Are there any simple ways to patch React to autoprefix styles, such that the rendered HTML doesn't differ on the client and server?
For example, is it possible to get
<div style={{display: 'flex'}}/>
to render to (ignoring data-reactid):
<div style="display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;"/>
In the specific case you posted, you may have to make a function in which you pass your style and it creates the correct styles. In cases where a simple prefix will work, you could use something like react-prefixr which just adds ms,Webkit,etc. to the style structure. If display:flex is not handled properly by react-prefixr, you can probably submit it as PR.
I've had the same issue and wanted an easy way to mixin styles. So I created a library that lets you use less/sass style mixins https://seogrady.github.io/style-mixin.
I've just today created a simple prefixing tool, react-prefixer. This handles prefixing possibilities for relevant browsers.
I say relevant because you call out display:-webkit-box syntax, which is basically Safari 5.1, its pretty non-existent these days. Additionally, it only adds the syntax needed, meaning you won't see the full string of styles as you showed ... based on browser support, it will either provide the prefixed version or the spec version, no need to clog up the markup with useless styles.
It's still pretty young (I coded it this morning), but maybe it can help.
Related
I have been investigating the inline styles & templates vs externals in the new Angular 2 components.
I was wondering what is the recommended route. I know it doesn't matter as far as functionality is concerned.
Having styles and templates together in the component reminds me of how reactjs tackles things. It does have its advantages.
Code Completion etc? Is this better for inline vs external? I am unsure which route to take or which is recommended.
I think it's about encapsulation and uniqueness of the component. Sometime you run into situation where certain elements require some special styles. With the traditional css, you would create a unique class, sometimes use !important to make sure it applies....
with ng components, your component can share global style and at the same time have it's own unique styles. Furthermore, component's styles can be contain within itself and/or share globally, given you more flexibility to do what you want.
https://egghead.io/lessons/angular-2-controlling-how-styles-are-shared-with-view-encapsulation?series=angular-2-fundamentals
From https://angular.io/styleguide
Extract Template and Styles to Their Own Files
Style 05-04
Do extract templates and styles into a separate file, when more than 3
lines.
Do name the template file [component-name].component.html, where
[component-name] is our component name.
Do name the style file [component-name].component.css, where
[component-name] is our component name.
Why? Syntax hints for inline templates in (.js and .ts) code files are
not supported by some editors.
Why? A component file's logic is easier to read when not mixed with
inline template and styles.
Having pretty complex angular application with many pages (states) and conditional sections that creates a lot of test scenarios I need to perform e2e tests. I'm tired of nested selectors like 'div.SomeComponent > ul:nth-child(2) > ... ' and so on even using BEM namings (especially when app is evolving and it's easy to spoil tests by little change of html structure).
The question is, would you guys opt for creating some dummy (empty) classes or data-* attrs just to simplify protractor (or groovy) selector at the expense of loosing semantics? What's the alternative?
To avoid changing your element definitions every time developers change the css and to avoid using long css strings to select your elements, you can try referring to them by other means (id, className, model, etc.). See https://github.com/angular/protractor/blob/master/docs/locators.md for examples.
My personal favorite is to use element(by.css('[ng-click="executeSomeAction()"]')) as this will most likely not change with any application updates. It also works for other directives as well.
As for testing applications with a high volume of pages and elements, it's nice to define your elements in a class(es) and then call them in the test spec as needed. This reduces the code in your specs and makes them easier to read. You may also want to create a separate file for actions/functions your tests perform.
Hope this helps answer to your questions.
I'm part of a team with about 6 UI devs, of varying quality and next to no Angular experience. Many are contractors, with little experience with the code base. The app has a very fancy (complicated) UI. It supports IE8+ (soon hopefully IE9+).
We're introducing Angular for a major extension to the app, and I've been asked to write guidelines on the use of Angular for the team.
We'll use directives to create fancy UI elements, all prefixed with "ipwr" to avoid name clashes. I'm trying to decide whether to mandate that devs give their directives the restriction "element" or "attribute". Mandating only one, to avoid chaos and confusion.
My question is: what restrict is better or more popular for directives, "element" or "attribute"?
My main concern is ease of use for people with little Angular experience who are new to the application code base, to reduce bugs, copy and paste behaviour, etc.
The angular guidance says that you should use the "element" restriction whenever the directive has full control over it's template meaning it has a template that it is rendering out, etc.
For attributes, they suggest to use these only when you are adding "behavior" to an existing element or decorating an existing element.
For example, think of the ng-click directive, this is used a attribute not as a element because the click directive is just adding the click behavior to some element.
Another example would be the ng-repeat directive, it is also used as an attribute not as a element because it is going to repeat the element in which it is being used in.
Now, this guidance is from the angular documentation; however, I don't know necessarily that element vs. attribute is going to give you a "better" approach it's more of a convention.
Now if you have to support older browsers, then you may want to consider using either the comment or class directives.
My personal preference is to just use the attribute restriction; mainly because people that are new to angular get overwhelmed at first when they see the restrict and it's variations of the options that can be used.
I usually defer to the John Papa AngularJS style guide when making these types of decisions. He says:
Lean towards implementing as an element when its standalone and as an
attribute when it enhances its existing DOM element.
If you want to keep your HTML valid you'd use attributes, e.g. if you have a directive ipwr-modal, you can declare it as <div data-ipwr-modal="you-could-put-some-binding-here"></div>.
When creating directives with a custom layout, however, you'd better use element declaration (if you don't need to have your HTML valid). This is the more obvious way to say: "hey, we have a custom component here".
This blog post explains it with some more ideas
Some points to consider:
Most of the time attributes is the best/most convenient option (it's not the default by chance).
Anything you can do with element-bound directives, you can do with attribute-bound as well.
Element-bound directives can be more descriptive/readable at times.
If you want your code to pass certain types of validation, you should use attributes.
Since you want to support IE8, keep in mind that custom tags have an extra overhead (more info), which hurts maintainability.
BTW, you can't limit directives to elements only (without affecting functionality), so it is more a question of allowing 'element' or not. Note that an element often has more than one directives and directives placed on the same element can cooperate and augment each other's behaviour. So limiting the use of directives to 'element', means limiting the number of custom directives per element to 1, which severly reduces the functionality-potential.
That said, this is what I ('d) do:
If IE8 is not an issue, allow both (mostly use attributes).
If IE8 (or the overhead for custom tags) is an issue, use only attributes.
In general, if only one form should be allowed, it should be attributes (works anywhere, no extra overhead, offers all functionality).
Is RactiveJS compatible with JSX?
I'm guessing some of the mark-up is not compatible. I like the thought of strong typing and being able to cleanly write the templates in JavaScript source. Maybe this is considered bad design?
No. React.js and Ractive.js have many similarities (for example, both work by constructing a lightweight virtual DOM in memory), but they have one very major difference - React completely rejects the idea of templates.
Which is to say that JSX isn't a templating language, it just looks like one! In React, if you have something like this...
<h1>Hello world!</h1>
...it gets converted to something like this by the JSX pre-processor:
React.DOM.h1(null, 'Hello world!');
In other words JSX describes functions, rather than templates. In Ractive, by contrast, Mustache templates are parsed into tree-like structures that can be transported as JSON.
Now, in the case of that example it doesn't really matter what process the original string goes through - it's still going to end up as an <h1> element in a browser somewhere. But it gets a lot harder when you start introducing arbitrary JavaScript which refers to this.state and this.props - things that can alter the fundamental structure of a component in React, but which have no meaning in Ractive.
Ractive might support templating languages other than Mustache in future, but JSX is unlikely to be one of them because they have such different approaches and design goals.
However there's a related issue here, which is being able to fully describe components in a single file. There's some ongoing work happening there - the most likely scenario is that we'll be able to describe components in an .html file (since you can use JavaScript and CSS inside HTML) rather than writing the template into your .js file.
Ui:include and xhtml based tag (the one with source elt) seem to be much the same for me. Both allow to reuse piece of markup. But I believe there should be some reason for having each. Could somebody please briefly explain it? (I guess if I read full facelets tutorial I will learn it, but I have not time to do it now, so no links to lengthy docs please :)
They are quite similar. The difference is mainly syntactical.
After observing their usage for some time it seems the convention is that fragments that you use only in a single situation are candidates for ui:include, while fragments that you re-use more often and have a more independent semantic are candidates for a custom tag.
E.g.
A single view might have a form with three sections; personal data, work history, preferences. If the page becomes unwieldy, you can divide it into smaller parts. Each of the 3 sections could be moved to their own Facelet file and will then be ui-include'ed into the original file.
On the other hand, you might have a specific way to display on image on many views in your application. Maybe you draw a line around it, have some text beneath it etc. Instead of repeating this over and over again you can abstract this to its own Facelet file again. Although you could ui:include it, most people seem to prefer to create a tag here, so you can use e.g. <my:image src="..." /> on your Facelets. This just looks nicer (more compact, more inline with other components).
In the Facelets version that's bundled with JSF 2.0, simple tags can be replaced by composite components. This is yet a third variant that on the first glance looks a lot like custom tags, but these things are technically different as they aren't merely an include but represent true components with declared attributes, ability to attach validators to, etc.