How would one create a REST web service to write a row into a databse table. Use the follwoing scenario:
The table is called Customer - the
data to be inserted into the row would
be the name, addresss, telephone
number, email.
I think its impossible to describe the whole thing end to end in Java or C#, and I would never expect that, but here are the questions I have popping into my head as I prepare for coding:
How the URI would look (eg. if you use this URL - http://www.example.com/)?
What info would go into the HTTP envelope?
Would I use POST when writing to the database in this way?
Do I use a resource to store the posted data from the client? Is this even necessary if the data is being written to a database anyway?
When the data to be writeen into the db is recieved by the server - how do I physically insert it into the database - do I call some method on the server to actually write the data (in Java)? - this doesn't seem to fit with truely REST architecture - shunning RPC calls.
Should I even be bothering writing to a DB - should I be storing my data as a resource?
As you can see I need a few issues clearing in my head. Any help much appreciated.
First of all, I'm not either java nor c# expert and I don't exactly know what means do these languages have to support REST design, but in general:
http://www.example.com/customers - customers is a collection of resources and you want to add a new resource to this collection
It depends on various things - you should probably set the content-type header (according to the data format in which you are sending the representation) and set some authentication headers if you need it.
Yes, you always use POST to create a new entry in a collection of resources.
I don't fully understand this question, to be honest. What do you mean by "inmediately writing data into the database"?
REST is primarily just a style of communication between server and a client. It doesn't say anything about how you should handle the data received by using it. The usual way how modern web approaches (MVC style frameworks) solve it, is by routing every REST action to a method of some class (usually a controller instance) where you handle the received parameters (eg. save them to the database) and generate a response to be sent back.
For a very brief and very clear introduction to REST have a look at this short video.
RESTful Web Services, published by O'Reilly and Associates, seems to fit the bill you're looking for.
As far as doing it in Java, Sun has a page on it.
Related
I would like to know if this scenario would be possible in any programming language combined with any database technology.
I would like to automatically save received pdf files that are attached in emails into a database. Is this possible? Is there any library or framework available to do so?
Yes, I would recommend using Google Apps Script for this. The approach you should follow is to use the GmailApp class (Documentation here) to get the messages you need, you can use methods like getInboxThreads() (Documentation), to retrieve the messages.
After you've found the message and retrieved the attachment (which you can do withgetAttachments() (Documentation)), you can use the JDBC Service to connect with external databases. The specifics here depend a lot on what database you want to connect with, but the documentation will lead you in the right direction.
I'm currently looking at building a lightweight integration between PivotalTracker and Salesforce.com. Reviewing this bit of PT documentation, it looks like I can do an update of Salesforce data based on PT activity. Awesome! I can't figure out how to access the XML data that is being posted however.
I can't see anything in ApexPages.CurrentPage() that looks like it will let me get to the XML. Has anyone done anything like this, without the use of an intermediate server?
I think we chatted about this over Twitter last week.
AFAIK there is (somewhat annoyingly) no way to access raw (i.e. not form posted key/values) POST data via SFDC. The Apex REST service support would be the closest thing, but requires authentication and still may not do exactly what you want.
Fairly certain you'll need some sort of middle-man proxy that simply takes the XML data and posts it to VF as a form-encoded key/value pair. That is a fairly trivial thing to do, but it's an unnecessary additional moving part and will require some sort of server resource.
I would probably first investigate if PT supports any other ping mechanism, or a way to write a custom extension to convert the raw POST into a form POST.
I'm stumped and need some ideas on how to do this or even whether it can be done at all.
I have a client who would like to build a website tailored to English-speaking travelers in a specific country (Thailand, in this case). The different modes of transportation (bus & train) have good web sites for providing their respective information. And both are very static in terms of the data they present (the schedules rarely change). Here's one of the sites I would need to get info from: train schedules The client wants to provide users the ability to search for a beginning and end location and determine, using the external website's information, how they can best get there, being provided a route with schedule times for the different modes of chosen transport.
Now, in my limited experience, I would think the way to do that would be to retrieve the original schedule info from the external site's server (via API or some other means) and retain the info in a database, which can be queried as needed. Our first thought was to contact the respective authorities to determine how/if this can be done, but this has proven to be problematic due to the language barrier, mainly.
My client suggested what is basically "screen scraping", but that sounds like it would be complicated at best, downloading the web page(s) and filtering through the HTML for relevant/necessary data to put into the database. My worry is that the info on these mainly static sites is so static, that the data isn't even kept in a database to build the page and the web page itself is updated (hard-coded) when something changes.
I could really use some help and suggestions here. Thanks!
Screen scraping is always problematic IMO as you are at the mercy of the person who wrote the page. If the content is static, then I think it would be easier to copy the data manually to your database. If you wanted to keep up to date with changes, you could then snapshot the page when you transcribe the info and run a job to periodically check whether the page has changed from the snapshot. When it does, it sends an email for you to update it.
The above method could also be used in conjunction with some sort of screen scaper which could fall back to a manual process if the page changes too drastically.
Ultimately, it is a case of how much effort (cost) is your client willing to bear for accuracy
I have done this for the following site: http://www.buscatchers.com/ so it's definitely more than doable! A key feature of a web scraping solution for travel sites is that it must send you emails if anything went wrong during the scraping process. On the site, I use a two day window so that I have two days to fix the code if the design changes. Only once or twice have I had to change my code, and it's very easy to do.
As for some examples. There is some simplified source code here: http://www.buscatchers.com/about/guide. The full source code for the project is here: https://github.com/nicodjimenez/bus_catchers. This should give you some ideas on how to get started.
I can tell that the data is dynamic, it's to well structured. It's not hard for someone who is familiar with xpath to scrape this site.
I need to build an offline database application on WP7.
App is simple - it's about making orders from our clients, then translate it to main server (MS SQL).
Spend a days read about existing techologies - but I'am still confused. Which is right for that project?
Sync Framework.
Looking good, but as I understand - it provides single tables - no reference beetwen them. All the references I have to build on client side. Sad.
Entity FrameWork on server side.
And I have no clue - what can I use on client side. Is there a way to serialize entity object to Isolate Store, then restore it, and continue work with it? May be I can use Sync FrameWork, but scheme will become strange then - kinda one way.)))
Working with WCF & XML - most simple for me. A lot of code and conversion, but in this case I understand the data flow. In other view - I already have app with pure SQL-queries. I wanna be advanced. ))))
Using ext. databases (siaqodb for example).
Which one? siaqodb suppots "Sync provider", but it doesn't support references beetwen objects - so I have to build them by myself? Any gain? I don't know.
Is there another way to build such apps? Point it please.
If this has to be done offline, then I would generally use something like:
storing the minimal amount of the required data within isolated using a WP7 specific database like Sterling
using either a new REST or a new RIA/WCF service with objects/functions you define in order to provide the required data synchronisation
I think this is your option 3?
I've never really liked automatic data synchronisation. I just find it easier to code the sync and deal with the error cases myself - this is especially the case if your wp7 client app uses quite a small footprint of data in relation to the larger main server db.
I'm asking for the advice. I'm working at the Silverlight 3 application and now I should select the mean how to save the information and get it. I could save the necessary info in files (from 1 to 300K size) or I could save them in database. If I would use WebClient for accessing to separate file there's very low loading of the server. If I get data from database the server would load much more I think and the code on the server too.
Please correct me if I'm not right.
I'm looking forward to hearing from you!
Thanks
there are additional considerations if you use a file that is localized to the users machine. If you wish to save data w/o any user intervention then you are limited to using Isolated Storage, which has constraints on the size of your data. Otherwise, you have to ask the user for information on where to save/load the file. This is due to the security model used by silverlight.
i am thinking that a Database and the RIA framework might be the way to go.
just my 2ยข
If you are saving and loading the entire file at a time, then it might be okay to use a WebClient. This might take a little coding to handle errors that may result in incomplete saves.
If you're serializing some objects or xml data and storing that in a file, then you should probably be using a database instead.
Edit: It can be a pain to get WebClient or HttpWebRequest working correctly with GET/POST, but WCF can also be a pain to configure if you haven't done it before. WCF is probably better style, and you'll want to use a binary binding and send the file across as a byte[].