HTML

O papel do HtmlHelper no CakePHP é fazer as ações relacionadas a HTML mais fáceis, rápidas e mais resistente a mudanças. O uso deste helper permitirá que suas aplicações sejam mais leves e mais flexíveis.

O objetivo do HtmlHelper foi significativamente modificado desde o CakePHP 1.1. Seus métodos relacionados a formulários tornaram-se obsoletos em favor do novo FormHelper. Se você estiver querendo auxílio para criação de elementos de formulários HTML, você deve conferir o FormHelper.

Antes de vermos os métodos do HtmlHelper, você precisará conhecer sobre as poucas configurações e situações que vão lhe ajudar a utilizar melhor esta classe. Primeiro de tudo, num esforço para acalmar aqueles que não gostam de tags curtas (<?= ?>) nem de muitas chamadas echo() no código de suas views, todos os métodos do HtmlHelper são passados para o método output(). Se você quiser permitir a exibição automática do conteúdo HTML gerado, você pode simplesmente implementar o método output() em seu AppHelper.

function output($str) {
    echo $str;
}

Fazendo isto você pode eliminar a necessidade de adicionar declarações echo no código de suas views.

Muitos métodos do HtmlHelper também incluem um parâmetro $htmlAttributes, que permite que você inclua atributos extras em suas tags. Aqui estão alguns poucos exemplo de como usar o parâmetro $htmlAttributes:

Atributos desejados: <tag class="someClass" />
Array de parâmetros: array('class'=>'someClass')

Atributos desejados: <tag name="foo" value="bar" />
Array de parâmetros:  array('name' => 'foo', 'value' => 'bar')

O HtmlHelper está disponível em todas as views por padrão. Se você estiver recebendo um erro dizendo que ele não pôde ser encontrado, é provável que ele esteja faltando numa definição manual que você tenha feito da variável $helpers em um controller.

Inserindo Elementos Bem-Formatados

A tarefa mais importante que o HtmlHelper realiza é a criação de marcações bem formadas. Não tenha medo de usá-lo muitas vezes - você pode armazenar em cache views em CakePHP, a fim de salvar alguns ciclos do processamento quando as views estão sendo renderizadas e liberadas. Esta seção irá cobrir alguns dos métodos da HtmlHelper e como usá-los.

charset

charset(string $charset=null)

Used to create a meta tag specifying the document’s character. Defaults to UTF-8.

<?php echo $this->Html->charset(); ?>

Will output:

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

Alternatively,

<?php echo $this->Html->charset('ISO-8859-1'); ?>

Will output:

<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />

css

css(mixed $path, string $rel = null, array $options = array())

Creates a link(s) to a CSS style-sheet. If key ‘inline’ is set to false in $options parameter, the link tags are added to the $scripts_for_layout variable which you can print inside the head tag of the document.

This method of CSS inclusion assumes that the CSS file specified resides inside the /app/webroot/css directory.

<?php echo $this->Html->css('forms'); ?>

Will output:

<link rel="stylesheet" type="text/css" href="/pt/css/forms.css" />

The first parameter can be an array to include multiple files.

<?php echo $this->Html->css(array('forms','tables','menu')); ?>

Will output:

<link rel="stylesheet" type="text/css" href="/pt/css/forms.css" />
<link rel="stylesheet" type="text/css" href="/pt/css/tables.css" />
<link rel="stylesheet" type="text/css" href="/pt/css/menu.css" />

This method included the CSS in the header.

<?php    $this->Html->css(array('forms','myplugin/css/forms'),'stylesheet', array('inline' => false ) ); ?>

Will output in header:

<link rel="stylesheet" type="text/css" href="/pt/css/forms.css" />
<link rel="stylesheet" type="text/css" href="/pt/myplugin/css/forms.css" />

meta

meta(string $type, string $url = null, array $attributes = array())

This method is handy for linking to external resources like RSS/Atom feeds and favicons. Like css(), you can specify whether or not you’d like this tag to appear inline or in the head tag by setting the ‘inline’ key in the $attributes parameter to false, ie - array('inline' => false).

If you set the “type” attribute using the $attributes parameter, CakePHP contains a few shortcuts:

type translated value
html text/html
rss application/rss+xml
atom application/atom+xml
icon image/x-icon
  <?php echo $this->Html->meta(
    'favicon.ico',
    '/favicon.ico',
    array('type' => 'icon')
);?> //Output (line breaks added) </p>
<link
    href="http://example.com/favicon.ico"
    title="favicon.ico" type="image/x-icon"
    rel="alternate"
/>

<?php echo $this->Html->meta(
    'Comments',
    '/comments/index.rss',
    array('type' => 'rss'));
?>

//Output (line breaks added)
<link
    href="http://example.com/comments/index.rss"
    title="Comments"
    type="application/rss+xml"
    rel="alternate"
/>

This method can also be used to add the meta keywords and descriptions. Example:

<?php echo $this->Html->meta(
    'keywords',
    'enter any meta keyword here'
);?>
//Output <meta name="keywords" content="enter any meta keyword here"/>
//

<?php echo $this->Html->meta(
    'description',
    'enter any meta description here'
   );?>

//Output <meta name="description" content="enter any meta description here"/>

If you want to add a custom meta tag then the first parameter should be set to an array. To output a robots noindex tag use the following code:

echo $this->Html->meta(array('name' => 'robots', 'content' => 'noindex'));

docType

docType(string $type = 'xhtml-strict')

Returns a (X)HTML doctype tag. Supply the doctype according to the following table:

type translated value
html text/html
html4-strict HTML4 Strict
html4-trans HTML4 Transitional
html4-frame HTML4 Frameset
xhtml-strict XHTML1 Strict
xhtml-trans XHTML1 Transitional
xhtml-frame XHTML1 Frameset
xhtml11 XHTML 1.1
<?php echo $this->Html->docType(); ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<?php echo $this->Html->docType('html4-trans'); ?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

style

style(array $data, boolean $oneline = true)

Builds CSS style definitions based on the keys and values of the array passed to the method. Especially handy if your CSS file is dynamic.

<?php echo $this->Html->style(array(
    'background'     => '#633',
    'border-bottom' => '1px solid #000',
    'padding' => '10px'
)); ?>

Will output:

background:#633; border-bottom:1px solid #000; padding:10px;

image

image(string $path, array $htmlAttributes = array())

Cria uma tag formatada de imagem. O caminho fornecido deve ser relativo a /app/webroot/img/ .

<?php echo $html->image('cake_logo.png', array('alt' => 'CakePHP'))?>

Saída será:

<img src="/img/cake_logo.png" alt="CakePHP" />

Para criar um link de imagem especificando o link de destino usando a opção de url em $htmlAttributes.

<?php echo $html->image("recipes/6.jpg", array(
    "alt" => "Brownies",
    'url' => array('controller' => 'recipes', 'action' => 'view', 6)
)); ?>

Saída será:

<a href="/pt/recipes/view/6">
    <img src="/img/recipes/6.jpg" alt="Brownies" />
</a>

tag

tag(string $tag, string $text, array $htmlAttributes)

Returns text wrapped in a specified tag. If no text is specified then only the opening <tag> is returned.

<?php echo $this->Html->tag('span', 'Hello World.', array('class' => 'welcome'));?>

//Output
<span class="welcome">Hello World</span>

//No text specified.
<?php echo $this->Html->tag('span', null, array('class' => 'welcome'));?>

//Output
<span class="welcome">

Text is not escaped by default but you may use $htmlOptions['escape'] = true to escape your text. This replaces a fourth parameter boolean $escape = false that was available in previous versions.

div

div(string $class, string $text, array $options)

Used for creating div-wrapped sections of markup. The first parameter specifies a CSS class, and the second is used to supply the text to be wrapped by div tags. If the last parameter has been set to true, $text will be printed HTML-escaped.

<?php echo $this->Html->div('error', 'Please enter your credit card number.');?>

//Output
<div class="error">Please enter your credit card number.</div>

If $text is set to null, only an opening div tag is returned.

<?php echo $this->Html->div('', null, array('id' => 'register'));?>

//Output
<div id="register" class="register">

para

para(string $class, string $text, array $htmlAttributes, boolean $escape = false)

Returns a text wrapped in a CSS-classed <p> tag. If no text is supplied, only a starting <p> tag is returned.

<?php echo $this->Html->para(null, 'Hello World.');?>

//Output
<p>Hello World.</p>

script

script(mixed $url, mixed $options)

Creates link(s) to a javascript file. If key inline is set to false in $options, the link tags are added to the $scripts_for_layout variable which you can print inside the head tag of the document.

Include a script file into the page. $options['inline'] controls whether or not a script should be returned inline or added to $scripts_for_layout. $options['once'] controls, whether or not you want to include this script once per request or more than once.

You can also use $options to set additional properties to the generated script tag. If an array of script tags is used, the attributes will be applied to all of the generated script tags.

This method of javascript file inclusion assumes that the javascript file specified resides inside the /app/webroot/js directory.

<?php echo $this->Html->script('scripts'); ?>

Will output:

<script type="text/javascript" href="/pt/js/scripts.js"></script>

You can link to files with absolute paths as well to link files that are not in app/webroot/js

<?php echo $this->Html->script('/otherdir/script_file'); ?>

The first parameter can be an array to include multiple files.

<?php echo $this->Html->script(array('jquery','wysiwyg','scripts')); ?>

Will output:

<script type="text/javascript" href="/pt/js/jquery.js"></script>
<script type="text/javascript" href="/pt/js/wysiwyg.js"></script>
<script type="text/javascript" href="/pt/js/scripts.js"></script>

scriptBlock

scriptBlock($code, $options = array())

Generate a code block containing $code set $options['inline'] to false to have the script block appear in $scripts_for_layout. Also new is the ability to add attributes to script tags. $this->Html->scriptBlock('stuff', array('defer' => true)); will create a script tag with defer="defer" attribute.

scriptStart

scriptStart($options = array())

Begin a buffering code block. This code block will capture all output between scriptStart() and scriptEnd() and create an script tag. Options are the same as scriptBlock()

scriptEnd

scriptEnd()

End a buffering script block, returns the generated script element or null if the script block was opened with inline = false.

An example of using scriptStart() and scriptEnd() would be:

$this->Html->scriptStart(array('inline' => false));

echo $this->Js->alert('I am in the javascript');

$this->Html->scriptEnd();

tableHeaders

tableHeaders(array $names, array $trOptions = null, array $thOptions = null)

Creates a row of table header cells to be placed inside of <table> tags.

<?php echo $this->Html->tableHeaders(array('Date','Title','Active'));?>

//Output
<tr>
    <th>Date</th>
    <th>Title</th>
    <th>Active</th>
</tr>

<?php echo $this->Html->tableHeaders(
    array('Date','Title','Active'),
    array('class' => 'status'),
    array('class' => 'product_table')
);?>

//Output
<tr class="status">
     <th class="product_table">Date</th>
     <th class="product_table">Title</th>
     <th class="product_table">Active</th>
</tr>

tableCells

tableCells(array $data, array $oddTrOptions = null, array $evenTrOptions = null, $useCount = false, $continueOddEven = true)

Creates table cells, in rows, assigning <tr> attributes differently for odd- and even-numbered rows. Wrap a single table cell within an array() for specific <td>-attributes.

<?php echo $this->Html->tableCells(array(
    array('Jul 7th, 2007', 'Best Brownies', 'Yes'),
    array('Jun 21st, 2007', 'Smart Cookies', 'Yes'),
    array('Aug 1st, 2006', 'Anti-Java Cake', 'No'),
));
?>

//Output
<tr><td>Jul 7th, 2007</td><td>Best Brownies</td><td>Yes</td></tr>
<tr><td>Jun 21st, 2007</td><td>Smart Cookies</td><td>Yes</td></tr>
<tr><td>Aug 1st, 2006</td><td>Anti-Java Cake</td><td>No</td></tr>

<?php echo $this->Html->tableCells(array(
    array('Jul 7th, 2007', array('Best Brownies', array('class'=>'highlight')) , 'Yes'),
    array('Jun 21st, 2007', 'Smart Cookies', 'Yes'),
    array('Aug 1st, 2006', 'Anti-Java Cake', array('No', array('id'=>'special'))),
));
?>

//Output
<tr><td>Jul 7th, 2007</td><td class="highlight">Best Brownies</td><td>Yes</td></tr>
<tr><td>Jun 21st, 2007</td><td>Smart Cookies</td><td>Yes</td></tr>
<tr><td>Aug 1st, 2006</td><td>Anti-Java Cake</td><td id="special">No</td></tr>

<?php echo $this->Html->tableCells(
    array(
        array('Red', 'Apple'),
        array('Orange', 'Orange'),
        array('Yellow', 'Banana'),
    ),
    array('class' => 'darker')
);
?>

//Output
<tr class="darker"><td>Red</td><td>Apple</td></tr>
<tr><td>Orange</td><td>Orange</td></tr>
<tr class="darker"><td>Yellow</td><td>Banana</td></tr>

View more details about the tableCells function in the API

url

url(mixed $url = NULL, boolean $full = false)

Returns an URL pointing to a combination of controller and action. If $url is empty, it returns the REQUEST_URI, otherwise it generates the url for the controller and action combo. If full is true, the full base URL will be prepended to the result.

<?php echo $this->Html->url(array(
    "controller" => "posts",
    "action" => "view",
    "bar"));?>

// Output
/posts/view/bar

Here are a few more usage examples:

URL with named parameters

<?php echo $this->Html->url(array(
    "controller" => "posts",
    "action" => "view",
    "foo" => "bar"));
?>

// Output
/posts/view/foo:bar

URL with extension

<?php echo $this->Html->url(array(
    "controller" => "posts",
    "action" => "list",
    "ext" => "rss"));
?>

// Output
/posts/list.rss

URL (starting with ‘/’) with the full base URL prepended.

<?php echo $this->Html->url('/posts', true); ?>

//Output
http://somedomain.com/posts

URL with GET params and named anchor

<?php echo $this->Html->url(array(
    "controller" => "posts",
    "action" => "search",
    "?" => array("foo" => "bar"),
    "#" => "first"));
?>

//Output
/posts/search?foo=bar#first

For further information check Router::url in the API.

Alterando a saída de tags pelo HtmlHelper

A definição de tags para o HtmlHelper segue o modelo XHTML. No entanto, se você precisa gerar HTML para HTML4 você vai precisar criar e carregar um arquivo de configuração contendo as tags que você gostaria de usar. Para mudar as tags utilizadas crie o arquivo app/config/tags.php com o conteúdo:

$tags = array(
    'metalink' => '<link href="%s" %s >',
    'input' => '<input name="%s" %s >',
    //...
);

Assim, você pode carregar a tag definida chamando $html->loadConfig('tags');

Creating breadcrumb trails with HtmlHelper

CakePHP has the built in ability to automatically create a breadcrumb trail in your app. To set this up, first add something similar to the following in your layout template.

echo $this->Html->getCrumbs(' > ','Home');

Now, in your view you’ll want to add the following to start the breadcrumb trails on each of the pages.

$this->Html->addCrumb('Users', '/users');
$this->Html->addCrumb('Add User', '/users/add');

This will add the output of “Home > Users > Add User” in your layout where getCrumbs was added.