<p>

The <a data-link-for="ShareTarget">params</a> keys correspond to the

key names in <a data-cite="WebShare#dom-sharedata">ShareData</a> from

[[!WebShare]], while the values are arbitrary names that will be used

as query parameters when the target is launched.

[[WebShare]], while the values are arbitrary names that will be used as

query parameters when the target is launched.

</p>

<p>

When a share takes place, if the user selects this share target, the

})());

});

</pre>

<p>

A <a data-link-for="ShareTargetParams">files</a> entry in params is

used to declare that files are accepted by the share target:

</p>

<pre class="example json" title="manifest.webmanifest">

{

"name": "Aggregator",

"share_target": {

"action": "/cgi-bin/aggregate",

"method": "POST",

"enctype": "multipart/form-data",

"params": {

"title": "name",

"text": "description",

"url": "link",

"files": [

{

"name": "records",

"accept": ["text/csv", ".csv"]

},

{

"name": "graphs",

"accept": "image/svg+xml"

}

]

}

}

}

</pre>

<p>

The target will be <a>invoked</a> with a

<code>multipart/form-data</code> POST request, with field names as

specified in params. Each shared file is assigned to the first files

entry that accepts its MIME type. (The <code>"POST"</code>

<code>method</code> and <code>"multipart/form-data"</code>

<code>enctype</code> are necessary when file sharing, as with HTML

forms.)

</p>

<p>

How the handler deals with the shared data is at the handler's

discretion, and will generally depend on the type of app. Here are some

<ul>

<li>An email client might draft a new email, using <code>title</code>

as the subject of an email, with <code>text</code> and <code>url</code>

concatenated together as the body.

concatenated together as the body, and <code>files</code> as

attachments.

</li>

<li>A social networking app might draft a new post, ignoring

<code>title</code>, using <code>text</code> as the body of the message

and adding <code>url</code> as a link. If <code>text</code> is missing,

it might use <code>url</code> in the body as well. If <code>url</code>

is missing, it might scan <code>text</code> looking for a URL and add

that as a link.

and adding <code>url</code> as a link. Image <code>files</code> would

be accepted by MIME type or file extension, and attached to the post.

If <code>text</code> is missing, it might use <code>url</code> in the

body as well. If <code>url</code> is missing, it might scan

<code>text</code> looking for a URL and add that as a link.

</li>

<li>A text messaging app might draft a new message, ignoring

<code>title</code> and using <code>text</code> and <code>url</code>

"!appmanifest#dom-webappmanifest">WebAppManifest</dfn> dictionary.

</p>

<pre class="idl">

dictionary ShareTargetFiles {

required USVString name;

(USVString or sequence&lt;USVString&gt;) accept = [];

};

dictionary ShareTargetParams {

USVString title;

USVString text;

USVString url;

(ShareTargetFiles or sequence&lt;ShareTargetFiles&gt;) files;

};

dictionary ShareTarget {

warning</a> that the enctype is not supported, and return

<code>undefined</code>.

</li>

<li>If <var>share target</var>["<a data-link-for=

"ShareTarget">params</a>"]["<a data-link-for=

"ShareTargetParams">files</a>"] is a <a>ShareTargetFiles</a>

dictionary, <var>bucket</var>, set <var>share

target</var>["<a data-link-for=

"ShareTarget">params</a>"]["<a data-link-for=

"ShareTargetParams">files</a>"] to [<var>bucket</var>].

</li>

<li>If <var>share target</var>["<a data-link-for=

"ShareTarget">params</a>"]["<a data-link-for=

"ShareTargetParams">files</a>"] contains one or more

<a>ShareTargetFiles</a> dictionaries, and <var>share

target</var>["<a data-link-for="ShareTarget">method</a>"] is not an

<a data-cite="!INFRA#ascii-case-insensitive">ASCII

case-insensitive</a> match for the string <code>"POST"</code>, or

<var>share target</var>["<a data-link-for="ShareTarget">enctype</a>"]

is not an <a data-cite="!INFRA#ascii-case-insensitive">ASCII

case-insensitive</a> match for the string

<code>"multipart/form-data"</code>, <a data-cite=

"!appmanifest#dfn-issue-a-developer-warning">issue a developer

warning</a> that files are only supported with multipart/form-data

POST, and return <code>undefined</code>.

</li>

<li>For each <var>bucket</var> in <var>share

target</var>["<a data-link-for=

"ShareTarget">params</a>"]["<a data-link-for=

"ShareTargetParams">files</a>"]:

<ol>

<li>If <var>bucket</var>["<a data-link-for=

"ShareTargetFiles">name</a>"] is an empty string, <a data-cite=

"!appmanifest#dfn-issue-a-developer-warning">issue a developer

warning</a> and return <code>undefined</code>.

</li>

<li>If <var>bucket</var>["<a data-link-for=

"ShareTargetFiles">accept</a>"] is a <a data-cite=

"!WEBIDL#idl-USVString">USVString</a>, <var>accept</var>, set

<var>bucket</var>["<a data-link-for=

"ShareTargetFiles">accept</a>"] to [<var>accept</var>].

</li>

<li>If <var>bucket</var>["<a data-link-for=

"ShareTargetFiles">accept</a>"] contains a string that does not

match any of the following, <a data-cite=

"!appmanifest#dfn-issue-a-developer-warning">issue a developer

warning</a> and return <code>undefined</code>.

<ul>

<li>a string whose first character is a U+002E FULL STOP

character (.)

</li>

<li>

<var>type</var><code>/</code><var>subtype</var> (where

<var>type</var> and <var>subtype</var> are <a data-cite=

"!RFC7230#section-3.2.6">RFC7230 tokens</a>)

</li>

<li>

<var>type</var><code>/*</code> (where <var>type</var> is a

<a data-cite="!RFC7230#section-3.2.6">RFC7230 token</a>)

</li>

<li>

<code>*/*</code>

</li>

</ul>

</li>

</ol>

</li>

<li>Let <var>action</var> be the result of <a data-cite=

"!URL#concept-url-parser">parsing</a> the <a data-cite=

"!URL#concept-url">URL</a> <var>share

The <dfn>url</dfn> member specifies the name of the query parameter

used for the URL string referring to a resource being shared.

</p>

<p>

The <dfn>files</dfn> member contains zero or more

<a>ShareTargetFiles</a> dictionaries.

</p>

</section>

<section data-dfn-for="ShareTargetFiles" data-link-for=

"ShareTargetFiles">

<h3>

<code>ShareTargetFiles</code> and its members

</h3>

<p>

The <dfn>ShareTargetFiles</dfn> dictionary contains the following

members.

</p>

<p>

The <dfn>name</dfn> member specifies the name of the form field used

to share the files.

</p>

<p>

The <dfn>accept</dfn> member specifies a sequence of accepted MIME

type(s) or file extension(s), the latter expressed as strings

starting with U+002E FULL STOP (.). An empty sequence indicates that

all files are accepted.

</p>

</section>

</section>

<section>

visited or explicitly registered.

</p>

<div class="issue" data-number="26"></div>

<p>

An implementation supports <dfn>filtering on MIME types</dfn> if it

takes into account the MIME types of the files being shared when

presenting the user with a choice of share targets.

</p>

<p>

An implementation supports <dfn>filtering on file extensions</dfn> if

it takes into account the extensions in the names of the files being

shared when presenting the user with a choice of share targets.

</p>

<p>

An implementation MUST support <a>filtering on MIME types</a> or

<a>filtering on file extensions</a>, or both.

</p>

<p>

If a file being shared is not <a>accepted</a> by any of a share

target's <a data-link-for="ShareTargetParams">files</a> entries, the

user MUST NOT be presented with that web share target as an option.

</p>

</section>

<section>

<h2>

"ShareTarget">action</a>"].

</li>

<li>Let <var>entry list</var> be a new empty list of name-value

tuples.

tuples. Each value can be either a <a data-cite=

"!WEBIDL#idl-USVString">USVString</a> or a <a data-cite=

"!FILE-API#file-section">File</a> list.

</li>

<li>For each <var>member</var> in the sequence «

<code>"title"</code>, <code>"text"</code>, <code>"url"</code> »,

</li>

</ol>

</li>

<li>Let <var>accepted</var> be an empty map of

name/<code><a data-cite="!FILE-API#file-section">File</a></code> list

pairs.

</li>

<li>For each <var>bucket</var> in the sequence

<var>manifest</var>["<a>share_target</a>"]["<a data-link-for=

"ShareTarget">params</a>"]["<a data-link-for=

"ShareTargetParams">files</a>"],

<ol>

<li>Set

<var>accepted</var>[<var>bucket</var>["<a data-link-for="ShareTargetFiles">name</a>"]]

to a new empty <code><a data-cite=

"!FILE-API#file-section">File</a></code> list.

</li>

</ol>

</li>

<li>For each <var>shared file</var> in the sequence

<var>data</var>[<code>"files"</code>],

<ol>

<li>Find the first <var>bucket</var> in the sequence

<var>manifest</var>["<a>share_target</a>"]["<a data-link-for=

"ShareTarget">params</a>"]["<a data-link-for=

"ShareTargetParams">files</a>"] that <a>accepts</a> <var>shared

file</var>.

</li>

<li>Append <var>shared file</var> to

<var>accepted</var>[<var>bucket</var>["<a data-link-for=

"ShareTargetFiles">name</a>"]].

</li>

</ol>

</li>

<li>For each <var>bucket</var> in the sequence

<var>manifest</var>["<a>share_target</a>"]["<a data-link-for=

"ShareTarget">params</a>"]["<a data-link-for=

"ShareTargetParams">files</a>"],

<ol>

<li>Let <var>name</var> be the value of

<var>bucket</var>["<a data-link-for=

"ShareTargetFiles">name</a>"].

</li>

<li>Let <var>value</var> be the value of

<var>accepted</var>[<var>name</var>], a (possibly empty)

<code><a data-cite="!FILE-API#file-section">File</a></code> list.

</li>

<li>

<a data-cite="!INFRA#list-append">Append</a> to <var>entry

list</var> a tuple with <var>name</var> and <var>value</var>.

</li>

</ol>

</li>

<li>Let <var>header list</var> be a new empty <a data-cite=

"!FETCH/#concept-header-list">header list</a>.

</li>

run on it and still has a <a>share_target</a> afterwards.

</p>

</section>

<section>

<h3>

Determining if a file is accepted

</h3>

<p>

The algorithm for determining if a <a>ShareTargetFiles</a>

<var>bucket</var> <dfn data-lt="accepted">accepts</dfn> a

<a data-cite="!FILE-API#file-section">File</a> <var>shared file</var>

is as follows:-

</p>

<ol>

<li>If <var>bucket</var>["<a data-link-for=

"ShareTargetFiles">accept</a>"] is empty, return <code>true</code>.

</li>

<li>For each <var>criterion</var> in

<var>bucket</var>["<a data-link-for="ShareTargetFiles">accept</a>"]:

<ol>

<li>If the first character of <var>criterion</var> is a U+002E

FULL STOP character (.) and <var>shared

file</var>[<code>"name"</code>] ends with <var>criterion</var>,

and the implementation supports <a>filtering on file

extensions</a>, return <code>true</code>.

</li>

<li>If <var>criterion</var> is

<var>type</var><code>/</code><var>subtype</var> (where

<var>type</var> and <var>subtype</var> are <a data-cite=

"!RFC7230#section-3.2.6">RFC7230 tokens</a>) and matches the MIME

type of <var>shared file</var>, and the implementation supports

<a>filtering on MIME types</a>, return <code>true</code>.

</li>

<li>If <var>criterion</var> is <var>type</var><code>/*</code>

(where <var>type</var> is a <a data-cite=

"!RFC7230#section-3.2.6">RFC7230 token</a>) and the MIME type of

<var>shared file</var> is a subtype of <code>type</code>, and the

implementation supports <a>filtering on MIME types</a>, return

<code>true</code>.

</li>

<li>If <var>criterion</var> is <code>*/*</code>, return

<code>true</code>.

</li>

</ol>

</li>

<li>Return <code>false</code>.

</li>

</ol>

</section>

</section>

<section class="informative">

<h2>