0.19.0

			api.KeyLang:       api.ValueLangEN,
			api.KeyCreated:    "20240703235900",
			api.KeyVisibility: api.ValueVisibilityLogin,
		},
		zettel.NewContent(nil)},
	id.DefaultHomeZid: {
		constHeader{
			api.KeyTitle:   "Home",
			api.KeyRole:    api.ValueRoleZettel,
			api.KeySyntax:  meta.SyntaxZmk,
			api.KeyLang:    api.ValueLangEN,
			api.KeyCreated: "20210210190757",

		},
		zettel.NewContent(contentHomeZettel)},
}

//go:embed license.txt
var contentLicense []byte

=== Thank you for using Zettelstore!

You will find the lastest information about Zettelstore at [[https://zettelstore.de]].
Check that website regulary for [[upgrades|https://zettelstore.de/home/doc/trunk/www/download.wiki]] to the latest version.
You should consult the [[change log|https://zettelstore.de/home/doc/trunk/www/changes.wiki]] before upgrading.
Sometimes, you have to edit some of your Zettelstore-related zettel before upgrading.
Since Zettelstore is currently in a development state, every upgrade might fix some of your problems.

If you have problems concerning Zettelstore,
do not hesitate to get in [[contact with the main developer|mailto:ds@zettelstore.de]].

=== Reporting errors
If you have encountered an error, please include the content of the following zettel in your mail (if possible):
* [[Zettelstore Version|00000000000001]]: {{00000000000001}}
* [[Zettelstore Operating System|00000000000003]]
* [[Zettelstore Startup Configuration|00000000000096]]
* [[Zettelstore Runtime Configuration|00000000000100]]

	if err := mgr.checkContinue(ctx); err != nil {
		return id.Invalid, err
	}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	if box, isWriteBox := mgr.boxes[0].(box.WriteBox); isWriteBox {
		ztl.Meta = mgr.cleanMetaProperties(ztl.Meta)
		zidO, err := box.CreateZettel(ctx, ztl)
		if err == nil {
			mgr.idxUpdateZettel(ctx, ztl)
		}
		return zidO, err
	}
	return id.Invalid, box.ErrReadOnly
}

// GetZettel retrieves a specific zettel.
func (mgr *Manager) GetZettel(ctx context.Context, zid id.Zid) (zettel.Zettel, error) {
	mgr.mgrLog.Debug().Zid(zid).Msg("GetZettel")

		if err != nil {
			return nil, err
		}
	}
	return result, nil
}

// FetchZidsO returns the set of all old-style zettel identifer managed by the box.
func (mgr *Manager) FetchZidsO(ctx context.Context) (*id.Set, error) {
	mgr.mgrLog.Debug().Msg("FetchZidsO")
	return mgr.fetchZids(ctx)
}

func (mgr *Manager) hasZettel(ctx context.Context, zid id.Zid) bool {
	mgr.mgrLog.Debug().Zid(zid).Msg("HasZettel")
	if err := mgr.checkContinue(ctx); err != nil {
		return false
	}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()

			return true
		}
	}
	return false
}

// DeleteZettel removes the zettel from the box.
func (mgr *Manager) DeleteZettel(ctx context.Context, zidO id.Zid) error {
	mgr.mgrLog.Debug().Zid(zidO).Msg("DeleteZettel")
	if err := mgr.checkContinue(ctx); err != nil {
		return err
	}
	mgr.mgrMx.RLock()
	defer mgr.mgrMx.RUnlock()
	for _, p := range mgr.boxes {
		err := p.DeleteZettel(ctx, zidO)
		if err == nil {
			mgr.idxDeleteZettel(ctx, zidO)
			return err
		}
		var errZNF box.ErrZettelNotFound
		if !errors.As(err, &errZNF) && !errors.Is(err, box.ErrReadOnly) {
			return err
		}
	}
	return box.ErrZettelNotFound{Zid: zidO}
}

// Remove all (computed) properties from metadata before storing the zettel.
func (mgr *Manager) cleanMetaProperties(m *meta.Meta) *meta.Meta {
	result := m.Clone()
	for _, p := range result.ComputedPairsRest() {
		if mgr.propertyKeys.Has(p.Key) {
			result.Delete(p.Key)
		}
	}
	return result
}

	cache[zid] = destutterData{
		deadAt: now.Add(500 * time.Millisecond),
		reason: reason,
	}
	return false
}

func (mgr *Manager) idxEnqueue(reason box.UpdateReason, zidO id.Zid) {
	switch reason {
	case box.OnReady:
		return
	case box.OnReload:
		mgr.idxAr.Reset()
	case box.OnZettel:
		mgr.idxAr.EnqueueZettel(zidO)
	case box.OnDelete:
		mgr.idxAr.EnqueueZettel(zidO)
	default:
		mgr.mgrLog.Error().Uint("reason", uint64(reason)).Zid(zidO).Msg("Unknown notification reason")
		return
	}
	select {
	case mgr.idxReady <- struct{}{}:
	default:
	}
}

id: 00001007031140
title: Zettelmarkup: Query Transclusion
role: manual
tags: #manual #search #zettelmarkup #zettelstore
syntax: zmk
created: 20220809132350
modified: 20240219161800

A query transclusion is specified by the following sequence, starting at the first position in a line: ''{{{query:query-expression}}}''.
The line must literally start with the sequence ''{{{query:''.
Everything after this prefix is interpreted as a [[query expression|00001007700000]].

When evaluated, the query expression is evaluated, often resulting in a list of [[links|00001007040310]] to zettel, matching the query expression.
The result replaces the query transclusion element.

: The resulting list will be a numbered list.
; ''MINn'' (parameter)
: Emit only those values with at least __n__ aggregated values.
  __n__ must be a positive integer, ''MIN'' must be given in upper-case letters.
; ''MAXn'' (parameter)
: Emit only those values with at most __n__ aggregated values.
  __n__ must be a positive integer, ''MAX'' must be given in upper-case letters.
; ''TITLE'' (parameter)
: All words following ''TITLE'' are joined together to form a title.
  It is used for the ''ATOM'' and ''RSS'' action.
; ''ATOM'' (aggregate)
: Transform the zettel list into an [[Atom 1.0|https://www.rfc-editor.org/rfc/rfc4287]]-conformant document / feed.
  The document is embedded into the referencing zettel.
; ''RSS'' (aggregate)
: Transform the zettel list into a [[RSS 2.0|https://www.rssboard.org/rss-specification]]-conformant document / feed.
  The document is embedded into the referencing zettel.
; ''KEYS'' (aggregate)
: Emit a list of all metadata keys, together with the number of zettel having the key.
; ''REDIRECT'', ''REINDEX'' (aggregate)
: Will be ignored.
  These actions may have been copied from an existing [[API query call|00001012051400]] (or from a WebUI query), but are here superfluous (and possibly harmful).
; Any [[metadata key|00001006020000]] of type [[Word|00001006035500]] or of type [[TagSet|00001006034000]] (aggregates)
: Emit an aggregate of the given metadata key.

id: 00001007780000
title: Formal syntax of query expressions
role: manual
tags: #manual #reference #search #zettelstore
syntax: zmk
created: 20220810144539
modified: 20240219155949

```
QueryExpression   := ZettelList? QueryDirective* SearchExpression ActionExpression?
ZettelList        := (ZID (SPACE+ ZID)*).
ZID               := '0'+ ('1' .. '9'') DIGIT*
                   | ('1' .. '9') DIGIT*.
QueryDirective    := ContextDirective

                   | ('!')? ('~' | ':' | '[' | '}').
ExistOperator     := '?'
                   | '!' '?'.
PosInt            := '0'
                   | ('1' .. '9') DIGIT*.
ActionExpression  := '|' (Word (SPACE+ Word)*)?
Action            := Word
                   | 'ATOM'
                   | 'KEYS'
                   | 'N' NO-SPACE*
                   | 'MAX' PosInt
                   | 'MIN' PosInt
                   | 'REDIRECT'
                   | 'REINDEX'
                   | 'RSS'
                   | 'TITLE' (SPACE Word)* .
Word              := NO-SPACE NO-SPACE*
```

id: 00001012051200
title: API: List all zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210126175322
modified: 20230807170810

To list all zettel just send a HTTP GET request to the [[endpoint|00001012920000]] ''/z''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header].
Always use the endpoint ''/z'' to work with a list of zettel.

Without further specifications, a plain text document is returned, with one line per zettel.
Each line contains in the first 14 characters the [[zettel identifier|00001006050000]].
Separated by a space character, the title of the zettel follows:

```sh

id: 00001012051400
title: API: Query the list of all zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20220912111111
modified: 20240711161320
precursor: 00001012051200

The [[endpoint|00001012920000]] ''/z'' also allows you to filter the list of all zettel[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header] and optionally to provide some actions.

A [[query|00001007700000]] is an optional [[search expression|00001007700000#search-expression]], together with an optional [[list of actions|00001007700000#action-list]] (described below).
An empty search expression will select all zettel.
An empty list of action, or no valid action, returns the list of all selected zettel metadata.

Search expression and action list are separated by a vertical bar character (""''|''"", U+007C), and must be given with the query parameter ''q''.

id: 00001012053300
title: API: Retrieve metadata and content of an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20211004093206
modified: 20230807170259

The [[endpoint|00001012920000]] to work with metadata and content of a specific zettel is ''/z/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]].

For example, to retrieve some data about this zettel you are currently viewing, just send a HTTP GET request to the endpoint ''/z/00001012053300''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header].

````sh
# curl 'http://127.0.0.1:23123/z/00001012053300'
The [[endpoint|00001012920000]] to work with metadata and content of a specific zettel is ''/z/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]].

For example, to retrieve some data about this zettel you are currently viewing, just send a HTTP GET request to the endpoint ''/z/00001012053300''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header].

```sh
...
````

Optionally, you may provide which parts of the zettel you are requesting.
In this case, add an additional query parameter ''part=PART''.

id: 00001012053400
title: API: Retrieve metadata of an existing zettel
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210726174524
modified: 20230807170155

The [[endpoint|00001012920000]] to work with metadata of a specific zettel is ''/z/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]][^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header].

To retrieve the plain metadata of a zettel, use the query parameter ''part=meta''

````sh
# curl 'http://127.0.0.1:23123/z/00001012053400?part=meta'
title: API: Retrieve metadata of an existing zettel
role: manual

id: 00001012053500
title: API: Retrieve evaluated metadata and content of an existing zettel in various encodings
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210726174524
modified: 20240620171057

The [[endpoint|00001012920000]] to work with evaluated metadata and content of a specific zettel is ''/z/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]].

For example, to retrieve some evaluated data about this zettel you are currently viewing in [[Sz encoding|00001012920516]], just send a HTTP GET request to the endpoint ''/z/00001012053500''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header] with the query parameter ''enc=sz''.
If successful, the output is a symbolic expression value:
```sh
# curl 'http://127.0.0.1:23123/z/00001012053500?enc=sz'
(BLOCK (PARA (TEXT "The ") (LINK-ZETTEL () "00001012920000" (TEXT "endpoint")) (TEXT " to work with parsed metadata and content of a specific zettel is ") (LITERAL-INPUT () "/z/{ID}") (TEXT ", where ") (LITERAL-INPUT () "{ID}") (TEXT " is a placeholder for the ") ...
```

To select another encoding, you must provide the query parameter ''enc=ENCODING''.

id: 00001012053600
title: API: Retrieve parsed metadata and content of an existing zettel in various encodings
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20210126175322
modified: 20240620170909

The [[endpoint|00001012920000]] to work with parsed metadata and content of a specific zettel is ''/z/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]].

A __parsed__ zettel is basically an [[unevaluated|00001012053500]] zettel: the zettel is read and analyzed, but its content is not __evaluated__.
By using this endpoint, you are able to retrieve the structure of a zettel before it is evaluated.

For example, to retrieve some data about this zettel you are currently viewing, just send a HTTP GET request to the endpoint ''/z/00001012053600''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header] with the query parameter ''parseonly'' (and other appropriate query parameter).
For example:
```sh
# curl 'http://127.0.0.1:23123/z/00001012053600?enc=sz&parseonly'
(BLOCK (PARA (TEXT "The ") (LINK-ZETTEL () "00001012920000" (TEXT "endpoint")) (TEXT " to work with parsed metadata and content of a specific zettel is ") (LITERAL-INPUT () "/z/{ID}") (TEXT ", where ") ...
```

Similar to [[retrieving an encoded zettel|00001012053500]], you can specify an [[encoding|00001012920500]] and state which [[part|00001012920800]] of a zettel you are interested in.

id: 00001012080200
title: API: Check for authentication
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20220103224858
modified: 20220908163156

API clients typically wants to know, whether [[authentication is enabled|00001010040100]] or not.
If authentication is enabled, they present some form of user interface to get user name and password for the actual authentication.
Then they try to [[obtain an access token|00001012050200]].
If authentication is disabled, these steps are not needed.

To check for enabled authentication, you must send a HTTP POST request to the [[endpoint|00001012920000]] ''/x'' and you must specify the query parameter ''cmd=authenticated''.

```sh

id: 00001012080500
title: API: Refresh internal data
role: manual
tags: #api #manual #zettelstore
syntax: zmk
created: 20211230230441
modified: 20220923104836

Zettelstore maintains some internal data to allow faster operations.

One example is the [[content search|00001012051400]] for a term: Zettelstore does not need to scan all zettel to find all occurrences for the term.
Instead, all word are stored internally, with a list of zettel where they occur.

Another example is the way to determine which zettel are stored in a [[ZIP file|00001004011200]].
Scanning a ZIP file is a lengthy operation, therefore Zettelstore maintains a directory of zettel for each ZIP file.

All these internal data may become stale.
This should not happen, but when it comes e.g. to file handling, every operating systems behaves differently in very subtle ways.

id: 00001012931400
title: Encoding of Sz Block Elements
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
created: 20230403161803
modified: 20240123120132

=== ''PARA''
:::syntax
__Paragraph__ **=** ''(PARA'' [[__InlineElement__|00001012931600]] … '')''.
:::
A paragraph is just a list of inline elements.

:::
A list element is either a block or an inline.
If it is a block, it may contain a nested list.
=== ''DESCRIPTION''
:::syntax
__Description__ **=** ''(DESCRIPTION'' __DescriptionTerm__ __DescriptionValues__ __DescriptionTerm__ __DescriptionValues__ … '')''.
:::
A description is a sequence of one ore more terms and values.

:::syntax
__DescriptionTerm__ **=** ''('' [[__InlineElement__|00001012931600]] … '')''.
:::
A description term is just an inline-structured value.

:::syntax

Attributes may further specify the quotation.
The inline typically describes author / source of the quotation.

:::syntax
__VerseRegion__ **=** ''(REGION-VERSE'' [[__Attributes__|00001012931000#attribute]] ''('' [[__BlockElement__|00001012931400]] … '')'' [[__InlineElement__|00001012931600]] … '')''.
:::
A block region just treats the block to contain a verse.
Soft line break are transformed into hard line breaks to save the structure of the verse / poem.
Attributes may further specify something.
The inline typically describes author / source of the verse.

=== ''VERBATIM-*''
The following lists specifies some literal text of more than one line.
The structure is always the same, the initial symbol denotes the actual usage.
The content is encoded as a string, most likely to contain control characters that signals the end of a line.

id: 00001012931600
title: Encoding of Sz Inline Elements
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
created: 20230403161845
modified: 20240620170546

=== ''TEXT''
:::syntax
__Text__ **=** ''(TEXT'' String '')''.
:::
Specifies the string as some text content, including white space characters.

=== ''EMBED-BLOB''
:::syntax
__EmbedBLOB__ **=** ''(EMBED-BLOB'' [[__Attributes__|00001012931000#attribute]] String,,1,, String,,2,, '')''.
:::
If used if some processed image has to be embedded inside some inline material.
The first string specifies the syntax of the image content.
The second string contains the image content.
If the syntax is ""SVG"", the image content is not further encoded.
Otherwise a base64 encoding is used.

=== ''CITE''
:::syntax
__CiteBLOB__ **=** ''(CITE'' [[__Attributes__|00001012931000#attribute]] String [[__InlineElement__|00001012931600]] … '')''.
:::
The string contains the citation key.

__InsertFormat__ **=** ''(FORMAT-INSERT'' [[__Attributes__|00001012931000#attribute]] [[__InlineElement__|00001012931600]] … '')''.
:::
The inline text should be treated as inserted.

:::syntax
__MarkFormat__ **=** ''(FORMAT-MARK'' [[__Attributes__|00001012931000#attribute]] [[__InlineElement__|00001012931600]] … '')''.
:::
The inline text should be treated as highlighted for the reader (but was not important fto the original author).

:::syntax
__QuoteFormat__ **=** ''(FORMAT-QUOTE'' [[__Attributes__|00001012931000#attribute]] [[__InlineElement__|00001012931600]] … '')''.
:::
The inline text should be treated as quoted text.

:::syntax

id: 00001017000000
title: Tips and Tricks
role: manual
tags: #manual #zettelstore
syntax: zmk
created: 20220803170112
modified: 20231012154803

=== Welcome Zettel
* **Problem:** You want to put your Zettelstore into the public and need a starting zettel for your users.
  In addition, you still want a ""home zettel"", with all your references to internal, non-public zettel.
  Zettelstore only allows to specify one [[''home-zettel''|00001004020000#home-zettel]].
* **Solution 1:**
*# Create a new zettel with all your references to internal, non-public zettel.

* **Solution 2:** If you typically start your Zettelstore on the command line, you could use the ''-d DIR'' option for the [[''run''|00001004051000#d]] sub-command.
  In this case you are allowed to use the character ""''~''"".

  ''zettelstore run -d ~/Library/Mobile\\ Documents/com\\~apple\\~CloudDocs/zettel''

  (The ""''\\''"" is needed by the command line processor to mask the following character to be processed in unintended ways.)
* **Discussion:** Zettel files are synchronized between your computers via iCloud.
  Is does not matter, if one of your computer is offline / switched off.
  iCloud will synchronize the zettel files if it later comes online.

  However, if you use more than one computer simultaneously, you must be aware that synchronization takes some time.
  It might take several seconds, maybe longer, that new new version of a zettel appears on the other computer.
  If you update the same zettel on multiple computers at nearly the same time, iCloud will not be able to synchronize the different versions in a safe manner.
  Zettelstore is intentionally not aware of any synchronization within its zettel boxes.

  If Zettelstore behaves strangely after a synchronization took place, the page about [[Troubleshooting|00001018000000#working-with-files]] might contain some useful information.

//-----------------------------------------------------------------------------
// Copyright (c) 2022-present Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2022-present Detlef Stern
//-----------------------------------------------------------------------------

// Package atom provides an Atom encoding.
package atom

import (
	"bytes"
	"time"

	"t73f.de/r/zsc/api"
	"zettelstore.de/z/config"
	"zettelstore.de/z/encoding"
	"zettelstore.de/z/encoding/xml"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/query"
	"zettelstore.de/z/strfun"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

// ContentType specifies the HTTP content type for Atom.
const ContentType = "application/atom+xml"

// Configuration contains data to configure the Atom encoding.
type Configuration struct {
	Title            string
	Generator        string
	NewURLBuilderAbs func() *api.URLBuilder
}

// Setup initializes the Configuration.
func (c *Configuration) Setup(cfg config.Config) {
	baseURL := kernel.Main.GetConfig(kernel.WebService, kernel.WebBaseURL).(string)

	c.Title = cfg.GetSiteName()
	c.Generator = (kernel.Main.GetConfig(kernel.CoreService, kernel.CoreProgname).(string) +
		" " +
		kernel.Main.GetConfig(kernel.CoreService, kernel.CoreVersion).(string))
	c.NewURLBuilderAbs = func() *api.URLBuilder { return api.NewURLBuilder(baseURL, 'h') }
}

// Marshal encodes the result of a query as Atom.
func (c *Configuration) Marshal(q *query.Query, ml []*meta.Meta) []byte {
	atomUpdated := encoding.LastUpdated(ml, time.RFC3339)
	feedLink := c.NewURLBuilderAbs().String()

	var buf bytes.Buffer
	buf.WriteString(`<feed xmlns="http://www.w3.org/2005/Atom">` + "\n")
	xml.WriteTag(&buf, "  ", "title", c.Title)
	xml.WriteTag(&buf, "  ", "id", feedLink)
	buf.WriteString(`  <link rel="self" href="`)
	if s := q.String(); s != "" {
		strfun.XMLEscape(&buf, c.NewURLBuilderAbs().AppendQuery(s).String())
	} else {
		strfun.XMLEscape(&buf, feedLink)
	}
	buf.WriteString(`"/>` + "\n")
	if atomUpdated != "" {
		xml.WriteTag(&buf, "  ", "updated", atomUpdated)
	}
	xml.WriteTag(&buf, "  ", "generator", c.Generator)
	buf.WriteString("  <author><name>Unknown</name></author>\n")

	for _, m := range ml {
		c.marshalMeta(&buf, m)
	}

	buf.WriteString("</feed>")
	return buf.Bytes()
}

func (c *Configuration) marshalMeta(buf *bytes.Buffer, m *meta.Meta) {
	entryUpdated := ""
	if val, found := m.Get(api.KeyPublished); found {
		if published, err := time.ParseInLocation(id.TimestampLayout, val, time.Local); err == nil {
			entryUpdated = published.UTC().Format(time.RFC3339)
		}
	}

	link := c.NewURLBuilderAbs().SetZid(m.Zid.ZettelID()).String()

	buf.WriteString("  <entry>\n")
	xml.WriteTag(buf, "    ", "title", encoding.TitleAsText(m))
	xml.WriteTag(buf, "    ", "id", link)
	buf.WriteString(`    <link rel="self" href="`)
	strfun.XMLEscape(buf, link)
	buf.WriteString(`"/>` + "\n")
	buf.WriteString(`    <link rel="alternate" type="text/html" href="`)
	strfun.XMLEscape(buf, link)
	buf.WriteString(`"/>` + "\n")

	if entryUpdated != "" {
		xml.WriteTag(buf, "    ", "updated", entryUpdated)
	}
	marshalTags(buf, m)
	buf.WriteString("  </entry>\n")
}

func marshalTags(buf *bytes.Buffer, m *meta.Meta) {
	if tags, found := m.GetList(api.KeyTags); found && len(tags) > 0 {
		for _, tag := range tags {
			for len(tag) > 0 && tag[0] == '#' {
				tag = tag[1:]
			}
			if tag != "" {
				buf.WriteString(`    <category term="`)
				strfun.XMLEscape(buf, tag)
				buf.WriteString("\"/>\n")
			}
		}
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2022-present Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2022-present Detlef Stern
//-----------------------------------------------------------------------------

// Package encoding provides helper functions for encodings.
package encoding

import (
	"time"

	"t73f.de/r/zsc/api"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

// LastUpdated returns the formated time of the zettel which was updated at the latest time.
func LastUpdated(ml []*meta.Meta, timeFormat string) string {
	maxPublished := time.Date(1, time.January, 1, 0, 0, 0, 0, time.Local)
	for _, m := range ml {
		if val, found := m.Get(api.KeyPublished); found {
			if published, err := time.ParseInLocation(id.TimestampLayout, val, time.Local); err == nil {
				if maxPublished.Before(published) {
					maxPublished = published
				}
			}
		}
	}
	if maxPublished.Year() > 1 {
		return maxPublished.UTC().Format(timeFormat)
	}
	return ""
}

// TitleAsText returns the title of a zettel as plain text
func TitleAsText(m *meta.Meta) string { return parser.NormalizedSpacedText(m.GetTitle()) }

//-----------------------------------------------------------------------------
// Copyright (c) 2022-present Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2022-present Detlef Stern
//-----------------------------------------------------------------------------

// Package rss provides a RSS encoding.
package rss

import (
	"bytes"
	"context"
	"time"

	"t73f.de/r/zsc/api"
	"zettelstore.de/z/config"
	"zettelstore.de/z/encoding"
	"zettelstore.de/z/encoding/xml"
	"zettelstore.de/z/kernel"
	"zettelstore.de/z/query"
	"zettelstore.de/z/strfun"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

// ContentType specifies the HTTP content type for RSS.
const ContentType = "application/rss+xml"

// Configuration contains data to configure the RSS encoding.
type Configuration struct {
	Title            string
	Language         string
	Copyright        string
	Generator        string
	NewURLBuilderAbs func() *api.URLBuilder
}

// Setup initializes the Configuration.
func (c *Configuration) Setup(ctx context.Context, cfg config.Config) {
	baseURL := kernel.Main.GetConfig(kernel.WebService, kernel.WebBaseURL).(string)
	defVals := cfg.AddDefaultValues(ctx, &meta.Meta{})

	c.Title = cfg.GetSiteName()
	c.Language = defVals.GetDefault(api.KeyLang, "")
	c.Copyright = defVals.GetDefault(api.KeyCopyright, "")
	c.Generator = (kernel.Main.GetConfig(kernel.CoreService, kernel.CoreProgname).(string) +
		" " +
		kernel.Main.GetConfig(kernel.CoreService, kernel.CoreVersion).(string))
	c.NewURLBuilderAbs = func() *api.URLBuilder { return api.NewURLBuilder(baseURL, 'h') }
}

// Marshal encodes the result of a query as Atom.
func (c *Configuration) Marshal(q *query.Query, ml []*meta.Meta) []byte {
	rssPublished := encoding.LastUpdated(ml, time.RFC1123Z)

	atomLink := ""
	if s := q.String(); s != "" {
		atomLink = c.NewURLBuilderAbs().AppendQuery(s).String()
	}
	var buf bytes.Buffer
	buf.WriteString(`<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">` + "\n<channel>\n")
	xml.WriteTag(&buf, "  ", "title", c.Title)
	xml.WriteTag(&buf, "  ", "link", c.NewURLBuilderAbs().String())
	xml.WriteTag(&buf, "  ", "description", "")
	xml.WriteTag(&buf, "  ", "language", c.Language)
	xml.WriteTag(&buf, "  ", "copyright", c.Copyright)
	if rssPublished != "" {
		xml.WriteTag(&buf, "  ", "pubDate", rssPublished)
		xml.WriteTag(&buf, "  ", "lastBuildDate", rssPublished)
	}
	xml.WriteTag(&buf, "  ", "generator", c.Generator)
	buf.WriteString("  <docs>https://www.rssboard.org/rss-specification</docs>\n")
	if atomLink != "" {
		buf.WriteString(`  <atom:link href="`)
		strfun.XMLEscape(&buf, atomLink)
		buf.WriteString(`" rel="self" type="application/rss+xml"></atom:link>` + "\n")
	}
	for _, m := range ml {
		c.marshalMeta(&buf, m)
	}

	buf.WriteString("</channel>\n</rss>")
	return buf.Bytes()
}

func (c *Configuration) marshalMeta(buf *bytes.Buffer, m *meta.Meta) {
	itemPublished := ""
	if val, found := m.Get(api.KeyPublished); found {
		if published, err := time.ParseInLocation(id.TimestampLayout, val, time.Local); err == nil {
			itemPublished = published.UTC().Format(time.RFC1123Z)
		}
	}

	link := c.NewURLBuilderAbs().SetZid(m.Zid.ZettelID()).String()

	buf.WriteString("  <item>\n")
	xml.WriteTag(buf, "    ", "title", encoding.TitleAsText(m))
	xml.WriteTag(buf, "    ", "link", link)
	xml.WriteTag(buf, "    ", "guid", link)
	if itemPublished != "" {
		xml.WriteTag(buf, "    ", "pubDate", itemPublished)
	}
	marshalTags(buf, m)
	buf.WriteString("  </item>\n")
}

func marshalTags(buf *bytes.Buffer, m *meta.Meta) {
	if tags, found := m.GetList(api.KeyTags); found && len(tags) > 0 {
		for _, tag := range tags {
			for len(tag) > 0 && tag[0] == '#' {
				tag = tag[1:]
			}
			if tag != "" {
				xml.WriteTag(buf, "    ", "category", tag)
			}
		}
	}
}

//-----------------------------------------------------------------------------
// Copyright (c) 2022-present Detlef Stern
//
// This file is part of Zettelstore.
//
// Zettelstore is licensed under the latest version of the EUPL (European Union
// Public License). Please see file LICENSE.txt for your rights and obligations
// under this license.
//
// SPDX-License-Identifier: EUPL-1.2
// SPDX-FileCopyrightText: 2022-present Detlef Stern
//-----------------------------------------------------------------------------

// Package xml provides helper for a XML-based encoding.
package xml

import (
	"bytes"

	"zettelstore.de/z/strfun"
)

// Header contains the string that should start all XML documents.
const Header = `<?xml version="1.0" encoding="UTF-8"?>` + "\n"

// WriteTag writes a simple XML tag with a given prefix and a specific value.
func WriteTag(buf *bytes.Buffer, prefix, tag, value string) {
	buf.WriteString(prefix)
	buf.WriteByte('<')
	buf.WriteString(tag)
	buf.WriteByte('>')
	strfun.XMLEscape(buf, value)
	buf.WriteString("</")
	buf.WriteString(tag)
	buf.WriteString(">\n")
}

	ml, err := e.port.QueryMeta(e.ctx, q)
	if err != nil {
		if errors.Is(err, &box.ErrNotAllowed{}) {
			return nil
		}
		return makeBlockNode(createInlineErrorText(nil, "Unable", "to", "search", "zettel"))
	}
	result, _ := QueryAction(e.ctx, q, ml, e.rtConfig)
	if result != nil {
		ast.Walk(e, result)
	}
	return result
}

func (e *evaluator) checkMaxTransclusions(ref *ast.Reference) ast.InlineNode {

	"slices"
	"strconv"
	"strings"

	"t73f.de/r/zsc/api"
	"t73f.de/r/zsc/attrs"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/config"
	"zettelstore.de/z/encoding/atom"
	"zettelstore.de/z/encoding/rss"
	"zettelstore.de/z/parser"
	"zettelstore.de/z/query"
	"zettelstore.de/z/zettel/meta"
)

// QueryAction transforms a list of metadata according to query actions into a AST nested list.
func QueryAction(ctx context.Context, q *query.Query, ml []*meta.Meta, rtConfig config.Config) (ast.BlockNode, int) {
	ap := actionPara{
		ctx:    ctx,
		q:      q,
		ml:     ml,
		kind:   ast.NestedListUnordered,
		minVal: -1,
		maxVal: -1,
		title:  rtConfig.GetSiteName(),
	}
	actions := q.Actions()
	if len(actions) == 0 {
		return ap.createBlockNodeMeta("")
	}

	acts := make([]string, 0, len(actions))
	for i, act := range actions {
		if strings.HasPrefix(act, api.NumberedAction[0:1]) {
			ap.kind = ast.NestedListOrdered
			continue
		}
		if strings.HasPrefix(act, api.MinAction) {
			if num, err := strconv.Atoi(act[3:]); err == nil && num > 0 {
				ap.minVal = num
				continue
			}
		}
		if strings.HasPrefix(act, api.MaxAction) {
			if num, err := strconv.Atoi(act[3:]); err == nil && num > 0 {
				ap.maxVal = num
				continue
			}
		}
		if act == api.TitleAction && i+1 < len(actions) {
			ap.title = strings.Join(actions[i+1:], " ")
			break
		}
		if act == api.ReIndexAction {
			continue
		}
		acts = append(acts, act)
	}
	var firstUnknowAct string
	for _, act := range acts {
		switch act {
		case api.AtomAction:
			return ap.createBlockNodeAtom(rtConfig)
		case api.RSSAction:
			return ap.createBlockNodeRSS(rtConfig)
		case api.KeysAction:
			return ap.createBlockNodeMetaKeys()
		}
		key := strings.ToLower(act)
		switch meta.Type(key) {
		case meta.TypeWord:
			return ap.createBlockNodeWord(key)

type actionPara struct {
	ctx    context.Context
	q      *query.Query
	ml     []*meta.Meta
	kind   ast.NestedListKind
	minVal int
	maxVal int
	title  string
}

func (ap *actionPara) createBlockNodeWord(key string) (ast.BlockNode, int) {
	var buf bytes.Buffer
	ccs, bufLen := ap.prepareCatAction(key, &buf)
	if len(ccs) == 0 {
		return nil, 0

			}
		}
	}
	return result
}

func calcBudget(total, curSize float64) float64 { return math.Round(total / (fontSizes64 - curSize)) }

func (ap *actionPara) createBlockNodeRSS(cfg config.Config) (ast.BlockNode, int) {
	var rssConfig rss.Configuration
	rssConfig.Setup(ap.ctx, cfg)
	rssConfig.Title = ap.title
	data := rssConfig.Marshal(ap.q, ap.ml)

	return &ast.VerbatimNode{
		Kind:    ast.VerbatimProg,
		Attrs:   attrs.Attributes{"lang": "xml"},
		Content: data,
	}, len(ap.ml)
}

func (ap *actionPara) createBlockNodeAtom(cfg config.Config) (ast.BlockNode, int) {
	var atomConfig atom.Configuration
	atomConfig.Setup(cfg)
	atomConfig.Title = ap.title
	data := atomConfig.Marshal(ap.q, ap.ml)

	return &ast.VerbatimNode{
		Kind:    ast.VerbatimProg,
		Attrs:   attrs.Attributes{"lang": "xml"},
		Content: data,
	}, len(ap.ml)
}

module zettelstore.de/z

go 1.23

require (
	github.com/fsnotify/fsnotify v1.8.0
	github.com/yuin/goldmark v1.7.8
	golang.org/x/crypto v0.31.0
	golang.org/x/term v0.27.0
	golang.org/x/text v0.21.0
	t73f.de/r/sx v0.0.0-20240814083626-4df0ec6454b5
	t73f.de/r/sxwebs v0.0.0-20241031144449-53c3b2ed1a6f
	t73f.de/r/zsc v0.0.0-20241213121052-fd15ae683e82
)

require (
	golang.org/x/sys v0.28.0 // indirect
	t73f.de/r/webs v0.0.0-20241031141359-cd4f76a622cd // indirect
)

golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
t73f.de/r/sx v0.0.0-20240814083626-4df0ec6454b5 h1:ug4hohM6pK28M8Uo0o3+XvjBure2wfEtuCnHVIdqBZY=
t73f.de/r/sx v0.0.0-20240814083626-4df0ec6454b5/go.mod h1:VRvsWoBErPKvMieDMMk1hsh1tb9sA4ijEQWGw/TbtQ0=
t73f.de/r/sxwebs v0.0.0-20241031144449-53c3b2ed1a6f h1:VJ4S7YWy9tCJuFz5MckqUjjktPaf0kpnTkNBVRVXpo4=
t73f.de/r/sxwebs v0.0.0-20241031144449-53c3b2ed1a6f/go.mod h1:IaM+U+LvYTYeuiIS5cwZW6kcEpdwoKBYVCU7LZr4Sgk=
t73f.de/r/webs v0.0.0-20241031141359-cd4f76a622cd h1:+7cqJonXKDso+uPvsvOPl7BiLkhj8VQT/Has8qC5VIQ=
t73f.de/r/webs v0.0.0-20241031141359-cd4f76a622cd/go.mod h1:NSoOON8be62MfQZzlCApK27Jt2zhIa6Vrmo9RJ4tOnQ=
t73f.de/r/zsc v0.0.0-20241213121052-fd15ae683e82 h1:Bl3iCW9bHx9CeIyWUMLi9xqRV7mHh/1HS6rBnt5QQQU=
t73f.de/r/zsc v0.0.0-20241213121052-fd15ae683e82/go.mod h1:sQWKzNp0I18aSFnKJjAyhL1zTWITIj1v2acWv4GvuIY=

	if q == nil {
		return false
	}
	if len(q.zids) > 0 {
		return true
	}
	if len(q.actions) > 0 {
		// Unknown, what an action will use. Example: RSS needs api.KeyPublished.
		return true
	}
	for _, term := range q.terms {
		for key := range term.keys {
			if meta.IsProperty(key) {
				return true
			}

	var sb strings.Builder
	for _, p := range m.PairsRest() {
		sb.WriteString(p.Key)
		sb.WriteString(": ")
		sb.WriteString(p.Value)
		sb.WriteByte('\n')
	}
	env, rb := wui.createRenderEnv(ctx, "form", wui.rtConfig.Get(ctx, nil, api.KeyLang), title, user)
	rb.bindString("heading", sx.MakeString(title))
	rb.bindString("form-action-url", sx.MakeString(formActionURL))
	rb.bindString("role-data", makeStringList(roleData))
	rb.bindString("syntax-data", makeStringList(syntaxData))
	rb.bindString("meta", sx.MakeString(sb.String()))
	if !ztl.Content.IsBinary() {
		rb.bindString("content", sx.MakeString(ztl.Content.AsString()))

		q := adapter.GetQuery(r.URL.Query())
		ctx := r.Context()
		metaSeq, err := queryMeta.Run(box.NoEnrichQuery(ctx, q), q)
		if err != nil {
			wui.reportError(ctx, w, err)
			return
		}
		entries, _ := evaluator.QueryAction(ctx, q, metaSeq, wui.rtConfig)
		bns := evaluate.RunBlockNode(ctx, entries)
		enc := zmkenc.Create()
		var zmkContent bytes.Buffer
		_, err = enc.WriteBlocks(&zmkContent, &bns)
		if err != nil {
			wui.reportError(ctx, w, err)
			return

			wui.reportError(ctx, w, err)
			return
		}
		m := zs[0].Meta

		user := server.GetUser(ctx)
		env, rb := wui.createRenderEnv(
			ctx, "delete",
			wui.rtConfig.Get(ctx, nil, api.KeyLang), "Delete Zettel "+m.Zid.String(), user)
		if len(zs) > 1 {
			rb.bindString("shadowed-box", sx.MakeString(zs[1].Meta.GetDefault(api.KeyBoxNumber, "???")))
			rb.bindString("incoming", nil)
		} else {
			rb.bindString("shadowed-box", nil)
			rb.bindString("incoming", wui.encodeIncoming(m, wui.makeGetTextTitle(ctx, getZettel)))
		}

		zn, err := ucParseZettel.Run(ctx, zid, q.Get(api.KeySyntax))
		if err != nil {
			wui.reportError(ctx, w, err)
			return
		}

		enc := wui.getSimpleHTMLEncoder(wui.rtConfig.Get(ctx, zn.InhMeta, api.KeyLang))
		getTextTitle := wui.makeGetTextTitle(ctx, ucGetZettel)
		evalMeta := func(val string) ast.InlineSlice {
			return ucEvaluate.RunMetadata(ctx, val)
		}
		pairs := zn.Meta.ComputedPairs()
		metadata := sx.Nil()
		for i := len(pairs) - 1; i >= 0; i-- {

		}
		unlinkedMeta, err := ucQuery.Run(ctx, createUnlinkedQuery(zid, phrase))
		if err != nil {
			wui.reportError(ctx, w, err)
			return
		}

		entries, _ := evaluator.QueryAction(ctx, nil, unlinkedMeta, wui.rtConfig)
		bns := ucEvaluate.RunBlockNode(ctx, entries)
		unlinkedContent, _, err := enc.BlocksSxn(&bns)
		if err != nil {
			wui.reportError(ctx, w, err)
			return
		}
		encTexts := encodingTexts()
		shadowLinks := getShadowLinks(ctx, zid, ucGetAllZettel)

		user := server.GetUser(ctx)
		env, rb := wui.createRenderEnv(ctx, "info", wui.rtConfig.Get(ctx, nil, api.KeyLang), title, user)
		rb.bindString("metadata", metadata)
		rb.bindString("local-links", locLinks)
		rb.bindString("query-links", queryLinks)
		rb.bindString("ext-links", extLinks)
		rb.bindString("unlinked-content", unlinkedContent)
		rb.bindString("phrase", sx.MakeString(phrase))
		rb.bindString("query-key-phrase", sx.MakeString(api.QueryKeyPhrase))

		q := r.URL.Query()
		zn, err := evaluate.Run(ctx, zid, q.Get(api.KeySyntax))
		if err != nil {
			wui.reportError(ctx, w, err)
			return
		}


		enc := wui.getSimpleHTMLEncoder(wui.rtConfig.Get(ctx, zn.InhMeta, api.KeyLang))
		metaObj := enc.MetaSxn(zn.InhMeta, createEvalMetadataFunc(ctx, evaluate))
		content, endnotes, err := enc.BlocksSxn(&zn.Ast)
		if err != nil {
			wui.reportError(ctx, w, err)
			return
		}

		user := server.GetUser(ctx)
		getTextTitle := wui.makeGetTextTitle(ctx, getZettel)

		title := parser.NormalizedSpacedText(zn.InhMeta.GetTitle())
		env, rb := wui.createRenderEnv(ctx, "zettel", wui.rtConfig.Get(ctx, zn.InhMeta, api.KeyLang), title, user)
		rb.bindSymbol(symMetaHeader, metaObj)
		rb.bindString("heading", sx.MakeString(title))
		if role, found := zn.InhMeta.Get(api.KeyRole); found && role != "" {
			rb.bindString("role-url", sx.MakeString(wui.NewURLBuilder('h').AppendQuery(api.KeyRole+api.SearchOperatorHas+role).String()))
		}
		if folgeRole, found := zn.InhMeta.Get(api.KeyFolgeRole); found && folgeRole != "" {
			rb.bindString("folge-role-url", sx.MakeString(wui.NewURLBuilder('h').AppendQuery(api.KeyRole+api.SearchOperatorHas+folgeRole).String()))

	}
	return result.List()
}

func (wui *WebUI) bindLinks(ctx context.Context, rb *renderBinder, varPrefix string, m *meta.Meta, key, configKey string, getTextTitle getTextTitleFunc) {
	varLinks := varPrefix + "-links"
	var symOpen *sx.Symbol
	switch wui.rtConfig.Get(ctx, m, configKey) {
	case "false":
		rb.bindString(varLinks, sx.Nil())
		return
	case "close":
	default:
		symOpen = shtml.SymAttrOpen
	}

func (wui *WebUI) MakeGetRootHandler(s getRootPort) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		ctx := r.Context()
		if p := r.URL.Path; p != "/" {
			wui.reportError(ctx, w, adapter.ErrResourceNotFound{Path: p})
			return
		}
		homeZid, _ := id.Parse(wui.rtConfig.Get(ctx, nil, config.KeyHomeZettel))
		apiHomeZid := homeZid.ZettelID()
		if homeZid != id.DefaultHomeZid {
			if _, err := s.GetZettel(ctx, homeZid); err == nil {
				wui.redirectFound(w, r, wui.NewURLBuilder('h').SetZid(apiHomeZid))
				return
			}
			homeZid = id.DefaultHomeZid

// SPDX-FileCopyrightText: 2020-present Detlef Stern
//-----------------------------------------------------------------------------

package webui

import (
	"context"
	"io"
	"net/http"
	"net/url"
	"slices"
	"strconv"
	"strings"

	"t73f.de/r/sx"
	"t73f.de/r/sxwebs/sxhtml"
	"t73f.de/r/zsc/api"
	"t73f.de/r/zsc/shtml"
	"zettelstore.de/z/ast"
	"zettelstore.de/z/encoding/atom"
	"zettelstore.de/z/encoding/rss"
	"zettelstore.de/z/encoding/xml"
	"zettelstore.de/z/evaluator"
	"zettelstore.de/z/query"
	"zettelstore.de/z/usecase"
	"zettelstore.de/z/web/adapter"
	"zettelstore.de/z/web/server"
	"zettelstore.de/z/zettel/id"
	"zettelstore.de/z/zettel/meta"
)

			return
		}
		actions, err := adapter.TryReIndex(ctx, q.Actions(), metaSeq, reIndex)
		if err != nil {
			wui.reportError(ctx, w, err)
			return
		}
		if len(actions) > 0 {
			if len(metaSeq) > 0 {
				for _, act := range actions {
					if act == api.RedirectAction {
						ub := wui.NewURLBuilder('h').SetZid(metaSeq[0].Zid.ZettelID())
						wui.redirectFound(w, r, ub)
						return
					}
				}
			}
			switch actions[0] {
			case api.AtomAction:
				wui.renderAtom(w, q, metaSeq)
				return
			case api.RSSAction:
				wui.renderRSS(ctx, w, q, metaSeq)
				return
			}

		}

		var content, endnotes *sx.Pair
		numEntries := 0
		if bn, cnt := evaluator.QueryAction(ctx, q, metaSeq, wui.rtConfig); bn != nil {
			enc := wui.getSimpleHTMLEncoder(wui.rtConfig.Get(ctx, nil, api.KeyLang))
			content, endnotes, err = enc.BlocksSxn(&ast.BlockSlice{bn})
			if err != nil {
				wui.reportError(ctx, w, err)
				return
			}
			numEntries = cnt
		}


		user := server.GetUser(ctx)
		env, rb := wui.createRenderEnv(
			ctx, "list",
			wui.rtConfig.Get(ctx, nil, api.KeyLang),
			wui.rtConfig.GetSiteName(), user)
		if q == nil {
			rb.bindString("heading", sx.MakeString(wui.rtConfig.GetSiteName()))
		} else {
			var sb strings.Builder
			q.PrintHuman(&sb)
			rb.bindString("heading", sx.MakeString(sb.String()))
		}
		rb.bindString("query-value", sx.MakeString(q.String()))
		if tzl := q.GetMetaValues(api.KeyTags, false); len(tzl) > 0 {

	)
	if sxZtl != nil {
		sxZtl = sxZtl.Cons(sx.MakeString(", "))
	}
	return sxZtl.Cons(link)
}

func (wui *WebUI) renderRSS(ctx context.Context, w http.ResponseWriter, q *query.Query, ml []*meta.Meta) {
	var rssConfig rss.Configuration
	rssConfig.Setup(ctx, wui.rtConfig)
	if actions := q.Actions(); len(actions) > 2 && actions[1] == api.TitleAction {
		rssConfig.Title = strings.Join(actions[2:], " ")
	}
	data := rssConfig.Marshal(q, ml)

	adapter.PrepareHeader(w, rss.ContentType)
	w.WriteHeader(http.StatusOK)
	var err error
	if _, err = io.WriteString(w, xml.Header); err == nil {
		_, err = w.Write(data)
	}
	if err != nil {
		wui.log.Error().Err(err).Msg("unable to write RSS data")
	}
}

func (wui *WebUI) renderAtom(w http.ResponseWriter, q *query.Query, ml []*meta.Meta) {
	var atomConfig atom.Configuration
	atomConfig.Setup(wui.rtConfig)
	if actions := q.Actions(); len(actions) > 2 && actions[1] == api.TitleAction {
		atomConfig.Title = strings.Join(actions[2:], " ")
	}
	data := atomConfig.Marshal(q, ml)

	adapter.PrepareHeader(w, atom.ContentType)
	w.WriteHeader(http.StatusOK)
	var err error
	if _, err = io.WriteString(w, xml.Header); err == nil {
		_, err = w.Write(data)
	}
	if err != nil {
		wui.log.Error().Err(err).Msg("unable to write Atom data")
	}
}

func (wui *WebUI) handleTagZettel(w http.ResponseWriter, r *http.Request, tagZettel *usecase.TagZettel, vals url.Values) bool {
	tag := vals.Get(api.QueryKeyTag)
	if tag == "" {
		return false
	}
	ctx := r.Context()
	z, err := tagZettel.Run(ctx, tag)

package webui

import (
	"context"
	"net/http"

	"t73f.de/r/sx"
	"t73f.de/r/zsc/api"
	"zettelstore.de/z/auth"
	"zettelstore.de/z/usecase"
	"zettelstore.de/z/web/adapter"
	"zettelstore.de/z/zettel/id"
)

// MakeGetLoginOutHandler creates a new HTTP handler to display the HTML login view,

			return
		}
		wui.renderLoginForm(wui.clearToken(r.Context(), w), w, false)
	})
}

func (wui *WebUI) renderLoginForm(ctx context.Context, w http.ResponseWriter, retry bool) {
	env, rb := wui.createRenderEnv(ctx, "login", wui.rtConfig.Get(ctx, nil, api.KeyLang), "Login", nil)
	rb.bindString("retry", sx.MakeBoolean(retry))
	if rb.err == nil {
		rb.err = wui.renderSxnTemplate(ctx, w, id.LoginTemplateZid, env)
	}
	if err := rb.err; err != nil {
		wui.reportError(ctx, w, err)
	}

			AppendKVQuery(queryKeyAction, valueActionNew).String())

		lst = lst.Cons(sx.Cons(text, link))
	}
	return lst
}
func (wui *WebUI) calculateFooterSxn(ctx context.Context) *sx.Pair {
	if footerZid, err := id.Parse(wui.rtConfig.Get(ctx, nil, config.KeyFooterZettel)); err == nil {
		if zn, err2 := wui.evalZettel.Run(ctx, footerZid, ""); err2 == nil {
			htmlEnc := wui.getSimpleHTMLEncoder(wui.rtConfig.Get(ctx, zn.InhMeta, api.KeyLang)).SetUnique("footer-")
			if content, endnotes, err3 := htmlEnc.BlocksSxn(&zn.Ast); err3 == nil {
				if content != nil && endnotes != nil {
					content.LastPair().SetCdr(sx.Cons(endnotes, nil))
				}
				return content
			}
		}

		genHTML:       sxhtml.NewGenerator().SetNewline(),
	}
	wui.rootBinding = wui.createRenderBinding()
	wui.observe(box.UpdateInfo{Box: mgr, Reason: box.OnReload, Zid: id.Invalid})
	mgr.RegisterObserver(wui.observe)
	return wui
}








var (
	symDetail     = sx.MakeSymbol("DETAIL")
	symMetaHeader = sx.MakeSymbol("META-HEADER")
)

func (wui *WebUI) observe(ci box.UpdateInfo) {

<title>Change Log</title>

<a id="0_20"></a>
<h2>Changes for Version 0.20.0 (pending)</h2>





<a id="0_19"></a>
<h2>Changes for Version 0.19.0 (2024-12-13)</h2>
  *  Remove support for renaming zettel, i.e. changing zettel identifier. Was
     announced as deprecated in version 0.18.
     (breaking: api, webui)
  *  Format of zettel identifier will be not changed. The deprecation message