astro examples

Astro design patterns examples, client-server state management, markdown, caching

MicroWebStacks

191

JavaScript

showcase examples for isolated simple usage patterns

01_basics

./01_basics

This is a minimal example that shows the node version running

Layout Slots
Note bumped to Astro v3 beta which discarded Node 16

02_ssr-counter

./02_ssr-counter

integration : @astrojs/node
adapter : node-standalone

shared global var demo. reload the page to increment the counter. All pages share the same counter

SSR Memory profiling, run with python test.py

output with the page being loaded from a browser and switching pages

Server listening on http://127.0.0.1:3000
Max memory consumption: 4.44 MB
Max memory consumption: 51.71 MB
Max memory consumption: 51.71 MB
Max memory consumption: 54.93 MB

03_sse-counter

./03_sse-counter

integration : @astrojs/node
adapter : node-standalone
Server Endpoints
ReadableStream
remove Listener on cancel () thanks to https://github.com/0xk1f0/astro-sse-example

SSE: Server Sent Events. global var using a timer and Emitter

Server keeps couter state. reloading the page has no effect on the counter

requires Node18 for ReadableStream(), currently only on Gitpod

04_client-counters

./04_client-counters

A simple approach for multiple instances of a component. A <script> is included once. It initiates all components of a class on page load without requiring unique identification

Card Astro Component
- Client-side Scripts
- Css Styles

05_client-uid-counters

./05_client-uid-counters

Decentralized scoping js execution on an Astro component used mutiple times on the same page

integration : @astrojs/node
adapter : node-standalone

Constraints :

decentralized : not conflicting with multiple integrations using the same concept
no global state management : which is not easy to fulfill when using components from different sources
multi instances used on the same page
components handle their own js scripts
each component has a lifecylce independence and its js only handles its own html and not one of other instances

Alternatives:

It is always possible to initialize all components from the top page js, but sometimes the js component code is preferrably placed within the component itself.
It is also possible within the component to have the code run on all components in the page of the same type, but this does not fit with lazy loading where each component has to be initialize separately
It is still possible to keep a component state in the window or as html attribute and still run init on all components everytime a new one wakes up, but this might incur incompatibilities when mixing versions
A centralized approach is also demonstrated but not recommend due to flaws that might happen when the sequence_uid function gets multiple instances for some reason such as being budled separately.

Optionally:

a hash function could be used if an unidentifieable id is desired that does not reflect the user input (using counting numbers or names,…), if the input data is too big such as complete file or if the uid is required to always have the same consistent format e.g. number of characters which the user cannot guarantee.

07_env-config

./07_env-config

using environment variables from file in astro.config.mjs and .js server files

integration : @astrojs/node
adapter : node-standalone
dotenv
todo test with loadEnv from ‘vite’

08_404-error-handling

./08_404-error-handling

Page not found redirect to 404

integration : @astrojs/node
output server
- adapter : node-standalone
output static
dotenv
Custom 404 Error page
Dynamic Route with Rest parameters [...path].astro

custom 404 page from : https://codepen.io/Stephane/pen/Jdozrp

09_dynamic-imports

./09_dynamic-imports

integration : @astrojs/node
adapter : node-standalone
Deferr loading of js on event or timeout
- setTimeout
- Dynamic import()
- Spinner while waiting : Astro Component with animated SVG

This is about dynamically importing a js script only when the component logic decides to do it. In this case, after 2 seconds from window load.

Not only <Card title="Test" client:visible/> is not supported by astro as directive reserved for framework components only, but also, it does not give fine granularity to decide exactly when to load a js script.

Note: Testing this example only makes sense in production mode (with build and run). Only gitpod left because it has a shell script that builds and runs by default while the others (StackBliz and Codesandbox) run in preview mode.

10_prerender

./10_prerender

This example uses the experimental prerender feature. index page '/' is prerendered while '/rerender' page is server side rendered on every fetch

integration : @astrojs/node
adapter : node-standalone
Hybrid Rendering with export const prerender=true

11_deno-env

./11_deno-env

integration : deno
adapter : deno

Testing environment variables in deno and deno.deploy

live demo : https://astro-env.deno.dev/

project : https://dash.deno.com/projects/astro-env

12_content-collections

./12_content-collections

markdown with image optimization
using node standalone
Content Collections
- get all frontmatter meta data with getCollection()
- rendering of multiple Markdown pages in one page with await Promise.all() and item.render()
- Single pages rendering in a dynamic path [...slug].astro with getEntryBySlug()

https://freesvg.org/1542512156 : tree

13_client-cookie-counter

./13_client-cookie-counter

integration : @astrojs/node
adapter : node-standalone
Astro API Astro.cookies.get()

This counter uses a cookie counter=1 to persist through pages relaod despite being a client counter.

For Astro SSR there is a simplicity advantage for using a cookie over using client sotrage :

Automatically sent with every client request
No display flicker
no need to create a server endpoint to submit the client updated value (to avoid the flicker)

Note : Only a single counter is used in this example given that a single cookie is used

Note : For a demo using cookies, the Astro.cookies could only be read in Gitpod

references

https://stackoverflow.com/questions/73341205/why-does-the-icon-in-this-astro-svelte-component-flicker-on-refresh/74873656#74873656
todo : check example with blocking head script can solve ssg

14_client-storage-counter

./14_client-storage-counter

This counter is using sessionStorage for client side persistency, and therefore avoids cookies.
For UI sensitive elements (such as menu, sidebar, modal,…) it is important to prevent flicker. Such Flicker can happen when the server sends a default value upon page refresh and then javascript adjusts the value after reading it from the session sotrage. To prevent that, every time the client changes the value, the server state needs to be updated through a put request to a server endpoint
For the server to know which client has whic counter, a counters map for each session_id is stored
The session ID is created by the server when a request URL does not contain session_id parameter, it is passed to the client within the html components, the client takes it upon page load and use it in case no sessionStorage session_id available. Then stick it to the URL parameters for future queries

Note : this implementation is for demo purpose only and suffers from memory leak as old session_id’s are not deleted.

references

https://stackoverflow.com/questions/73341205/why-does-the-icon-in-this-astro-svelte-component-flicker-on-refresh/74873656#74873656

15_server-cookie-counter

./15_server-cookie-counter

adapter : node-standalone

Counts the pages load for a specific client with cookies. This examples shows how to get and set a cookie from a .astro page while example 13 gets the cookie from the server and set it from the client.

16_html-string

./16_html-string

example to show how to generate an html string out of a component using a Wrapper and Astro.slots.render()

references

https://stackoverflow.com/questions/73382889/how-can-i-render-a-astro-component-to-a-html-string/74853279#74853279

17_dynamic-javascript

./17_dynamic-javascript

Generate javascript that can be executed on the client. The UID set by the server, is fetched by the client inside a javascript file

Note : although functional, this method is not recommended due to Vite complaning about dynamic import and security risk it implies.

18_simple-integration

./18_simple-integration

example using astrojs/image integration

19_images-integration

./19_images-integration

adapter : node-standalone
integration : image

example using astrojs/image integration

20_ssr-cache-proxy

./20_ssr-cache-proxy

adapter : node-standalone
proxy : express
cache event-drive content
call purge method
put pass througn

Running mode :

astro starts with pnpm run preview listens on port 4000
express starts with pnpm run proxy listens on port 3000
first client page load from proxy : cache miss, proxy fetches data from SSR
SSR generates the page and and on creation assigns a page hash
for the example purpose a 2 seconds timeout is added to a page render
the page hash is updated on the proxy (in the example through a shared hashes.json but could be with a db or API)
when the proxy fetches the page it identifies the cached page with its hash (as it is always actual on the hashes.json)
follow up request checks if page is available and if hash is fresh
when the user updates the data, the server updates the page hash
follow up requests on the proxy show the page to be stale due to old cached page, the proxy fetches the page with the new hash

21_ssr-cache-middleware

./21_ssr-cache-middleware

Same concept as the previous example but here the cache proxy and Astro SSR are combined in the same express App with Astro running in middleware mode

once a request is fetched from the SSR server, the response contains an ETag with the hash to ensure immediate page update with the just produced hash value

22_mdx-svg

./22_mdx-svg

Example for testing SVG usage within .astro, .md and .mdx

This highlights incompatibility of inlined SVG when injected from remark/rehype plugins in an mdx file

attributes with ‘:’ e.g. xmlns:xlink gets treated as .jsx and converted to xmlnsXlink, xmlns or xmlnsxlink, all of which break the SVG rendering

Note :

html comments not supported
html empty new lines of spaces also break the html parsing as indentation takes precendence

references

23_remote-markdown

./23_remote-markdown

adapter : node-standalone

features

astro-remote works with astr v2 but not an official integration
Passing default components only Heading, CodeBlock, CodeSpan, Note no mapping of custom components, e.g. images,…

references

24_api-proxy

./24_api-proxy

4 Locations where to alter server config

/vite.config.js
/astro.config.mjs:server.port,proxy
/astro.config.mjs:site.server.port,proxy
/src/libs/inetgration-test.js:config_setup().update_config()

summary

can Astro proxy a service with the Vite server.proxy feature ?
- No, Astro does not forward server.proxy to Vite
does Astro need a proxy to access a different port running on the same host ?
- No, because Astro frontmatter runs on the server so has access to localhost ports

references

Vite feature : https://vitejs.dev/config/server-options.html#server-proxy
Stack issue : https://stackoverflow.com/questions/73212935/astro-how-to-proxy-service-calls

25_markdown-scale

./25_markdown-scale

Benchmark results charts : https://microwebstacks.github.io/astro-examples/

scalability stress test and limiting facrors (e.g. 15000 pages)
markdown pages generator
- pages markdown
- pages mdx
- local markdown in .astro
- local mdx in .astro
- remote markdown

References

Discord 4k pages, static, json ~10kB/page https://discord.com/channels/830184174198718474/1066464117327659111
nodejs limit 1.7GB https://stackoverflow.com/questions/38558989/node-js-heap-out-of-memory

26_serverless-counter-netlify

./26_serverless-counter-netlify

integration : @astrojs/netlify
adapter : netlify

shared global var demo. reload the page to increment the counter. All pages share the same counter

Note ! in serverless deployment, the in-memory state only persistes temporarily until a different instance is started

live demo on netlify : https://astro-serverless-counter.netlify.app/

27_serverless-counter-cloudflare

./27_serverless-counter-cloudflare

integration : cloudflare
adapter : cloudflare
NODE_VERSION : 16.19.1
cannot rename deployment url after creation

shared global var demo. reload the page to increment the counter. All pages share the same counter

Note ! in serverless deployment, the in-memory state only persistes temporarily until a different instance is started

live demo on cloudflare : https://astro-serverless-counter.pages.dev/

28_serverless-counter-vercel

./28_serverless-counter-vercel

integration : vercel
adapter : vercel
free account does not deploy from github organization

shared global var demo. reload the page to increment the counter. All pages share the same counter

Note ! in serverless deployment, the in-memory state only persistes temporarily until a different instance is started

live demo in vercel : https://astro-serverless-counter.vercel.app/

29_serverless-counter-denodeploy

./29_serverless-counter-denodeploy

integration : deno
adapter : deno
deployment from command line

shared global var demo. reload the page to increment the counter. All pages share the same counter

Note ! in serverless deployment, the in-memory state only persistes temporarily until a different instance is started

.env not taken has to manually inject env var DENO_DEPLOY_TOKEN

live demo in deno deploy : https://astro-serverless-counter.deno.dev/

30_serverless-counter-deno-redis

./30_serverless-counter-deno-redis

integration : deno
adapter : deno
database : redis
Deno.version not working resulting in crash on deploy

demo for variable persisted on redis database. reload the page to increment the counter. All pages share the same counter.

expected environment variables

local DENO_DEPLOY_TOKEN : to be manually injected in the env before calling deploy
your redis credentials, needed both locally to be injected manually and on deploy entered on the project settings
- REDIS_URL=******.redislabs.com
- REDIS_PORT=*****
- REDIS_PASSWORD=***********
live demo in deno deploy : https://astro-redis-counter.deno.dev/

31_collections-markdoc

./31_collections-markdoc

integration : @astrojs/markdoc
Content Collections mandatory for markdoc

Status

render : OK
custom components - nodes : OK
custom components - tags : wip

32_cms-storyblok

./32_cms-storyblok

integration : @storyblok/astro
env variable in .env file STORYBLOK_TOKEN loaded with vite loadEnv in config.js
test with story.http using VSCode REST Client and dotenv from .env

Status

render : WIP

33_ssr-astro-middleware

testing Astro middleware see https://docs.astro.build/en/guides/middleware/
SSG : Middleware called during build

simple example where Middleware outputs log and sets an Astro.locals variable consumed by the page to set the title in the layout.

34_assets

./34_assets

Astro assets https://docs.astro.build/en/guides/assets/
note ‘pnpm install sharp’ needed for optimizations

tests

relative import within .astro file index.astro : OK
alias tested OK with a custom path src/custom_assets used from @/custom_assets
in .md although these two tests are identical, one of them takes the same directory path, the other a neighboring directory that a bit further away but both are strictly relative and have no special character
- ‘/md/colocation’ OK ![Tree](./tree.svg) note ![Tree](tree.svg) will not work the ‘./’ is needed
- ‘/md/relative’ OK relative all the way back to assets ![Tree](../../assets/tree.svg)
<Image /> component now part of Astro core
- SVG : Not OK, as svg rendered within an image tag which deprive it from text selection capabilities, probably not being the main use case for the Image component and needed for some Hero images that do not consider the text to be an important use case
content collections : OK. import image with checks

35_mdx-math

./35_mdx-math

Testing Math in MDX with Katex - !! WIP !!

36_cms-tina

testing https://docs.astro.build/en/guides/cms/tina-cms/
works ok, admin edit and save
dev to be replaced as follow

    "dev": "tinacms dev -c \"astro dev\"",

37_ssr-forms

./37_ssr-forms

testing Forms with POST method https://docs.astro.build/en/recipes/build-forms/
status : OK

38_cached-component

./38_cached-component

caches the rendering of slot components passed to it

usage is as simple as this

    <Cache>
        <Menu />
    </Cache>

can also have different names that act as store keys

    <Cache name="section1">
        <Menu section="section1"/>
    </Cache>

Note1 : This will cache all calls from all isntances, if the intended usage is a different cache set for every astro component file, then it is still required that the user gives a different name for every instance, e.g. prefix component path (with e.g. a vite __filedir plugin )

Note2: This is caching production only for convenience during development, if caching is also intended during development (not recommended) then this line in Cache.astro can be changed to remove the PROD condition

if(cache_has(name) && import.meta.env.PROD){

Test, see build log, both pages build are logged while the rendering of the cached component is logged only once

index> rendering index page
 ** rendering ** 'default' => cache_set()
page2> rendering page2

References

51_lib-lottie-react

./51_lib-lottie-react

Astro example integrating lottie librarie with react

https://airbnb.design/lottie/
https://github.com/Gamote/lottie-react
groovyWalk.json from https://www.npmjs.com/package/lottie-react

references

https://stackoverflow.com/questions/74551923/how-to-use-lottie-react-in-astro-build-framework/74851823#74851823

52_kutejs-morph

./52_kutejs-morph

simple Astro example for integration of a Kute.js morph

References

https://stackoverflow.com/questions/77117676/kute-js-integration-on-astro/77118218#77118218

53_splide-slider

./53_splide-slider

example integration of splider.js following https://splidejs.com/guides/getting-started/

54_swiper-slider

./54_swiper-slider

example integration of swiper.js following https://swiperjs.com/get-started

55_revealjs

./55_revealjs

example integration of reveal.js https://revealjs.com/

ideas

glob import of a list of Astro components
custom client directive for predictive load before client visible
check math katex for mdx examples

More Astro examples

Official repo examples : https://github.com/withastro/astro/tree/main/examples
Astro Themes : https://astro.build/themes/

astro-big doc

Astro Theme for big doc websites. Hierarchical pages menu from files structure, table of content, Markdown rendered as CMS with Astro components for panzoom, 3D, links, interactive tables and more.

Astro Theme Link https://astro.build/themes/details/astro-big-doc/
Github repo : https://github.com/MicroWebStacks/astro-big-doc
Live demo : https://astro-big-doc.netlify.app/

Main features :

Markdown CMS : using https://github.com/MicroWebStacks/content-structure
Pure Markdown with GFM : Augmented with Astro components
Enhancement with Astro components : standard tags can be replaced with an Astro component without touching the Markdown files
Modal Images and Gallery Components
Nav Bar, Hierarchical menu, Table of Content with scroll spy,…

screenshot :

astro-home-control

Github repo : https://github.com/MicroWebStacks/astro-home-control

Main features :

Home Automation MQTT Client running on Astro as SSR
Client page update with Server Sent Events
Custom switches with feedback and custom sliders with animated SVG

screenshot :