In the example
var user = context.Cache.FetchObject<User>(redisKey, () =>
GetUserNameFromDatabase(id));
string GetUserNameFromDatabase(string userid)
{
return string.empty();
}
how do I prevent the string.empty result to be added to the cache.... causing it to call the function again next timeGetUserNameFromDatabase
Would be nice with some kind of check delegate, that if returns true will cause the result to be added and otherwise not.
I don't think that's needed since you can actually prevent results to being added to the cache by just returning NULL. When the invoked delegate returns NULL, no value will be added to the redis cache. Check RedisCacheProvider.cs code.
So you can do the validations in your delegate:
var user = context.Cache.FetchObject<User>(redisKey, () => GetUserNameFromDatabase(id));
string GetUserNameFromDatabase(string userid)
{
return (GetUserFromDb(userid) == String.Empty) ? null : user;
}
Related
I have a field in my database with duplicates. I want to use it in a dropdown list, which has to return distinct data.
Here is the method that I created to do this:
public IEnumerable<SelectListItem> GetBranches(string username)
{
using (var objData = new BranchEntities())
{
IEnumerable<SelectListItem> objdataresult = objData.ABC_USER.Select(c => new SelectListItem
{
Value = c.BRANCH_CODE.ToString(),
Text = c.BRANCH_CODE
}).Distinct(new Reuseablecomp.SelectListItemComparer());
return objdataresult;
}
}
Here is the class I am using:
public static class Reuseablecomp
{
public class SelectListItemComparer : IEqualityComparer<SelectListItem>
{
public bool Equals(SelectListItem x, SelectListItem y)
{
return x.Text == y.Text && x.Value == y.Value;
}
public int GetHashCode(SelectListItem item)
{
int hashText = item.Text == null ? 0 : item.Text.GetHashCode();
int hashValue = item.Value == null ? 0 : item.Value.GetHashCode();
return hashText ^ hashValue;
}
}
}
Nothing is returned and I get the error below. When I try a basic query without Distinct, everything works fine.
{"The operation cannot be completed because the DbContext has been disposed."}
System.Exception {System.InvalidOperationException}
Inner exception = null
How can I return distinct data for my dropdown?
Technically, your problem can be solved simply by appending .ToList() after your Distinct(...) call. The problem is that queries are evaluated JIT (just in time). In other words, until the actual data the query represents is needed, the query is not actually sent to the database. Calling ToList is one such thing that requires the actual data, and therefore will cause the query to be evaluated immediately.
However, the root cause of your problem is that you are doing this within a using statement. When the method exits, the query has not yet been evaluated, but you have now disposed of your context. Therefore, when it comes time to actually evaluate that query, there's no context to do it with and you get that exception. You should really never use a database context in conjuction with using. It's just a recipe for disaster. Your context should ideally be request-scoped and you should use dependency injection to feed it to whatever objects or methods need it.
Also, for what it's worth, you can simply move your Distinct call to before your Select and you won't need a custom IEqualityComparer any more. For example:
var objdataresult = objData.ABC_USER.Distinct().Select(c => new SelectListItem
{
Value = c.BRANCH_CODE.ToString(),
Text = c.BRANCH_CODE
});
Order of ops does matter here. Calling Distinct first includes it as part of the query to the database, but calling it after, as you're doing, runs it on the in-memory collection, once evaluated. The latter requires, then, custom logic to determine what constitutes distinct items in an IEnumerable<SelectListItem>, which is obviously not necessary for the database query version.
Because much of our imported data technically has validation errors, users are unable to update fields without first correcting previously entered bad data. This wouldn't be a problem except that many times this user doesn't have the information needed to enter a correct value into that field but we still need to save their update.
Is it possible to disable the validate on submit for a DynamicForm?
Is it possible to disable the validate on submit for a DynamicForm?
there's a disableValidation attribute, it disables client-side validators.
The best solution I could find thus far.
I'm disabling validation and overridding getValues, which is called as part of saveData so I manually parse through any fields and look for errors. If I find an error I remove it from the return value and store it under the valuesManager.invalidatedFields.
If a field had an error it will not be included in the save, but because the server will return the original value I had to override setValues as well to prevent your (bad) change from being overridden.
Also, because getValues is called on initial load it validates on load as well.
isc.ValuesManager.create({
disableValidation: true,
invalidatedFields: {},
setValues: function(values){
console.log("setting values..", this.invalidatedFields);
for (var key in this.invalidatedFields) {
if (this.invalidatedFields.hasOwnProperty(key)) {
values[key] = this.invalidatedFields[key];
}
}
this.Super("setValues", arguments);
},
getValues: function () {
this.invalidatedFields = [];
var data = this.Super("getValues");
for (var key in data) {
if (data.hasOwnProperty(key)) {
var form = this.getMemberForField(key);
if (form && !form.getField(key).validate()) {
console.log(key + " failed validation", data[key]);
this.invalidatedFields[key] = data[key];
delete data[key];
}
}
}
return data;
}
});
I am using Phalcon and have a model Order that has a one-to-many relationship with model OrderAddress. I access those addresses through the following function:
public function getAddresses($params = null) {
return $this->getRelated("addresses", array(
"conditions" => "[OrderAddress].active = 'Y'"
));
}
The OrderAddress model has a public property errors that I do not want persisted to the database. The problem I am having is that everytime I access the getAddresses function, it reloads the object from MySQL which completely wipes the values that I set against that property.
I really only want the OrderAddress models to be loaded once, so that each call to getAddresses doesn't make another trip to the DB- it just iterates over the collection that was already loaded.
Is this possible?
I suppose there's no such option in phalcon, so it has to be implemented in your code.
You could create an additional object property for cached addresses, and return it if it's already been initialized:
protected $cachedAddresses = null;
public function getAddresses($params = null) {
if ($this->cachedAddresses === null) {
$this->cachedAddresses = $this->getRelated("addresses", array(
"conditions" => "[OrderAddress].active = 'Y'"
));
}
return $this->cachedAddresses;
}
This could be a quick solution, but it will be painful to repeat it if you have other relations in your code. So to keep it DRY, you could redefine a 'getRelated' method in base model so it would try to return cached relations, if they already were initialized.
It may look like this:
protected $cachedRelations = [];
public function getRelated($name, $params = [], $useCache = true) {
//generate unique cache object id for current arguments,
//so different 'getRelated' calls will return different results, as expected
$cacheId = md5(serialize([$name, $params]));
if (isset($this->cachedRelations[$cacheId]) && $useCache)
return $this->cachedRelations[$cacheId];
else {
$this->cachedRelations[$cacheId] = parent::getRelated($name, $params);
return $this->cachedRelations[$cacheId];
}
}
Then, you can leave 'getAddresses' method as is, and it will perform only one database query. In case you need to update cached value, pass false as a third parameter.
And, this is completely untested, but even if there're any minor errors, the general logic should be clear.
I'm trying to load, edit and save a record with CakePHP 2.0 but I get a generic error during the save method that don't help me to understand where is the problem.
if I try with debug($this->User->invalidFields()); I get an empty array, but I get false from $this->User->save() condition.
Here is the controller action where I get the error:
public function activate ($code = false) {
if (!empty ($code)) {
// if I printr $user I get the right user
$user = $this->User->find('first', array('activation_key' => $code));
if (!empty($user)) {
$this->User->set(array (
'activation_key' => null,
'active' => 1
));
if ($this->User->save()) {
$this->render('activation_successful');
} else {
// I get this error
$this->set('status', 'Save error message');
$this->set('user_data', $user);
$this->render('activation_fail');
}
debug($this->User->invalidFields());
} else {
$this->set('status', 'Account not found for this key');
$this->render('activation_fail');
}
} else {
$this->set('status', 'Empty key');
$this->render('activation_fail');
}
}
When I try the action test.com/users/activate/hashedkey I get the activation_fail template page with Save error message message.
If I printr the $user var I get the right user from cake's find method.
Where I'm wrong?
I think the problem may be in the way you're querying for the User record. When you do this:
$user = $this->User->find('first', array('activation_key' => $code));
The variable $user is populated with the User record as an array. You check to ensure it's not empty, then proceed; but the problem is that $this->User hasn't been populated. I think if you tried debug($this->User->id) it would be empty. The read() method works the way you're thinking.
You could try using the ID from that $user array to set the Model ID first, like so:
if (!empty($user)) {
$this->User->id = $user['User']['id']; // ensure the Model has the ID to use
$this->User->set(array (
'activation_key' => null,
'active' => 1
));
if ($this->User->save()) {
...
Edit: Well another possible approach is to use the $user array instead of modifying the current model. You said that you get back a valid user if you debug($user), so if that's true you can do something like this:
if (!empty($user)) {
$user['User']['activation_key'] = null;
$user['User']['active'] = 1;
if ($this->User->save($user)) {
...
This method works in the same way as receiving form data from $this->request->data, and is described on the Saving Your Data part of the book.
I'm curious though if there's another part of your setup that's getting in the way. Can other parts of your app write to the database properly? You should also check to make sure you aren't having validation errors, like their example:
<?php
if ($this->Recipe->save($this->request->data)) {
// handle the success.
}
debug($this->Recipe->validationErrors);
I want to pass a parameter in my method call, if set (its a boolean), then return a Stateless session.
I don't want to duplicate the QueryOver code, is there a way to have it like:
public virtual IList<User> GetAllUsers(bool isStateless)
{
var query = QueryOver<User>().Where(x => x.UserType == 1).ToList();
if(isStateless)
return NHibernateHelper.Session(query);
else
return NHibernateHelper.StatelessSession(query);
}
I know the above won't work, but I hope it is clear what I am after.
The only way I know is to basically duplicate the entire queryover code, and the only different between the code blocks will be that one will use .Session and the other will use .StatelessSession.
Hoping there is a cleaner way.
var query = QueryOver.Of<User>().Where(x => x.UserType == 1);
IQueryOver<User, User> executableQuery;
if(isStateless)
executableQuery = query.GetExecutableQueryOver(NHibernateHelper.Session);
else
executableQuery = query.GetExecutableQueryOver(NHibernateHelper.StatelessSession);
return executableQuery.ToList();