I need a help from you about REST Arch.
I've a resource and I can retrieve it with the classical GET /resource/ID URI, but this resource has an alias and someone want to GET this resource by calling it via alias.
There is a good way to do so by calling a GET /resource/?alias=x, take the ID and then go to the details /resource/ID.
Do you have any good idea about other ways to do this?
Thanks in advance
There is nothing wrong with a resource having two URIs (or two URIs pointing to the same resource, to put it another way). For example
GET www.myweatherapi.com/2013/11/18/rainfall
GET www.myweatherapi.com/today/rainfall
can both point to the same resource. You could say the latter is an alias of the former, or vice versa, it doesn't really matter, they both identify the same resource. You don't need to start explicitly labeling something as an alias of something else.
If the alias is temporary and may be gone in the future you could use the 307 response, temporary redirect. This tells the client that they should go to a different URI to find the resource, but not to assume that will be true in the future (eg limit how long you cache this).
As an aside, the client should not construct URIs, the server should return a content type format (HTML, JSON etc) that contains a way to identify the resources the client wants along with the URI of where to find them. For example a link in HTML saying "Todays Rainfall" with the URI to that resource. The user follows that link if they want todays rainfall
If you want to stay within the constraints of the REST architecture, you definitely need to stay with the verb GET. You can't add other methods.
Now you need to decide how the resource is named. You have a canonical name (your id), and an alias. One approach is to set up the controller for
GET /things/:id
so that :id can be either the canonical id or the alias. So you'd have
app.get('/resources/id', function (req, res) {
var id = req.params.id;
if (isAlias(id)) id = resolveAlias(id);
Thing.findById(id, null, function (err, thing) {
if (err) res.json(400, err)
if (thing === null) res.json(404, {"No such id": id})
res.json(thing)
});
});
You can also put in the alias as a query parameter, like you suggested.
I suspect the only other way might be to use a different url (somethng other than things) but I think this is disingenuous because you want to return the same representation whether or not you use the id or the alias. It should be the same controller, and you should be using GET, so I believe you need to go with the path parameter or query parameter.
This choice is independent of query rewriting, by the way.
Related
I am new to node.js and have my first node.js Restful API built in hapi.js framework. All the services do is basically doing database query. An example of the services is like this:
let myservice = {
method: "POST",
path: "/updateRule",
config: {
handler: (request, reply) => {
updateRule(request.payload)
.then((result) => {
reply(successResponse(request, result));
})
.catch((err) => reply(failResponse(request, err)).code(500));
},
validate: {
payload: {
ruleId: joi.number().required(),
ruleName: joi.string().required(),
ruleDesc: joi.string().required()
}
},
auth: "jwt",
tags: ["api", "a3i"]
},
}
updateRule(input): Promise<any> {
return new Promise((resolve, reject) => {
let query = `select a3i.update_rule(p_rul_id := ${input.ruleId}, p_rul_name := '${input.ruleName}', p_rul_desc := '${input.ruleDesc}')`;
postgresQuery(lbPostgres, query, (data, commit, rollback) => {
try {
let count = data.rows[0].update_rule.count;
if (count === 1) {
let ruleId = data.rows[0].update_rule.result[0];
let payload: SuccessPayload = {
type: "string",
content: `Rule ${ruleId} has been updated`
};
commit();
resolve(payload);
} else {
let thisErr = new Error("No rule can be found.");
thisErr.name = "4003";
throw thisErr;
}
}
catch (err) {
rollback();
if (err.name === "4003") {
reject(detailError(4003, err.message));
} else {
reject(detailError(4001, err.message));
}
}
}, reject);
});
}
As you can see, when the service is called, it evokes a database call (query) and updates specified row in database table. Similarly, I have other services named createRule/deleteRule creating/deleting records in database table. In my opinion, the difference between the services is doing different database query. I read this post PUT vs. POST in REST but couldn't see any difference of POST and PUT in my case.
Here are my questions:
What HTTP method should I used in this case?
Most of Restful API examples (for example https://www.codementor.io/olatundegaruba/nodejs-restful-apis-in-10-minutes-q0sgsfhbd) use the same URL with different HTTP methods to do different operations on same "resource", which in my opinion is usually a database table. What's the benefit of this architecture compared with my practice in which one URL only has one HTTP method and only do one type of operation?
I know this question does not refer to a problem and is not specific. Some people may give it a down-vote. But as a beginner I really want to know what's a typical Restful API and make sure my API is "best practice". Please help!
If the resource already exists and thus you have a specific URI to that exact resource and you want to update it, then use PUT.
If the resource does not exist yet and you want to create it and you will let the server pick the URI that represents that new resource, then use POST and the POST URI will be a generic "create new resource" URI, not a URI to a specific resource and it will create the URI that represents that resource.
You can also use PUT to create a new resource if the caller is going to create the resource URI that represents the new resource. In that case, you would just PUT to that new resource and, if a resource with that URI already exists, it would be updated, if not, it would be created.
You do not have to support both. You can decide to make your api work in a way that you just use one or the other.
In your specific case, an update of a specific row in your database that already exists would pretty much always be a PUT because it already exists so you're doing a PUT to a specific URI that represents that row.
What's the benefit of this architecture compared with my practice in which one URL only has one HTTP method and only do one type of operation?
It's really up to you how you want to present your API. The general concept behind REST is that you have several components:
resource identifier
data
method
In some cases, the method can be subsumed by GET, PUT, POST or DELETE so you just need the resource identifier, data and GET, PUT, POST or DELETE.
In other cases or other designs, the method is more detailed than can be expressed in just a PUT or POST, so you have a method actually in the URL in which case, you may not need the distinction between PUT and POST as much.
For example, an action might be "buy". While you could capture that in a POST where the method is implied by the rest of the URL, you may want to actually POST to a URL that has a method in it: /buy for clarity and then you may use that same endpoint prefix with other methods such as /addToCart, etc... It really depends upon what the objects are in your REST design and what operations you want to surface on them. Sometimes, the objects lends themselves to just GET, PUT, POST and DELETE and sometimes, you want more info in the URL as to the specific operation to be carried out on that resource.
If you want to be Rest compliant, you can just use Post and Get.
If you want to be Restfull, you need to base your method on the CRUD
Create -> Post
Read -> Get
Update -> Put or Patch
Delete -> Delete
About building a full API, using method on the same URL could be easier to build / understand. All queries about your user will be on the user url and not user/get, user/add, user/update ... It let you have the same functionality, without too much different URL.
When you build an API, you will want to have some logs, for stats analysis and other stuff. This way, if you split with your method, you can just have a filter to logs how many Post requests, or Get requests.
In fact, you could build an API only with Get requests too. But spliting with methods and URL is the best way to avoid complexes URL (or URL with too much action name) and to have an easiest way to log every requests going through your API
- List item
Level 1 is Rest
Level 2 is Restfull
Level 3 is Hateoas
You should find more informations inside some books or articles written by Martin Fowler
What I usually do is use "POST" for creating a new resource, and use "PUT" for updating an already existing resource.
For your second question, yes most API's use the same URL to do different things on the same resource. That could be because of security where you don't want to expose what you are doing in your URL's (/delete for example). Also, many frameworks generate an auto URL for a resource (Object Class), that is then differentiated on the request method. People just don't tend to use custom URL's for those.
Here is below my code of route:-
app.get('/server/lead/get/:id?', leadCtrl.get);
app.get('/server/lead/filter/:filterQuery', leadCtrl.get);
As you see above i am using different route to access same controller method leadCtrl.get.
Now, i want something like route app.get('/server/lead/get/:id?:filter?', leadCtrl.get);. So, i can get params either req.params.id or req.params.filter but only one at a time.
What you asked in the question is not possible in the form that you describe it.
Now, i want something like route
app.get('/server/lead/get/:id?:filter?', leadCtrl.get);. So, i can get
params either req.params.id or req.params.filter but only one at a
time.
Your router would have no way to differentiate those two parameters. If it got a request to /server/lead/get/X then what is X? A filter or an ID?
Your options
You have few solutions here:
You can either keep using two routes like you did before.
You can use a common parameter for both cases as Robert explained in the comments.
Or you can use what seems to me the perfect solution for your use case - named query parameters - just use a route /server/lead/get and use query parameters to pass id and the filter.
Example URLs:
/server/lead/get?id=xxx
/server/lead/get?filterQuery=xxx
You will only have to make sure in your handler that only one of those two are set at a time with something like:
if (req.query.id && req.query.filterQuery) {
// respond with error
}
You can even mix the two if you have app.get('/server/lead/get/:id?') route you can have the id in the route and filterQuery as a query parameter. Now the URLs would be:
/server/lead/get/xxx (for id)
/server/lead/get?filterQuery=xxx (for filter)
For more info see: http://expressjs.com/en/api.html#req.query
Better way
If you follow some REST conventions then you can use:
app.get('/server/lead/:id') for one object with id (not optional)
app.get('/server/lead') for a list of objects (with optional filterQuery passed as a query parameter)
That way you would always know that when you access:
/server/lead/xxx - then it's one object with ID = xxx
/server/lead - then it's a list of any objects
/server/lead?filterQuery=xxx - then it's a list of objects that match the query
If you follow the REST conventions for things like this instead of inventing your own, it would be much easier for you to design the routes and handlers, and it would be much easier for other people to use your system.
You may also want to use plural /server/leads instead of /server/lead which is common with REST. That way it will be more obvious that leads is a list and leads/id is one of its elements.
For more info see:
https://en.wikipedia.org/wiki/Representational_state_transfer
http://www.restapitutorial.com/lessons/whatisrest.html
https://spring.io/understanding/REST
You have to realize that the following two routes match exactly the same:
app.get('/server/lead/get/:id?', leadCtrl.get);
app.get('/server/lead/get/:filter?', leadCtrl.get);
Express doesn't care about how you name the placeholders, so any requests for /server/lead/get/SOMEVALUE will always match the first (the one with :id).
You can add a distinction yourself, by only allowing a parameter to match a particular regular expression. From your code, it looks like :id should match MongoDB ObjectId's, so you can create a specific match for those:
app.get('/server/lead/get/:id([a-fA-F0-9]{24})?', leadCtrl.get);
If SOMEVALUE matches an ObjectId, it will call leadCtrl.get and populate req.params.id. If you also add another router for "the rest", you can also cover the req.params.filter case:
app.get('/server/lead/get/:filter?', leadCtrl.get);
As an aside: you're saying that you're passing JSON to the "filter" routes, in the URL. I would strongly suggest using a POST route for that, and post the JSON as request body content.
My code is like below:
server.get('/currency/:code', currency.find);
server.get('/currency/rates', currency.rate_getall);
Whenever I try to reach [/rates] endpoint, the server will assume I am passing parameter to '/currency/:code' route. How can I fix this? Thank you.
Ryan
If you can I would consider changing up your rest interface just a little.
server.get('/currency/:code', currency.find);
server.get('/currency/rates/:type', currency.rate);
That way it solves your initial problem and allows for flexibility in the future if you just want to return a rate for a particular currency.
Inside your currency.rate function you could check for either an id or the literal 'all' and return what is appropriate.
I'm writing a REST api in node js that will execute a sql query and send the results;
in the request I need to send the WHERE conditions; ex:
GET 127.0.0.1:5007/users //gets the list of users
GET 127.0.0.1:5007/users
id = 1 //gets the user with id 1
Right now the conditions are passed from the client to the rest api in the request's headers.
In the API I'm using sequelize, an ORM that needs to receive WHERE conditions in a particular form (an object); ex: having the condition:
(x=1 AND (y=2 OR z=3)) OR (x=3 AND y=1)
this needs to be formatted as a nested object:
-- x=1
-- AND -| -- y=2
| -- OR ----|
| -- z=3
-- OR -|
|
| -- x=3
-- AND -|
-- y=1
so the object would be:
Sequelize.or (
Sequelize.and (
{x=1},
Sequelize.or(
{y=2},
{z=3}
)
),
Sequelize.and (
{x=3},
{y=1}
)
)
Now I'm trying to pass a simple string (like "(x=1 AND (y=2 OR z=3)) OR (x=3 AND y=1)"), but then I will need a function on the server that can convert the string in the needed object (this method in my opinion has the advantage that the developer writing the client, can pass the where conditions in a simple way, like using sql, and this method is also indipendent from the used ORM, with no need to change the client if we need to change the server or use a different ORM);
The function to read and convert the conditions' string into an object is giving me headache (I'm trying to write one without success, so if you have some examples about how to do something like this...)
What I would like to get is a route capable of executing almost any kind of sql query and give the results:
now I have a different route for everything:
127.0.0.1:5007/users //to get all users
127.0.0.1:5007/users/1 //to get a single user
127.0.0.1:5007/lastusers //to get user registered in the last month
and so on for the other tables i need to query (one route for every kind of request I need in the client);
instead I would like to have only one route, something like:
127.0.0.1:5007/request
(when calling this route I will pass the table name and the conditions' string)
Do you think this solution would be a good solution or you generally use other ways to handle this kind of things?
Do you have any idea on how to write a function to convert the conditions' string into the desired object?
Any suggestion would be appreciated ;)
I would strongly advise you not to expose any part of your database model to your clients. Doing so means you can't change anything you expose without the risk of breaking the clients. One suggestion as far as what you've supplied is that you can and should use query parameters to cut down on the number of endpoints you've got.
GET /users //to get all users
GET /users?registeredInPastDays=30 //to get user registered in the last month
GET /users/1 //to get a single user
Obviously "registeredInPastDays" should be renamed to something less clumsy .. it's just an example.
As far as the conditions string, there ought to be plenty of parsers available online. The grammar looks very straightforward.
IMHO the main disadvantage of your solution is that you are creating just another API for quering data. Why create sthm from scratch if it is already created? You should use existing mature query API and focus on your business logic rather then inventing sthm new.
For example, you can take query syntax from Odata. Many people have been developing that standard for a long time. They have already considered different use cases and obstacles for query API.
Resources are located with a URI. You can use or mix three ways to address them:
Hierarchically with a sequence of path segments:
/users/john/posts/4711
Non hierarchically with query parameters:
/users/john/posts?minVotes=10&minViews=1000&tags=java
With matrix parameters which affect only one path segment:
/users;country=ukraine/posts
This is normally sufficient enough but it has limitations like the maximum length. In your case a problem is that you can't easily describe and and or conjunctions with query parameters. But you can use a custom or standard query syntax. For instance if you want to find all cars or vehicles from Ford except the Capri with a price between $10000 and $20000 Google uses the search parameter
q=cars+OR+vehicles+%22ford%22+-capri+%2410000..%2420000
(the %22 is a escaped ", the %24 a escaped $).
If this does not work for your case and you want to pass data outside of the URI the format is just a matter of your taste. Adding a custom header like X-Filter may be a valid approach. I would tend to use a POST. Although you just want to query data this is still RESTful if you treat your request as the creation of a search result resource:
POST /search HTTP/1.1
your query-data
Your server should return the newly created resource in the Location header:
HTTP/1.1 201 Created
Location: /search/3
The result can still be cached and you can bookmark it or send the link. The downside is that you need an additional POST.
I need to redirect the URLs like this http://mysite.com/store/store-name to http://mysite.com/stores/products/store-id. Note that i need to get the store id from the database. So is it possible to do db operations in routes.php?
And in documentation the syntax is give as $route['store/:any']. How to get the value of second parameter here which is mentioned as :any.
There's not really any good nor simple way of running database queries through the routes. You can however have in the beginning of the controller function a validation.
I asume your store-name is some sort of slug for the product? Basicly you can validate if value is numeric or not, and if not find by slug and then redirect.
config/routes.php
$route["store/(.*)"] = 'stores/products/$1';
/* () and $1 together passes the values */
controllers/stores.php
/* Class etc. */
function products($mix) {
if (is_numeric($mix))
$int_id = $mix;
else {
$row = $this->get_where('products', array('slug' => $mix))->row();
$this->load->helper('url');
redirect("stores/products/{$row->id}");
}
/* Do stuff with the $int_id */
}
This asumes that you have:
A table named products
A column named id that's your products id
A column named slug that that's based on your store-name
I may be a little late to the party, but I may have an alternative suggestion.
I use the following for my routes:
http://mysite.com/store/1/store-name
Reason being... Based on your method, if you create
http://mysite.com/store/store-name
but then after a period of time (of which no doubt Google has indexed your page) you decide for what ever reason you have to change the name of the store to "Wonderful store name", you would naturally change your link to
http://mysite.com/store/wonderful-store-name
Which kills your SEO and any index links.
My solution of using http://mysite.com/store/1/store-name means that you can change store-name to anything you want, but it will always reference 1 meaning the user will still see the related page.
Anything is possible with CodeIgniter routes. Its all in the way you code it. Routing in CI is really flexible. You can use regular expressions besides the standard CI wildcards (:any)(:num). You can even add prefixes or suffixes to the path variables if you have to like:
$route['store/(:any)'] = "redircontroller/redirfunction/$1";
// for instance the namelookup method of the mystores controller
$route['stores/products/(:any)'] = "mystores/namelookup/$1";
You get the second parameter(and third and so on) by defining the variables in your route value which get passed to the controller method you define. If 'products' in you new url is also a variant you should start your wildcard expression there instead. You could also pull parameters out of the url using the URI class ($this->uri->segment(n)).
You don't, however, do database operations in routes.php. You do your database operations in the controller where you route to. My guess is that you'll have to match the store id using whatever is used in the url in a query.
In any case the path that you are using the routes file for is the path the user will see. To do the redirect you have to accept the original path and then redirect the user to the new path like so:
// in some controller that's attached to the original url
public function redirfunct($var){
$this->load->helper('url');
redirect(base_url('stores/products/' . $var));
}
I hope this helps you.
Yes that is easy, you only need to show the ID instead of the name,
you must be doing like storeName> Click to view details
Make it as
storeId> Click to view details
and when you are passing the parameter to the database, change the check of mysql, change it to id instead of name , that can be some like
" select yourRequiredColumn from table_name where id=".parameter."
Thanks