I developed an open-source APP in Cordova (it uses Javascript) and I'm using the Google Maps API, though as the APP is becoming popular my bill is increasing (not nice for a free, ad-free APP). Thus I'd like to move to Open Street Maps.
I've been reading the docs about the Overpass API but I see no simple clear examples of code implementation. I know the sever to use, that I should use HTTP GET requests and use their special XML syntax. But it's not clear how do I pass that XML to the GET request. Furthermore the examples regarding coordinates provides as input a boundary box, not a point (or a point is regarded as a square whose corners are the same?).
<union>
<bbox-query s="51.249" w="7.148" n="51.251" e="7.152"/>
<recurse type="up"/>
</union>
<print mode="meta"/>
Could you kindly provide a simple example in Javascript (for example with $.ajax) on how to get the address of a certain location by providing the geo-coordinates to the API?
Another endpoint, and a short snippet:
fetch("https://nominatim.openstreetmap.org/search.php?q=48.886,2.343&polygon_geojson=1&format=json")
.then(response => response.json())
.then(j => {
console.log(j[0].display_name)
})
After some hours around, I share with you the working solution. Apparently, we should use the Nominatim service from Open Street Maps, and therein the reverse geocoding service. Please read the usage policy to avoid abuses, since this is a completely free service.
const coord = [38.748666, -9.103002]
fetch(`https://nominatim.openstreetmap.org/reverse?lat=${coord[0]}&lon=${coord[1]}&format=json`, {
headers: {
'User-Agent': 'ID of your APP/service/website/etc. v0.1'
}
}).then(res => res.json())
.then(res => {
console.log(res.display_name)
console.log(res.address)
})
Related
Inertia is providing a very cool helper method, which is based on axios, I suggest, e.g.:
Inertia.post('/users', {
name: 'John Doe',
email: 'john.doe#example.com',
})
I haven't found it in the Inertia docs, so I ask here - is there a possibility to do multiple HTTP requests with Inertia like it's possible with axios?
// execute simultaneous requests
axios.all([
axios.get('https://api.github.com/users/mapbox'),
axios.get('https://api.github.com/users/phantomjs')
])
.then(responseArr => {
//this will be executed only when all requests are complete
console.log('Date created: ', responseArr[0].data.created_at);
console.log('Date created: ', responseArr[1].data.created_at);
});
Or should I just use axios to do that?
As far as I am aware of; no, you cannot do multiple HTTP requests with Inertia like it's possible with axios. So, I would use axios to do that.
I interpret the docs as follows: Inertia works by intercepting clicks on the frontend, and making the visit by XHR. As such it is designed to do this one click at a time. The visit method also shows that it makes this visit by calling axios with one url.
Also, since you're requesting plain JSON, the Inertia's author recommends to use XHR directly when dealing with plain JSON, because "an Inertia request must receive an Inertia response" (source).
We are using Route REST API and we experience problem when passing many POIs to HTTP request (parameters "poixN"). Our request has about 1000 POIs and some of them are truncated (hard to count, but definitely not all are shown). Here's an example request (first line is URL, the others are parameters passed with POST):
http://maps.nlp.nokia.com/mia/1.6/route?app_code=<APP_CODE>&app_id=<APP_ID>
h=440
w=1030
poix0=52.2420610745,21.0951604874;FFFFEA00;FFFFEA00;1;.
poix1=52.2420610745,21.0952168365;FFFFEA00;FFFFEA00;1;.
poix2=52.2420610745,21.0951024308;FFFFEA00;FFFFEA00;1;.
poix3=52.2047067699,20.9944339802;FFFFEA00;FFFFEA00;1;.
...
poix940=52.1749134848,20.9056261531;FFEE7AFF;FFEE7AFF;1;.
q=100
Is there a limit for number of POIs? What about other parameters like "r"?
We use enterprise version. Thank you in advance.
Edit
Ok, after some research I know the limit for "poixN" is 99. Any way to increase the limit?
I don't think it is possible to increase the number of POIs available using the Map Image API, but it would be possible to obtain a screenshot of a more complex map using the Enterprise Maps API for JavaScript using the ContextMenu.captureHandler
You can add the captureHandler to a context menu as shown:
var contextMenu = new nokia.maps.map.component.ContextMenu();
contextMenu.addHandler(nokia.maps.map.component.ContextMenu.captureHandler);
map.components.add(contextMenu);
You can then obtain a screenshot with all your POIs, which could then be used for printing for example.The HERE Maps Community on GitHub hosts a working example specifically for printing which uses hi-res tiles from the Map Tile API as well. Note that screen capture only works on the Firefox Browser.
Since you have such a high number of POIs, I would also recommend looking at clustering to avoid overwhelming your users with too much information.
I have been reading a lot lately, and even more experimenting with web Development. There are some things that I simply cant understand, therefore any help is appreciated.
I am not trying to get my homework done for me. I have some holes in my knowledge, that I desire to fill. Please, help me out with your views :)
REST questions:
Reading documentation this is perfectly understandable (NODE.JS / Express) example:
EXAMPLE ONE (get):
app.get('/', function(req, res) {
res.send('please select a collection, e.g., /collections/messages')
})
My explanation: When the root of the server is hit, send thie following message
EXAMPLE TWO (get):
app.get('/collections/:collectionName/:id', function(req, res) {
req.collection.findOne({name: req.collection.id(req.params.id)},
function(e, result){
if (e) return next(e)
res.send(result)
})
})
My explanation: When the url in hit, take id from the URL (that is located in params.id) and make search based on it (that is MongoDB).
EXAMPLE THREE (post):
app.post('/collections/:collectionName', function(req, res) {
req.collection.insert(req.body, {}, function(e, results){
if (e) return next(e)
res.send(results)
})
})
My explanation: When the URL is hit, take the payload(JSON in this case) that is located in req.body, and insert it as a new document.
Questions:
Are example one and two both RESTfull?
I am now totally confused with params.id. I do understand that POST is transmitted in rew.body... what is params.id? Is it containing URL variables, such as :ID?
My explanations... are they correct?
Example three is also REST, regardless of the fact that POST is used?
Example three, '/collections/:collectionName. Why is the ':collectionName' passed in URL, I could have placed it in req.body as a parameter (along with new data) and take it from there? What is the benefit of doing it?
Thank you
An API must be using HATEOAS to be RESTful. On first example, if / is the entry point of your API, the response should contain links for the available collections, not a human readable string like that. That's definitely not RESTful.
Exactly.
They're OK, except that there's nothing in the third example implying it's a JSON body. It should check for a Content-Type header sent by the client.
REST isn't dependent on HTTP. As long as you're using the HTTP methods as they were standardized, it's fine. POST is the method to use for any action that isn't standardized, so it's fine to use POST for anything, if there isn't a method specific for that. For instance, it's not correct to use POST for retrieval, but it's fine to use it for creating a new resource if you don't have the full representation.
POST means the data body is subordinated to the resource at the target URI. If collectionName were in the POST body, this would mean you were POSTing to /collections, which would make more sense to create a new collection, not a new item of a collection.
I was wondering if there were any features hidden in Angular or exposed by some 3rd-party libraries to easily create HATEOAS-compliant Restful clients.
On backend side, I am using Spring Data/REST to produce an HATEOAS JSON API.
Consuming it, though, is quite another story.
For instance, I've got those 3 entities:
Company {name, address}
Employee {firstName, lastName, employer[Company]}
Activity {rate, day, employee[Employee], client[Company]}
and requesting an activity (the most complex entity of the model) produces something like this:
{
links: [],
content: [{
rate: 456,
day: 1366754400000,
links: [{
rel: "self",
href: "http://localhost:8080/api/activities/1"
},
{
rel: "activities.activity.client",
href: "http://localhost:8080/api/activities/1/client"
},
{
rel: "activities.activity.employee",
href: "http://localhost:8080/api/activities/1/employee"
}]
}]
}
My API talks in terms of REST (resources identified by links).
An Activity has an Employee for instance. What I really want to use is : {rate: 456, day: 1366754400000, employee: {firstName:"xxx", lastName:"xxx" ...}}.
However, as you can see in the first output, my Activity only contains a link to the employee, not its data. Is there anything in Angular or in a 3rd-party library to resolve those links and embed the resulting data instead?
Any input on this?
Thanks in advance!
Checkout angular-hateoas. ITs an AngularJS module for using $resource with a HATEOAS-enabled REST API.
You could write a Response Transformation that would inspect your returned object, check for links, and resolve them before returning the response. See the section "Transforming Requests and Responses" in the $http service documentation.
Something like this:
transformResponse: function(rawData) {
var json = JSON.parse( rawData );
forEach( json.content.links, function(link) {
// resolve link...
});
return json;
}
Since the "resolve link" step is itself an $http call, sub-references would also be resolved. HOWEVER, since these are asynchronous, you would likely return a promise instead of the real value; I don't know if the transform function is allowed to do this.
As #charlietfl pointed out, however, please note that this will result in several HTTP calls to return a single entity. Even though I like the concept of HATEOAS, this will likely result in sluggishness if too many calls are made. I'd suggest that your server return the data, or some of it, directly, PLUS the link for details.
Based on your comment about wanting to work with data as against links on the client, I think Restangular would be a good fit.
I've been using angular-hal for one of my projects. It was a Spring HATEOAS backend. And I didn't run into any issues. It handles parametrized resources. I suspect it only supports HAL so since you're using Spring Data Rest you probably have to configure it to generate HAL compliant responses.
I think the confusion may be that you are asking for an Angular solution, when what you really want to do is have Spring Data send a more complete JSON response. I.e, you really just want the server to return the employee data as part of the response JSON, rather than having the client perform extra steps to look it up. I don't know what data store you are using in Spring Data, but the general solution would be to add public getEmployee() method to your Activity class and then annotate the method with #RelatedTo and #Fetch (this would be the setup for Neo4J -- may be different annotations for your flavor of Spring Data). This should cause Spring HATEOAS to include the Employee record within the response for /activity. Hope this helps.
Does anyone have a definitive way to post to a user's wall, using nothing but the .NET Framework, or Silverlight?
Problems deriving from people's attempts have been asked here on SO, but I cannot find a full, clear explanation of the Graph API spec and a simple example using WebClient or some similar class from System.Net.
Do I have to send all feed item properties as parameters in the query string? Can I construct a JSON object to represent the feed item and send that (with the access token as the only parameter)?
I expect its no more than a 5 line code snippet, else, point me at the spec in the FB docs.
Thanks for your help,
Luke
This is taken from how we post to a user's wall. We place the data for the post in the request body (I think we found this to be more reliable than including all the parameters in the query part of the request), it has the same format as a URL encoded query string.
I agree that the documentation is rather poor at explaining how to interact with a lot of resources. Typically I look at the documentation for information on fields and connections, then work with the Graph API Explorer to understand how the request needs to be constructed. Once I've got that down it's pretty easy to implement in C# or whatever. The only SDK I use is Facebook's Javascript SDK. I've found the others (especially 3rd party) are more complicated, buggy, or broken than rolling my own.
private void PostStatus (string accessToken, string userId)
{
UriBuilder address = new UriBuilder ();
address.Scheme = "https";
address.Host = "graph.facebook.com";
address.Path = userId + "/feed";
address.Query = "access_token=" + accessToken;
StringBuilder data = new StringBuilder ();
data.Append ("caption=" + HttpUtility.UrlEncodeUnicode ("Set by app to describe the app."));
data.Append ("&link=" + HttpUtility.UrlEncodeUnicode ("http://example.com/some_resource_to_go_to_when_clicked"));
data.Append ("&description=" + HttpUtility.UrlEncodeUnicode ("Message set by user."));
data.Append ("&name=" + HttpUtility.UrlEncodeUnicode ("App. name"));
data.Append ("&picture=" + HttpUtility.UrlEncodeUnicode ("http://example.com/image.jpg"));
WebClient client = new WebClient ();
string response = client.UploadString (address.ToString (), data.ToString ());
}
I don't know much about .net or silverlight, but the facebook api works with simple http requests.
All the different sdks (with the exception of the javascript one) are mainly just wrappers for the http requests with the "feature" of adding the access token to all requests.
Not in all requests the parameters are sent as querystring, in some POST requests you need to send them in the request body (application/x-www-form-urlencoded), and you can not send the data as json.
If the C# sdk is not to your liking, you can simply create one for your exact needs.
As I wrote, you just need to wrap the requests, and you can of course have a method that will get a json as parameter and will break it to the different parameters to be sent along with the request.
I would point you to the facebook documentation but you haven't asked anything specific so there's nothing to point you to except for the landing page.