Using hilite.me

I discovered that you can use hilite.me to format source code so it looks nice on blogger.

Paste the source into hilite.me. It gives you pretty html that you can paste into an html editor

print("Hello World");

Write code that uses django's settings.py file if django is installed

 

I'm writing a library file for django, and I want it to store settings in the settings.py file, which is django's default configuration location for settings. However, I still want the library to work if django isn't installed. Here's how I did it :

You can wrap an import statement in a try except block

This way, it doesn't crash if the reference doesn't exist

try:
    from django.conf import settings
except ImportError:
    pass

Test to see if the referenced object exists before using it in code

Research online said python doesn't have a direct way to check if the reference exists, so you can use a try / except block instead

try: settings
   except NameError: settings = None

Test to see if 'settings' is None

If settings exists, use the django settings.py file. Otherwise use a flat file

if settings != None:
   if not settings.configured:
      settings.configure()
      self._key_list = settings.MY_LIB_SETTINGS
   else:
      filename = "lib_api_config.txt"
      f = open(filename,"r")
      file_contents = f.read()
      f.close()
      self._key_list = json.loads(file_contents)

ArcGIS Developer Account "Hello World"

I just signed up for an ArcGIS developer account here. I'm working with the javascript developer SDK, and found some issues with the example code found in the edit api link tab

The edit api page has a sample html / javascript code that you can put on your server to display a "Hello World" type application that displays a map.

I had some issues, which I've noted above

• The api key needs to be surrounded in quotes
• The first time I loaded the page, I got a bunch of errors because I didn't expand the bottom section before I copied the code out of the editor with the "copy" button

Once I fixed these issues, I got a pretty map of highway 1 in Malibu.  Hooray!

How to Install / Uninstall VMware on SUSE

This page tells me how to unistall VMware on SUSE linux.  I was having trouble finding it.  Now I have.

Placekitten.com : Placeholder images for demos

Found a new site called placekitten.com that auto-generates placeholder images.  Just pass the image size in the url, like this : http://placekitten.com/g/200/300. 

JQuery templates and tables : use tbody tag

Lets say you have a table, and you want to hide and show a couple of rows with JQuery.  If you're obsessed with div tags, you might try something like this :

<table id="tbData">
<tr><td>Name</td><td>Phone</td></tr>
<div id="phoneList">
</div>
</table>

You set up a template like this :

<script id="phoneTmp" type="text/x-jquery-tmpl">
<tr><td>${firstname},${lastname}</td><td>${address}</td><td>${phone}</td></tr>
</script>

If you do this, your header will show up at the bottom of the table in Firefox, but Internet Explorer will hate you. Or you will hate Internet Explorer. One of those. I get confused. The solution : use tbody tags instead of div tags when you're inserting, showing, or hiding rows in a table with jquery. This forces me to break my longstanding policy of not using any html tags developed after 2000, but it's saved me a lot of headaches.

<table id="tbData">
<tr><td>Name</td><td>Phone</td></tr>
<tbody id="phoneList">
</tbody>
</table>

Click "Result", or the little "play" arrow to see what this code does

JSFiddle : Javascript example website

JSFiddle lets you create editable javascript examples similar to those found on my previous post.  You can create an account and start building examples that other people can play with.  I'm looking forward to trying it out, but for now, I'll show what their examples look like when embedded in a page.

The example window needs to be 500px wide, or it won't work. I had to mess with my blog settings and make the main window wider to get it to work.

It looks like you can't edit the code and experiment with it when the code is embedded in another page. You have to go to the main site here to do that. So it's not as great as I thought it would be. Still useful for complicated examples though.

The following is one of their default examples that uses jquery to display a message and do an animated fade after a second.  Click the "run" arrow, or the "result" tab to see what the code does.