{"id":252,"date":"2024-05-21T10:08:35","date_gmt":"2024-05-21T08:08:35","guid":{"rendered":"https:\/\/blog.sutilweb.eu\/?page_id=252"},"modified":"2024-05-21T10:08:35","modified_gmt":"2024-05-21T08:08:35","slug":"55-elementos-de-formulario","status":"publish","type":"page","link":"https:\/\/sutilweb.eu\/index.php\/lenguajes\/html5\/html5-manual\/55-elementos-de-formulario\/","title":{"rendered":"55. Elementos de formulario"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">El elemento HTML <strong><em>&lt;form&gt;<\/em><\/strong> puede contener uno o m\u00e1s de los siguientes elementos de formulario:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><em>&lt;input><\/em><\/strong><\/li>\n\n\n\n<li><strong><em>&lt;label><\/em><\/strong><\/li>\n\n\n\n<li><strong><em>&lt;select><\/em><\/strong><\/li>\n\n\n\n<li><strong><em>&lt;textarea><\/em><\/strong><\/li>\n\n\n\n<li><strong><em>&lt;button><\/em><\/strong><\/li>\n\n\n\n<li><strong><em>&lt;fieldset><\/em><\/strong><\/li>\n\n\n\n<li><strong><em>&lt;legend><\/em><\/strong><\/li>\n\n\n\n<li><strong><em>&lt;datalist><\/em><\/strong><\/li>\n\n\n\n<li><strong><em>&lt;output&lt;<\/em><\/strong><\/li>\n\n\n\n<li><strong><em>&lt;option><\/em><\/strong><\/li>\n\n\n\n<li><strong><em>&lt;optgroup><\/em><\/strong><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">El elemento &lt;input&gt;<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Uno de los elementos de formulario m\u00e1s utilizados es el elemento <strong><em>&lt;input&gt;<\/em><\/strong>. El elemento <strong><em>&lt;input&gt;<\/em><\/strong> se puede mostrar de varias formas, seg\u00fan el atributo de tipo.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">El elemento &lt;label&gt;<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">El elemento <strong><em>&lt;label&gt;<\/em><\/strong> define una etiqueta para varios elementos de formulario. El elemento <strong><em>&lt;label&gt;<\/em><\/strong> es \u00fatil para los usuarios de lectores de pantalla, porque el lector de pantalla leer\u00e1 en voz alta la etiqueta cuando el usuario se concentre en el elemento de entrada.&nbsp;El elemento <strong><em>&lt;label&gt;<\/em><\/strong> tambi\u00e9n ayuda a los usuarios que tienen dificultades para hacer clic en regiones muy peque\u00f1as (como <strong>botones de radio<\/strong> o <strong>casillas de verificaci\u00f3n<\/strong>), porque cuando el usuario hace clic en el texto dentro del elemento <strong><em>&lt;label&gt;<\/em><\/strong>, alterna el bot\u00f3n de radio\/casilla de verificaci\u00f3n.&nbsp;El atributo <strong><em>for<\/em> <\/strong>de la etiqueta <strong><em>&lt;label&gt;<\/em><\/strong> debe ser igual al atributo id del elemento &lt;input&gt; para unirlos.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">El elemento &lt;select&gt;<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">El elemento <strong><em>&lt;select&gt;<\/em><\/strong> define una lista desplegable:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Ejm<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">&lt;label&nbsp;for=\"cars\"&gt;Choose a car:&lt;\/label&gt;\n&lt;select&nbsp;id=\"cars\"&nbsp;name=\"cars\"&gt;\n&nbsp;&nbsp;&lt;option&nbsp;value=\"volvo\"&gt;Volvo&lt;\/option&gt;\n&nbsp;&nbsp;&lt;option&nbsp;value=\"saab\"&gt;Saab&lt;\/option&gt;\n&nbsp;&nbsp;&lt;option&nbsp;value=\"fiat\"&gt;Fiat&lt;\/option&gt;\n&nbsp;&nbsp;&lt;option&nbsp;value=\"audi\"&gt;Audi&lt;\/option&gt;\n&lt;\/select&gt;<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Los elementos <strong><em>&lt;option&gt;<\/em><\/strong> definen una opci\u00f3n que se puede seleccionar. De forma predeterminada, se selecciona el primer elemento de la lista desplegable. Para definir una opci\u00f3n preseleccionada, agregue el atributo <strong><em>selected<\/em> <\/strong>a la opci\u00f3n.<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">&lt;option&nbsp;value=\"fiat\"&nbsp;selected&gt;Fiat&lt;\/option&gt;<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Valores visibles<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Utiliza el atributo <strong><em>size<\/em> <\/strong>para especificar el n\u00famero de valores visibles:<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">&lt;label&nbsp;for=\"cars\"&gt;Choose a car:&lt;\/label&gt;\n&lt;select&nbsp;id=\"cars\"&nbsp;name=\"cars\"&nbsp;size=\"3\"&gt;\n&nbsp;&nbsp;&lt;option&nbsp;value=\"volvo\"&gt;Volvo&lt;\/option&gt;\n&nbsp;&nbsp;&lt;option&nbsp;value=\"saab\"&gt;Saab&lt;\/option&gt;\n&nbsp;&nbsp;&lt;option&nbsp;value=\"fiat\"&gt;Fiat&lt;\/option&gt;\n&nbsp;&nbsp;&lt;option&nbsp;value=\"audi\"&gt;Audi&lt;\/option&gt;\n&lt;\/select&gt;<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Permitir m\u00faltiples selecciones<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Utiliza el atributo <strong><em>multiple<\/em> <\/strong>para permitir que el usuario seleccione m\u00e1s de un valor:<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">&lt;label&nbsp;for=\"cars\"&gt;Choose a car:&lt;\/label&gt;\n&lt;select&nbsp;id=\"cars\"&nbsp;name=\"cars\"&nbsp;size=\"4\"multiple&gt;\n&nbsp;&nbsp;&lt;option&nbsp;value=\"volvo\"&gt;Volvo&lt;\/option&gt;\n&nbsp;&nbsp;&lt;option&nbsp;value=\"saab\"&gt;Saab&lt;\/option&gt;\n&nbsp;&nbsp;&lt;option&nbsp;value=\"fiat\"&gt;Fiat&lt;\/option&gt;\n&nbsp;&nbsp;&lt;option&nbsp;value=\"audi\"&gt;Audi&lt;\/option&gt;\n&lt;\/select&gt;<\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">El elemento &lt;textarea&gt;<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">El elemento <strong><em>&lt;textarea&gt;<\/em><\/strong> define un campo de entrada de varias l\u00edneas (un \u00e1rea de texto).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Ejm<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">&lt;textarea&nbsp;name=\"message\"&nbsp;rows=\"10\"&nbsp;cols=\"30\"&gt;\nThe cat was playing in the garden.\n&lt;\/textarea&gt;<\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">El atributo <strong><em>rows<\/em> <\/strong>especifica el n\u00famero visible de l\u00edneas en un \u00e1rea de texto. El atributo <strong><em>cols<\/em> <\/strong>especifica el ancho visible de un \u00e1rea de texto. As\u00ed es como se mostrar\u00e1 el c\u00f3digo HTML anterior en un navegador.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Tambi\u00e9n puedes definir el tama\u00f1o del \u00e1rea de texto usando CSS.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Ejm<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">&lt;textarea&nbsp;name=\"message\"&nbsp;style=\"width:200px; height:600px;\"&gt;\nThe cat was playing in the garden.\n&lt;\/textarea&gt;<\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">El elemento &lt;button&gt;<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">El elemento <strong><em>&lt;button&gt;<\/em><\/strong> define un bot\u00f3n en el que se puede hacer clic:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Ejm<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">&lt;button&nbsp;type=\"button\"&nbsp;onclick=\"alert('Hello World!')\"&gt;Click Me!&lt;\/button&gt;<\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">Los elementos &lt;fieldset&gt; y &lt;legend&gt;<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">El elemento <strong><em>&lt;fieldset&gt;<\/em><\/strong> se utiliza para agrupar datos relacionados en un formulario. El elemento <strong><em>&lt;legend&gt;<\/em><\/strong> define un t\u00edtulo para el elemento <strong><em>&lt;fieldset&gt;<\/em><\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Ejm<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">&lt;form&nbsp;action=\"\/action_page.php\"&gt;\n&nbsp;&nbsp;&lt;fieldset&gt;\n&nbsp;&nbsp;&nbsp;&nbsp;&lt;legend&gt;Personalia:&lt;\/legend&gt;\n&nbsp;&nbsp;&nbsp;&nbsp;&lt;label&nbsp;for=\"fname\"&gt;First name:&lt;\/label&gt;&lt;br&gt;\n&nbsp;&nbsp;&nbsp;&nbsp;&lt;input&nbsp;type=\"text\"&nbsp;id=\"fname\"&nbsp;name=\"fname\"&nbsp;value=\"John\"&gt;&lt;br&gt;\n&nbsp;&nbsp;&nbsp;&nbsp;&lt;label&nbsp;for=\"lname\"&gt;Last name:&lt;\/label&gt;&lt;br&gt;\n&nbsp;&nbsp;&nbsp;&nbsp;&lt;input&nbsp;type=\"text\"&nbsp;id=\"lname\"&nbsp;name=\"lname\"&nbsp;value=\"Doe\"&gt;&lt;br&gt;&lt;br&gt;\n&nbsp;&nbsp;&nbsp;&nbsp;&lt;input&nbsp;type=\"submit\"&nbsp;value=\"Submit\"&gt;\n&nbsp;&nbsp;&lt;\/fieldset&gt;\n&lt;\/form&gt;<\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">El elemento &lt;datalist&gt;<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">El elemento <strong><em>&lt;datalist&gt;<\/em><\/strong> especifica una lista de opciones predefinidas para un elemento <strong><em>&lt;input&gt;<\/em><\/strong>. Los usuarios ver\u00e1n una lista desplegable de las opciones predefinidas a medida que ingresan los datos. El atributo <strong><em>list<\/em> <\/strong>del elemento <strong><em>&lt;input&gt;<\/em><\/strong> debe hacer referencia al atributo <strong><em>id<\/em> <\/strong>del elemento <strong><em>&lt;datalist&gt;<\/em><\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Ejm<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">&lt;form&nbsp;action=\"\/action_page.php\"&gt;\n&nbsp;&nbsp;&lt;input&nbsp;list=\"browsers\"&gt;\n&nbsp;&nbsp;&lt;datalist&nbsp;id=\"browsers\"&gt;\n&nbsp;&nbsp;&nbsp;&nbsp;&lt;option&nbsp;value=\"Internet Explorer\"&gt;\n&nbsp; &nbsp;&nbsp;&lt;option&nbsp;value=\"Firefox\"&gt;\n&nbsp;&nbsp;&nbsp;&nbsp;&lt;option&nbsp;value=\"Chrome\"&gt;\n&nbsp; &nbsp;&nbsp;&lt;option&nbsp;value=\"Opera\"&gt;\n&nbsp;&nbsp;&nbsp;&nbsp;&lt;option&nbsp;value=\"Safari\"&gt;\n&nbsp;&nbsp;&lt;\/datalist&gt;\n&lt;\/form&gt;<\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">El elemento &lt;output&gt;<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">El elemento <strong><em>&lt;output&gt;<\/em><\/strong> representa el resultado de un c\u00e1lculo (como el realizado por un <strong>script<\/strong>).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Ejm<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">&lt;form&nbsp;action=\"\/action_page.php\"\n&nbsp; oninput=\"x.value=parseInt(a.value)+parseInt(b.value)\"&gt;\n&nbsp; 0\n&nbsp;&nbsp;&lt;input&nbsp;type=\"range\"&nbsp; id=\"a\"&nbsp;name=\"a\"&nbsp;value=\"50\"&gt;\n&nbsp; 100 +\n&nbsp;&nbsp;&lt;input&nbsp;type=\"number\"&nbsp;id=\"b\"&nbsp;name=\"b\"&nbsp;value=\"50\"&gt;\n&nbsp; =\n&nbsp;&nbsp;&lt;output&nbsp;name=\"x\"&nbsp;for=\"a b\"&gt;&lt;\/output&gt;\n&nbsp;&nbsp;&lt;br&gt;&lt;br&gt;\n&nbsp;&nbsp;&lt;input&nbsp;type=\"submit\"&gt;\n&lt;\/form&gt;<\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">Resumen<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><th>Etiqueta<\/th><th>Descripci\u00f3n<\/th><\/tr><tr><td>&lt;form&gt;<\/td><td>Define un formulario HTML para la entrada del usuario.<\/td><\/tr><tr><td>&lt;input&gt;<\/td><td>Define un control de entrada.<\/td><\/tr><tr><td>&lt;textarea&gt;<\/td><td>Define un control de entrada multil\u00ednea (\u00e1rea de texto).<\/td><\/tr><tr><td>&lt;label&gt;<\/td><td>Define una etiqueta para un elemento &lt;input&gt;.<\/td><\/tr><tr><td>&lt;fieldset&gt;<\/td><td>Agrupa elementos relacionados en un formulario.<\/td><\/tr><tr><td>&lt;legend&gt;<\/td><td>Define un t\u00edtulo para un elemento &lt;fieldset&gt;.<\/td><\/tr><tr><td>&lt;select&gt;<\/td><td>Define una lista desplegable.<\/td><\/tr><tr><td>&lt;optgroup&gt;<\/td><td>Define un grupo de opciones relacionadas en una lista desplegable.<\/td><\/tr><tr><td>&lt;option&gt;<\/td><td>Define una opci\u00f3n en una lista desplegable.<\/td><\/tr><tr><td>&lt;button&gt;<\/td><td>Define un bot\u00f3n en el que se puede hacer clic.<\/td><\/tr><tr><td>&lt;datalist&gt;<\/td><td>Especifica una lista de opciones predefinidas para controles de entrada.<\/td><\/tr><tr><td>&lt;output&gt;<\/td><td>Define el resultado de un c\u00e1lculo.<\/td><\/tr><\/tbody><\/table><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>El elemento HTML &lt;form&gt; puede contener uno o m\u00e1s de los siguientes elementos de formulario: El elemento &lt;input&gt; Uno de los elementos&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":41,"menu_order":54,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_uag_custom_page_level_css":"","footnotes":""},"class_list":["post-252","page","type-page","status-publish","hentry"],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false},"uagb_author_info":{"display_name":"Sutil Web","author_link":"https:\/\/sutilweb.eu\/index.php\/author\/sutilweb\/"},"uagb_comment_info":0,"uagb_excerpt":"El elemento HTML &lt;form&gt; puede contener uno o m\u00e1s de los siguientes elementos de formulario: El elemento &lt;input&gt; Uno de los elementos...","_links":{"self":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/252","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/comments?post=252"}],"version-history":[{"count":2,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/252\/revisions"}],"predecessor-version":[{"id":254,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/252\/revisions\/254"}],"up":[{"embeddable":true,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/41"}],"wp:attachment":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/media?parent=252"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}