Running multiple versions of Cordova 3.x

cordova, the command line interface to the Cordova development framework, is a node package. npm, the node package manager, has the concept of a ‘global’ install and ‘local’ installs. Typical installs of the cordova command line interface instruct you to perform a global installation. That is what the -g in npm install -g cordova (from the docs) means. Installing globally means that one version of cordova is available to every user on that computer, and will be installed in a system directory (for example, /usr/local/lib/node_modules, on linux). If you upgrade that one version, everyone and every project on the system will be upgraded (or forced to upgrade, depending on your perspective).

If you want to run different versions of cordova for different projects, you have to install locally. That means that all the cordova code will be installed in a local directory, rather than a system wide directory.

Why might you want do this? Any number of reasons, but primarily because the relationship between your application and a particular version of Cordova is important.

  • If your application depends on bugs or feature behavior that has changed between versions, you could need to freeze your application at a given version of Cordova, at least until you were able to update your application and test it against a newer version.
  • You could have multiple applications that were developed at different times, and the older ones could crash if upgraded (or perhaps you don’t have the time to test against the latest cordova version).
  • Applications under active development may be at the latest and greatest version of cordova, while the others may be sitting at what was the latest and greatest when they were last modified.
  • A local install will let you test your application against a new version of cordova without committing a global install, which might affect other team members, other projects, or necessitate a downgrade if the new version has issues.
  • You might be working on a platform that is not amenable to being place in a virtual machine (like iOS) and yet still want to run different versions of Cordova on the same machine.

Below, I outline steps to follow if you want to have one project using Cordova 3.3 and another using Cordova 3.1. npm view cordova lets you view the available versions–typically you want the latest minor revision (3.3.1-0.1.2 is better than 3.3.0-0.1.0). These are steps for Android, but it would be similar for any target platforms. And these steps assume you have successfully installed the target platform tools for Android previously.

mkdir cordova3.3 # or cordova3.1
cd cordova3.3 # or cordova3.1
npm install cordova@3.3.1-0.1.2 # or 3.1.0-0.2.0
mkdir project
cd project 
../node_modules/cordova/bin/cordova create test33 io.cordova.HelloWorld33 # or test31 io.cordova.HelloWorld31
cd test33 #(or test31)
../../node_modules/cordova/bin/cordova platform add android
../../node_modules/cordova/bin/cordova plugin add org.apache.cordova.device

Don’t forget to add the device feature to your config.xml

<feature name="Device">
    <param name="android-package" value="org.apache.cordova.device.Device" />

You need to update the www/js/index.js file to display your Cordova version. This is only to prove you have different versions of Cordova running on the same machine

onDeviceReady: function() {

Finally build the application and run it on your emulator:

emulator -avd avdname # start a previously created avd via the android command
../../node_modules/cordova/bin/cordova build android
../../node_modules/cordova/bin/cordova emulate android

Note that there should be no issues with running applications built with different versions of cordova on the same device–the applications are all sandboxed.

If you are often in this situation, you can create aliases that point to the correct version of the cordova command, since the results are indeterminate if you mix and match calls to different versions. For example:

alias cordova31='/path/to/cordova3.1/node_modules/cordova/bin/cordova'
alias cordova33='/path/to/cordova3.3/node_modules/cordova/bin/cordova'

Incidentally, I tried these steps out with the latest version of the android tools (version 19 of the Android build tools) with all four of the latest minor revisions of cordova: 3.0.10, 3.1.0-0.2.0, 3.2.0-0.4.0, and 3.3.1-0.1.2, and could only get the 3.1.x and 3.3.x versions to work. So another reason to do a local install is to perform a quick check to see if your platform installation is compatible with a given version of Cordova.

Do you have different versions of Cordova installed on the same machine?

Finding company phone numbers

I ran into a situation recently at work where I was trying to find the phone number of a company. Checked the company site, including the footer and contact us page, and no phone number was available.

Now, I can see why, as a small startup (which is what this company was), you would not want a phone number available. But we were doing due diligence and I thought a phone call or two would be appropriate.

So, here’s a list of places to go to find a company’s phone number, if it isn’t available on their site:

  • Dun and Bradstreet. Especially useful if the company has an iphone app, because Apple requires DNB registration for a corporate developer account.
  • Facebook often has different information than a corporate website, if they have a facebook page at all.
  • The whois database sometimes has address and phone numbers associated with a domain.
  • The Secretary of State office, for whatever state they are in. This is where business documents are file, and is worth checking.
  • Twitter. Depending on your situation, you can also just tweet them directly: “@foo, I’m looking to call you, do you have a phone number”.
  • LinkedIn, to look for people who know people who work there. This may be more or less useful based on the spheres you run in and where you live.
  • The Wayback Machine, which lets you see how websites appeared at various points in time. This is useful if the company at one point had a phone number on their website, but now does not.
  • Use the above methods on any other names you have turned up during your search, as well.

It is simply amazing what you can find on the internet with some digging. So, if you are looking to find the phone number of that company, because you need to talk to them, don’t give up.

Google Spreadsheets as REST API sources

I recently built out a read only JSON API with a Google spreadsheet as the back end data source.

Why do such a thing? I didn’t need to modify the back end, but wanted to make the data available to other software. The people who maintain this data are very comfortable using Google spreadsheets. While I could have written a custom CRUD app, this didn’t seem like a good use of time when Google spreadsheets had served us well in the past.

How did I do this? I first of all created a sanitized spreadsheet, using importrange and regexreplace. This level of indirection assures me that if the source data changes, I can adjust fairly easily. If the user managing the spreadsheet wants to rearrange columns, I can adjust my sanitized spreadsheet easily.

Then I created a Google apps script and used doGet to respond to requests and the spreadsheet service to retrieve the data. The content service lets you serve JSON with the appropriate mime type. I used qunit for Google apps script (invaluable when you are working in the loosely typed javascript world and relying on cloud resources). I also worked with the parameters to build the querying needed for our application.

Then, in order to make it look like a normal API call, I fronted the script with Varnish and did some regsub magic in my VCL file (as well as some light authentication).

This approach has the benefit of keeping everything in Google’s cloud, and allowing you to access the spreadsheet data easily.

This approach has significant limitations, however.

  • Google apps scripts calls are slow, especially when accessing spreadsheet data. Using the cache service can help.
  • You cannot return anything other than a 200 response code. None of the other response codes are available.
  • The actual content is served after a redirect, so caching it at the Varnish level is difficult (though possible), and clients must be able to follow redirects.
  • Google changes the ip of the server running the script. This is not such a big problem, unless your version of Varnish only takes IP addresses in the VCL file, not hostnames. Like ours.

Was this a good idea? Well, it let me build out the API relatively quickly without affecting the users managing the data or finding any other place to put it. But we’ll probably move away from this due to the limitations listed above. One we’ve found particularly painful is the IP address switching, which usually only shows up in our automated testing.

We’ll probably start pushing the data daily (it doesn’t change all that often) to a local JDBC database using the JDBC service and use either RestSQL or DropWizard to generate an API for it. (RestSQL is quicker, but DropWizard lets us maintain format compatibility.)

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