Ten pitfalls for framework developers #

This page is for developers in their first weeks with Exponential. Each pitfall comes from a habit that is right in another framework and wrong here.

Contents #

1. Printing without wash
2. A new class is "not found"
3. A setting does not take effect
4. A template change does not show
5. State leaks between requests
6. Writing SQL into content tables
7. A table for what should be content
8. Checking permissions only in templates
9. Forgetting the siteaccess on the command line
10. Comparisons with symbols

1. Printing without wash #

Symptom: text with < or & breaks the page, or a script runs. Cause: templates do not escape automatically. Fix: {$value|wash} on everything from users or the database (The view layer).

2. A new class is "not found" #

Cause: classes are found through generated class maps, not by PSR-4 for extension classes. Fix: php bin/php/ezpgenerateautoloads.php -e, then deploy; --kernel for kernel classes (Autoloads and class naming).

3. A setting does not take effect #

Causes: the INI cache; or the value is overridden by a later layer, for example an extension's global settings win over settings/siteaccess/. Fix: ./console exp:ini where <file>/<block>/<key> <siteaccess>, then php bin/php/ezcache.php --clear-tag=ini (Configuration).

4. A template change does not show #

Causes: the view cache, a cache block, or the override cache for a new template file. Fix: clear template-override after adding a template file, clear content and template-block when cached output is stale; exp:velocity deploy does all of it in order (Caching).

5. State leaks between requests #

Symptom: one user sees another user's data, or a listener runs twice, only under Velocity. Cause: persistent workers keep static properties and attached listeners. Fix: no per-request state in statics; register listeners in settings (Servers and deployment).

6. Writing SQL into content tables #

Symptom: a change does not appear, or appears without history, search or cache updates. Cause: content tables are not your tables. Fix: eZContentFunctions or the operations, which run workflows and clear caches (The content model).

7. A table for what should be content #

Symptom: you are building an admin screen, a revisions table and a translations table. Fix: make it a content class and get all three (ORM).

8. Checking permissions only in templates #

Cause: hiding a link is not access control. Fix: name the function in the view's functions, check object access in the view, filter lists in the query (Authorization).

9. Forgetting the siteaccess on the command line #

Symptom: a command or cron part cannot find your module, setting or job type. Cause: your extension is active only in a siteaccess. Fix: -s <siteaccess> (Command line).

10. Comparisons with symbols #

Symptom: an {if} behaves randomly and the log shows a parser error. Cause: the template language has no infix operators. Fix: gt, lt, eq, ne, and, or (No infix comparison).

Related pages #

• Checklists for framework developers
• Common template mistakes
• When something goes wrong
• Free documentation: this page is free to copy, translate and improve under the GNU FDL 1.3.