I'm currently developing an order entry application for my company. This means I need to download approximately 1900 product images to the iPad, and that's just the normal images. I also need to download an equal amount of thumbnails. The reason for downloading the images to the iPad instead of just displaying them from a given URL is that our reps wander into large stores which often don't have stable internet connections.
What would be the best course of action? The images are stored on our servers, but you need to be authenticated using Basic Auth before you can access those. I have thought of just downloading them one-by-one, which is tedious, or group them together on the server as a zip-file but that would be a large file.
A one-by-one is a valid options for the download. I have done projects with similar specs, so what I advise:
Use some 3rd party library to help you with the download of the images. MKNetworkKit for example. If you feel confortable enough, NSURLConnection is more than enough.
Store the images in the application sandbox.
Instead of downloading the thumbs, just create them on the go when you need them (Lazy pattern). Unless your image's thumbs are somewhat different than the original (some special effect).
Related
I am developing a Win8 Store app which allows users to download different types of files from an online learning platform and store them locally. I am also considering the function to help users organize these downloaded files by placing them in different folders (based on course name and etc.).
I was using Documents Library previously. But for every type of file that the user could download, I need to add a file type association, which does not make a lot of sense since my app would be able to open such files. So which local storage should my app use?
Many thanks in advance.
Kaizhi
The access to storage by Windows Store apps is quite restrictive, especially the DocumentsLibrary.
As you have noticed, you need to declare a file type association for every file type you want to read from or write to the DocumentsLibrary. This means your app need to handle file activations for these types in a meaningful way, which your app probably should not do.
But even if you jump through this hoop, there is another one that is not documented on the MSDN page of the DocumentsLibrary, but "hidden" in a lengthy page about app capability declarations: According to the current rules, you are not allowed to use the DocumentsLibrary for anything but offline access to SkyDrive! Bummer...
So what's left?
You can use SkyDrive or another cloud storage to put files in a well known place (which might or might not be somewhere on the hard disk). This is probably both overkill and undesirable in your case.
Or you save the files in the local app storage, provide your own in-app file browser and open the files with their default app. Seems viable to me.
Or, maybe, you can do something with share contracts or other contracts. I don't know much about these yet, but I doubt that they are helpful in your situation.
And that's it...
(Based on my current experience. No guaranty for correctness or completeness)
I have an e-commerce website I made for a client.
As with any e-commerce site, there are a lot of pictures.
About a hundred of these pictures were uploaded by me, provided by my client.
The other 400 were uploaded by client.
The problem is that the first set of images that my client provided me with were about 100kb each, which is not such a big deal. The second set of images, the ones my client uploaded, were about 5-9 MBs in size. Obviously I didn't see this until it was too late.
So my question is this: How can I reduce the image size of all those load-heavy images to something more around 100-200kb through ssh/commandline/php.
I'm also talking about re-scaling the images to something smaller (currently they are about 3700px x 5600px).
Please note: I don't need a solution to re-scale the images when they are being uploaded.
I need a solution to re-scale the images that are already on the server.
Assuming your server is a Unix, you can use imagemagick/convert tool:
http://doc.ubuntu-fr.org/imagemagick
You can also use PHP+GD, see:
http://fr.php.net/manual/en/book.image.php
I was wanting to use a file sharing server to keep certain files up-to-date and constant across multiple instances of my application across multiple computers - like (for example) writing a multiplayer game, which stores all the player's positions in a text file, and uses something like Dropbox to keep the text file constant across all the applications, and each application instance can change the file with that application's player's position, and then the rest of the applications can update accordingly. This is only an example, and is not what I intend to do using this technology. What I want to do does not rely on fast sharing of data very quickly - but only periodically downloading and updating the text file.
I was wondering how I might be able to do this using the Dropbox API for Objective-C without prompting the user for any Dropbox username/password - just store a single Dropbox account's login information, log into it automatically and update/download the file stored on it?
From what I have found out from experimenting, Dropbox prompts users for their passwords via a web-broswer, and is designed to accommodate multiple accounts, whereas I only need to accommodate the 'Server' account.
So, is there anyway to do this sort of thing using the Dropbox API, or should I use something else. Or do I need to find out how to write my own server. Using some sort of file sharing API seems a lot easier to me than writing an actual server.
Thanks for any help,
Ben
You might think about using Google App Engine (GAE). I had a similar requirement recently and I'm thinking this is a good option when you want centralized data. Plus you can do the no-browser account login by using your own custom authentication, or I think it's even possible via OAuth? Depends on how sensitive the data is I guess. I just rolled my own.
From my research I found that using Dropbox as a server has some issues with scalability, since you'll be limited to maybe 5,000 calls per day. source It's built on Amazon S3, so you could also look at using that directly.
GAE lifts that limit up to 675,000, but can be increased up to 91 million for free.
https://developers.google.com/appengine/docs/quotas
I did find an open-source project for doing this with Java, alternative you could look at Python example
I've written a daemon that continuously checks for updated files and syncs them. I wrote it for my own file manager iOS app. You can find the implementation here:
https://github.com/H2CO3/MyFile/tree/master/DropboxDaemon
I'm personally not an iOS developer but I came across this question while looking for something else and thought I would offer up another potential solution to the OP's question.
Microsoft just released something called Azure Mobile Services which supports iOS development (among other platforms). It's basically a convenient way to set up a back end system complete with push notifications, authentication, etc. without rolling your own. You don't need to know anything about Azure or servers as the setup process walks you through most of it. It is new so keep that in mind, but it looks promising for situations like this.
Here's a 10 minute video explaining how to use it with an iOS developed app along with links to more documentation:
http://channel9.msdn.com/posts/iOS-Support-in-Windows-Azure-Mobile-Services/
Hope this helps.
So I am in the process of moving all the thumbnails of my major sites to S3 and now I am thinking about how I can consistently put all my CSS/JS/images that power the actual sites to it. It's easy enough to upload everything the first time but I am trying to think of a way to somehow automate the process everytime I push out to production.
Does anyone have any clever ways of doing this?
I used to use s3sync to compare and update the assets just before upload the site files using a bash file to iterate through my files
This works well but when the amount of likes to compare (lets say thousands) gets big this process start being really slow. If you have an small architecture (in term of assets) this would do the trick
to make this better I would recommend capistrano or some other assistant that helps you to deploy...this way you can run at all once..
upload assets
deploy your files
In the other hand you could take a look to cloudfront (amazon's CDN) and set it up using ORIGIN..this way you dont need to worry about upload the files to s3 since they will be automatically pulled on demand. The down side of this approach is the caching if you need to update a file and keep the same name (AKA expire the object)...you can do this in cloudfront but will need an script to do the task.
Depending in the traffic (and other factors, ofcourse) one or other path will fit the best.
I'm building an application that needs to download web content for offline viewing on an iPad. At present I'm loading some web content from the web for test purposes and displaying this with a UIWebView. Implementing that was simple enough. Now I need to make some modifications to support offline content. Eventually that offline content would be downloaded in user selectable bundles.
As I see it I have a number of options but I may have missed some:
Pack content in a ZIP (or other archive) file and unpack the content when it is downloaded to the iPad.
Put the content in a SQLite database. This seems to require some 3rd party libs like FMDB.
Use Core Data. From what I understand this supports a number of storage formats including SQLite.
Use the filesystem and download each required file individually. OK, not really a bundle but maybe this is the best option?
Considerations/Questions:
What are the storage limitations and performance limitations for each of these methods? And is there an overall storage limit per iPad app?
If I'm going to have the user navigate through the downloaded content, what option is easier to code up?
It would seem like spinning up a local web server would be one of the most efficient ways to handle the runtime aspects of displaying the content. Are there any open source examples of this which load from a bundle like options 1-3?
The other side of this is the content creation and it seems like zipping up the content (option 1) is the simplest from this angle. The other options would appear to require creation of tools to support the content creator.
If you have the control over the content, I'd recommend a mix of both the first and the third option. If the content is created by you (like levels, etc) then simply store it on the server, download a zip and store it locally. Use CoreData to store an Index about the things you've downloaded, like the path of the folder it's stored in and it's name/origin/etc, but not the raw data. Databases are not thought to hold massive amounts of raw content, rather to hold structured data. And even if they can -- I'd not do so.
For your considerations:
Disk space is the only limit I know on the iPad. However, databases tend to get slower if they grow too large. If you barely scan though the data, use the file system directly -- may prove faster and cheaper.
The index in CoreData could store all relevant data. You will have very easy and very quick access. Opening a content will load it from the file system, which is quick, cheap and doesn't strain the index.
Why would you do so? Redirect your WebView to a file:// URL will have the same effect, won't it?
Should be answered by now.
If you don't have control then use the same as above but download each file separately, as suggested in option four. after unzipping both cases are basically the same.
Please get back if you have questions.
You could create a xml file for each bundle, containing the path to each file in the bundle, place it in a folder common to each bundle. When downloading, download and parse the xml first and download each ressource one by one. This will spare you the overhead of zipping and unzipping the content. Create a folder for each bundle locally and recreate the folder structure of the bundle there. This way the content will work online and offline without changes.
With a little effort, you could even keep track of file versions by including version numbers in the xml file for each ressource, so if your content has been partially updated only the files with changed version numbers have to be downloaded again.