reading a destination where the site is built」にあります。 利用中にリンク先を調べるプロダクト（アドレスを含むメッセージなど）は、それを自前のサービスで行い、同じ値をカードに渡してください。そのサービスは、公開されていないアドレスをすべて拒否し、リダイレクトのたびに、また接続の瞬間にも確認し直し、応答の時間とサイズに上限を設け、マークアップではなくテキストを返し、画像を自分のオリジンから配信し、ホストは決して返さないようにする必要があります。ホストはカードが計算します。Tanrei はそのようなサービスを提供しません。 ### 推奨 - リンク先の本当のタイトルを渡します。ホストやアドレスをタイトルに入れてはいけません。 - 画像は自分のサイトのファイルとして持ちます。別のサイトから読み込む画像は、誰が読んでいるかをそのサイトに伝えてしまいます。 - 本文の中では `outlined` を使います。すでに線の多いページでは `filled` を使います。 ### 非推奨 - リンクカードの中にボタンや 2 つ目のリンクを入れない。入れたものは操作不能にされ、報告されます。 - 読み手に必ず伝えたいテキストをリンクカードに入れない。カードのテキストはプレビューで、切り詰められることがあります。 - 画像がタイトルにない内容を伝えるのでなければ、`image-alt` を渡さない。 ## アクセシビリティ ### コンポーネントが担うこと - カードは 1 つのリンクで、フォーカスが止まる位置も 1 つです。Enter でリンク先へ進みます。Space は、ほかのリンクと同じくページをスクロールします。 - 名前はタイトルです。タイトルがなければアドレスです。名前には何も付け加えません。 - 説明は順に、説明文、画像の代替テキスト、サイト名、ホスト、最後に新しいタブまたは別のサイトを伝える言葉です。 - 画面上で切り詰められたタイトルや説明も、全文が支援技術に伝わります。 - 画像、サイトのアイコン、中黒、印は装飾で、読み上げられません。 - フォーカスリングはカードの外側に描かれるので、画像に隠れることはありません。 - 幅 320 の場所で文字を 200% にすると、画像はテキストの上に移り、ホストは全体が表示され、横スクロールは生じません。 - 強制カラーモードでは、どちらの外観にも縁が付き、タイトルはシステムのリンク色になります。 - 右から左（RTL）のレイアウトでは、画像は左に置かれ、テキストは右から始まります。左から右のタイトルは自分の並び順を保ちます。ホストは常に左から右です。 - 渡されたテキストはただのテキストとして描かれます。テキストの並び順を反転させる文字は取り除かれます。 ### 利用者側で行うこと - `target` が `new` のときは必ず `target-label` を渡し、外部リンクにも言葉を渡します。 - タイトルを渡します。アドレスは名前として不十分です。 - レイアウトからカードに幅を与えます。