I wanted to auto fetch data(gold price) from a website and update a variable. Do i have to load the whole .html file in a string and find the price? Is there any other way? Even if I updated the variable, how do i save it, so it retains it's updated value(price)?
Do i have to load the whole .html file
in a string and find the price?
Yes
Is there any other way?
Only if the web site also provides an API that gives you access to just the data you need.
Even if I updated the variable, how do
i save it, so it retains it's updated
value(price)?
A variable will keep it's value until you change it. However if you want to preserve it even when the user quits your app, so that it starts again from the same value, you could save it in NSUserDefaults for example.
Do be aware however, that the data is almost certainly copyright, you can't just scrape data from a website and publish an app based on that data without considering the legal perspective. Price data is normally owned by the exchange and you will need a license to re-publish it.
Related
I am in a situation where I need to store a document which can be of any type like. pdf, Docx, excel or an image. now I don't have the option to force only one type.
The issue is what to do for an app to work for ios/android as same. should I ask the user to upload the file and store it on the server and ask them to download every time they need it? or upload a copy to server and store it locally where they can access it.
if later is the way to go as a user might need to access the document offline. so what to do for this?
any plugin to use for the same.
I'm trying to develop word add-in which allows to modify word content. One of the requirement is to select some text and mark it:
change its style (look) - and that is done
Associate that piece of text with some custom/hidden data, ex. an ID.
I want to somehow persist that data within the document, so that:
My add-in can read the document on the start and build a list of 'marked' elements
It should work on different machines - I can create a document on one machine, later open in on other machine, and add-in should be able to retrieve that data.
So far I tried to persist that data by first, getting data as HTML, and add attributes to tags, but that didn't work.
Also tried to add some hidden div, but it was only available during word app lifetime.
Recently, found this link: https://github.com/OfficeDev/Excel-Add-in-JavaScript-PersistCustomSettings , but still it allows to persist data in scope of "browser", so, I assume that on other machine it won't work.
What are my possibilities? Maybe I shouldn't store it within a document, but if not, where?
Developing it using office-js - it should work for both Word 2013 and Word 2016 (so I don't have an access to Word 2016 specific API).
Check out https://dev.office.com/reference/add-ins/shared/settings
The Office JS Settings object allows you to save custom data that persists with the document. It is pretty straight-forward to use. Getting settings is synchronous - saving settings is async. The biggest thing is that you have to remember to call Office.settings.saveAsync() after you have made your changes using Office.settings.set() in order to actually save the changes to the document.
Moreover to Nick's answer which is absolutely correct, you can use "Binding" mechanism.
Bindings are stored in document out-of-the-box, so that, you can access those later at any time.
An example, which fits my needs:
Select some text and click on button in add-in (to call some method)
Call addFromSelectionAsync() method (you can specify an id for it to reference it later)
Access it using getAllAsync() or getByIdAsync() method at any time you need it.
More about it: https://dev.office.com/docs/add-ins/develop/bind-to-regions-in-a-document-or-spreadsheet
I've experimented with several ways on seeing if I need to update my user's UITableView data source only if the server one is newer. Over the past few years I've done these scenarios: 1: Having a seperate .txt file with a character as the version # then simply comparing them through code and downloading the new .plist, then saving that .txt to the user's NSDocumentDirectory along with the .plist to compare again in the future, and 2: Actually checking the server's file modification date, which worked even better, as there was no .txt file to download along with the .plist (the less stuff to download the better)
But, now I want to try a different way to account for the fact that I ship a .plist file in the App Bundle. Since the .plist file creation date is always later then the server date for new users, they don't get the new .plist file, whereas older users of the app get the new file. Sure, on the first app launch I could grab the server's modification date and overwrite the app's since I copy it from the main bundle to the NSDocumentDirectory, but I don't think I want to go that route, as I've never liked checking launch counts.
Basically, it needs to continue to be lightweight in network request time and be reliable like it's been for me. I was thinking about creating a version # key in my .plist and simply comparing that with the local .plist, but I highly doubt this will be as lightweight, as I would have to download the whole .plist into an NSDictionary first before I can compare the key values.
I'm really sorry this post is long, and I appreciate your help!
Why not ship the app with out the data_source.plist file and download it on first launch, or any other time it does not exist on disk (you never know). After that, you could send a HEAD request and check the modification date (maybe even the e-tag), and download as necessary.
UPDATE:
Depending on how much control you have over the server, you could add a hash of the file to the response headers (as mentioned in the comments: MD5,SHA*) along side Last-Modified.
You could add the data_source.plist to the bundle at build time, along with last_modified.plist where you can set the hash, last modified, and any other meta data you want, as starting point.
Checking for updates could look something like:
Send HEAD request for http://server.com/data_source.plist
Pull Last-Modified (and hash if you can send it) from the response headers
Validate against corresponding values in last_modifed.plist
Download updated data_source.plist if needed
If the download was successful, update last_modifed.plist with new meta data (last modified and has, be sure pull this from actual download response headers).
This way, the user has something to start with, and the app can download the resource when needed.
The advantage of a HEAD request is it is light weight since there is no message body, but returns the same response headers as a GET request. It is a common method to check if a resource has been updated. The trick with your scenario is to get a starting point onto the device at build time.
Problem:
Building Enterprise Applications of a Suite Nature, and need to be able to pass data from one application to another. Example: App1 is a barcode reader that produces and inventory list. App2 needs a "fresh" copy of the same inventory list information that App1 just produced in order to accomplish its goal of producing purchase orders. The two apps and databases are two large to squeeze together in single app, plus the suite will continue to grow with more and more apps.
Understanding:
I fully understand that "Each" application is in it's own sandbox. However, in reading through the documents regarding the new UIDocumentInteractionController API, it appears that an application can dip outside of the sandbox just a little to "Read-In", "View", or "Open-In" a document that was not apart of the bundle or created within the application.
Data Flow:
I'm trying to keep it simple. I have been using the DocInteraction sample application downloaded from Apple, and another application...called App1 to try and work with a simple text file. In App1, I create a simple txt file, and save it to the documents folder. (But this is still inside the app's sandbox?). in the DocInteraction modified sample, I have been trying to figure a way to "View", "Open-In", or better yet "Read-In" the created txt file. If I can pass a simple txt file between the two, I can include a CSV structure to update the databases on each side when ever the applications are opened.
I have tried to utilize the Launch Options Keys with no luck.
In short, I just can't seem to get my head around:
Where App1's data needs to go?
How to find the data in the other App, say App2?
How do you "Open" the file that exist inside another application's sandbox?
End Result:
I have tried to stay away from the
The Document Interaction docs outline:
Previewing a Document or Presenting Options
Registering Your Support of File Types
Opening Files From Other Apps
Displaying and Printing Quick Look Previews
It is the "Opening Files From Other Apps" that I am most interested with. It directs me to utilize the application:didFinishLaunchingWithOptions: method by passing in dictionary values for the keys. This is where I get lost?? How do I set the keys so that it knows "WHERE" and "WHAT" to look for? And I'm still not clear the proper director that App1 should be saving information to in order for the keys to point to the correct place?
Opening email file attachments and opening pdfs in iBooks can't be the only places where you can utilize this API or else Apple wouldn't have went through all the work, they are already allow to talk from App-To-App.
Note: I'm not trying to get App1 to directly transmit data into App2's files. I don't think that would be allowed by Apple at all! I'm trying to get App1 to zip up its data, save it in proper location, so when user decides to use App2, the data can then be available to App2 by "reading-in" the data.
If someone has a sample application, tutorial, or even a solid idea how to get this working I would really appreciate the help.
-Thanks!
P.S. Somebody with 1,500 or higher reputation please create a "UIDocumentInteraction" tag for stackoverflow!
I got it working last month. Here's my mental model:
App1 creates a file anywhere in its sandbox.
App1 calls docinteraction to display the "Open In" GUI for that file
User picks "Open in App2"
The iOS copies the file from one sandbox to the other and launches App2.
App2 implements didfinishlaunchingwithURL and loads the supplied URL (which is the copy in its sandbox)
I'm creating a cms and have not yet settled on the matter of where to store the complete url for a given page in the structure.
Every page have a slug (url friendly name of the page) and every page has a nullable (for top-level pages) parent and children.
Where do I store the complete url (/first-page/sub-page) for a given page? Should this go in the database along with the other properties of the page or in some cache?
Update
It's not the database design I'm asking about, rather where to store the complete url to a given page so I don't need to traverse the entire url to get the page that the user requested (/first-page/sub-page)
Update 2
I need to find which page belongs to the currently requested url. If the requested url is /first-page/sub-page I don't want to split the url and looping through the database (obviously).
I'd rather have the entire url in the table so that I can just do a single query (WHERE url = '/first-page/sub-page') but this does not seem ideal, what if I change the slug for the parent page? Then I also need to update the url-field for all descendants.
How do other people solve this issue? Are they putting it in the database? In a cache that maps /first-page-/sub-page to the id for the page? Or are they splitting the requested url and looping though the database?
Thanks
Anders
Store it in a cache, because the web servers will need to be looking up URLs constantly. Unless you expect the URLs of pages to change very rapidly, caching will greatly reduce load on the database, which is usually your bottleneck in database driven web sites.
Basically, you want a dictionary that maps URL -> whatever you need to render the page. Many web servers will automatically use the operating system's file system as the dictionary and will often have a built-in cache that can recognize when a file changes in the file system. This would probably be much more efficient than anything you can write in your CMS. It might be better, therefore, to have you CMS implement the structure directly in the file system and handle additional mapping with hard or soft links.
I just did this for MvcCms. I went with the idea of content categories/sub categories and content pages. When a content category / subcategory is created I go recursively through the parents and build the entire route and then store it in the category table. Then when the page is requested I can find the correct content page and find out when going through a nav structure if the current nav being built is the current or active route.
This approach requires some rules about what happens when a category is edited. The approach right now is that once the full path is set for a sub category it can't be change later with the normal tools.
The source is a mvccms.codeplex.com