API

API for developers. We developers.

1. Developer kit
2. Folder structure
3. Objects
3.1. Yellow page
3.2. Yellow page collection
3.3. Yellow content
3.4. Yellow media
3.5. Yellow system
3.6. Yellow text
3.7. Yellow text encoding
3.8. Yellow toolbox
3.9. Yellow extensions
4. Events
4.1. Yellow core events
4.2. Yellow edit events
4.3. Yellow command events
5. Troubleshooting

Developer kit

Install the developer kit. The developer kit for Datenstrom Yellow includes examples and tests. You can try out how to make small web pages, blogs and wikis. You can learn how to customise your website. It's a great place to get started.

When there are problems, please check the server configuration or ask the support.

Folder structure

The following folders are available:

├── content               = content files
├── media                 = media files
│   ├── downloads         = files to download
│   ├── images            = image files for the content
│   └── thumbnails        = image thumbnails
└── system                = system files
    ├── extensions        = installed extensions
    ├── layouts           = layout files, HTML files
    ├── resources         = resource files, CSS files etc.
    ├── settings          = configuration files, INI files
    └── trash             = deleted files

Objects

The following objects are available:

$this->yellow->page = access to current page
$this->yellow->content = access to content files from file system
$this->yellow->media = access to media files from file system
$this->yellow->system = access to system settings
$this->yellow->text = access to text settings
$this->yellow->toolbox = access to toolbox with helpers
$this->yellow->extensions = access to features and themes

Yellow page

Yellow page gives access to current page:

$this->yellow->page->get($key)
Return page setting

$this->yellow->page->getHtml($key)
Return page setting, HTML encoded

$this->yellow->page->getDate($key, $format = "")
Return page setting as language specific date format

$this->yellow->page->getDateHtml($key, $format = "")
Return page setting as language specific date format, HTML encoded

$this->yellow->page->getDateRelative($key, $format = "", $daysLimit = 30)
Return page setting as language specific date format, relative to today

$this->yellow->page->getDateRelativeHtml($key, $format = "", $daysLimit = 30)
Return page setting as language specific date format, relative to today, HTML encoded

$this->yellow->page->getDateFormatted($key, $format)
Return page setting with custom date format

$this->yellow->page->getDateFormattedHtml($key, $format)
Return page setting with custom date format, HTML encoded

$this->yellow->page->getContent($rawFormat = false, $sizeMax = 0)
Return page content, HTML encoded or raw format

$this->yellow->page->getParent()
Return parent page, null if none

$this->yellow->page->getParentTop($homeFallback = false)
Return top-level parent page, null if none

$this->yellow->page->getSiblings($showInvisible = false)
Return page collection with pages on the same level

$this->yellow->page->getChildren($showInvisible = false)
Return page collection with child pages

$this->yellow->page->getPages()
Return page collection with additional pages

$this->yellow->page->getPage($key)
Return related page

$this->yellow->page->getBase($multiLanguage = false)
Return page base

$this->yellow->page->getLocation($absoluteLocation = false)
Return page location

$this->yellow->page->getUrl()
Return page URL

$this->yellow->page->getExtra($name)
Return page extra data

$this->yellow->page->getHeader($key)
Return page response header

$this->yellow->page->getModified($httpFormat = false)
Return page modification date, Unix time or HTTP format

$this->yellow->page->getLastModified($httpFormat = false)
Return last modification date, Unix time or HTTP format

$this->yellow->page->getStatusCode($httpFormat = false)
Return page status code, number or HTTP format

$this->yellow->page->error($statusCode, $pageError = "")
Respond with error page

$this->yellow->page->clean($statusCode, location = "")
Respond with status code, no page content

$this->yellow->page->isAvailable()
Check if page is available

$this->yellow->page->isVisible()
Check if page is visible

$this->yellow->page->isActive()
Check if page is within current HTTP request

$this->yellow->page->isCacheable()
Check if page is cacheable

$this->yellow->page->isError()
Check if page with error

$this->yellow->page->isHeader($key)
Check if response header exists

$this->yellow->page->isExisting($key)
Check if page setting exists

$this->yellow->page->isPage($key)
Check if related page exists

Here's an example layout for showing page content:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<?php echo $this->yellow->page->getContent() ?>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for showing page content with additional setting:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<p><?php echo $this->yellow->page->getHtml("author") ?></p>
<?php echo $this->yellow->page->getContent() ?>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for showing page content with additional date:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<p><?php echo $this->yellow->page->getDateHtml("modified", "dateFormatMedium") ?></p>
<?php echo $this->yellow->page->getContent() ?>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Yellow page collection

Yellow page collection gives access to multiple pages:

$pages->filter($key, $value, $exactMatch = true)
Filter page collection by setting

$pages->match($regex = "/.*/")
Filter page collection by file name

$pages->sort($key, $ascendingOrder = true)
Sort page collection by setting

$pages->similar($page, $ascendingOrder = false)
Sort page collection by settings similarity

$pages->merge($input)
Merge page collection

$pages->append($page)
Append to end of page collection

$pages->prepend($page)
Prepend to start of page collection

$pages->limit($pagesMax)
Limit the number of pages in page collection

$pages->reverse()
Reverse page collection

$pages->shuffle()
Randomize page collection

$pages->pagination($limit, $reverse = true)
Paginate page collection

$pages->getPaginationNumber()
Return current page number in pagination

$pages->getPaginationCount()
Return highest page number in pagination

$pages->getPaginationLocation($absoluteLocation = true, $pageNumber = 1)
Return location for a page in pagination

$pages->getPaginationPrevious($absoluteLocation = true)
Return location for previous page in pagination

$pages->getPaginationNext($absoluteLocation = true)
Return location for next page in pagination

$pages->getPagePrevious($page)
Return previous page in collection, null if none

$pages->getPageNext($page)
Return next page in collection, null if none

$pages->getFilter()
Return current page filter

$pages->getModified($httpFormat = false)
Return page collection modification date, Unix time or HTTP format

$pages->isPagination()
Check if there is a pagination

Here's an example layout for showing three random pages:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<?php $pages = $this->yellow->content->index()->shuffle()->limit(3) ?>
<?php $this->yellow->page->setLastModified($pages->getModified()) ?>
<ul>
<?php foreach ($pages as $page): ?>
<li><?php echo $page->getHtml("title") ?></li>
<?php endforeach ?>
</ul>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for showing latest pages:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<?php $pages = $this->yellow->content->index()->sort("modified", false) ?>
<?php $this->yellow->page->setLastModified($pages->getModified()) ?>
<ul>
<?php foreach ($pages as $page): ?>
<li><?php echo $page->getHtml("title") ?></li>
<?php endforeach ?>
</ul>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for showing draft pages:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<?php $pages = $this->yellow->content->index(true, true)->filter("status", "draft") ?>
<?php $this->yellow->page->setLastModified($pages->getModified()) ?>
<ul>
<?php foreach ($pages as $page): ?>
<li><?php echo $page->getHtml("title") ?></li>
<?php endforeach ?>
</ul>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Yellow content

Yellow content gives access to content files from file system:

$this->yellow->content->find($location, $absoluteLocation = false)
Return page from file system, null if not found

$this->yellow->content->index($showInvisible = false, $multiLang = false, $levelMax = 0)
Return page collection with all pages

$this->yellow->content->top($showInvisible = false)
Return page collection with top-level navigation

$this->yellow->content->path($location, $absoluteLocation = false)
Return page collection with path ancestry

$this->yellow->content->multi($location, $absoluteLocation = false, $showInvisible = false)
Return page collection with multiple languages in multi language mode

$this->yellow->content->shared($name)
Return page with shared content, null if not found

$this->yellow->content->clean()
Return page collection that is empty

Here's an example layout for showing all pages:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<?php $pages = $this->yellow->content->index(true, true) ?>
<?php $this->yellow->page->setLastModified($pages->getModified()) ?>
<ul>
<?php foreach ($pages as $page): ?>
<li><?php echo $page->getHtml("title") ?></li>
<?php endforeach ?>
</ul>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for showing pages below a specific location:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<?php $pages = $this->yellow->content->find("/help/")->getChildren(true) ?>
<?php $this->yellow->page->setLastModified($pages->getModified()) ?>
<ul>
<?php foreach ($pages as $page): ?>
<li><?php echo $page->getHtml("title") ?></li>
<?php endforeach ?>
</ul>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for showing top-level navigation pages:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<?php $pages = $this->yellow->content->top() ?>
<?php $this->yellow->page->setLastModified($pages->getModified()) ?>
<ul>
<?php foreach ($pages as $page): ?>
<li><?php echo $page->getHtml("titleNavigation") ?></li>
<?php endforeach ?>
</ul>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Yellow media

Yellow media gives access to media files from file system:

$this->yellow->media->find($location, $absoluteLocation = false)
Return page with media file information, null if not found

$this->yellow->media->index($showInvisible = false, $multiPass = false, $levelMax = 0)
Return page collection with all media files

$this->yellow->media->clean()
Return page collection that is empty

Here's an example layout for showing all media files:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<?php $files = $this->yellow->media->index(true) ?>
<?php $this->yellow->page->setLastModified($files->getModified()) ?>
<ul>
<?php foreach ($files as $file): ?>
<li><?php echo $file->getLocation(true) ?></li>
<?php endforeach ?>
</ul>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for showing latest media files:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<?php $files = $this->yellow->media->index(true)->sort("modified", false) ?>
<?php $this->yellow->page->setLastModified($files->getModified()) ?>
<ul>
<?php foreach ($files as $file): ?>
<li><?php echo $file->getLocation(true) ?></li>
<?php endforeach ?>
</ul>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for showing media files of a specific type:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<?php $files = $this->yellow->media->index(true)->filter("type", "pdf") ?>
<?php $this->yellow->page->setLastModified($files->getModified()) ?>
<ul>
<?php foreach ($files as $file): ?>
<li><?php echo $file->getLocation(true) ?></li>
<?php endforeach ?>
</ul>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Yellow system

Yellow system gives access to system settings:

$this->yellow->system->get($key)
Return system setting

$this->yellow->system->getHtml($key)
Return system setting, HTML encoded

$this->yellow->system->getData($filterStart = "", $filterEnd = "")
Return system settings

$this->yellow->system->getModified($httpFormat = false)
Return system settings modification date, Unix time or HTTP format

$this->yellow->system->isExisting($key)
Check if system setting exists

Here's an example layout for showing static website settings:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<p>
<?php foreach ($this->yellow->system->getData("static") as $key=>$value): ?>
<?php echo htmlspecialchars("$key: $value") ?><br />
<?php endforeach ?>
</p>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for showing webmaster settings:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<p>
<?php echo "Author: ".$this->yellow->system->getHtml("author")."<br />" ?>
<?php echo "Email: ".$this->yellow->system->getHtml("email")."<br />" ?>
</p>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for showing if safe mode is activated:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<p>
<?php $safeMode = $this->yellow->system->get("safeMode") ?>
Safe mode is <?php echo htmlspecialchars($safeMode ? "on" : "off") ?>.
</p>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Yellow text

Yellow text gives access to text settings:

$this->yellow->text->get($key)
Return text setting

$this->yellow->text->getHtml($key)
Return text setting, HTML encoded

$this->yellow->text->getText($key, $language )
Return text setting for specific language

$this->yellow->text->getTextHtml($key, $language )
Return text setting for specific language, HTML encoded

$this->yellow->text->getData($filterStart = "", $language = "")
Return text settings

$this->yellow->text->getModified($httpFormat = false)
Return text settings modification date, Unix time or HTTP format

$this->yellow->text->getLanguages()
Return languages

$this->yellow->text->isLanguage($language)
Check if language exists

$this->yellow->text->isExisting($key, $language = "")
Check if text setting exists

Here's an example layout for showing error messages:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<p>
<?php foreach ($this->yellow->text->getData("error") as $key=>$value): ?>
<?php echo htmlspecialchars("$key: $value") ?><br />
<?php endforeach ?>
</p>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for showing languages and translators:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<p>
<?php foreach ($this->yellow->text->getLanguages() as $language): ?>
<?php echo $this->yellow->text->getTextHtml("languageDescription", $language) ?> - 
<?php echo $this->yellow->text->getTextHtml("languageTranslator", $language) ?><br />
<?php endforeach ?>
</p>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for checking if a specific language exists:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<?php $swedish = $this->yellow->text->isLanguage("sv") ?>
<p>Swedish language <?php echo htmlspecialchars($swedish ? "" : "not") ?> installed.</p>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Yellow text encoding

The following functions are available to encode text:

htmlspecialchars($string) = encode text string into HTML format
rawurlencode($string) = encode URL, e.g. hyperlink arguments
strencode($string) = encode string, e.g. JavaScript arguments

Here's an example layout for encoding HTML arguments:

<?php list($name, $class) = $this->yellow->getLayoutArgs() ?>
<?php if (empty($class)) $class = "regular" ?>
<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<p><img src="https://unsplash.it/210/140/?random" class="<?php echo htmlspecialchars($class) ?>" /></p>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for encoding hyperlink arguments:

<?php list($name, $id) = $this->yellow->getLayoutArgs() ?>
<?php if (empty($id)) $id = "821" ?>
<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<p><img src="https://unsplash.it/210/140/?image=<?php echo rawurlencode($id) ?>" /></p>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for encoding JavaScript arguments:

<?php list($name, $message) = $this->yellow->getLayoutArgs() ?>
<?php if (empty($message)) $message = "Hello world" ?>
<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<script type="text/javascript">
console.log("<?php echo strencode($message) ?>");
</script>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Yellow toolbox

Yellow toolbox gives access to toolbox with helpers:

$this->yellow->toolbox->getLocation($filterStrict = true)
Return location from current HTTP request

$this->yellow->toolbox->getLocationArgs()
Return location arguments from current HTTP request

$this->yellow->toolbox->isLocationArgs($location = "")
Check if there are location arguments in current HTTP request

$this->yellow->toolbox->normaliseArgs($text, $appendSlash = true, $filterStrict = true)
Normalise location arguments

$this->yellow->toolbox->getDirectoryEntries($path, $regex = "/.*/", $sort = true, $directories = true, $includePath = true)
Return files and directories

$this->yellow->toolbox->readFile($fileName, $sizeMax = 0)
Read file, empty string if not found

$this->yellow->toolbox->createFile($fileName, $fileData, $mkdir = false)
Create file

$this->yellow->toolbox->appendFile($fileName, $fileData, $mkdir = false)
Append file

$this->yellow->toolbox->copyFile($fileNameSource, $fileNameDestination, $mkdir = false)
Copy file

$this->yellow->toolbox->renameFile($fileNameSource, $fileNameDestination, $mkdir = false)
Rename file

$this->yellow->toolbox->renameDirectory($pathSource, $pathDestination, $mkdir = false)
Rename directory

$this->yellow->toolbox->deleteFile($fileName, $pathTrash = "")
Delete file

$this->yellow->toolbox->deleteDirectory($path, $pathTrash = "")
Delete directory

$this->yellow->toolbox->modifyFile($fileName, $modified)
Set file modification date, Unix time

$this->yellow->toolbox->getFileModified($fileName)
Return file modification date, Unix time

$this->yellow->toolbox->getTextLines($text)
Return lines from text string, including newline

$this->yellow->toolbox->getTextArgs($text, $optional = "-")
Return arguments from text string, space separated

Here's an example layout for showing location and arguments:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<p>
<?php echo htmlspecialchars($this->yellow->toolbox->getLocation()) ?><br />
<?php foreach ($_REQUEST as $key=>$value): ?>
<?php echo htmlspecialchars("$key: $value") ?><br />
<?php endforeach ?>
</p>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for showing files in a directory:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<p>
<?php $path = $this->yellow->system->get("settingDir") ?>
<?php foreach ($this->yellow->toolbox->getDirectoryEntries($path, "/.*/", true, false) as $entry): ?>
<?php echo htmlspecialchars($entry) ?><br />
<?php endforeach ?>
</p>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example layout for reading text lines from file:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<p>
<?php $fileName = $this->yellow->system->get("settingDir").$this->yellow->system->get("systemFile") ?>
<?php $fileData = $this->yellow->toolbox->readFile($fileName) ?>
<?php foreach ($this->yellow->toolbox->getTextLines($fileData) as $line): ?>
<?php echo htmlspecialchars($line) ?><br />
<?php endforeach ?>
</p>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Yellow extensions

Yellow extensions gives access to features and themes:

$this->yellow->extensions->get($name)
Return extension

$this->yellow->extensions->getData($type = "")
Return extensions version

$this->yellow->extensions->getModified($httpFormat = false)
Return extensions modification date, Unix time or HTTP format

$this->yellow->extensions->getExtensions($type = "")
Return extensions

$this->yellow->extensions->isExisting($name)
Check if extension exists

Here's an example layout for showing information about extensions:

<?php $this->yellow->layout("header") ?>
<div class="content">
<div class="main" role="main">
<h1><?php echo $this->yellow->page->getHtml("titleContent") ?></h1>
<p>
<?php foreach($this->yellow->extensions->getData() as $key=>$value): ?>
<?php echo htmlspecialchars("$key $value") ?><br />
<?php endforeach ?>
</p>
</div>
</div>
<?php $this->yellow->layout("footer") ?>

Here's an example extension for creating own features:

<?php
class YellowExample {
    const VERSION = "0.1.0";
    const TYPE = "feature";
}

Here's an example extension for creating own themes:

<?php
class YellowExample {
    const VERSION = "0.1.0";
    const TYPE = "theme";
}

Events

The following events are available in extensions:

onLoad ───────▶ onStartup ─────────────────────────────────────────┐
                    │                                              │
                    ▼                                              │
                onRequest ─────────────────┐                       │
                    │                      │                       │
                    ▼                      ▼                       ▼
                onParseMeta             onEditUserRestriction  onCommand
                onParseContentRaw       onEditUserAccount      onCommandHelp
                onParseContentShortcut  onEditContentFile          │
                onParseContentText      onEditMediaFile            │
                onParsePageLayout          │                       ▼
                onParsePageExtra           │                   onLog
                onParsePageOutput          │                   onUpdate
                    │                      │                       │
                    ▼                      │                       │
exit ◀───────── onShutDown ◀───────────────┴───────────────────────┘

When a page is displayed, the extensions are loaded and onLoad will be called. As soon as all extensions are loaded onStartup will be called. After that the core informs with onRequest that there's a request. The page can be analysed with various onParse events. Then the page content will be generated. If an error occurs, an error page will be generated. Finally the page is output and onShutdown will be called.

When a page is edited, the extensions are loaded and onLoad will be called. As soon as all extensions are loaded onStartup will be called. After that the core informs with onRequest that there's a request, which will be handled by the edit extension. Changes at the page can be analysed with various onEdit events. Then the page will be saved in the file system. Finally a status code is output to reload the page and onShutdown will be called.

When a command is executed, the extensions are loaded and onLoad will be called. As soon as all extensions are loaded onStartup will be called. After that the core informs with onCommand that there's a command, which will be handled by the corresponding extension. If no command has been entered at the command line, then onCommandHelp will be called and extensions can provide a help. Finally a return code is output and onShutdown will be called.

Yellow core events

Yellow core events notify when a state has changed.

public function onLoad($yellow)
Handle initialisation

public function onStartup()
Handle startup

public function onRequest($scheme, $address, $base, $location, $fileName)
Handle request

public function onParseMeta($page)
Handle page meta data

public function onParseContentRaw($page, $text)
Handle page content in raw format

public function onParseContentShortcut($page, $name, $text, $type)
Handle page content of shortcut

public function onParseContentText($page, $text)
Handle page content

public function onParsePageLayout($page, $name)
Handle page layout

public function onParsePageExtra($page, $name)
Handle page extra data

public function onParsePageOutput($page, $text)
Handle page output data

public function onLog($action, $message)
Handle logging

public function onUpdate($action)
Handle update

public function onShutdown()
Handle shutdown

Here's an example extension for handling an [example] shortcut:

<?php
class YellowExample {
    const VERSION = "0.1.1";
    const TYPE = "feature";
    public $yellow;         //access to API

    // Handle initialisation
    public function onLoad($yellow) {
        $this->yellow = $yellow;
    }

    // Handle page content of shortcut
    public function onParseContentShortcut($page, $name, $text, $type) {
        $output = null;
        if ($name=="example" && ($type=="block" || $type=="inline")) {
            $output = "<div class=\"".htmlspecialchars($name)."\">";
            $output .= "Add more HTML code here";
            $output .= "</div>";
        }
        return $output;
    }
}

Yellow edit events

Yellow edit events notify when a page is edited in the web browser.

public function onEditUserRestriction($email, $location, $fileName, $users)
Handle user restriction

public function onEditUserAccount($email, $password, $action, $users)
Handle user account changes

public function onEditContentFile($page, $action)
Handle content file changes

public function onEditMediaFile($file, $action)
Handle media file changes

Here's an example extension for restricting certain users:

<?php
class YellowExample {
    const VERSION = "0.1.3";
    const TYPE = "feature";
    public $yellow;         //access to API

    // Handle initialisation
    public function onLoad($yellow) {
        $this->yellow = $yellow;
    }

    // Handle user restriction
    public function onEditUserRestriction($email, $location, $fileName, $users) {
        return $users->getHome($email)=="/guests/";
    }
}

Yellow command events

Yellow command events notify when a command is executed.

public function onCommand($args)
Handle command

public function onCommandHelp()
Handle command help

Here's an example extension for handling a command:

<?php
class YellowExample {
    const VERSION = "0.1.2";
    const TYPE = "feature";
    public $yellow;         //access to API

    // Handle initialisation
    public function onLoad($yellow) {
        $this->yellow = $yellow;
    }

    // Handle command help
    public function onCommandHelp() {
        return "example\n";
    }

    // Handle command
    public function onCommand($args) {
        $statusCode = 0;
        list($command) = $args;
        if ($command=="example") {
            echo "Yellow $command: Add more text here\n";
            $statusCode = 200;
        }
        return $statusCode;
    }
}

Troubleshooting

You can find system diagnostics in file system/extensions/yellow.log. Here's an example:

2019-03-12 13:33:37 info Datenstrom Yellow 0.8.3, PHP 7.1.23, Apache/2.4.33 Darwin
2019-03-12 13:33:37 info Checked Apache server configuration
2019-03-12 13:33:37 info Install language 'English'
2019-03-12 13:33:37 info Install language 'French'
2019-03-12 13:33:37 info Install language 'German'
2019-03-12 13:33:49 info Install webmaster 'Anna'
2019-03-12 13:33:49 info Install extension 'Blog 0.8.2'

Or open file system/extensions/core.php and change <?php define("DEBUG", 1);

YellowCore::sendPage Cache-Control: max-age=60
YellowCore::sendPage Content-Type: text/html; charset=utf-8
YellowCore::sendPage Content-Modified: Wed, 06 Feb 2019 13:54:17 GMT
YellowCore::sendPage Last-Modified: Thu, 07 Feb 2019 09:37:48 GMT
YellowCore::sendPage layout:blogpages theme:flatsite parser:markdown
YellowCore::processRequest file:content/1-en/2-features/1-blog/page.md
YellowCore::request status:200 handler:core time:19 ms

Get file system information by increasing debug level to <?php define("DEBUG", 2);

YellowSystem::load file:system/settings/system.ini
YellowEditUsers::load file:system/settings/user.ini
YellowText::load file:system/extensions/english-language.txt
YellowText::load file:system/extensions/french-language.txt
YellowText::load file:system/extensions/german-language.txt
YellowText::load file:system/settings/text.ini
YellowCore::load extensions:43 time:10 ms

Get maximum information by increasing debug level to <?php define("DEBUG", 3);

YellowCore::load Datenstrom Yellow 0.8.3, PHP 7.1.23, Apache/2.4.33 Darwin
YellowSystem::load file:system/settings/system.ini
YellowSystem::load Sitename:Datenstrom developers
YellowSystem::load Author:Datenstrom
YellowSystem::load Email:webmaster
YellowSystem::load Language:en
YellowSystem::load Timezone:Europe/Stockholm

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