What jinja2 can achieve, the same can be achieved with Angular.js. My question is- are there any advantages of replacing jinja2 with angular.js completely ?
I think most problems came from the same obvious difference: Jinja2 is server-side, Angular is client-side, this makes they really different.
SEO. Google don't understand Angular magics. It is just a heavy Javascript code and Google can't understand it fine. Sure, you have some workarounds to show your important text to Google, but to solve it you'll have to render some things server-side, going back to Jinja2 or some hack to render things to improve your SEO. (it is not important if you don't care about Google searches)
Performance Server-side rendering is way faster than Javascript rendering. I'm talking about your average user, maybe with an outdated Internet Explorer and a crappy internet connection. With Angular, you have to wait at least some Javascript assets to be loaded before the page is usable. Users notice this and we know a slow site will hit your conversions. Check this Twitter article about "time for first tweet": https://blog.twitter.com/2012/improving-performance-on-twittercom
Compatibility. Yes, they claim the framework supports all common browsers, but have full documentation about hacks to make it work for IE7. Depends of your audience.
Maturity. Jinja2 is really stable, has a pretty API and is deployed with almost all Flask websites. Angular is still evolving and sometimes things just change a lot.
Inexperience. You can't just replace Angular with Jinja2. When you try it, you will understand they are different and you must not work the same way with both. You will make a lot of mistakes before you make things right, just like with any new awesome tool you use.
Of course you can claim against all my arguments based on your specific needs, this is just some things you must understand before you go to Angular.
That said, I'm using Angular in several projects, mostly for single page apps. This is an awesome use case for Angular. In all these projects, I still use Jinja2 to some rendering, so this is not a complete replacement.
UPDATE:
Some updates almost two years after my initial response.
Google is better understanding dynamic rendering, but I still don't trust it.
I don't think the client-side rendering is a thing. Only realtime data is rendered client side, but the base HTML is generated server side.
Angular dropped IE7/IE8 support. It is definitelly a good thing for the web, but unfortunately I still must support these browsers in some cases.
Angular 2 is on the way, changing everything you know about current versions. I don't remember any major Jinja2 change.
Why is replacement your objective? Use the power of both Jinja and other server side frameworks together with the power of client side frameworks.
The benefits of using both:
less and easy code
better performance
more easy to maintain
and much more. You have a choice.
Choosing for one or the other will make your work frustrating and complex.
Related
So far, I have been using prerender.io to make my angularjs websites seo friendly. I have worked okay when it comes to urls with hashbangs (website.com/#!).
Currently, I am making my websites go to html5mode, which doesn't contain hashbangs on url and looks a way prettier. However, even since I went to html5 url, prerender.io doesn't work properly.
Also, I came up with a Google article that claims their new technology allow the engine render Javascript framework websites automatically (https://webmasters.googleblog.com/2015/10/deprecating-our-ajax-crawling-scheme.html). However, as I use 'Fetch as Google' tool in Google Search Console. It renders very poorly and my title and meta description spit angularjs syntax ({{seo.tile}} or {{seo.desc}}), which are not rendered.
I am quite lost where I should start and fix the problems I came across with. I tried to get away from prerender.io cause I don't think we necessarily need it anymore.
Sorry for my poorly organized post and questions. Let me try to clear and tie the questions below.
1) Do we still need to teach the Google bot about the angularjs?
2) What is the most stable and best practice for AngularJS+ExpressJS SEO? I don't wanna try unstable and easily crashable method for this.
Thank you very much for your time.
EDIT
At the time of writing this article, I didn't know about using javascript compiler such as babel. I will say here make sure use webpack or gulp to compile your ES6 codes into stable ones so that your codes can be written as you expect it to be and works well with any 3rd party tools or pacakges.
It's the era of ES6!!!
Finally, I solved my problem and for future reference and others who struggling with the sample problem I had gone through, let me leave what I found.
First of all, the very reason why I was tremendously confused was that even if I take html snapshot with phantomjs, I saw still bare angular syntax like {{seo.title}} and . Very awkwardly the reason was that I was using ES6 syntax across my angularjs module. Since phantomjs wasn't fully adopted with ES6 syntax, it failed to interpret angularjs module and just spat html with unconpiled angularjs... From this, I came up with a unexpected conclusion that it's not a good time to implement ES6 for production.
Secondly, I would not count on what Google confidently announced that their bots can handle the websites with dynamic javascript frameworks like angularjs. Even if phantomjs works, 'Fetch as Google' tool doesn't give me a good result. Some times (actually very often) it resulted in just empty html file. Since still Ajax crawling is supported as a 'fall back', but more stable method, I would count it rather than counting on their very unstable smart bots.
In conclusion, DON'T BE EARLY ADOPTOR especially if you are making business out of it!! For angularJS SEO, (1) follow the Ajax calling guideline even if considered to be deprecated, (2) Don't use ES6 syntax for serious programming stuff.
I'm working on a project which has the luxury of using ECMA 6 on the latest browsers for a product that will be shipped in 1.5 years. So we thought why not use Web Components now that Angular 2 isn't available (which is going to be ECMA 6). And while we are at it, can we replace Angular altogether without having to go back to stone age?
How to replace Angular?
There's this site called youmightnotneedjquery.com which is basically about how modern browsers actually have most of the stuff that jQuery was traditionally used for. I'm interested to see something like that for Angular.
We mainly use four Angular features. What are my options for replacing them?
Angular Directives --> Web Components
Angular Modules --> ECMA 6 Modules (not exactly the same thing)
Angular Routes --> ???
Angular 2-way databinding --> ???
PS. We don't want to replace Angular with something similar like Backbone or Ember. We want to replace it with standard web technologies but if we have to use small tools to fill the gap, we'll consider it.
I've been researching in the past 3 weeks and turns out many people are thinking about an alternative after Angular took a drastic change path. Fortunately the upcomming W3C Web Components standard actually has all we need and it works right now with polyfills from the Polymer project. So to answer the question:
Angular Directives --> Web Components use the polyfill until all browsers support it.
Angular Modules --> ECMA 6 Modules part of the problem is solved with HTML imports. But you can also use Traceur until the browsers support it.
Angular Routes --> There's a component for that™ use <app-router>.
Angular 2-way databinding --> Polymer adds a "magic" layer on top of the plain standard web components. This includes many features including data-binding.
+Plus More
If you're wondering about the build process for concatenating files in order to reduce the number of HTTP requests, take a look at Addy Osmani's post about Vulcanize. Spoiler: you may not need it with the upcoming HTTP 2 optimizations.
Many Angular projects use Twitter Bootstrap for the layout. Polymer can do that plus it plays nicely with Google's Paper elements (totally optional but superbly awesome).
If you want to make yourself familiar with web components in general, here is a bunch of nice articles: http://webcomponents.org/articles/
And here is a wealth of web components: http://customelements.io/ I don't know if it's going to be a new NPM, but the list components is pretty impressive and growing.
It's relatively complicated to expose an API for an Angular component. People have come up with all sorts of methods from link function to emitting events. In Web Components, however, it's really easy to make your component interact with the world outside and indeed the API and events you expose aren't much different from standard HTML tags like <audio>.
Just like Angular, you can use Polymer with Dart as well.
Conclusion
Overall, I don't see any reason to use Angular except if:
You have a huge source code investment in angular and don't want to port everything to standard web. (Angular 2.0 will deprecate your code anyway, so you're stuck with Angular 1.*)
Your team is too lazy to learn a new technology (in that case web might not be the right platform for this attitude anyway).
Angular was good for what it was doing and had its own Hype cycle. Web components solve many of the issues Angular was trying to address. Probably Angular had a role as a proof of concept for the Web components. But now it's time to move on. Web is reinventing itself everyday and it's inevitable to moves someone's cheese.
I'm not saying that Polymer is the ultimate answer to everything. At best it's another Angular which will render useless in a couple of years, but now it's a good time to learn and use it. The W3C standards don't die easily though, and Polymer tends to be much closer to them.
There's an element for that™ is the new There's an app for that™
TLDR: seriously consider writing an almost Angular 2.0-compatable Angular 1.3 app before rolling your own framework
It seems as if you've identified that Angular does a lot of things the right way and that's why you're attempting to replicate it, so basically you're going to roll your own by combining a hodgepodge of libraries. Unless you have an enormous investment of Engineering hours, the framework you build will likely be:
Lightly documented
A cross-browser maintenance nightmare and (worst of all)
Difficult for new hires to learn
If there wasn't a framework out there that did what you want to do already, I think rolling your own makes sense, but by trying to recreate Angular you're:
Taking on a lot of Engineering work that has already been done by a dedicated team, that could have been spent on building product
Made it MUCH more difficult to onboard new employees because you have to:
Find candidates that are willing to use a home-grown framework instead of growing their skills at an open source framework they could use elsewhere
Train these employees to use your framework (and good luck unless your documentation is mature)
I know your question asks how to replace Angular, but I've seen too many companies go the route of rolling their own and paying for it down the road. Again, if your budget includes a ton of core resources to build out (and document, and maintain) the framework and you don't think there is any chance corners will get cut when push comes to shove later if timelines get tight, then rolling your own might make sense. However, I think you should seriously consider reading up on how to write Angular 1.3 apps so that they're easy to port to Angular 2.0 and go the Angular route. Just look at the size of the community you're missing out on:
http://www.airpair.com/js/javascript-framework-comparison
Does it make sense having a solution that uses both Freemarker and AngularJS?
I tried to convince everyone on my team of switching to Angular, and a more experienced developer than me pointed out that he prefers server-side rendering, which is both arguable and valid. But then he told me that if I still want to use Angular just use it with Freemarker instead of replacing it.
I'm a junior programmer, as far as I can understand they are designed to the same purpose.
It depends on the needs.
For example, if you want to break your page into individual re-usable components that you can tie based on some logic on the server side, then using freemarker or velocity for building these components makes sense.
The freemarker or velocity templates might in-turn use angularJS components that would be rendered on the browser and evaluated on the client side.
The server side templating would give you the ability to design re-usable angular components.
Now, some may try to use the Object component in HTML5 for doing the same thing, but this is not recommended as using Object expects a fully formed HTML element with its own <html> opening and closing tag.
Not something that is intended for a small reusable component.
As an example consider having your page header and footer in its own html template file that you would like to tie in for all the pages in your application.
As I google for Freemarker i realize it is just a templating engine. AngularJS is not a templating engine. Templating engine is just part within this framework. So both of them cannot be compared.
AngularJS is a full fledged framework for creating Single Page Applications (SPA). So if you want just templating capabilities on client side, i suggest you better look for some other light weight libraries.
If you want to use AngularJS you need to decide
Whether you can structure your app as a SPA
Does the site needs to be SEO optimized. Which has limited support in Angular or as a matter of fact in any client side framework.
Ready to use the AngularJS templating engine because it is awesome with its support for oneway\two way active bindings. If you don't use it templating engine you are loosing a lot.
No it clearly does not make sense as they serve very different purposes. All I can think of is that you either misunderstood the more experienced developer or he really has not understood the business case (WHY something is worth using) of using either technology. In my experience as a j2ee developer, I find that many server side developers (experienced or not) may not be too educated on the many new advances recently made in client side development. With Angular you are not limited to SPA. You need an insight into the overall architecture of your current project to determine if its a good fit. There are ways around the SEO issues or you can purchase an SEO solution. But clearly not a best choice if SEO is essential.
Unless it is a team decision and there are clear problems Angular solves for you, I would not suggest getting stuck alone with a new technology that only you know. Keep it as a hobby and when you really understand the best practices and benefits you can then try being an evangelist.
I'm wondering if anyone has found a solution to this problem. Is there a way to get the best of both worlds:
build a page-based site, with permanent links, accessibility, SEO, and graceful fallback / progressive enhancement (basically all the best practices of web development)
and, for those with javascript, a responsive front-end experience with ajax loading of content, no page refreshes while navigating the underlying site pages, minimal redundant downloading of scripts/content/css/etc. (all the benefits of a client-side framework like AngularJs or Ember.js)
I see a few major sites are able to manage this (gmail, stackoverflow), and I see that Jeff's new site builds a bare-bones version of the site in a noscript tag.
Is the solution to the hybrid page-based/single-page app to build two versions of the site, send both, and let the client decide which it can show? (is this what gmail does?)
Or is the problem that AngularJS et al. are simply not designed to allow for graceful degradation?
It hurts my DRY brains to think that #1 is the answer.
(The reason I am focusing on AngularJs is that I like its support for html templating, declarative style, and its attempts to fix js scoping. Ember and other frameworks are excellent too; maybe one of them would be a better fit for a hybrid site?)
This questions is a bit of a nuanced one because the answer is "it depends". For example you mentioned Gmail, there isn't any reasons whatsoever that an application like Gmail would need to be indexed for SEO, though depending on what you want or need to support you may want to ensure you can support not having Javascript.
However even the "no-javascript" argument is getting tired and weak these days, at least for the class of "web applications". If I want to use a Windows application I need Windows, if I want to use a javascript powered web application it isn't unreasonable to assume that I'm going to need a browser that isn't crippled to use it.
However back to your question I can only speak to AngularJS because I'm the most familiar with it. For the most part it does allow you to support a progressive enhancement approach, though don't expect to use things like URL routing if this is what you want to support. What you can do is use AngularJS controllers, bindings and directives similar to how you might use jQuery as a way of enhancing the interactions and behaviours of the page.
Just keep in mind this approach will seriously limit what you can do with Angular (or Ember for that matter) and it may start to be debatable what you are getting from this approach that you couldn't easily do with jQuery alone.
The alternative these days is to do what sites like Twitter are doing. That is basically serve fully rendered HTML from the server for any view on the initial load and then use Javascript for subsequent loading and enhanced UI behaviour. This is very effective (though perhaps quite challenging to implement) if you really need to support browsing with and without Javascript and has the added benefit of improve the rendering/load times for the first request. Again "it depends" because it depends a lot on how your site actually works if it is possible to use this. You have to design for it, and it isn't going to be trivial or easy.
Update:
For what it's worth we are taking the Year of Moo approach and rendering the pages that need SEO using PhantomJS and sticking the cached initial state of them somewhere to serve them up. We have a rake task we run on deployments to update this. Again this is just the initial state but it helps get around the issue for now.
Things are always changing though and I'm sure I will have changed my mind on this approach in a year or so.
Have you read Google's Making AJAX Applications Crawlable. You can have JavaScript single page app and crawlable content.
If you stick with angular, there is interesting article: Turns out it is possible to have your AngularJS application indexed
I'm hoping to test different versions of a form with Google Optimizer (Multivariate testing). The form is in an ASP include, but what the server-side code will load before Google's JS does. Any ideas about how to approach this? Thanks.
I think I understand your problem. The trouble is that Google's multivariate test is designed to allow you to test two or more snippets of HTML and the multivariate test itself is controlled via Javascript.
So I'm afraid the only way this will work is if you can specify the HTML for Google Optimizer to use for the two versions of the form. This could be made to work with basic forms, but if the form itself is dynamically created in ASP due to some other application requirement then I don't think Google Optimizer will work so well for you.
I think this helps you
Gwo Tricks
My answer is probably out-topic, but I guess you should implement the Multivariate testing by yourself in the ASP.
In the simple case, It is quite simple to implement on top of your existing application, so maybe this can do the trick in your case.
I've made progress on a similar problem. Basically, we want to A/B test 2 different page layout headers. There are some structural differences (it's not just switching out the CSS). We also don't want to wait for Google to flip the coin to determine which variation the visitor should see; instead, we want to choose the variation server-side and avoid a page redirect. I'm now using Google Analytics Content Experiments instead of the deprecated Google Website Optimizer. I don't know whether it's completely working yet, but my code is here:
Google Analytics Content Experiments A/B testing server-side code without page refresh