{"id":1569,"date":"2024-08-02T07:25:14","date_gmt":"2024-08-02T05:25:14","guid":{"rendered":"https:\/\/blog.sutilweb.eu\/?page_id=1569"},"modified":"2024-08-02T07:25:15","modified_gmt":"2024-08-02T05:25:15","slug":"003-ajax-api-fetch","status":"publish","type":"page","link":"https:\/\/sutilweb.eu\/index.php\/lenguajes\/javascript\/javascript-practico\/15-ajax\/003-ajax-api-fetch\/","title":{"rendered":"003. AJAX: API Fetch"},"content":{"rendered":"\n

El API de Fetch<\/strong>, la documentaci\u00f3n de MDN<\/strong> <\/a>lo menciona como un mecanismo m\u00e1s \u00f3ptimo para hacer peticiones XMLHttpRequest<\/strong>, lo que significa que tras bambalinas, Fetch<\/strong> trabaja con XMLHttpRequest<\/strong>. A d\u00eda de hoy, Fetch<\/strong> es compatible con todos los navegadores, salvo Internet Explorer<\/strong>.<\/p>\n\n\n\n\n\n\n\n

Fetch<\/strong> es mucho m\u00e1s r\u00e1pido que XMLHttpRequest<\/strong> a la hora de consumir APIs<\/strong>.<\/p>\n\n\n\n

Funcionamiento de Fetch<\/h2>\n\n\n\n

Para ello utilizamos el m\u00e9todo fetch()<\/em><\/strong> haciendo referencia al recurso. Adicionalmente podemos pasar un objeto con opciones, que las veremos cuando hagamos un CRUD<\/strong> con Fetch<\/strong>.<\/p>\n\n\n\n

\n

Nota<\/strong>: el m\u00e9todo por defecto para Fetch es GET<\/p>\n<\/blockquote>\n\n\n\n

Fetch<\/strong> es un mecanismo que trabaja con promesas, con lo que la resultante de fetch<\/strong> nos devolver\u00e1 un m\u00e9todo then()<\/em><\/strong> para la siguiente iteraci\u00f3n de c\u00f3digo, y para capturar nuestro c\u00f3digo de error utilizaremos el m\u00e9todo catch()<\/em><\/strong>, y si necesitamos ejecutar un c\u00f3digo s\u00ed o s\u00ed, utilizaremos el m\u00e9todo finally()<\/em><\/strong>.<\/p>\n\n\n\n

Archivos<\/h2>\n\n\n\n

Vamos a tener dos archivos, fetch.html<\/em> y fetch.js<\/em>, que tienen la siguiente sintaxis.<\/p>\n\n\n\n

La sintaxis de fetch.html<\/em> es.<\/p>\n\n\n\n

<!DOCTYPE html>\n<html lang=\"en\">\n  <head>\n    <meta charset=\"UTF-8\" \/>\n    <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\" \/>\n    <title>Fetch Ajax<\/title>\n  <\/head>\n  <body>\n    <h1>Ajax<\/h1>\n    <h2>Fetch Ajax<\/h2>\n    <ol id=\"fetch\"><\/ol>\n    <script src=\".\/02fetch.js\"><\/script>\n  <\/body>\n<\/html><\/pre>\n\n\n\n
La sintaxis de fetch.js<\/em> es<\/p>\n\n\n\n
(() => {\n  const $fetch = document.getElementById(\"fetch\"),\n    $fragment = document.createDocumentFragment();\n  fetch(\"https:\/\/jsonplaceholder.typicode.com\/users\")\n    .then((res) => {\n      return res.ok ? res.json() : Promise.reject(res);\n    })\n    .then((json) => {\n      json.forEach((el) => {\n        const $li = document.createElement(\"li\");\n        $li.innerHTML = `${el.name} --- ${el.email} --- ${el.phone}`;\n        $fragment.appendChild($li);\n      });\n      $fetch.appendChild($fragment);\n    })\n    .catch((err) => {\n      let message = err.statusText || \"Ocurri\u00f3 un error\";\n      $fetch.innerHTML = `Error: ${err.status}: ${message}`;\n    })\n    .finally(() => {\n      console.log(\n        \"Esto se ejecutar\u00e1 independientemente del resultado de la promesa Fetch\"\n      );\n    });\n})();<\/pre>\n","protected":false},"excerpt":{"rendered":"
El API de Fetch, la documentaci\u00f3n de MDN lo menciona como un mecanismo m\u00e1s \u00f3ptimo para hacer peticiones XMLHttpRequest, lo […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1561,"menu_order":2,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_uag_custom_page_level_css":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"class_list":["post-1569","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 API de Fetch, la documentaci\u00f3n de MDN lo menciona como un mecanismo m\u00e1s \u00f3ptimo para hacer peticiones XMLHttpRequest, lo […]","_links":{"self":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/1569","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=1569"}],"version-history":[{"count":1,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/1569\/revisions"}],"predecessor-version":[{"id":1570,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/1569\/revisions\/1570"}],"up":[{"embeddable":true,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/1561"}],"wp:attachment":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/media?parent=1569"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}