The Hitchhiker’s Guide to Ruby On Rails Galaxy

Records of my voyage through RoR Galaxy

Posts Tagged ‘programming’

Using ERB as a dynamic template to create a file whose contents are dynamic

Posted by arjunghosh on February 17, 2009

The following code will create a temporary file for say attaching a vcard file to email.The following code is dynamic to use ERB as a template to create the file dynamically every time with the variable “telephone”,”location”,”email” which gets binded to the ERB file and is under scope.
The code is:-

telephone = “347-27456”
location = “New Delhi”
email = “”
vcard =‘address.vcard.erb’ ){ |f| } ).result( binding )
f =“temp_file.vcf”,”wb”)
f.puts vcard

and in pastie is here


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To make text in TextArea selectable onclick of mouse

Posted by arjunghosh on April 28, 2008

I am very sure most know about this and is a very simple thing. But as I have found sometimes that small things are the one which are missed.

So wanted a quick note on – How to make the text inside a textarea selectable on mouse click.

Well, we use the Javascript event system
[def: An event in Javascript is something that happens with or on the web page ].

Specifically we use the onclick Event to achieve the above stated goal. onClick applies to buttons (submit, reset, and button), checkboxes, radio buttons, and form upload buttons.

This is how we do it:

<textarea rows="3" cols="43" name="none" onclick=";">This is the text which when clicked on will get selected</textarea>

The main syntactic sugar here is the “onclick=”;”

Here the “this” helps us to access the textarea object and then we fire the DOM event “select()”
dynamically on it, which in turns selects the text inside the textarea.
ciao until next time 🙂

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How to determine whether a request was Ajax or not?

Posted by arjunghosh on April 18, 2008

This is something I wanted to remind self also:
Never do the following:

if request.xhr?
render(:update) { |page| ... }

And instead do the following:

respond_to do |format|
format.html { redirect_to(...) }
format.js { render(:update) { |page| ... } }

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Sanity testing your code

Posted by arjunghosh on April 18, 2008

This is a very simple way of testing your code or hypothesis, but lot of people don’t do it and end up wasting lot of time on exhaustive round of bug testing.
According to Wikipedia:

A sanity test or sanity check is a basic test to quickly evaluate the validity of a claim or calculation. In mathematics, for example, when multiplying by three or nine, verifying that the sum of the digits of the result is a multiple of 3 or 9 (casting out nines) respectively is a sanity test.
In computer science it is a very brief run-through of the functionality of a computer program, system, calculation, or other analysis, to assure that the system or methodology works as expected, often prior to a more exhaustive round of testing.

In software development, the sanity test determines whether it is reasonable to proceed with further testing. Software sanity tests are commonly conflated with smoke tests. A smoke test determines whether it is possible to continue testing, as opposed to whether it is reasonable. A software smoke test determines whether the program launches and whether its interfaces are accessible and responsible (for example, the responsiveness of a web page or an input button). If the smoke test fails, it is impossible to conduct a sanity test. In contrast, the ideal sanity test exercises the smallest subset of application functions needed to determine whether the application logic is generally functional and correct (for example, an interest rate calculation for a financial application). If the sanity test fails, it is not reasonable to attempt more rigorous testing. Both sanity tests and smoke tests are ways to avoid wasting time and effort by quickly determining whether an application is too flawed to merit any rigorous testing.

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