web notes - a blog

This was the answer to a question that came in an email - "Do you know of a good XML to JSON converter?"

Obviously you need php-cli, JSON, and SimpleXML. :)

The "xml" is the name of the file that contains the XML, the output can be piped to a different file.

php -r 'echo json_encode(simplexml_load_file("xml"));'

If you would like it pretty printed, this page is really nice: http://jsonprettyprint.com/

If you are upgrading PHP from 5.3 to 5.4 for an existing application, you can use the following commands to check for parse errors.

tree -fi application | grep -E '.php|.phtml' | sed "s/^/php -l /" > files
source files > results

The output is really what comes out of stderr, which will be the parse errors.

Be sure to check out the short_open_tag directive (http://www.php.net/manual/en/ini.core.php#ini.short-open-tag).

By default <?= is enabled, to use <? for statements other than echo, you must enable the short_open_tag option in /etc/php.ini.

For years I've enjoyed http://www.oneplusyou.com/bb/html_quiz. I have never named all the tags, but I return periodically to see if I can.

For fun, I created and HTML5 version.

I still can't name all the tags.

In some cases, environment variables are used to store configuration information. If the values are referenced from different sources, such as through a web server and on the command line, it is a good idea to define them in a single place and gracefully make them available.

This is one way to set the environment variables in one place, then source them into accounts for use (CentOS 6.4):

1. Create /opt/webapp/etc/appconfig/common and put the environment variables in it

export TEST_ENV_VAR="Test Environment Variable"

2. Add these two lines to /opt/webapp/etc/sysconfig/httpd

if [ -f /opt/webapp/etc/appconfig/common ]; then
. /opt/webapp/etc/appconfig/common
fi

3. Add these two lines to /etc/sysconfig/httpd

if [ -f /opt/webapp/etc/sysconfig/httpd ]; then
. /opt/webapp/etc/sysconfig/httpd
fi

4. Add this line to /etc/httpd/conf.d/webapp.conf (webapp Apache conf file)

PassEnv TEST_ENV_VAR

4. Restart Apache with service httpd restart

5. Test with http://webapp/phpinfo.php (<?php phpinfo(); ?>

6. Add these two lines to /home/admin/.bashrc - or whatever the account is that will use the variables.

if [ -f /opt/webapp/etc/appconfig/common ]; then
. /opt/webapp/etc/appconfig/common
fi

7. Test with echo $TEST_ENV_VAR

What this does is creates a common place to store the environment variables and makes them accessible to both Apache and the shell of admin (and any other account that includes them). That way, when a script is run as a cron job or on the command line, it has the environment variables all set. If new environment variables are needed, or if they change, the common file is updated as well as any others that reference the new variables. Then you restart Apache.

The goal of this fiddle was to provide a CSS and JavaScript method to switch between a list and card or grid view.

It uses jQuery and a very simple filter that fires on keyup.

The code is commented here, you can see it run at http://jsfiddle.net/PbCV3/5/

$(document).ready(function () {

    $("#filter").keyup(function () {
        var filter = $(this).val().toLowerCase();
        var len = filter.length;
        $("li").each(function () {
            /* You may want to use indexOf instead of substring to filter */ 
            if ($(this).html().substring(0, len).toLowerCase() != filter) {
                $(this).addClass('hidden');
            } else {
                $(this).removeClass('hidden');
            }
        });
        /* Check if the list is in card view or list view */
        if ($("ul").hasClass("cards")) {
            cards();
        } else {
            list();
        }
    });
    $("#controls").delegate("button", "click", function () {
        /* The id of the button clicked corresponds to the class of the list */
        var id = $(this).attr("id");
        $("ul").removeClass();
        $("ul").addClass(id);
        if (id == "cards") {
            cards();
        } else {
            list();
        }
    });

    function cards() {
        var count = 0,
            adjacent, adjHeight, thisHeight, newHeight;
        /* The visible pseudo class is a jQuery extension */
        $("li:visible").each(function () {
            /* adjacent is the item of the list which is on the same row */
            adjacent = (count % 2) ? $(this).prev("li:visible") : $(this).next("li:visible");
            if (adjacent) {
                adjHeight = $(adjacent).height();
                thisHeight = $(this).height();
                /* The new height should be the height of the taller item */ 
                newHeight = Math.max(adjHeight, thisHeight);
                if (newHeight == thisHeight) {
                    $(adjacent).height(newHeight);
                } else {
                    $(this).height(newHeight);
                }
            }
            /* count is used to determine whether the item is on the left or right */
            count++;
        });
    }

    function list() {
        /* Restore the heights to auto */
        $("li").each(function () {
            $(this).height("auto");
        });
    }

});