Update from 7.1 to 7.2

This document guides you through the update from Camunda BPM 7.1.x to 7.2.0. It covers these use cases:

  1. For administrators and developers: Database Updates
  2. For administrators and developers: Full Distribution Update
  3. For administrators and developers: Application with Embedded Process Engine Update
  4. For developers: Migrating Task Forms
  5. For developers: Migrating Cockpit Plugins

This guide covers mandatory migration steps as well as optional considerations for initial configuration of new functionality included in Camunda BPM 7.2.

Noteworthy new Features in 7.2:

  • CMMN: Case Management Model And Notation (CMMN) is a modelling standard similar to BPMN that focuses on human-centric processes. Camunda BPM 7.2 implements this standard and therefore extends the database schema during upgrade. If you do not plan to use CMMN, these tables will stay empty.
  • Spin/Connect: Camunda Spin and Connect are optional Camunda extensions that ease the use of text-based data formats and connectivity in processes. Spin and Connect are separate modules that have to be explicitly added to and configured in an existing installation. This guide shows you how to enable/disable the usage of Spin and Connect.
  • Freemarker: This optional Camunda extension provides a scripting engine for the templating language Freemarker that allows to use Freemarker as scripts in process constructs.

Before migrating, decide whether you additionally want to enable Spin/Connect and Freemarker. Based on this decision, you may have to carry out additional migration steps.

No Rolling Upgrades

It is not possible to migrate process engines from Camunda 7.1 to 7.2 in a rolling fashion. This means, it is not possible to run process engines of version 7.1 and 7.2 in parallel with the same database configuration. The reason is that a 7.1 engine may not be able to execute process instances that have been previously executed by a 7.2 engine, as these may use features that were not available yet in 7.1.

Database Updates

The first step consists in updating the database.

  1. Check for available database patch scripts for your database that are within the bounds of your upgrade path. Locate the scripts at $DISTRIBUTION_PATH/sql/upgrade in the pre-packaged distribution or in the Camunda Nexus. We highly recommend to execute these patches before upgrading. Execute them in ascending order by version number. The naming pattern is $DATABASENAME_engine_7.1_patch_?.sql.

  2. Execute the corresponding upgrade scripts named

    • $DATABASENAME_engine_7.1_to_7.2.sql
    • $DATABASENAME_identity_7.1_to_7.2.sql

    The scripts update the database from one minor version to the next one and change the underlying database structure, so make sure to backup your database in case there are any failures during the upgrade process.

  3. We highly recommend to also check for any existing patch scripts for your database that are within the bounds of the new minor version you are upgrading to. Execute them in ascending order by version number. Attention: This step is only relevant when you are using an enterprise version of the Camunda BPM platform, e.g., 7.1.X where X > 0. The procedure is the same as in step 1, only for the new minor version.

Full Distribution

This section is applicable if you installed the Full Distribution with a shared process engine.

The following steps are required:

  1. Upgrade Camunda Libraries and Applications inside the application server
  2. Migrate custom Process Applications

Before starting, make sure that you have downloaded the Camunda BPM 7.3 distribution for the application server you use. It contains the SQL scripts and libraries required for upgrade. This guide assumes you have unpacked the distribution to a path named $DISTRIBUTION_PATH.

Camunda Libraries and Applications

Please choose the application server you are working with from the following list:

Custom Process Applications

For every process application, the Camunda dependencies have to be updated to the new version. Which dependencies you have is application- and server-specific. Typically, the dependencies consist of any of the following:

  • camunda-engine
  • camunda-bpmn-model
  • camunda-engine-spring
  • camunda-engine-cdi
  • camunda-ejb-client

There are no new mandatory dependencies. That means, upgrading the version should suffice to migrate a process application in terms of dependencies.

Application with Embedded Process Engine

This section is applicable if you have a custom application with an embedded process engine.

Basic Procedure

Updating an application with embedded process engineUpgrade the dependencies declared in your application’s pom.xml file to the new version. Which dependencies you have is application-specific. Typically, the dependencies consist of any of the following:

  • camunda-engine
  • camunda-bpmn-model
  • camunda-engine-spring
  • camunda-engine-cdi

Special Considerations

This section describes a change in the engine’s default behavior. While the change is reasonable, your implementation may rely on the previous default behavior. Thus, the previous behavior can be restored by explicitly setting a configuration option. Accordingly, this section applies to any embedded process engine but is not required for a successful upgrade.

Script Variable Storing

As of 7.2, the default behavior of script variables has changed. Script variables are set in e.g., a BPMN Script Task that uses a language such as JavaScript or Groovy. In previous versions, the process engine automatically stored all script variables as process variables. Starting with 7.2, this behavior has changed and the process engine does not automatically store script variables any longer. You can re-enable the legacy behavior by setting the boolean property autoStoreScriptVariables to true in your process engines’ configurations.

As an alternative, script code can be migrated by replacing all implicit declarations of process variables in scripts with an explicit call to execution.setVariable('varName', 'value').

Embedded Task Forms

Embedded form support has been redesigned in Camunda BPM 7.2 and existing forms must be migrated.

Documentation on embedded forms support in 7.2 can be found in the Embedded Forms Reference

Overview

The following APIs / behavior has changed:

  • The form-field directive has been replaced with cam-variable-name and cam-variable-type.
  • The form now has a defined lifecycle (form-loaded, variables-fetched, …) for which callbacks / event listeners can be provided.
  • In 7.1, all process instance scope variables were fetched. In 7.2 only the variables used in the form are fetched. The variables are retrieved from the task scope and its parent scopes.

In the remainder of this section, we walk through these changes in detail.

The form-field Directive

The form field directive is not supported in 7.2. HTML controls using the form-field directive need to be migrated.

The form-field directive was replaced by

  • cam-variable-name: provides the name of the variable.
  • cam-variable-type: provides the type of the variable.

The form-field Directive on Input Fields

In 7.1, the form-field directive was used on input fields of the following form

<input form-field name="[variableName]" type="[type]" />

The name Attribute

In 7.2, the HTML name attribute is not used anymore for providing the name of the process variable. In 7.2, the cam-variable-name attribute must be used:

<input name="someName"
       cam-variable-name="[variableName]" />

The type Attribute

In 7.2 the HTML type attribute is not used anymore for providing the type of the variable. Instead, the cam-variable-type attribute is used:

<input name="someName"
       type="text|checkbox|hidden|..."
       cam-variable-name="[variableName]"
       cam-variable-type="[variableType]" />

Note: The cam-variable-type attribute is only required if the variable does not yet exist. If the variable already exists in the process, the attribute is not required.

Boolean

In 7.1 a boolean input field looked like this:

<input form-field name="VAR_NAME" type="boolean" />

In 7.2 it looks like this:

<input type="checkbox"
       cam-variable-name="VAR_NAME"
       cam-variable-type="Boolean" />

String

In 7.1 a string input field looked like this:

<input form-field name="VAR_NAME" type="string" />

In 7.2 it looks like this:

<input type="text"
       cam-variable-name="VAR_NAME"
       cam-variable-type="String" />

Number

In 7.1 a number input field looked like this:

<input form-field name="VAR_NAME" type="number" />

In 7.2 it looks like this:

<input type="text"
       cam-variable-name="VAR_NAME"
       cam-variable-type="Integer|Long|Short|Float|Double" />

Date

In 7.1 a date input field looked like this:

<input form-field name="VAR_NAME" type="date" />

In 7.2 it looks like this:

<input type="text"
       cam-variable-name="VAR_NAME"
       cam-variable-type="Date" />

The form-field Directive on Select Boxes

In 7.1, select boxes had the following form:

<select form-field
        name="[variableName]"
        type="[type]"
        form-values="[optionsVarName]">
  <option value="[value]">[label]</option>
  <option value="[value]">[label]</option>
</select>

In 7.2, select boxes have the following form:

<select cam-variable-name="[variableName]"
        cam-variable-type="[type]"
        cam-choices="[optionsVarName]">
  <option value="[value]">[label]</option>
  <option value="[value]">[label]</option>
</select>

Serialized List and Map

In 7.1 a serialized java.util.List and java.util.Map instance could be used for populating the form-values="[optionsVarName]". In 7.2, this is possible in combination with the cam-choices="[optionsVarName]" directive. However, the lists and maps need to be serialized using the application/json dataformat:

Map<String, String> productTypes = new HashMap<String, String>();
productTypes.put("001", "Notebook");
productTypes.put("002", "Server");
productTypes.put("003", "Workstation");

execution.setVariable("AVAILABLE_PRODUCT_TYPES",
  objectValue(customerData)
    .serializationDataFormat(SerializationDataFormats.JSON)
    .create());

The form-field Directive on a Textarea

In 7.1 a textarea control had the following form:

<textarea form-field name="[variableName]"></textarea>

In 7.2, it has the following form:

<textarea name="someName"
          cam-variable-name="[variableName]"
          cam-variable-type="String"></textarea>

Fetching Additional Variables

In 7.1 all variables from the process instance scope were fetched. In 7.2 the form needs to declare the variables it wants to fetch. This can be achieved declaratively or programmatically.

Fetching a Variable Using cam-variable-name

If you use the cam-variable-name directive, the corresponding process variable will be fetched.

Fetching a Variable Using JavaScript

Additional variables can be fetched by hooking into the form lifecycle.

<form role="form">

Value: {{customValue}}.

<script cam-script type="text/form-script">
var variableManager = camForm.variableManager;

camForm.on('form-loaded', function() {
  // this callback is executed *before* the variables are loaded from the server.
  // if we declare a variable here, its value will be fetched as well
  variableManager.fetchVariable('customVariable');
});

camForm.on('variables-fetched', function() {
  // this callback is executed *after* the variables have been fetched from the server
  $scope.customValue = variableManager.variableValue('customVariable');

});
</script>

</form>

Cockpit Plugins

As of version 7.2, Cockpit uses updated (and unpatched) versions of AngularJS (1.2.16) and Twitter Bootstrap (3.1.1). These updates introduce breaking changes in some heavily used features, such as JS promises, modal windows and a few more things described in detail below. Confer the AngularJS changelog and the Bootstrap migration guide for details.

First of all, bootstrap.js is not used anymore (it has been replaced by the angular-ui/bootstrap project), Only the CSS parts are kept (and they are being rewritten in order to leverage less compilation and avoid unnecessary declarations).

JS Promises

The most critical change is probably the way JavaScript promises are implemented/used. If you had something like this in the 7.1 release:

SomeResource.$then(function(response) {
  var bar = response.data.something;
});

in the 7.2 release, it should look like:

// the resource returns an object having "$promise" (which has a method "then")
SomeResource.$promise.then(function(response) {
  // and the response does not have a "data" property
  var bar = response.something;
});

Dialog/Modal Windows

Also widely used in web interfaces, the dialogues (a.k.a. modal windows) were completely rewritten. With the 7.1 release, you might have something like:

// a controller to open the dialog
module.controller('YadaYada', [
        'BimBamBum', '$dialog', '$scope',
function(BimBamBum,   $dialog,   $scope) {
  var dialogInstance = $dialog.dialog({
    // and a controller for the dialog content
    resolve: {
      foo: function() {
        return $scope.foo;
      },
      bar: function() {
        return BimBamBum.bar;
      }
    },
    // for the example, I wrote the dialog controller here
    // but it was generally found in a separate file (could have been "BimBamBum" for instance)
    controller: [
    // here "dialog" is the dialogInstance and "foo" and "bar" are _resolved_ (see above)
            'dialog', 'foo', 'bar',
    function(dialog,   foo,   bar) {
      // ...
    }]
  });

  // and finally, you would have open the dialog...
  dialogInstance.open().then(function() {
    // ...
  });
}];

From 7.2 onwards - using angular-ui/bootstrap - you have something like this:

// a controller to open the dialog
module.controller('YadaYada', [
        'BimBamBum', '$modal', '$scope',
function(BimBamBum,   $modal,   $scope) {
  // calling the "open" method of the "$modal" will create an instance
  $modal.open({
    // and a controller for the dialog content
    resolve: {
      // .. you know what comes here, right?
    },
    // again, for the example, I wrote the dialog controller here
    controller: [
            '$modalInstance', 'foo', 'bar',
    function($modalInstance,   foo,   bar) {
      // ...
    }]
  });
}];

Tooltips

In the 7.1 release, you could add tool tips using a help attribute like this:

<div class="yada-yada"
     help
     help-text="The text shown when mouse comes over this DIV"
     help-placement="'top'">
  ...
</div>

With the 7.2 release, the attributes would be:

<div class="yada-yada"
     tooltip="The text shown when mouse comes over this DIV"
     tooltip-placement="top">
  ...
</div>

Note the tooltip-placement value is not wrapped between single quotes anymore.

Pagers

Pagers need special attention because you might need to adapt setup and change your HTML. But generally speaking, if you have something like this with the 7.1 release:

$scope.pages = {
  size: 10,
  total: 0,
  current: 1
};
// ...
$http.post(Uri.appUri('plugin://base/:engine/incident/count'), params).success(function(data) {
  pages.total = Math.ceil(data.count / pages.size);
});
<div paginator total-pages="pages.total" current-page="pages.current"></div>

Then you will have something like this with the 7.2 release:

$scope.pages = {
  size: 10,
  total: 0,
  current: 1
};
// ...
$http.post(Uri.appUri('plugin://base/:engine/incident/count'), params).success(function(data) {
  pages.total = data.count;
});
<pagination ng-if="pages.total > pages.size"
            class="pagination-sm"
            page="pages.current"
            ng-model="pages.current"
            total-items="pages.total"
            items-per-page="pages.size"
            max-size="7"
            boundary-links="true"></pagination>

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