I did a google search, but I could not find what I really need.
I need to query an API, which have the same route, but with different parameters.
Example:
router.get('/items/:query, function(){})
In this case, I would search for all items
router.get('/items/:id, function(){})
Here, I would look for a specific item
At the core of your issue is that you are trying to specify two different resources at the same location. If you design your API to adhere to restful principles you'll see why that's not a wise choice. Here are two good starting points:
https://en.wikipedia.org/wiki/Representational_state_transfer
http://www.restapitutorial.com/lessons/whatisrest.html
In restful api's the root resource represents the item collection:
/api/items
...and when you specify an id that indicates you want only one item:
/api/items/abc123
If you really still want to accomplish what you asked in your question you'll need to add a url parameter like /items/query?query=true or /items/abc123?detail=true but this will be confusing to 99% of web developers who ever look at your code.
Also I'm not sure if you really meant this, but when you pass a variable named "query" to the server that seems to indicate that you're going to send a SQL query (or similar data definition language) from the client into the server. This is a dangerous practice for several reasons - it's best to leave all of this type of code on your server.
Edit: if you really absolutely positively have to do it this way then maybe have a query parameter that says ?collection=true. This would at least be understood by other developers that might have to maintain the code in future. Also make sure you add comments to explain why you weren't able to implement rest so you're not leaving behind a bad reputation :)
The issue is that without additional pattern matching there isn't a way Express will be able to distinguish between /items/:query and /items/:id, they are the same route pattern, just with different aliases for the parameter.
Depending on how you intend to structure your query you may want to consider having the route /items and then use query string parameters or have a separate /items/search/:query endpoint.
Related
I use MEAN stack to develop an application.
I'm trying to develop a restful API to get users by first name or lastname
Should I write one get function to get the users for both firstname and lastname?
What is the best practice to write the URL to be handled by the backend?
Should I use the following?
To get user by firstname: localhost:3000/users?firstname=Joe
To get user by name:localhost:3000/users?firstname=Terry
And then check what is the parameter in my code and proceed.
In other words,What is the best practice if I want to pass one of multiple parameters to restful API and search by only one parameter?
Should I use content-location header?
There is no single best practice. There are lots of different ways to design a REST interface. You can use a scheme that is primarily path based such as:
http://myserver.com/query/users?firstname=Joe
Or primarily query parameter based:
http://myserver.com/query?type=users&firstname=Joe
Or, even entirely path based:
http://myserver.com/query/users/firstname/Joe
Only the last scheme dictates that only one search criteria can be passed, but this is likely also a limiting aspect of this scheme because if you, at some time in the future, want to be able to search on more than one parameter, you'd probably need to redesign.
In general, you want to take into account these considerations:
Make a list of all the things you think your REST API will want to do now and possibly in the future.
Design a scheme that anticipates all the things in your above list and feels extensible (you could easily add more things on to it without having to redesign anything).
Design a scheme that feels consistent for all of the different things a client will do with it. For example, there should be a consistent use of path and query parameters. You don't want some parts of your API using exclusively path segments and another part looking like a completely different design that uses only query parameters. An appropriate mix of the two is often the cleanest design.
Pick a design that "makes sense" to people who don't know your functionality. It should read logically and with a good REST API, the URL is often fairly self describing.
So, we can't really make a concrete recommendation on your one URL because it really needs to be considered in the totality of your whole API.
Of the three examples above, without knowing anything more about the rest of what you're trying to do, I like the first one because it puts what feels to me like the action into the path /query/users and then puts the parameters to that action into the query string and is easily extensible to add more arguments to the query. And, it reads very clearly.
There are clearly many different ways to successfully design and structure a REST API so there is no single best practice.
a portion of my application involves creating tests (i.e., picking x-number of questions from a filtered set of questions). The user is able to determine how big they want the test but to do so I need to calculate on the server how many questions are available. The function which creates the test is sent through this post:
app.post('/user/create_test', users.create_test);
As the user changes filters, I would like to determine the number of questions available... All I can think of is to use AJAX post to send the filter information but it will be passed to the same function as creating a test would... is there any way to post to the same URL but determine which function you execute?
Consider creating another function. - The best way to do Restful API's.
Consider renaming to app.post('/user/test').
The second function could be app.post('/user/test/filters').
Or make a single POST request and make sure your function does both creating and filtering.
In general, the design of the app lacks maturity. Rethink the client-server communications.
I'm not sure how to put this right.
I need to use yii to create an application which needs to use objects and fields.
Let's say that in my app I want to have those three objects: Computers, Servers, IPs. Each of these three objects will have it's own attributes:
Computer: CPU, Motherboard, Video adapter, IP (related to the object IP), Aquisition Date
Servers: Name, IP (related to object IP), etc...
IP: IP Address.
As you can see I also need a way to link my objects between them.
Every kind of attribute (object field) must be treated in it's own way, after it's own type. For example, we have a field called CPU which can be in a list of values. We have Aquisition Date and it must be treated like a date.
Well, the problem is that I need an extension to help me in creating those object types and setting their attributes. I don't know how to search for something appropriate.
Implementing this functionalities will take me a lot of time which I don't have right now. If there are no extensions, do you have any solution to implement one? I have some ideas for creating classes for every user field, classes which will implement an interface that render the methods properly for insert, update, etc.
Thank you!
You don't need any extension if you use Yii. You'd rather yake some time to read the tutorials. My advice is to begin with Larry Ullman's Learning Yii Series and then to go to the Definitive Guide
Once you have set your database and build your tables, you will only have to activate the Gii component of Yii framework and to use it's automated code generators to build your basic models, views and controllers.
The only thing you've left will be customization, of course. Yii + Gii save you all the repetitive work. But... read the docs.
[EDIT] after the OP comment below.
Is it an EAV model that you are looking for ? There is an unofficial Yii extension dealing with that : EAV Behavior. I have no idea whether it's good or not, as I definitely avoid to work with EAV databases. Let us know your opinion if you try to use it.
I'm looking into converting part of an large existing VB6 system, into .net. I'm trying to use domain driven design, but I'm having a hard time getting my head around some things.
One thing that I'm completely stumped on is how I should handle complex find statements. For example, we currently have a screen that displays a list of saved documents, that the user can select and print off, email, edit or delete. I have a SavedDocument object that does the trick for all the actions, but it only has the properties relevant to it, and I need to display the client name that the document is for and their email address if they have one. I also need to show the policy reference that this document may have come from. The Client and Policy are linked to the SavedDocument but are their own aggregate roots, so are not loaded at the same time the SavedDocuments are.
The user is also allowed to specify several filters to reduce the list down. These to can be from properties that are stored on the SavedDocument or the Client and Policy.
I'm not sure how to handle this from a Domain driven design point of view.
Do I have a function on a repository that takes the filters and returns me a list of SavedDocuments, that I then have to turn into a different object or DTO, and fill with the additional client and policy information? That seem a little slow as I have to load all the details using multiple calls.
Do I have a function on a repository that takes the filters and returns me a list of SavedDocumentsForList objects that contain just the information I want? This seems the quickest but doesn't feel like I'm using DDD.
Do I load everything from their objects and do all the filtering and column selection in a service? This seems the slowest, but also appears to be very domain orientated.
I'm just really confused how to handle these situations, and I've not really seeing any other people asking questions about it, which masks me feel that I'm missing something.
Queries can be handled in a few ways in DDD. Sometimes you can use the domain entities themselves to serve queries. This approach can become cumbersome in scenarios such as yours when queries require projections of multiple aggregates. In this case, it is easier to use objects explicitly designed for the respective queries - effectively DTOs. These DTOs will be read-only and won't have any behavior. This can be referred to as the read-model pattern.
I have certain objects in my domain which are not aggregate roots/entities, yet I still need to retrieve them from a database. I don't want to confuse things by creating repositories for these things. So, what are alternative data access patterns? Would you simply create a DAO for them, while still of course separating the interface?
Edit:
Some more detail on what I'm doing. I need to create a code. This code has certain rules as to its format. One of the rules is that the final character must be a unique number incremented by one from the last code generated. For example:
ABCD1
ABCD2
ABCD3
So, I'm keeping a table with one row, one column to store the number in question. Now, I don't want to consider this number an entity and create a repository for it - that's overkill. I just need a way of retrieving the number, adding 1 to it, and saving it. I know there are myriad ways I could do it, but I'm wondering if there's an customary way.
There are several data access patterns that could apply, in theory. You'd need to provide more detail though if you want us to suggest a specific pattern.
Without more detail, all I can suggest is to consider looking into Martin Fowler's Patterns of Enterprise Application Architecture book.
Edit: Customary way? No, not that I can think of - it really depends on where and how you're using this unique code in your domain. If I were doing this, I'd probably create a small service that speaks directly to the database to perform this function - not as heavy-weight as a repository, and very focused on the problem at hand.
Based on the edit: I would look first at the context in which you need to create that code. Perhaps there are some related entities or something that you are missing.
btw, I find the question really interesting as it comes up from time to time while coding specific features. I usually end up finding I was missing something on the scenario and it ends up fitting well with the normal repository pattern.
After surveying the options I'm going with the Table Gateway pattern.