Drupal 7 在Drupal7上被难住了-通过hook_form#alter添加用户配置文件_form#验证回调

我搜索、阅读、再阅读。我甚至把一个测试模块剥离到了最基本的元素

我认为这段代码应该可以工作，但是从来没有调用过验证回调。我将回调添加到表单中，但在接下来的步骤中它将消失

最终，我的目标是“验证”提交的用户名，以满足特定的业务目标。我在添加表单验证回调时遇到了困难，但我相信，一旦克服了这一障碍，其余的功能就会迎刃而解

能不能请比我聪明的人给我指出正确的方向来正确添加验证回调

<?php
/*
    Implements hook_form_alter();
*/
function mymod_form_alter($form, $form_state, $form_id) {
    // catch the user profile form.
    if('user_profile_form' == $form_id) {
        // set debug message
        drupal_set_message(t('adding validation callback in hook_form_alter()...'), 'warning');
        // add a validation callback
        $form['#validate'][] = 'mymod_user_profile_form_validate';
    }
}

/*
    Implements hook_form_<form_id>_alter();
    If mymod_form_alter() was successful, I wouldn't need this hook, it's just here for verification.
*/
function mymod_form_user_profile_form_alter($form, $form_state, $form_id) {
    // check to see if our validation callback is present
    if(!in_array('mymod_user_profile_form_validate', $form['#validate'])) {
        // our validatiation callback is not present
        drupal_set_message(t('The validation callback is missing from #validate in hook_form_[form_id]_alter()'), 'error');
        // since it's not there, try re-adding it?
        $form['#validate'][] = 'mymod_user_profile_form_validate';
    } else {
        // We should see this message, but don't.
        drupal_set_message(t('The validation callback exists!'), 'status');
    }
}

/*
    ?? Implements hook_form_validate(); (or not...) ??
*/
function mymod_user_profile_form_validate($form, $form_state) {
    // why is mymod_user_profile_form_validate() never called??
    drupal_set_message(t('Validation callback called! Whoopee! Success!'), 'status'); // This never happens!

    // if this was working, we would do a bit of logic here on the username.  
    //for this test, let's assume we want to return an error on the username field.
    form_set_error('name', t('Blah, blah, blah, something about your username...'));
}

---

变量
$form
和
$form\u state
应该是这样的，以便钩子函数可以实际修改它们（否则函数只需获得一个副本）

您需要使用函数签名中变量参数之前添加的
&
（与号）符号：

function mymod_form_alter(&$form, &$form_state, $form_id) {
  # $form is referenced from the global scope using '&' symbol
  $form['#validate'][] = 'mymod_user_profile_form_validate';
}

感谢您的解释，包括通过参考链接！这正是我所需要的！