Wednesday, February 21, 2018

Using the Slack webhook API from PL/SQL

Slack is a web-based chat room popular with many companies. Slack also has an API that can be used to post messages to a given "channel" or chat room. The simplest API offered is the "webhook" integration, which is "a simple way to post messages from external sources into Slack. They make use of normal HTTP requests with a JSON payload that includes the message text and some options."



To create a new Slack webhook, login to Slack and go to "Apps" in the left sidebar menu. Click "Manage apps..." and click "Custom Integrations" and then "Incoming Webhooks". Click on "Add Configuration" to create a new webhook. Specify the channel the webhook will post in, and click "Add incoming webhooks integration".


Next, take a note of the Webhook URL:



Then go to the Alexandria PL/SQL Utility Library and install the SLACK_UTIL_PKG package in your database schema. Modify your database Network ACL settings to include "hooks.slack.com" (port 443) to allow connections to the Slack site from the database.

Then use the package like this (see also demo script):



In addition to application-specific messages you could perhaps also set up the database (via a background job) to notify you when you are about to run out of disk space, when the number of APEX page views reach a certain threshold, when a specific user logs in, and so on. Use your imagination! :-)





Saturday, February 10, 2018

Pivot Table plugin for APEX (Updated)

Some years ago I created an APEX region plugin for displaying the results of a query as a Pivot Table. You can read the original blog post about that here.

The plugin proved quite popular, but people were having problems using it with APEX 5 due to a jQuery versioning conflict.

I've now updated the plugin so it works with APEX, both 5.0 and 5.1.



To use it, simply add a region to the page, change the region type to "Pivot Table" and write an SQL query as the region source:



On the region attributes page, specify the options. I've added some help text to explain the various options. Note that you can have more than one Pivot Table region on the same page, but be sure to use a unique name in the "DOM Element Name" attribute for each pivot table.


I've also added/enabled some extra features such as spreadsheet export (via TSV - tab separated values) and charting.



It should be noted that the plugin is just an APEX wrapper for the Javascript Pivot Table component by Nicolas Kruchten who did all the hard work. I merely packaged it up for use with APEX.

You can download the plugin from my APEX plugins page. Enjoy! :-)