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Safe Expressions

TeaQL E expressions provide safe value access across nested object graphs. They are designed to reduce null-check noise and avoid fragile nested getter chains.

The Problem​

Plain Java access can become noisy when a value is several relations away:

if (item != null
    && item.getCustomOrder() != null
    && item.getCustomOrder().getCustomer() != null
    && item.getCustomOrder().getCustomer().getContactName() != null) {
    // your logic
}

The code is defensive, but it hides the value being read.

Safe Null Check​

if (E.customerOrderItem(item)
    .getCustomOrder()
    .getCustomer()
    .getContactName()
    .isNull()) {
    // your logic
}

The expression keeps the property path readable while avoiding direct nested null access.

Safe Value Evaluation​

String contactName = E.customerOrderItem(item)
    .getCustomOrder()
    .getCustomer()
    .getContactName()
    .eval();

Use eval() when you need the current value.

Empty Callback​

E.customerOrderItem(item)
    .getCustomOrder()
    .getCustomer()
    .getContactName()
    .whenIsEmpty(() -> {
        // do something
    });

This is useful for business checks, fallback behavior, or response shaping.

Enum-style Helpers​

Generated helpers can also make enum-style checks readable:

E.user(user)
    .getGender()
    .whenUserGenderIsFemale(() -> {
        // do something
    });

When to Use E​

Use E when:

  • the value path crosses multiple relations;
  • optional data is expected;
  • the logic should stay readable;
  • null checks would distract from business intent.

Use ordinary getters when the object is local, required, and simple.