Lesson 1.1: The Exponential family and choosing a path #

Every migration starts with two questions: where does the site come from, and where should it go? This lesson gives learners the map of the Exponential family and the decision table of the migration hub, so that the rest of the course always starts from the right guide.

At a glance #

Learning objectives #

After this lesson, learners can:

• name the products of the Exponential family and say which of them contain the Exponential 6 legacy kernel;
• explain the difference between the legacy kernel (INI, TPL) and the Symfony-based platforms (YAML, Twig);
• use the decision table of the migration hub to find the guide for a described site;
• apply the rule "one change at a time" to a migration plan.

Trainer's notes #

How to present it #

Source: Migrating to and from Exponential, sections 1 and 2.

1. The family (8 minutes). Show the product table of the hub (section 1.1). Do not read every row. Point out the three groups: the Exponential 6 kernel itself (and its starter), the Symfony-only platforms (Exponential Platform, DXP), and the hybrids and distributions that carry both (Platform Legacy, Nexus on its older lines). Exponential Basic is a different code base (the continuation of the classic 2.x CMS), and Exponential Velocity is an application server, not a content product.
2. What each has (5 minutes). Show the table in section 1.3: content model, templates, page building, REST, database engines. The message: the legacy kernel and the Symfony platforms share the content model (classes or content types, objects, locations) but differ in templates, configuration and custom code.
3. History, in one sentence (2 minutes). Exponential 6 is the continuation of the eZ Publish legacy kernel, a product its creator discontinued after almost 18 years. The old name appears in the migration chapters only to identify the releases learners migrate from.
4. The decision table (6 minutes). Walk through section 2 of the hub: answer the questions in order, the first "yes" gives the guide.
5. The rules of thumb (4 minutes). Content first, presentation second; one change at a time; keep every old address working; rehearse.

Common questions #

Is Exponential Platform the same as Exponential? No. "Exponential Platform" without a suffix is the Symfony-only distribution; "Exponential 6" is the legacy kernel this help belongs to. The hub has a table "The names you may have heard and what they mean" for exactly this confusion.

Which product should a new project choose? That is not a migration question. Point to the hub's decision table for migrations, and to the introduction of the installation book for new sites.

Can we change the product, the PHP version and the database engine in one go? The hub advises against it: move to the closest target first, let it settle, then change the next thing.

Is "Nexus 5" a version number? No. The numbers 2.5, 4.x or 5.x after Nexus are platform generations inside Nexus, not Nexus versions. The hub explains the release lines in section 1.2.

Pitfalls #

• Teaching from memory. Version numbers and release lines change. Always show the hub, never a slide with numbers you typed months ago.
• Getting lost in the product table. Learners need the three groups, not every package name. Keep the details for module 6.
• Promising a tool that does not exist. If a learner asks for a one-click converter from another system, the honest answer is in the hub: every guide names the real tools and where a script of your own is needed.

Hands-on exercise #

This is a paper exercise with the migration hub open in a browser or in the help center of the training installation. Work in pairs.

1. Open Migrating to and from Exponential.
2. Read section 2, Which path fits?
3. For each site below, write down the guide the decision table gives, and the first question that said "yes":
   • a site on a 4.6 release of the old legacy kernel, on PHP 5;
   • a WordPress blog with 800 posts;
   • an Ibexa 4.6 site with custom Symfony bundles, whose team wants to keep its Twig templates;
   • a hand-made HTML site of 40 pages;
   • an Exponential 6 site whose owner wants the Symfony stack but must keep the legacy admin for a year.
4. For the Ibexa 4.6 site, open chapter 16.2 and write down which Nexus line has the same generation.
5. Pick one of the five sites and write a three-step plan that follows "one change at a time".
6. Compare your answers with another pair.

Expected result #

• Each pair has a guide per site: chapter 14 (or "Older releases of this kernel"), the WordPress guide, chapter 16 then the family guide of the target, the static HTML guide, and the Platform Legacy guide.
• For the Ibexa 4.6 site the pair named the Nexus 1.2.0.x line, the 4.6 generation.
• The three-step plan changes one thing per step (for example: same generation first, then the PHP version, then the design).
• The trainer checks by asking two pairs to read their answers aloud and comparing them with the hub.

Quiz #

1. Which of these products is a different code base and data model from Exponential 6? A. Exponential Platform Legacy B. Exponential Basic C. Exponential Starter D. CJW Exponential Platform Nexus
2. What do the legacy kernel and the Symfony-based platforms share?
3. True or false: Exponential Velocity is a content product you can migrate a site to.
4. The decision table: what do you do with the questions, and when do you stop?
5. Name two of the four rules of thumb that hold for every migration path.

Further reading #

• Migrating to and from Exponential: the hub with the product table and the decision guide.
• Chapter 16.1: The two destinations: the release lines of Nexus and Platform Legacy in detail.
• Older releases of this kernel: which chapter fits which old release.

Related pages #

• Module 1: Planning a migration
• Migrating to Exponential: course overview
• Trainers: start here
• Free documentation: this page is free to copy, translate and improve under the GNU FDL 1.3.