I am building my first sailsjs and nodejs application, and it great :)
My situation, I have about 100 tables with the same stucture, I would like to decide "on the fly" which table to load.
my first thought was use somehow a dynamic class names. But I dont know how to do this with nodejs, maybe some one have an idea.
So I would create 100 "modelName".js files in my models folder.
I can use this in browser
window["fileName"].find()....
But I don't have any window object in nodejs
Second idea was to pass the tableName to the model, the problem is, I have to reinit the model, don't know how.
Any solutions?
Found a solution
var modelName = req.param('p');
this[modelName].find()...
Own answer by author is correct, but I will add something just for people who will use it in the future - you can get modelName from req.options.model when you are using Blueprints.
Unfortunately you can't use this[modelName] as option is giving you model name starting with small letter, so first you have to upper case first letter with e.g. var modelName = req.options.model.charAt(0).toUpperCase() + req.options.model.slice(1);
and then you are free to use this[modelName].whateverYouNeed
I used it for generic policy to let user editing only his own group elements.
var modelName = req.options.model.charAt(0).toUpperCase() + req.options.model.slice(1)
var elementID = null
if (req.params.id) { // To handle DELETE, PUT
elementID = req.params.id
}
if (req.body.id) { // To handle POST
elementID = req.body.id
}
this[modelName].findOne({
id: elementID
}).exec(function(err, contextElement) {
if(err) {
return res.serverError(err)
}
if(contextElement.group=== req.user.group.id) {
sails.log('accessing own: ' + modelName)
return next()
}
else {
return res.forbidden('Tried to access not owned object')
}
})
An alternative:
sails.models[Model].findOne({...})
Make sure to have your "Model" name as string in lowercase. It works like accessing a property inside an object
Another option that worked for me:
var modelName = "User";
global[modelName].find()....
Related
This is a really trivial problem. I am just curious on how to deal with this in a "professional" manner.
I am trying to stick to variable naming convention. For NodeJs I am doing camelCasing. For database, I am using PostgreSQL and using underscore_casing.
Now the problem arises when I query data from PostgreSQL. I'll get a user object with following format,
{user_id: 1, account_type : "Admin"}
I can pass this object directly to server side-render and will have to use underscore casing to access account_type. Of course, I can manually create a new user JSON object with property userId and accountType but that is unnecessary work.
Is it possible to follow variable naming convention for both language and avoid having mixed variable names casing in some files? What is a good way to stay organized?
The are two good ways to approach this issue. The simplest one - do no conversion, use the exact database names. And the second one is to camel-case columns automatically.
Either way, you should always follow the underscore notation for all PostgreSQL declarations, as it will give you the option to activate camel-casing in your app at a later time, if it becomes necessary. Never use camel-case inside the database, or you will end up in a lot of pain later.
If you want the best of both worlds, follow the underscore notation for all PostgreSQL declarations, and convert to camel-case as you read data.
Below is an example of how to do it properly with pg-promise, copied from event receive example:
// Example below shows the fastest way to camelize column names:
const options = {
receive(e) {
camelizeColumns(e.data);
}
};
function camelizeColumns(data) {
const template = data[0];
for (var prop in template) {
const camel = pgp.utils.camelize(prop);
if (!(camel in template)) {
for (var i = 0; i < data.length; i++) {
const d = data[i];
d[camel] = d[prop];
delete d[prop];
}
}
}
}
Also see the following article: Pg-promise and case sensitivity in column names.
UPDATE
The code above has been updated for use of pg-promise v11 or later.
I've struggled with this too, and I've concluded that there's really no way to avoid this kind of ugliness unless you rewrite the objects that come from the database. Fortunately, that's not too difficult in Javascript:
const fromDBtoJS = (obj) => {
// declare a variable to hold the result
const result = {};
// iterate over the keys on the object
Object.keys(obj).forEach((key) => {
// adjust the key
const newKey = key.replace(/_[a-z]/g, (x) => x[1].toUpperCase());
// add the value from the old object with the new key
result[newKey] = obj[key];
});
// return the result
return result;
};
Here's a JSFiddle. The "replace" code above was found here
If you wanted to use classes for models in your application, you could incorporate this code into the constructor or database load method so it's all handled more-or-less automatically.
I have been searching for hours, but I cannot find anything about this.
Situation:
Backend, existing of NodeJS + Express + Mongoose (+ MongoDB ofcourse).
Frontend retrieves object from the Backend.
Frontend makes some changes (adds/updates/removes some attributes).
Now I use mongoose: PersonModel.findByIdAndUpdate(id, updatedPersonObject);
Result: added properties are added. Updated properties are updated. Removed properties... are still there!
Now I've been searching for an elegant way to solve this, but the best I could come up with is something like:
var properties = Object.keys(PersonModel.schema.paths);
for (var i = 0, len = properties.length; i < len; i++) {
// explicitly remove values that are not in the update
var property = properties[i];
if (typeof(updatedPersonObject[property]) === 'undefined') {
// Mongoose does not like it if I remove the _id property
if (property !== '_id') {
oldPersonDocument[property] = undefined;
}
}
}
oldPersonDocument.save(function() {
PersonModel.findByIdAndUpdate(id, updatedPersonObject);
});
(I did not even include trivial code to fetch the old document).
I have to write this for every Object I want to update. I find it hard to believe that this is the best way to handle this. Any suggestions anyone?
Edit:
Another workaround I found: to unset a value in MongoDB you have to set it to undefined.
If I set this value in the frontend, it is lost in the REST-call. So I set it to null in the frontend, and then in the backend I convert all null-values to undefined.
Still ugly though. There must be a better way.
You could use replaceOne() if you want to know how many documents matched your filter condition and how many were changed (I believe it only changes one document, so this may not be useful to know). Docs: https://mongoosejs.com/docs/api/model.html#model_Model.replaceOne
Or you could use findOneAndReplace if you want to see the document. I don't know if it is the old doc or the new doc that is passed to the callback; the docs say Finds a matching document, replaces it with the provided doc, and passes the returned doc to the callback., but you could test that on your own. Docs: https://mongoosejs.com/docs/api.html#model_Model.findOneAndReplace
So, instead of:
PersonModel.findByIdAndUpdate(id, updatedPersonObject);, you could do:
PersonModel.replaceOne({ _id: id }, updatedPersonObject);
As long as you have all the properties you want on the object you will use to replace the old doc, you should be good to go.
Also really struggling with this but I don't think your solution is too bad. Our setup is frontend -> update function backend -> sanitize users input -> save in db. For the sanitization part, we use a helper function where we integrate your approach.
private static patchModel(dbDocToUpdate: IModel, dataFromUser: Record<string, any>): IModel {
const sanitized = {};
const properties = Object.keys(PersonModel.schema.paths);
for (const key of properties) {
if (key in dbDocToUpdate) {
sanitized[key] = data[key];
}
}
Object.assign(dbDocToUpdate, sanitized);
return dbDocToUpdate;
}
That works smoothly and sets the values to undefined. Hence, they get removed from the document in the db.
The only problem that remains for us is that we wanted to allow partial updates. With that solution that's not possible and you always have to send everything to the backend.
EDIT
Another workaround we found is setting the property to an empty string in the frontend. Mongo then also removes the property in the database
I'm doin a simple query linq to retrieve a label from an optionSet. Looks like the formatted value for the option set is missing. Someone knows why is not getting generated?
Best Regards
Sorry for the unclear post. I discovered the problem, and the reason of the missing key as formattedvalue.
The issue is with the way you retrieve the property. With this query:
var invoiceDetails = from d in xrmService.InvoiceSet
where d.InvoiceId.Value.Equals(invId)
select new
{
name = d.Name,
paymenttermscode = d.PaymentTermsCode
}
I was retrieving the correct int value for the option set, but what i needed was only the text. I changed the query this way:
var invoiceDetails = from d in xrmService.InvoiceSet
where d.InvoiceId.Value.Equals(invId)
select new
{
name = d.Name,
paymenttermscode = d.FormattedValues["paymenttermscode"]
}
In this case I had an error stating that the key was not present. After many attempts, i tried to pass both the key value and the option set text, and that attempt worked just fine.
var invoiceDetails = from d in xrmService.InvoiceSet
where d.InvoiceId.Value.Equals(invId)
select new
{
name = d.Name,
paymenttermscode = d.PaymentTermsCode,
paymenttermscodeValue = d.FormattedValues["paymenttermscode"]
}
My guess is that to retrieve the correct text associated to that option set, in that specific entity, you need to retrieve the int value too.
I hope this will be helpful.
Best Regards
You're question is rather confusing for a couple reasons. I'm going to assume that what you mean when you say you're trying to "retrieve a label from an OptionSet" is that you're attempting to get the Text Value of a particular OptionSetValue and you're not querying the OptionSetMetadata directly to retrieve the actual LocalizedLabels text value. I'm also assuming "formatted value for the option set is missing" is referring to the FormattedValues collection. If these assumptions are correct, I refer you to this: CRM 2011 - Retrieving FormattedValues from joined entity
The option set metadata has to be queried.
Here is an extension method that I wrote:
public static class OrganizationServiceHelper
{
public static string GetOptionSetLabel(this IOrganizationService service, string optionSetName, int optionSetValue)
{
RetrieveOptionSetRequest retrieve = new RetrieveOptionSetRequest
{
Name = optionSetName
};
try
{
RetrieveOptionSetResponse response = (RetrieveOptionSetResponse)service.Execute(retrieve);
OptionSetMetadata metaData = (OptionSetMetadata)response.OptionSetMetadata;
return metaData.Options
.Where(o => o.Value == optionSetValue)
.Select(o => o.Label.UserLocalizedLabel.Label)
.FirstOrDefault();
}
catch { }
return null;
}
}
RetrieveOptionSetRequest and RetrieveOptionSetResponse are on Microsoft.Xrm.Sdk.Messages.
Call it like this:
string label = service.GetOptionSetLabel("wim_continent", 102730000);
If you are going to be querying the same option set multiple times, I recommend that you write a method that returns the OptionSetMetadata instead of the label; then query the OptionSetMetadata locally. Calling the above extension method multiple times will result in the same query being executed over and over.
Looking at Str::slug for my frontend URL generation but just wondering how you guys go about implementing it with routes etc, for example, how would you guys go about changing http://www.example.com/courses/1 to http://www.example.com/courses/this-course
OK, I did it this way:
// I have a slug field in my courses table and a slug field in my categories table, along with a category_id field in my courses table.
// Route
Route::get('courses/{categorySlug}/{slug?}', function($categorySlug, $slug) {
$course = Course::leftJoin('categories', 'categories.id', 'courses.category_id')
->where('categories.slug', $categorySlug)
->where('courses.slug', $slug)
->firstOrFail();
return View::make('courses.show')->with('course', $course);
});
Works like a charm. It gets the $categorySlug and $slug variables then uses them to filter the Eloquent model Course to get the correct course object from the database.
EDIT: You can generate a URL in your view like:
http://www.example.com/courses/it-training/mcse
By doing something like:
{{ $course->title }}
A have a method in my Category like below that retrieves the parent category slug. This could be better achieved though using some sort of presenter class which would allow you to simply use $course->url but I haven't got around to doing this yet. I will update the answer when I do.
public function parentCategorySlug($parentId)
{
if ($parentId === '0')
{
return $this->slug;
}
return $this->where('id', $parentId)->first()->slug;
}
You can use the cvierbrock's Eloquent-Sluggable package.
As for me I created a helper function and used the following method taken from here.
public static function getSlug($title, $model) {
$slug = Str::slug($title);
$slugCount = count( $model->whereRaw("url REGEXP '^{$slug}(-[0-9]*)?$'")->get() );
return ($slugCount > 0) ? "{$slug}-{$slugCount}" : $slug;
}
You can create a related model Slug, and approach the course in your methods like so:
$course = Slug::where('slug', $slug) -> firstOrFail() -> course;
I have also implemented a similar URL mapping but I preferred to have both the ID and the slug in the requested URL, like this:
http://www.example.com/courses/1/my-laravel-course
This method allows me to get the requested course object from the ID given in the URL, rather than having to store the slugs in my DB table.
Route::post('courses/(:num)/(:any)', function ($courseid, $slug) {
$course = Course::where('id', '=', $courseid)->get();
return View::make('courses.show')->with('course', $course);
}
For Laravel 8:
Given my URL:
http://www.example.com/courses/this-course
My route:
Route::get('/courses/{course:slug}' , function(Course $course){
return view('showCourse' , [
'course' => $course
])
})
I am using Entity Framework 5 (DBContext) and I am trying to find the best way to deep copy an entity (i.e. copy the entity and all related objects) and then save the new entities in the database. How can I do this? I have looked into using extension methods such as CloneHelper but I am not sure if it applies to DBContext.
One cheap easy way of cloning an entity is to do something like this:
var originalEntity = Context.MySet.AsNoTracking()
.FirstOrDefault(e => e.Id == 1);
Context.MySet.Add(originalEntity);
Context.SaveChanges();
the trick here is AsNoTracking() - when you load an entity like this, your context do not know about it and when you call SaveChanges, it will treat it like a new entity.
If MySet has a reference to MyProperty and you want a copy of it too, just use an Include:
var originalEntity = Context.MySet.Include("MyProperty")
.AsNoTracking()
.FirstOrDefault(e => e.Id == 1);
Here's another option.
I prefer it in some cases because it does not require you to run a query specifically to get data to be cloned. You can use this method to create clones of entities you've already obtained from the database.
//Get entity to be cloned
var source = Context.ExampleRows.FirstOrDefault();
//Create and add clone object to context before setting its values
var clone = new ExampleRow();
Context.ExampleRows.Add(clone);
//Copy values from source to clone
var sourceValues = Context.Entry(source).CurrentValues;
Context.Entry(clone).CurrentValues.SetValues(sourceValues);
//Change values of the copied entity
clone.ExampleProperty = "New Value";
//Insert clone with changes into database
Context.SaveChanges();
This method copies the current values from the source to a new row that has been added.
This is a generic extension method which allows generic cloning.
You have to fetch System.Linq.Dynamic from nuget.
public TEntity Clone<TEntity>(this DbContext context, TEntity entity) where TEntity : class
{
var keyName = GetKeyName<TEntity>();
var keyValue = context.Entry(entity).Property(keyName).CurrentValue;
var keyType = typeof(TEntity).GetProperty(keyName, System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance).PropertyType;
var dbSet = context.Set<TEntity>();
var newEntity = dbSet
.Where(keyName + " = #0", keyValue)
.AsNoTracking()
.Single();
context.Entry(newEntity).Property(keyName).CurrentValue = keyType.GetDefault();
context.Add(newEntity);
return newEntity;
}
The only thing you have to implement yourself is the GetKeyName method. This could be anything from return typeof(TEntity).Name + "Id" to return the first guid property or return the first property marked with DatabaseGenerated(DatabaseGeneratedOption.Identity)].
In my case I already marked my classes with [DataServiceKeyAttribute("EntityId")]
private string GetKeyName<TEntity>() where TEntity : class
{
return ((DataServiceKeyAttribute)typeof(TEntity)
.GetCustomAttributes(typeof(DataServiceKeyAttribute), true).First())
.KeyNames.Single();
}
I had the same issue in Entity Framework Core where deep clone involves multiple steps when children entities are lazy loaded. One way to clone the whole structure is the following:
var clonedItem = Context.Parent.AsNoTracking()
.Include(u => u.Child1)
.Include(u => u.Child2)
// deep includes might go here (see ThenInclude)
.FirstOrDefault(u => u.ParentId == parentId);
// remove old id from parent
clonedItem.ParentId = 0;
// remove old ids from children
clonedItem.Parent1.ForEach(x =>
{
x.Child1Id = 0;
x.ParentId= 0;
});
clonedItem.Parent2.ForEach(x =>
{
x.Child2Id = 0;
x.ParentId= 0;
});
// customize entities before inserting it
// mark everything for insert
Context.Parent.Add(clonedItem);
// save everything in one single transaction
Context.SaveChanges();
Of course, there are ways to make generic functions to eager load everything and/or reset values for all keys, but this should make all the steps much clear and customizable (e.g. all for some children to not be cloned at all, by skipping their Include).