Using Backbone.js offline - backbone.js

I'm evaluating Backbone.js for keeping data and UI synchronized in my web app. However, much of Backbone's value seems to lie in its use of RESTful interfaces. Though I may add server-side backup in the future, my primary use case involves storing all data offline using HTML5 local storage.
Is Backbone overkill for such a use case? If so, is there a better solution, focused solely on updating UI when data changes, and vice versa? (I'm also looking into Knockout and Javascript MVC.)
EDIT: I'm also now looking into Angular.js and jQuery Data Link.

Backbone.js works just as well with local storage as it does with RESTful queries.
I'm a learn-by-example kind of guy so here are some links to get you started:
Todos, a todo application
that uses local storage and
backbone.js, check out the annotated
source to see how it works.
The localStorage adapter is
all you need to get started, take a
look at the annotated source of
that too.

In the past weeks I have evaluated different solution for a scenario close to yours; being a project done in my personal free time and not being a good Javascript programmer, all I needed was something easy to learn to avoid starting from scratch.
Not surprisingly, I had the same candidate: Backbone.js, Javascript MVC and Knockout.js.
Backbone.js won:
I wasn't be required to follow conventions or replace what was already in place
I've easly hacked in its codebase to understand what wasn't clear from the documentation
I've successfully ignored a large amount of its features that was not interesting for me
It gave acceptable performance on busy pages
It works
Backbone.js is lightweight and relatively magic-free; you will probably use a small subset of its feature but it provieds a solid base to develop your solution.

I know it's been a while but you may want to check out backbone-offline project on github: https://github.com/Ask11/backbone.offline

You can also take a look at AFrameJS. I have created a bare-bones proof of concept note-taking app that works offline using HTML5 WebSQL spec, but also want to create an adapter that uses localStorage as well. My personal opinion (and I am biased) is that using an MVC library of any sorts is going to help you in the long run - the value of libraries such as Backbone, Knockout, and AFrame lie in their ability to reduce the cognitive load of the developer by enforcing a good separation of concerns. Data related functionality reside in models, displaying that data resides in Views, and the glue is kept in Controllers. Separating these three concepts might seem pedantic at first, but the end result is code that is easier to develop, easier to test, easier to maintain, and easier to reuse. A basic tutorial on using AFrameJS can be found on my site at: http://www.shanetomlinson.com/2011/aframejs-tutorial-for-noobs/

Related

Is there consensus on a view engine for Nancy?

I was a little startled to learn that Nancy has its own razor implementation, that may or may not behave like razor. In practice, does this cause issues? What are "most people" using for a Nancy view engine? Why was the real razor not used?
First the easy answer. The Razor engine is, by far, the most downloaded view engine available for Nancy https://www.nuget.org/packages?q=nancy.viewengines
Now for the more complicated questions
Why was the real razor not used?
Because the "real" (and by real I'm going to assume that you mean the one used by the ASP.NET stack) Razor engine is tied to the HTTP abstractions that are built into the ASP.NET stack (HttpContext and all its friends) so there is no straight forward way to use it with Nancy.
The slightly longer answer for this is that you have to understand that Razor is really a parser and a Razor view engine is what sits in the middle of the consumer and the parser.
Nancy uses the Razor parser but we have to have our own view engine because that's what enabled Nancy to parse and execute Razor templates.
Now, it does get even more complicated. Many of the features you see in the ASP.NET Razor view engines, such as master pages, partials, various helpers, _ViewStart and so on, are not Razor (the parser) features, but they are an additional feature set that have been built into the view engine (you can almost think of it as middleware).
This means that for our engine we've had to re-implement much of these features because that's what's come to be expected from a Razor view engine.
I would like to point out that, if it was possible, then we would love to ditch our own implementation and use the one built by Microsoft (less code for us to maintain and it would mean we'd support 100% the same feature set), but unfortunately that's not our decision to make.. we can't take a dependency on their abstractions I am afraid
Hope this clears things up
/A
We have been using the Razor implementation from Nancy for a while now. We have run into a couple of issues that are making us either switch to SSVE or abandon Nancy (we do really love Nancy).
The first issue with Razor is you cannot precompile views like you can in MVC which leads to much longer startup times. We have had many complaints about this.
The second issue is there seems to be a long-standing bug in the Razor implementation with Nancy which causes a situation that is only resolved by recycling the application pool. I'm not an expert but it seems when the project is loaded there is a temporary DLL being compiled and generated at that time (this explains the slower load times) but sometimes there a problem which leaves to the instance not being able to be created. It seems to be at this location: https://github.com/NancyFx/Nancy/blob/master/src/Nancy.ViewEngines.Razor/RazorViewEngine.cs#L238. Basically "viewAssembly.GetType("RazorOutput.RazorView")" is NULL at various times which causes only an error message to be displayed on every page, for every user, at all times and the only way to fix it is to reload the application (recycle the application pool)
Just my two cents and I know this post is older but maybe others will see some of the problems we have run into. I've opened a GitHub issue but the bug is hard to reproduce for us and it hasn't gone anywhere.

Integrating markdown into angularjs?

I've started writing a simple app using AngularJS + NodeJS to learn more about the stack, and it appears that getting markdown to work is a bit tricky and not that well supported. I'm coming from a ruby background, and I used the redcarpet markdown library, which was pretty standard and straightforward.
I've come across the angular-markdown-directive:
Pros
Simple to setup
Uses ngSanitize to clean user-submitted markdown. This library is supported by the official Angular team.
Cons
It uses showdown under the hood, which seems to have died a while back, but small progress seems to be picking up with the new maintainer. However, it has quite a few outstanding bugs, two particular bug reports dating back to 2013 and 2014 are worrying:
(1) Underscores are apparently interpreted to be italicized (will create malformed links):
https://github.com/showdownjs/showdown/issues/96
(2) Security issue that allows XSS still not patched:
https://github.com/showdownjs/showdown/issues/57
I'm not sure if (2) will be an issue in my case, since ngSanitize may help.
There is another library called markdown-it, but this library handles markdown in Nodejs instead of Angular. But their examples doesn't say much about best security practices.
--
Are there any full examples on how markdown can be securely integrated into a Node/Angular app? angular-markdown-directive seems like a good fit but has some painful problems, and most other markdown libraries are either dying/dead or they gloss over security in a production environment.
I decided to use markdown-it. It's pretty flexible; it actually allows parsing from either server or the client so it's up to you how and where you'd like to parse the markdown.
For me, I've opted to save the markdown text in the database and then parse the markdown on the client, and it works very well.
As for security, markdown-it comes with some built-in security measures, which is very nice. There is also a separate security module that you can use with it that offers additional features.

Is Mapstraction still the way to go

I was starting to write a multi-Map JS library, but I see that Mapstraction does that exactly..
I really would like to use Maptraction but it looks a little old (The commit's on GITHUB) (Not a issue if it is still "supported"), also The tutorial page, the Maps do not show up in my browsers.
Any input is highly appreciated.
Thanks
Kim
Depends what your use case is - if you don't want to be tied in to any one map provider and only need standard features then, yes.
Version 2.1 of Mapstraction is currently being prepared (on the release-2.1 branch) which brings some improvements in behavioural consistency across the providers.
Because of the nature of the library development isn't continuous and tends to be reactive to changes in the underlying providers or issues being raised. That said the community is fairly active and you can sign up to the mailing list via the site.

amplify.js and backbone.js

recently i had a chance to watch beautiful course from john papa on building single page application. i' d love it. it touches every aspect of application both server and client side.
i was more into client side. during his implementation mr.papa had similar structure in clientside. such as data services, mocking, data caching and offline features it was impressive. one of libraries that frequently was mentioned is amplify.js
since in his work mr.papa has referred to knockout, as someone who has started digging and working in backbone.js. want to find out does similar structure would be applicable for backbone. or more precisely could backbone also benefited from amplify.js or it s already built in underhood of backbone.async method?
ref:jonhpapa.net
could backbone also benefited from amplify.js
Yes, but you'd have to override Backbone.Sync in order to use the client-side persistence provided by the Amplify.js Store API.
Backbone.amplify looks promising, but I haven't tested it yet.

Language/Framework support for Interacting With CouchDB

I am interested in knowing if there are any server-side web application frameworks which integrate nicely with CouchDB? Does anyone have any experience in doing this? It seems like a dynamic language would be well-suited for playing with the JSON, but I am more interested in hearing about how it would fit in with the framework and the application's design.
Two frameworks that I would suggest for CouchDB are Ruby on Rails and Django. Both have a small file you can include that allows for easy interaction with CouchDB. For Ruby/Rails, this gives you the ability to write code that looks like this (code snippets yanked from here):
# Create the database
server = Couch::Server.new("localhost", "5984")
server.put("/foo/", "")
# Insert a new document into the database
doc = <<-JSON
{"type":"comment","body":"First Post!"}
JSON
server.put("/foo/document_id", doc)
# Get the document back later
res = server.get("/foo/document_id")
json = res.body
puts json
Python/Django lets you do the same with a relatively minimal amount of work (see here). Both of these aren't at the web framework level but they require a minimal amount of work to set up and are pretty easy to get going in Rails and Django. The Django approach still requires some packages to be installed so if you just can't do that for some reason the Rails approach is the way to go.
Another good how-to on Python on Django can be found here (also lifted from the CouchDB FAQ).
The only web framework that dedicates itself to CouchDB is currently CouchDBKit for Python.
Check out the official wiki page that lists how to get started in your language:
http://wiki.apache.org/couchdb/Basics
Pick the language and framework that suits you best and then use one of the light CouchDB libraries with it.
It seems that things are move quite quickly at the moment for CouchDB. I'm sure there will be more frameworks out there soon with CouchDB support. I'm currently looking into building one for PHP.
I have had good success with jcouchdb for Java and CouchApp for JavaScript and CouchDBKit with Python. All of these are actively developed, open source and well designed and easy to enhance if they are missing something you really need. I have submitted patches and feature enhancements for jcouchdb and couchapp both.
Actually, you don't really need such a framework. Instead, you can just write the whole web application in CouchDB. It allows you to generate HTML files, or any other XML derived format, and you can even use HTML-templates. I consider this a good choice, because JavaScript is a rich and flexible language. On the other hand you don't have the overkill of a connection between the database and your web application.
For more details, check out: http://books.couchdb.org/relax/design-documents/shows
There's also a related question: Using CouchDB to serve HTML
Depending on what you want to build CouchApp may be something to look at: It's specially designed for writing apps with CouchDB:
https://github.com/jchris/couchapp/wiki/manual

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