Understanding map reduce with CouchDB

AuthNet iOS Integration Part 2

There are quite a few gaps in the sample code provided by AuthNet, we will discuss the logs indicating the problem and what chunk of code needs to be added/removed to get to a complete sample that works. This blog entry assumes that you've cleared the challenges of adding AuthNet binaries to your Xcode project. If not then have a peek at AuthNet iOS Integration Part 1 before continuing.

1. Create a header & an implementation class containing the sample code
2. If you happen to be using PayPal as well as AuthNet in your code then you may run into some syntactical problems. To resolve any such issues, please have a look at this post on stackoverflow.
3. When substituting values in the code, if you provide the "API Login ID" and "Transaction Key" as the name / password values in your call to AuthNet then you will run into the following error as seen in the logs:
4. This fails as password and transactionKey are distinctly different variables in the header files.
5. So make sure to substitute the sample code with the username and password used with https://developer.authorize.net/ or https://test.authorize.net/
6. If you run the code at this point and end up calling loginToGateway, you will run into the following error logs:
7. This is not the same as being at the point where you simply need to login to the sandbox (https://test.authorize.net/) and enable the new device. No, this is very different and you need to get past this to get to the next point. So you need to add some additional code which is talked about on the forums as well:
8. Now you should be at a point where running the code results in the following error logs:
9. This is more like it! So head over to https://test.authorize.net/ and enable your new device. Here are some screenshots: screenshot_1 and screenshot_2
10. Sadly we aren't done yet, we see a message about the mobile device being ready for use but we also notice that the sessionToken has come back as null and therefore the next call's response displays an error ... claiming that the request content was incomplete:
11. Even I don't have a solution past this point, feel free to follow this forum thread for any progress on the matter.

AuthNet iOS Integration Part 1

1. You can start with the official instructions to get an account with Authorize.Net and download their iOS SDK. Afterwards the instructions are bit out of date, so you can follow along below.
2. After you download and unzip the SDK, you can move the files around to have them structured in this manner:
3. The structure above has the following pros:
   • Clarity around which version has been downloaded and in use at any point of time: anet_ios_sdk-X.X.X
   • If you work long enough to have multiple versions, then having them in your repository (assumption - GIT repo) helps figure out any migration issues
     • $(SRCROOT)/anet_ios_sdk-1.0.0/ANMobilePaymentLib/
     • $(SRCROOT)/anet_ios_sdk-1.0.1/ANMobilePaymentLib/
     • $(SRCROOT)/anet_ios_sdk-1.0.2/ANMobilePaymentLib/
     • ...
     • $(SRCROOT)/anet_ios_sdk-X.X.X/ANMobilePaymentLib/
4. Goto MyProject > Targets > Build Settings in Xcode and set:
   1. Header Search Paths
      1. "${SDK_DIR}"/usr/include/libxml2
         • Mark the Recursive checkbox as checked
      2. "$(SRCROOT)/anet_ios_sdk-1.0.0/ANMobilePaymentLib"
   2. Library Search Paths
      1. "$(SRCROOT)/anet_ios_sdk-1.0.0/ANMobilePaymentLib"
   3. Other Linker Flags
      1. -lxml2
5. Drag & Drop the ANMobilePaymentLib.xcodeproj file from a Finder window into Xcode under MyProject.
   • If you don't follow this step then you will face compilation issues like:
6. Goto MyProject > Targets > Build Phases in Xcode and set:
   1. Link Binary With Libraries
      1. libANMobilePaymentLib.a
7. For a discussion on the fixes to the sample code, head over to AuthNet iOS Integration Part 2

How to use the ElasticSearch Query DSL

I'm also in the process of developing an ElasticSearch Client based in Objective-C using RestKit, feel free to have a look & use it ... and shoot me an email if you want to contribute: https://github.com/pulkitsinghal/ElasticSearchClient

How to build a webapp with CouchApp and CouchDB

This is a chronicle of the additional work I had to do as I followed Ed Parcell's Tutorial: Using jQuery and CouchDB to build a simple AJAX web application. It is supposed to serve as a supplement.

Ed's post covers the use of CouchApp as far as generating templates to work on is concerned. As a supplement, my post will leverage the Evently framework (already a part of the generated CouchApp 0.8.1) to do the same exact thing.

1. When asked to edit index.html for the first time in Ed's post, here is how the content will differ if you want to do things the Evently way:
   

   <!DOCTYPE html>
     <html>
   
     <head>
       <title>Address Book</title>
       <link rel="stylesheet" href="style/main.css" type="text/css">
     </head>
   
     <body>
       <h1>Address Book</h1>
       <div id="add"><button type="button" id="add">Add</button></div>
       <div id="addressbook"></div>
     </body>
   
     <script src="vendor/couchapp/loader.js"></script>
   
     <script type="text/javascript" charset="utf-8">
       $.couch.app(function(app) {
         $("#addressbook").evently("addressbook", app);
       });
     </script>
   </html>
   

2. Lets take a moment to acknowledge all the differences:
   
   1. Links to json2.js, jquery.js or jquery.couch.js are not present in the head section. This is now taken care of by loader.js (view source +/-), which loads all of the required javascript files.
      

      function couchapp_load(scripts) {
        for (var i=0; i < scripts.length; i++) {
          document.write('<script src="'+scripts[i]+'"><\/script>')
        };
      };
      couchapp_load([
        "/_utils/script/sha1.js",
        "/_utils/script/json2.js",
        "/_utils/script/jquery.js",
        "/_utils/script/jquery.couch.js",
        "vendor/couchapp/jquery.couch.app.js",
        "vendor/couchapp/jquery.couch.app.util.js",
        "vendor/couchapp/jquery.mustache.js",
        "vendor/couchapp/jquery.evently.js"
      ]);
      

      • If you took note of the relative URLs that start with _utils then you should realize that the JS files are being referenced from another application known as Futon which serves as CouchDB's Admin Interface.
      • Now this may cause some concerns about exposing Futon to your user populace!
      • As a workaround you can always move such files to your own CouchApp, such as the AddressBook webapp that we are working on right now and then simply change these links.
      • Based on what I read (somewhere on the web) if folks really want to then they can simply host their own Futon and point it to your CouchDB server! I admit that this is hearsay and I haven't really experimented with such a hack myself. But overall what I personally took away from all this ... is that removing Futon from your CouchDB is not really what secures it, rather setting up proper accounts so that login is required to perform non-read operations is what truly makes an instance secure.
   2. An additional script section:
      

      $.couch.app(function(app) {
            $("#addressbook").evently("addressbook", app);
          });
      

      is used to wire-up the addressbook div element with an evently widget (also named addressbook but the names don't really have to match, its not a requirement) which we will be writing later in this tutorial.
      
3. The Evently approach also mandates a rewrite of Ed's refreshAddressbook function such that the html and javascript are placed in separate files and tied together via the use of the Mustache template engine. So instead of injecting any more javascript into your index.html, follow these steps:
   
   1. Navigate to the addressbook directory, which was generated by couchapp for you when you ran, in the past:
      

      couchapp generate app addressbook
      cd addressbook
      

   2. Create an evently widget named addressbook by simply creating the appropriate directory structure:
      

      mkdir -p evently/addressbook/
      

   3. Create _query.js file to hold the view which should be loaded from CouchDB when the addressbook div element is hooked-up with the addressbook widget (refer to line # 19 in index.html source provided earlier):
      

      function () {
        $.log('Inside evently/addressbook/_init/query.js');
      
        return {
          "view" : "phonenumbers",
        };
      }

   4. Create data.js file to process the data returned by CouchDB which will be available for the Mustache template engine's use:
      

      function(data) {
        $.log('Inside evently/addressbook/_init/data.js');
        $.log(data.rows);
        return {
          "addressbook" : data.rows
        };
      }

   5. Create mustache.html file to substitute the data and render the html directly into the addressbook div element:
      

      {{#addressbook}}
      <div class="address">
        <span class="name">{{key}}</span>
        <span class="phonenumber">{{value}}</span>
        <a href="#edit" class="edit">edit</a>
        <a href="#delete" class="delete">delete</a>
      </div>
      {{/addressbook}}
      

   6. Uplaod the app:
      

      couchapp push

   7. Before we go any further let's test what we've written so far. You'll notice that I've thrown in logs and alerts into the javascript above. If all is well then we should see an alert pop up with the data being retrieved from the server. Also if you have debugging tools like Firebug or Web Inspector at your disposal, then you should be able to see the data printed out in the console.
      
      1. Safari and Firefox on my mac work well and I hope that you too see a popup stating [object Object] and your console output looks something like:
         

         Entering view callback in evently/addressbook/_init.js
         jquery...util.js (line 3)
         Object { total_rows=2, offset=0, rows=[2]}
         jquery...util.js (line 3)
         Exiting view callback in evently/addressbook/_init.js
         

      2. B U T ... if you head over to your iPhone's safari browser and try the same thing, you may be in for a huge disappointment! Nothing will happen. And if you enable the Debug Console, you'll see javascript errors stating that jQuery does not exist!
         
         • If you run into this then based on the wisdom gleaned from this post on stackoverflow, here's what you need to do:
           
           1. Get all the supporting JS files listed under the _utils URL to be directly present in your own addressbook couchapp:
              

              cd vendor/couchapp/_attachments/
              wget http://fermyon.iriscouch.com/_utils/script/jquery.couch.js
              wget http://fermyon.iriscouch.com/_utils/script/sha1.js
              wget http://fermyon.iriscouch.com/_utils/script/json2.js
              wget http://fermyon.iriscouch.com/_utils/script/jquery.js
              

           2. Update loader.js to serve the files out of your own addressbook couchapp:
              

              vi vendor/couchapp/_attachments/loader.js
              

              ...
              couchapp_load([
                "vendor/couchapp/sha1.js",
                "vendor/couchapp/json2.js",
                "vendor/couchapp/jquery.js",
                "vendor/couchapp/jquery.couch.js",
                "vendor/couchapp/jquery.couch.app.js",
                "vendor/couchapp/jquery.couch.app.util.js",
                "vendor/couchapp/jquery.mustache.js",
                "vendor/couchapp/jquery.evently.js"
              ]);
              

         • If things are still breaking then there is one other analysis & workaround for this dilemma presented here in a blog post by Lee Boonstra.
         • If you are still having issues then use the Safari on your Mac's iOS Simulator to browse the couchapp because it gives more detailed information in its Debug Console than the actual browser on the iPhone. If you are still seeing something like the following image:
           
           
           Then you still haven't fixed the problem as described in the steps above so go back and make sure you follow all the instructions to get it resolved.
   8. Now lets finish off editing _init.js:
      

      put code here...
      

4. mustache stuff