Coderguy's Blog » Quick Tip

jQuery Ajax Call Return Value

coderguy — Wed, 23 Jun 2010 20:12:09 +0000

I found myself needing a really quick way to do an ajax call and get the value returned to a single var. I did a lot of searching and found a lot of convoluted responses that involved callbacks. Using callbacks would be overkill for what I was doing. After much searching I finally found this jQuery API comment. The comment explains how to just get a single value returned from an ajax call. Here is the key points:

Make sure the call is synchronized. (async: false) This will allow you to wait for the response and not assign a blank value.
Understand that when you make the $.ajax() call this the data that is normally passed to the callbacks is stored in $.ajax().responseText.

var response = $.ajax({ type: "GET", url: "check.php", async: false }).responseText;

Show Forgein Keys in MySQL

coderguy — Wed, 25 Nov 2009 15:20:19 +0000

Here is a handy query I found the mysql reference manual for how to see all the foreign keys in a database:

SELECT ke.referenced_table_name parent, ke.table_name child, ke.constraint_name
FROM information_schema.KEY_COLUMN_USAGE ke
WHERE ke.referenced_table_name IS NOT NULL
ORDER BY ke.referenced_table_name;

Couchdb CURL gotcha

coderguy — Mon, 05 Oct 2009 16:04:19 +0000

So this is one of those stupid little development issues that eats up an hour of your time. I am documenting this in hopes that it will save someone from wasting an hour of your time.

I am learning couchdb and using curl to interact with it’s RESTful api. I wrote a view and was trying to limit it by a key. I was issuing the commands:

curl -X GET http://127.0.0.1:5984/blog/_design/posts/_view/by_author?key="rob"

I was getting a 500 error for invalid json. When I pasted the URL in the web browser I got a valid response. The problem was that you needed to escape the quotes on the curl call as %22 not “.

curl -X GET http://127.0.0.1:5984/blog/_design/posts/_view/by_author?key=%22rob%22

Keep in mind you only have to put the quotes around string values a not around numeric values.

Get the Mime Type of a File

coderguy — Thu, 06 Aug 2009 15:30:57 +0000

If you would like to know the mime type of the file you can use the file command with the -i -b options. Example:

> file -i -b 20090731.flv

application/octet-stream

PHP Session Numeric Key Bug

coderguy — Wed, 08 Jul 2009 16:03:07 +0000

I was working on a 404 page today. The pages that detected the 404 and routed it to the 404 page, would try and set the $_SESSION['404'] variable. After setting the variable I was able to use it on that page. However, after the redirect the variable was missing. I could set other variables, and they would remain from page to page. I put in some extra debugging and received the message:

Notice: Unknown: Skipping numeric key 404

This lead me to rename my variable to $_SESSION['url404'], which would stay set on the redirect. I have not found any documentation that says that numeric keys are illegal for sessions vars, but I believe it to be the case.

Hope this saves you time in your PHP coding.

Refresh MySQL Autocomplete: \#

coderguy — Thu, 25 Jun 2009 20:16:30 +0000

Here is nifty little tip. If you need to have your command line MySQL autocomplete enabled or refresh the just type \# at the command line.

mysql>\#

This is great for those times when you creating a lot of tables.