Difference between revisions of "Scheduler"

Latest revision as of 20:47, 4 October 2011

Overview

The scheduler is used to run a series of commands in different server requests. This prevents too much load on the server and allows a long process to have a progress bar instead of simply waiting for the page to load forever. The scheduler can call commands/urls and has the ability to set a wait interval between batches. It also has the ability to render a pause/resume button along with a progress bar.

Code Update - 2011-09-27

!!! IMPORTANT: UPDATE MAY BREAK CURRENT SCHEDULER IMPLEMENTATIONS !!!

Scheduler_1_0 Modifications:

application.schedule:

1. The variable scope 'application.schedule' has been removed
2. 'application.schedule' has been replaced with the variable scope 'application.ADFscheduler'

application.ADFscheduler:

1. The Scheduler LIB now creates a persistent variable name that can be identified as a variable that was created by a component of the ADF.
2. Reduces the risk of conflicting with other custom code
3. Added a getSchedulerVars() method

Now to access the task information stored within the 'application.ADFscheduler' variable from within your Apps and/or Site code it is a best practice to call this Scheduler LIB method: application.ADF.scheduler.getSchedulerVars();

NOTE: Using the getSchedulerVars() method call from within Apps and Site Code will insure
that your code remains compatible even if this variable name changes or is moved in the future.

• It is recommended that you update any App code that uses the Scheduler to reflect these changes before the ADF 1.5 truck code is updated with these updates.

• When the ADF 1.5 trunk is updated to include these changes it is also recommended that you update any Customers that use the Scheduler components in Apps or in Site code to reflect these updates.

Usage

The scheduler can be used to call URLS directly or can run commands using ADF.utils.runCommand style arguments.

To schedule a process call the scheduleProcess command with the following arguments:

• scheduleName - Required - which we use later, if you use a duplicate name the existing schedule gets overriden and stops wherever it was running.
• commands - Required - Array of URL's or array of structures
  • If using structures the layout looks like so:

scheduleItem = StructNew();
scheduleItem.bean = "csContent";
scheduleItem.method = "populateContent";
scheduleItem.args.elementName = "My Test Element";
scheduleItem.args.data.fieldName = "fieldValue";

• scheduleParams - Optional - Structure of parameters to override.

scheduleParams = StructNew();//Default Values
scheduleParams.delay = 5; //minutes till next schedule item
scheduleParams.tasksPerBatch = 1; //how many tasks to do per iteration
scheduleParams.scheduleStart = 1; //Where in the command list to start processing
scheduleParams.scheduleStop = ArrayLen(commands); //When to stop processing (say stop at position 11)

• startProcessNow - Optional - By default the process will run its first step immediately in the current request, for faster response time to the scheduler simply change this value to false.

Now that you have the parameters that you need to know, see an example of a schedule to call http://www.google.com 4 times. You would typically have this hit a URL that does some sort of processing.

commands = ArrayNew(1);
commands[1] = "http://www.google.com";
commands[2] = "http://www.google.com";
commands[3] = "http://www.google.com";
commands[4] = "http://www.google.com";
application.ADF.scheduler.scheduleProcess("Call Google",commands);

We can also have it call a custom function:

commands = ArrayNew(1);
commands[1] = StructNew();
commands[1].bean = "myCustomBean";
commands[1].method = "myCustomMethod";
commands[1].args = StructNew();
commands[1].args.argName1 = "argValue1";
commands[2] = StructNew();
commands[2].bean = "myCustomBean";
commands[2].method = "myCustomMethod";
commands[2].args = StructNew();
commands[2].args.argName1 = "argValue1";
application.ADF.scheduler.scheduleProcess("Call Custom Command",commands);

Now that is all fine and dandy, however, how do you get a response that allows you to monitor the process? Simply add this to your output:

#application.ADF.scheduler.getScheduleHTML("Call Google")#

It will render a progress bar and give you the ability to pause/resume the process.