I've been doing some research on the HTML5 local storage/offline capabilities and I'm beginning to get a better understanding of it. I've been designing a billing application with Grails and I'm just wondering if it is possible to set up a Grails application to be an offline web application, like you can with HTML5 (by utilizing a Manifest file). If so, would it be set up in the same way that you'd set it up with HTML5, or would there be any key differences to make a note of? Also, what is the best way to implement the local storage functionality of HTML5 in Grails? Is there any plugin or framwork available for this purpose . Has anyone ever used this plugin/framework before, and if so, do you know if there are any guides or examples that use it anywhere that would be really able help me get started with it?
I'd appreciate the information on making a Grails app work "offline
Thanks in advance!
I am developing an offline HTML5 app, myself. The biggest difference is that it is a single page rather than many small ones (but it might work that way if you tried it; you would need to be sure it got all the data it needs at startup).
Don't forget to add the application cache mime type to your configuration.
I never thought to look for a plugin for local storage. In my project, the local tables (I'm using WebSQL because it's in Webkit browsers) are different from the domain classes because they have a different function; that is, they have to hold the data for the domain tables untilthe device can sync with the host.
I hope there is something useful here.
Ed
Related
I have been tasked with researching technology for generating a dynamic report with charts & visuals.
There are countless BI tools available and online solutions that fit the bill, however, the customers have considerable IT restrictions preventing the installation of applications or sharing data across the internet.
One solution I've dreamed up is to serve up an HTML document for offline consumption in a browser. With javaScript bundled in & data added dynamically prior to sending to the client, I believe this would be possible in much the same way a website functioning offline is possible.
How feasible is this? If it's possible, what technologies are recommended? So far I've considered building this using AngularJS since an SPA could mimic a one-page report well & javaScript bundling is readily available.
Are there better solutions? Which?
May be your clients will be okay with providing them files by SFTP. Say, if you are not using a database and are ok with building charts based on files, you can try to provide end users with the files (txt, csv, xml...). Then you will be able to execute client-side code with no server needed. You may even go for some open-source Javascript libraries for data visualisation like D3. All you have to do is to allow local file access for user's browser.
Otherwise you need a local server. I would recommend you to use Python python's SimpleHTTPServer or node.js may fit you.
I have a simple offline html5/javascript single-html-file web application that I store in my dropbox. It's a sort of time tracking tool I wrote, and it saves the application data to local storage. Since its for my own use, I like the convenience of an offline app.
But I have several computers, and I've been trying to come up with any sort of hacky way to synchronize this app's data (which is currently using local storage) between my various machines.
It seems that chrome allows synchronization of data, but only for chrome extensions. I also thought I could perhaps have the web page automatically save/load its data from a file in a dropbox folder, but there doesn't appear to be a way to automatically sync with a specific file without user prompting.
I suppose the "obvious" solution is to put the page on a server and store the data in a database. But suppose I don't want a solution which requires me to maintain apps on a server - is there another way, however hacky, to cobble together synchronization?
I even looked for a while to see if there was a vendor offering a web database service - where I could, say, post/get a blob of json on demand, and then somehow have my offline app sync with this service, but the same-origin policy seems to invalidate that plan (and besides I couldn't find such a service).
Is there a tricky/sneaky solution to this problem using chrome, or google drive, or dropbox, or some other tool I'm not aware of? Or am I stuck setting up my own server?
I have been working on a Project that basically gives you versioned localStorage with support for conflict resolution if the same resource ends up being edited by two different clients. At this point there are no drivers for server or client (they are async in-memory at the moment for testing purposes) but there is a lot of code and abstraction to make writing your own drivers really easy... I was even thinking of doing a dropbox/google docs driver myself, except I want DynamoDB/MongoDB and Lawnchair done first.
The code is not dependent on jQuery or any other libraries and there's a pretty full features (though ugly) demo for it as are well.
Anyway the URL is https://github.com/forbesmyester/SyncIt
Apparently, I have exactly the same issue and invetigated it thoroghly. The best choice would be remoteStorage, if you could manage to make it work. It allows to use 3rd party server for data storage or run your own instance.
I am developing a JavaScript SPA using DurandalJs and BreezeJs as main technologies in the client side. I would like to know what libraries I can use to do my application support different languages. I have been doing a little of searching and I have found that JED.js (http://slexaxton.github.com/Jed/) can be a good option for this task.
However I am not very sure, can somebody recommend nay library for this task, or give me some opinion about JED.js.
Also I would like to ask about some library for store information in the browser. Can somebody recommend me one? I have thought in amplify.js, it gives good functionality for doing request to the server and caching this information. But in my application I am using breezejs, so this part is not needed. I only need to store some data like the username and some little information.
Very thanks.
MY SOLUTION:
I have implemented my system using amplify.storage for storing information in the browser and i18next (http://i18next.com/) to make my application avaliable in different human-languages.
I am not much help on the first part of your question. I'm quite interested in the response myself!
I do have some thoughts on local storage. AmplifyJS is really three independent libraries. One of them, amplify.store, is dedicated to the local storage issue and is worth looking at. You might look at lawnchair. Finally, look at the Breeze DocCode sample for examples of storing full and partial entity caches in browser local storage; it's primitive but gives you hints.
I want to create an internally used web app that can be run with just a copy of the web app and the DB (anything from a text file to MS Access/Excel would work fine). Is this possible? I don't want users to have to setup a SQL server to get the app to work. Having the files necessary to run the web app stored on a shared network drive would be ideal, for example. The problem is that JS can't write to a DB. Is there anything that can use to do this?
Like mentioned, I can assume that Access/Excel are installed, if there's anything that might help there.
It's most certainly possible. W3 has put up the specs for a client side database that can be accessed by JavaScript. The modern browsers have good support for it, and since this is for an internal application, you would have some level of control I believe.
Checkout this slide that shows a live demo of Indexed Database. The full spec can be found here. See this link for browsers that currently support IndexedDB. Here's another set of slides showcasing how to use IndexedDB.
However, with this approach, each user's browser has its own DB locally. If you want a centralized DB, then you will need a server.
You can perform database transactions with JavaScript. This is generally discouraged, because it has terrible security implications. However, in a completely local environment, you are probably not causing any additional security risks. (Because, your database is already on the user's machine.) You can see an example of how to use ADO in JavaScript at How to connect to SQL Server database from JavaScript in the browser? .
Possible, yes, Like Making cars that can float in the sea but could not work on dry roads.
Use winforms or something similar. Use the right tool.
If you insists, Firefox plugins can behave in the way you mentioned, and there is a way to bundle a web application with it's server (check the beginner tutorials for RoR to have an example for something similar with webrick).
If I understand your requirements, you might look into ColdFusion.
For example, you can run a DB query pretty simply, check here, in Adobe
I'm looking to create a cross platform Mobile App and have been looking into Developing using PhoneGap. I'm an amateur programmer and most of my knowledge is in ASP.Net and C#.
Will only being able to use HTML, CSS and Javascript with PhoneGap limit me to specific functionality of my App? and would migrating to HTML5 help in adding more functionality to an App?
I'm looking to be able to Populate Drop-Downs from a Database, Add/Edit/Delete Items from a Database, Create Reports Ect...
Your only real limitation as far as data access goes is that you're limited to an SQLite database, which to be honest isn't much of a limitation since it performs great for single-user access.
The short of it is that you have access to a database from within your app, so you can do whatever you need to. The tools are HTML & JS as opposed to C# with some graphics layer, so doing things like creating graphs is quite different, but it's all possible.
Also note that depending on what your app is doing, PhoneGap is one of several solutions. If you want a "native" look/feel, consider TitaniumUI -- it takes common code (still JS) and pushes it through some translation layers to create native UI components.