Acquia FE Specialist (D10) flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

HTTP statelessness

Each HTTP request is independent; servers retain no memory of prior requests. State is carried explicitly via cookies, sessions, tokens, or URL parameters across requests.

Idempotent methods

GET, PUT, DELETE, and HEAD are idempotent: repeating the same request yields the same server state. POST is not idempotent and may create duplicate records on retry.

HTTP 304 Not Modified

Returned when a conditional request (If-None-Match or If-Modified-Since) matches the cached version, so the client reuses its stored copy and no body is sent.

Critical rendering path

The sequence browsers follow to render a page: parse HTML into DOM, parse CSS into CSSOM, combine into render tree, then layout, paint, and composite.

Same-origin policy

A browser rule permitting scripts to read responses only from the same scheme, host, and port. CORS response headers grant explicit exceptions for cross-origin requests.

Progressive enhancement

A build strategy starting with semantic HTML that works without CSS or JavaScript, then layering styling and behavior so core content stays available in all conditions.

Theme .info.yml file

The required metadata file for a Drupal theme. It declares the theme name, base theme, regions, libraries, and stylesheets, and its filename must match the theme directory.

Base theme key

A .info.yml property naming the parent theme. Templates, libraries, and preprocess functions from the base theme are inherited and can be overridden by the subtheme.

Template suggestion specificity

Suggestions are ordered most specific to most general, for example node--article--1 then node--article then node. The first match in the registry is used.

Preprocess function order

Preprocess hooks run modules first, then the base theme, then the active theme, so a subtheme's preprocess can modify variables set by earlier layers.

Twig debug mode

A services.yml setting (twig.config debug: true) that adds HTML comments listing the theme hook and candidate template names, and enables the dump function.

Theme regions

Named areas declared under the regions key in .info.yml, such as header and sidebar. Blocks are assigned to them and printed in page.html.twig via page.regionname.

Stable 9 base theme

The default Drupal base theme from Drupal 9 onward. In Drupal 10 it absorbed the Classy templates, so core markup classes come from Stable 9.

Drupal libraries.yml

A theme or module file declaring named asset bundles with their CSS, JS, and dependencies. Bundles are attached per page, template, or render array.

Twig delimiters

Twig uses three delimiter pairs: double braces output an expression, percent braces execute a tag such as if or for, and hash braces mark a comment with no output.

Twig autoescaping

By default Twig HTML-escapes printed variables, preventing injection. The raw filter disables escaping and should only be applied to trusted, pre-sanitized markup.

Twig t filter

The t filter marks a string for translation through Drupal's translation system and escapes it for the output context, keeping interface text localizable.

Twig attributes object

A special variable holding classes, IDs, and data attributes added by core or modules. Printing it whole preserves those additions instead of discarding them.

Twig loop variable

Inside a for tag, the loop object exposes index, index0, first, last, length, and revindex, enabling conditional markup without manual counters.

Twig whitespace control

Adding a hyphen inside a delimiter, as in a percent tag with a leading dash, trims adjacent whitespace from rendered output for cleaner HTML.

Twig filter versus function

Filters transform a value using pipe syntax, such as upper or length. Functions are called by name and return values, such as attach_library, url, path, or dump.

Subtheme template override

Placing a template with a matching name in the subtheme directory overrides the base theme and core versions, because subtheme paths rank higher in the suggestion chain.

Single directory components

A pattern co-locating a component's Twig template, CSS, JS, and metadata in one directory, keeping markup and styles together and improving reuse across templates.

BEM class naming

A convention using block, block__element, and block--modifier names. It scopes styles to a component and prevents selector collisions across independently developed templates.

Cacheable render arrays

Render arrays declare cache tags, contexts, and max-age so Drupal can reuse rendered output. Correct metadata prevents stale content and avoids unnecessary cache invalidation.

Library dependency declaration

Listing dependencies in libraries.yml guarantees deterministic load order, so a script relying on jQuery or another bundle always loads after its prerequisite.

Logic outside Twig

Preprocess functions and plugins prepare variables, leaving templates to presentation only. This keeps templates readable, testable, and safe from business-logic drift.

Theme-agnostic markup

Markup that avoids hardcoded paths and literal strings, using url and path functions plus translation filters, so it survives URL changes and supports multiple languages.

Core Web Vitals thresholds

Good ratings at the 75th percentile: Largest Contentful Paint at or under 2.5 seconds, Interaction to Next Paint at or under 200 milliseconds, Cumulative Layout Shift at or under 0.1.

Cumulative Layout Shift prevention

Declaring width and height attributes or an aspect ratio on images and reserving space for embeds stops content from jumping as resources load, lowering the CLS metric.

Lazy loading images

The loading attribute set to lazy defers offscreen image fetches until near the viewport. Above-the-fold and LCP images should load eagerly to avoid delaying paint.

WCAG contrast minimums

Level AA requires a 4.5 to 1 contrast ratio for normal text and 3 to 1 for large text and user interface components, measured against the adjacent background color.

Decorative image alt text

Images conveying no information use an empty alt attribute so screen readers skip them. Informative images need concise alternative text describing their purpose or content.