Grails Resources plugin, modules and <r:img> to render images? - image

trying to learn the Resources plugin
From my understanding, it helps to define 'resources' such as css and javascript files and automatically pull them into your gsp's when needed. I understand how to create modules that can then be loaded in using tags etc.
The part im not understanding is this: http://grails-plugins.github.com/grails-resources/guide/4.%20Using%20resources.html#4.2%20Linking%20to%20images
So ive created a module called 'images' in Config.groovy as follows:
grails.resources.modules = {
images {
resource url:'/images/view.jpg', attrs:[width: 1280, height:720 , alt: 'my view']
resource url:'/images/breakfast.jpg', attrs:[width: 1280, height:720, alt: 'breakfast']
}
}
The resources are included in the .gsp page in the head section as follows:
<head>
<r:require modules="jquery-ui, blueprint"/>
</head>
i know the resources have been successfully added to the head section because when i inspect the page source i see them there:
<link href="/ResourceTest/static/Aa7jV0N2qZjOz7TLZ9cl5cREIh2y5jJYV0ytn4nQg9r.jpg" rel="shortcut icon" width="1280" height="720" alt="my view" />
<link href="/ResourceTest/static/IpQBSjrYeLDdSUBGbP3jhf6Kkhvu1zV3XRtwWfKOIMn.jpg" rel="shortcut icon" width="1280" height="720" alt="breakfast" />
My question is this: how are the image resources then used? i mean i know if it was javascript, the importing of the resource gives you access to use the functions in the html code, but with regards to images, the site says "Once you have done this, using to reference them would automatically set the width, height and other attributes."
How? I've tried the following:
<r:img module="images">
<r:img alt="breakfast">
and a handful of others with no success
what does work is:
<r:img uri="/images/breakfast.jpg">
but this works regardless of whether or not you add the module with the r:require tag.. So whats the point of using this plugin for images then and how would i use it?

The <r:img> tag works just fine with our without <r:require>; it even works with undeclared image resources.
The point of the require tag is to prevent resource duplication. So, for instance, suppose you have multiple javascript resources that rely on jQuery, and they're all required. Add another layer of complication: say you're actually pulling together different gsp templates via sitemesh, and they each have their own resource dependencies. If you just put the normal HTML code to reference those resources in the head of each gsp layout, you might get multiple instances of them in your page header, which could prove problematic. Using the resources plugin makes sure you only get one instance of the required resource.
See http://grails-plugins.github.io/grails-resources/ref/Tags/require.html and http://grails-plugins.github.io/grails-resources/ref/Tags/layoutResources.html.
With images, though, this is not really necessary. If you have an image more than once on a page, it's probably because you wanted it, or because you're applying redundant layouts and need to refactor a bit. So, you are correct that the require tag doesn't really do much for images called via <r:img>. This is simply because images are a different sort of resource, so they're treated differently. Don't sweat it. :)

Related

Where to put images with SvelteKit

I have been using Svelte for a little while and now I have switched to SvelteKit so I can add multiple pages. I want to add some images to my site but I don't know where to put them. In Svelte I would just put them in public/images but there is no public folder with SvelteKit (I set it up with npm init svelte#next my-app if that matters). Would I put them in static?
Thanks!
I added the images in static/images and referenced them with src="/images/photo.jpg" like #b2m9 said and it works perfectly.
I recommend putting images under src/lib, not static. For example you could make a src/lib/images or src/lib/assets folder and put them there.
The reason is performance:
For files imported from anywhere under src, at compile time Vite adds a hash to the filename. myImage.png might end up as myImage-a89cfcb3.png. The hash is based on the image contents. So if you change the image, it gets a new hash. This enables the server to send a very long cache expiration to the browser, so the browser can cache it forever or until it changes. It's key-based cache expiration, which IMO is the best kind: cached exactly as long as it needs to be. (Whether the server actually sends the right caching headers in the response may depend on which SvelteKit adapter you use and what host you're on.)
By contrast, images under static don't have a hash added to their name. You can use the static directory for things like robots.txt that need to have a specific filename. Since the filename stays unchanged even if its contents change these files by necessity end up having a cache-control value that includes max-age=0, must-revalidate and an etag, which means even if the browser caches the image it still has to make a server round-trip to validate that the cached image is correct. This slows down every image on your site.
Usage:
When putting images under src/lib, you reference them like this:
<script>
import img from '$lib/images/img.png';
</script>
<img src={img} alt="Image" />
I recommend simplifying by adding svelte-preprocess-import-assets to your project, which automates the process of importing images and cleans up your code. You wrote the following and it generates the code above:
<img src="$lib/images/img.png" alt="Image" />
As Sveltekit uses Vitejs, there is a easy solution mentioned in Vitejs official web site (Click Here).
First inside the script tag :
<script>
const imgUrl = new URL('./img.png', import.meta.url).href
</script>
then inside your Image tag just use that variable,
<img src="{imgUrl}" alt="" />
or,
<div class=" h-screen w-full" style="background-image: url('{bgUrl}') ;">
</div>
You can import static images from any relative path.
there is also svelte-image.
"Svelte image is a pre-processor which automates image optimization using sharp.
It parses your img tags, optimizes or inlines them and replaces src accordingly. (External images are not optimized.)
Image component enables lazyloading and serving multiple sizes via srcset.
This package is heavily inspired by gatsby image.
Kudos to #jkdoshi for great video tutorial to Svelte Image."
-https://github.com/matyunya/svelte-image

Elimante render-blocking resources

I'm trying to optimalize web for speed and wanna ask about Eliminating render-blocking CSS and JS.
by JS 'm only using async attr. - lets say, throwin' it at plugins like flexslider, lightbox.. but should I also use this with the base scripts like ?:
<script src="https://cdnjs.cloudflare.com/.../4.5.3/js/bootstrap.min.js" async></script>
<script src="js/script.js" async></script>
Whenever i add async on some script and test it, that .js script won't just operate - as if not linked. What am I doing wrong? And is this enough ... ?
-by CSS - tring to impove it like this :
<link rel="preload" href="https://use.fontawesome.com/releases/v5.2.0/css/all.css" media="print" as="style" onload="this.onload=null;this.rel='stylesheet'" integrity="sha384-hWVjflwFxL6sNzntih27bfxkr27PmbbK/iSvJ+a4+0owXq79v+lsFkW54bOGbiDQ" crossorigin="anonymous"><noscript><link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.2.0/css/all.css"></noscript>
This cuts down the time of rendering CSS resources, but again when using it on e.g fontawesome - icons are not loaded as if link was't there...So, is this a good way of rendering CSS please ?
JavaScript
When using async you have to ensure that load order does not affect your implementation.
Async basically says "load everything as quickly as you can, I don't care about load order".
If you haven't accounted for this then the easiest fix is to use defer on your JavaScript instead of async. This basically says "load everything after the HTML has loaded but please keep the order as some scripts depend on others".
This will be slightly slower overall but still fix the JavaScript being render blocking.
You should defer all scripts, except any scripts that are essential for above the fold operations (and then you should inline those scripts in a <script> tag in the <header>, obviously keep this to a minimum).
CSS
Render blocking CSS is anything sitting in an external file that relates to content "above the fold".
To understand this fully you need to understand how the browser render things but in essence anything that is visible without scrolling ("above the fold" content) is delayed if your CSS is in an external file as it needs that information to know how to present and lay things out.
What you need to do is find all the styles that apply to your above the fold content and inline them in a <style> tag in the page <header>. Yet again this needs to be kept to a minimum so you may need to make the above the fold CSS custom rather than using bootstrap....including the whole of bootstrap inline would not be good!
Then all other styles can sit in external style sheets.
This way the second the page's HTML is downloaded it has everything it needs to layout the page without waiting for any other requests.
Font Awesome
Ah fonts for icons. I won't go into why that is a bad practice from an accessibility and performance perspective as I have covered that numerous times before.
Instead I will simply say that for any "above the fold" icons you should instead swap them for inline SVGs. This is for the same reason as inlining your CSS, inline SVGs do not need a network request to render so the second the HTML is loaded your page can be displayed.
just a suggestion, have no way of testing atm but try putting 'async' before the source attribute. also, try adding a copied line with the attribute defer instead of async for wider browser support.

Arrange UI-Elements in HTML (with containers, layouts, etc.)

I'm working on a SAPUI5 application with XML-Views.
Now I want to arrange my buttons for example. They should be arranged so they form a numberpad like on a keyboard.
I only know the layout managers from Java or the layouts of a SAP Web Dynpro where I also used transparent containers.
So how can I arrange my elements in HTML? How can I use layout managers and is there such a thing as a transparent container?
Thanks for any hints! :)
Arranging HTML elements in SAPUI5 is how you would in normal HTML. SAP does emphasize that code in index.html is to be minimal, however, so do your best to keep your coding done inside of your views. Your elements are likely to be contained in <div>, </div> tags, which, like any other HTML tag, can be manipulated using CSS.
You'll need to create a CSS file and reference it in your index.html file like so:
<link rel="stylesheet" type="text/css" href="css/style.css" />.
Additionally, you should be aware of the native SAPUI5 layout controls and use them when you can as opposed to writing up your own solution.
You might find this post useful as well.

Richer Coloring and Typesetting in DDoc Output

Can I make the generated HTML page from my DDoc-marked-up D program use richer coloring and type-setting? The default is black-and-white.
I'm currently calling DMD as
dmd -debug -gc -unittest -D -Dd$OUTPUT_DIR
Well, you should probably read through http://dlang.org/ddoc.html to get some of the details, but ultimately, what you need is a css file which tells it how to present the page. That can be set via the DDOC macro.
What I'd suggest doing is taking a look at https://github.com/D-Programming-Language/dlang.org, which contains the code for dlang.org - including the ddoc stuff. In particular, you want to grab std.ddoc along with the css, images, and js folders (as they are all referenced by std.ddoc). If you then give std.ddoc to dmd as part of your documentation build and have those folders in the parent directory of the documentation, the generated documentation should end up looking like the documentation on dlang.org. If you want to put the folders elsewhere, then just tweak the paths to them in std.ddoc.
If you want to change what the documentation looks like, just adjust std.ddoc and the css files accordingly. At that point, it's html and css stuff that you're dealing with, so you'll have to have some clue how those work to make the necessary changes to either the macros in std.ddoc or to the css files themselves. And of course, if you want to do anything with the js files, you'll need to know javascript. You can strip out all of the js and images if you want to. They're just what's used for dlang.org, but again, you'll have to have some clue how html and friends work to know what to do with that. I'm not particularly well versed in any of that, so when I've generated documentation, I've typically made only minimal changes to what dlang.org uses, but all I've typically been looking for is to get more legible colors than the default rather than anything specific.
Sorry that I can't be more specific or helpful than that, but the best that I've done with it is stumble through it enough to get pages looking like dlang.org, since I know next to nothing about web development. Hopefully this will point you in the right direction though.
Something else that you might want to look into is ddox, which uses ddoc comments to generate better looking documentation than dmd does. And it's likely that dlang.org will be switching to using ddox-generated documentation sometime in the relatively near future (some of the details still need to be sorted out, so I don't know when exactly, but that's the current plan). So, using ddox may ultimately end up becoming more common than using dmd to generate the documentation.
You can create your own .ddoc config file in which you override or create new ddoc macros to use class names and id's. Then you can style the page using CSS.
Sample .ddoc file containing custom CSS, Notice the theme.css file in the head HTML section:
DDOC = <!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<link type="text/css" href="theme.css" rel="stylesheet" media="all" />
<title>$(TITLE)</title>
</head>
<body>
<h1>$(TITLE)</h1>
$(BODY)
</body>
</html>
H2 = <h2>$0</h2>
H3 = <h3>$0</h3>
STRONG = <strong>$0</strong>
EM = <em>$0</em>
DDOC_DECL = $(H2 $0)
DDOC_DECL_DD = <div class="declaration-description">$0</div>
DDOC_CLASS_MEMBERS = <div class="class-members">$0</div>
DDOC_SUMMARY = $(P $0)
DDOC_DESCRIPTION = $(P $0)
DDOC_MEMBERS = <div class="members">$0</div>
DDOC_ENUM_MEMBERS = <div class="enum-members">$0</div>
DDOC_MODULE_MEMBERS = <div class="module-members">$0</div>
DDOC_STRUCT_MEMBERS = <div class="struct-members">$0</div>
DDOC_TEMPLATE_MEMBERS = <div class="template-members">$0</div>
This file should be saved somewhere and added to the sc.ini file (in the case of Windows) or the dmd.conf file (in the case of Mac/Linux) like this:
DDOCFILE=myproject.ddoc
Then the next time you compile using -D, HTML is read from the custom ddoc macros instead of the built-in stuff and viola, you have style-able class names and id's to use with CSS.
Here's a preview of pretty documentation using a custom style-sheet and macros: http://htmlpreview.github.io/?https://github.com/kalekold/dunit/master/docs/dunit/toolkit.html
HTML files: https://github.com/nomad-software/dunit/tree/master/docs/dunit
Full ddoc macro listings can be found here: http://dlang.org/ddoc.html

Razor extention method to read and render Master layouts

Our group needs to have a standard Common Look and Feel (CLF) for all our web applications. the base line for them all is the same, and certain items like the css references can have customization.
We want to find a way to create either one full layout file or partials that can be shared by all.
I have read many postings and the layout variable on views do not have the ability to read absolute paths.
Can we get a razor method to read XML and render to our layouts, much like the renderbody() does?
EDIT:
We would like to have items like the css, standard layouts etc in one project. Then this could become a distributable package for development teams.
Example of the final output we are looking for:
_base.cshtml example.
#model CLFModel
#CLF.Header(...)
#CLF.LeftMenu(...)
#CLF.OptionalRightMenu(...)
#CLF.Body(...)
#CFL.Footer(...)
The CLF.Header would contain something like below, and would be render from either a file or a pre compiled reference.
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="#Model.dcLanguage" lang="#Model.dcLanguage">
<head>
<meta charset="utf-8" />
<title>#Model.PageTitle</title>
meta tags.....
CSS required links ....
CSS section for custom link references ...
script tags(required)
optional section for script tags
</head>
You can create as many partial view as you want and just include them into the view you are rendering using #Html.Partial("YourPartialView"). You can create a _MasteLayout, which contains various partial views and #RenderBody for maintaining a consistent feel

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