This is regarding the mentioned methods of sap.ui.model.json.JSONModel in SAPUI5:
setJSON
setData
loadData
What is the difference between these 3 methods? When do we use these methods and can we use more than 1 of them for the same purpose?
Have a look at the well documented API Reference for JSONModel.
In summary (from SAP Documentation):
setData: Sets the data, passed as a JS object tree, to the model.
e.g
var data = {
"ProductCollection": [{
"titleId": 0,
"Name": "Olayinka O",
"ProductId": "001",
"chartValue": 75,
"ProductPicUrl": "sap-icon://competitor"
}]
};
var oModel = new sap.ui.model.json.JSONModel(data);
//OR
var oModel = new sap.ui.model.json.JSONModel();
oModel.setData(data);
/*setdata, could also be a odata url in json format*/
loadData:
Load JSON-encoded data from the server using a GET HTTP request and store the resulting JSON data in the model. Note: Due to browser security restrictions, most "Ajax" requests are subject to the same origin policy, the request can not successfully retrieve data from a different domain, subdomain, or protocol.
e.g. you can use this to load/GET changes to the data/model and automatically updates the view if that specific model has being binded by reloading the url. If you use load, you don't need the other two in my opinion and loadData with not work on local json data.
var sURL = "https://cors-anywhere.herokuapp.com/https://services.odata.org/V3/Northwind/Northwind.svc/Products?$format=json";
var oModel = new sap.ui.model.json.JSONModel();
//if called in setInterval, all changes in the backend will be updated in the view if binded in this case every second
setInterval(oModel.loadData(sURL, true), 1000);
setJSON :
Sets the data, passed as a string in JSON format, to the model.
i.e. Same as Set Data but strict JSON
Luckily, the source code of UI5 is quite readable and often the better documentation than most of the API descriptions. Here is what each one of the APIs does basically:
setJSON
"Parse the JSON text and call setData"
JSONModel.prototype.setJSON = function(sJSON, bMerge) {
var oJSONData;
try {
oJSONData = jQuery.parseJSON(sJSON);
this.setData(oJSONData, bMerge);
} catch (e) {
// ...
}
};
Source
setData
"Store the data and notify all dependent bindings (checkUpdate)"
JSONModel.prototype.setData = function(oData/*plain JS object*/, bMerge){
if (bMerge) {
this.oData = /* merge with existing data */;
} else {
this.oData = oData;
} // ...
this.checkUpdate(); // notifies dependent bindings
};
Source
loadData
"Load data from the given remote URL and call setData" --> Please check the source here.
In short, they all call setData at some point.
Which API to call in which situation depends on in which format you have the data available.
The data are in JSON text --> setJSON
The data are somewhere else --> loadData
I already have the data in JS object / array ---> setData
setData
You have a JavaScript object and want to use this data as your model
const oJSONData = {
data: {
id: 4,
first_name: "Eve",
last_name: "Holt",
avatar: "https://s3.amazonaws.com/uifaces/faces/twitter/marcoramires/128.jpg"
}
};
oJSONModel.setData(oData);
setJSON
You have a String that when parsed represents a JavaScript object and want to use this data as your model
const sJSONData = '{"data":{"id":4,"first_name":"Eve","last_name":"Holt","avatar":"https://s3.amazonaws.com/uifaces/faces/twitter/marcoramires/128.jpg"}}';
oJSONModel.setJSON(sJSONData);
loadData
You want to access a remote API which returns data as JSON and want to use this data as your model
const sURL = "https://reqres.in/api/users/4";
oJSONModel.loadData(sURL);
Related
I have the following coding in my SAP UI5 application Controller:
var myView = this.getView();
var data1 = { "myDate": new Date() };
oModel.loadData("products.json");
oModel.setData(data1);
myView.setModel(oModel);
Where products.json - just a simple data for the table on the screen.
And I can see only products.json data on the screen as a result, and myDate with empty value inside oModel (checked in debug).
In case I comment loadData string, myDate value is on the screen and looks good.
How I can use them together? What is the best practice for such cases?
The model's loadData is an asynchronous process, so it will update the model after you have set it synchronously with data1.
Also, setData() will wipe everything already in the model, so better use setProperty and update only a specific node in your model.
You should add the static data once you have loaded it from file:
oModel.attachRequestCompleted(function() {
oModel.setProperty("/myExtraData", data1);
});
Your added date is then available via /myExtraData/myData
Merge new data with existing one with bMerge parameter of setData().
oModel.loadData("products.json");
var data1 = {
"myDate": new Date()
};
oModel.attachRequestCompleted(function() {
oModel.setData(data1, true);
});
The API loadData has also a bMerge option.
oModel.setData({ myDate: new Date() });
oModel.loadData("products.json", null, true, "GET", /*bMerge*/true);
// Merged results:
{
myDate: /*date object*/,
produces: [/*...*/]
}
No need to register an event handler for requestCompleted.
I've setup a simple "product" model (ie {id:"string","name":string, etc}) and setup a datasource using the REST connector to a remote URL that returns a JSON blob containing dozens of fields, how do I go about mapping the fields from the remote response to my local model? Whenever I execute my method I'm getting back the raw response from the remote....I was expecting, at a minimum, to get back an empty version of my model.
I'm pretty sure you will have to override the find() method on your model and perform this mapping work manually.
Something like this:
module.exports = function(app) {
var Product = app.models.Product;
var find = Product.find;
Product.find = function(filter, cb) {
// invoke the default method
find.call(Product, function(err, original_results) {
var results = {}; // a placeholder for your expected results
results.name = original_results.id;
results.name = original_results.name;
results.description = original_results.long_description;
// and so on
cb(null, results)
});
}
}
I see several questions on SO attempting to solve this problem of sending POST requests to nested API resource routes.
See:
- [Sending REST requests to a nested API endpoint URL using Ember Data(Sending REST requests to a nested API endpoint URL using Ember Data)
- Custom request URLs in Ember model
I've started overloading the createRecord, updateRecord, and deleteRecord methods on the RESTAdapter to attempt some sort of hackery solution to building the correct URL. Now, using a method similar to this is the route I've taken so far.
Here is the updateRecord method in their solution:
App.UserAdapter = DS.RESTAdapter.extend({
updateRecord: function(store, type, record) {
if(!record.get('parent') || null === record.get('parent')){
return this._super(store, type, record);
}
var data = {};
var serializer = store.serializerFor(type.typeKey);
var parent_type = record.get('parent');
var parent_id = record.get(parent_type).get('id');
var child_parts = Ember.String.decamelize(type.typeKey).split('_');
var path = Ember.String.pluralize(parent_type) + '/' + parent_id + '/' + Ember.String.pluralize(child_parts.pop());
serializer.serializeIntoHash(data, type, record);
var id = record.get('id');
return this.ajax(this.buildURL(path, id), "PUT", { data: data });
}
....
});
This method should work great in tandem with adding the parent type to the model and ensuring the related parent model id is also represented on the model. For PUT and DELETE requests, this shouldn't be a problem, as we already have the parent ID relation on the object in store.
Project model:
App.ProjectModel = DS.Model.extend({
name: DS.attr('string'),
createdAt: DS.attr('date'),
updatedAt: DS.attr('date'),
workspace : DS.belongsTo('workspace'),
parent: 'workspace',
....
});
Where this method appears to go awry for me is in creating new resources with a post. I've attempted it, but since the payload hasn't been returned from the API server with the related parent ID, I actually don't have access to it.
Here's my crappy first attempt, that doesn't work. The workspace id always returns null.
createRecord: function(store, type, record) {
if (!record.get('parent') || null === record.get('parent')){
return this._super(store, type, record);
}
var data = {};
var serializer = store.serializerFor(type.typeKey);
var parent_type = record.get('parent');
var parent_id = record.get(parent_type).get('id');
var path = Ember.String.pluralize(parent_type) + '/' + parent_id + '/' + type.typeKey);
serializer.serializeIntoHash(data, type, record, { includeId: true });
return this.ajax(this._buildURL(path, null), "POST", { data: data });
},
Got any thoughts on how I can get the parent ID, before I have a saved record?
I am the author of the solution you cited in your question.
What does your model hook look like in the route where you are creating the new ProjectModel?
Assuming your Workspace route looks something like:
App.WorkspaceRoute = Ember.Route.extend({
model: function (params) {
return this.store.find('workspace', params.id);
}
});
Then your Workspace Project add/create route's model hook would need to be something like:
App.WorkspaceProjectAddRoute = Ember.Route.extend({
model: function () {
var workspace = this.modelFor('workspace');
return this.store.createRecord('project', {
workspace: workspace
});
}
}
I hope this makes some sense...
Getting blank values for title and description in serveResource method.Is this the right way to send the parameters from io request?
After inserting blank values in database I have to reload the page to see the inserted values?So io-request is not ajax request?
<aui:script use="aui-base">
A.one('#<portlet:namespace/>save').on('click', function(event) {
var A = AUI();
var title=A.one('#<portlet:namespace/>title').val();
alert(title);
var description=A.one('#<portlet:namespace/>description');
var url = '<%= newJob.toString() %>';
A.io.request(
url,
{
method:'POST',
data: {
<portlet:namespace />title: title,
<portlet:namespace />description: description,
},
}
['aui-io-deprecated']
);
Liferay.Util.getOpener().<portlet:namespace/>closePopup('<portlet:namespace/>dialog');
});
AUI's io request is ajax request only.
You can get parameters in serveResource method using code below:
ParamUtil.get(resourceRequest, "NAMEOFPARAMETER");
Modify your javascript function and provide data attribute as below:
data: {
'<portlet:namespace />title': title,
'<portlet:namespace />description': description,
}
I assume both title and description are textfields. If so, description is missing a .val() call, or more appropriately, .get('value'). I didn't use a dialog/modal in my source, but the overall approach should be the same.
<script>
AUI().use('aui-base', 'aui-io-request', function(A){
A.one('#<portlet:namespace />save').on('click', function(event) {
var title= A.one('#<portlet:namespace />title').get('value');
var description=A.one('#<portlet:namespace />description').get('value');
var url = '<%=myResourceURL.toString()%>';
A.io.request(url,
{
method:'POST',
data: {
title: title,
description: description,
},
});
});
});
</script>
I'm still relatively new to Liferay and have had trouble with this as well. I've noticed that the data parameters are not in the parametersMap of the default ResourceRequest, as you have stated. Out of curiosity, I decided to use
UploadPortletRequest req = PortalUtil.getUploadPortletRequest(resourceRequest);
in the serveResource method and check it's parametersMap. The title and description parameters are available therein. I'm still learning where and how to access data from Liferay objects, but it would seem that for the UploadPortletRequest to have the data, it would be plucked from somewhere within the default ResourceRequest ... where still remains elusive to me.
After inserting blank values in database I have to reload the page to see the inserted values?
You have to reload the page because a resource action does not trigger a page refresh. If you are manipulating data that you want reflected in some other "view" you'll need to configure the appropriate communication or use one of the other available url types that does trigger the doView method of your other "view".
I'm using backbone.js to interact with a REST API that, when posting to it to create a new resource, responds with a status of 201, a 'Location' header pointing to the resource's URI, but an empty body.
When I create a new model at the moment, its successful, but the local representation of the model only contains the properties I explicitly set, not any of the properties that would be set on the server (created_date, etc.)
From what I understand, Backbone would update its representation of the model with data in the body, if there were any. But, since there isn't, it doesn't.
So, clearly, I need to use the location in the Location header to update the model, but what's the best way to do this.
My current mindset is that I would have to parse the url from the header, split out the id, set the id for the model, then tell the model to fetch().
This seems really messy. Is there a cleaner way to do it?
I have some influence over the API. Is the best solution to try to get the API author to return the new model as the body of the response (keeping the 201 and the location header as well)?
Thanks!
Sounds like you will have to do a little customization.
Perhaps override the parse method and url method of your model class inherited from
Backbone.Model.
The inherited functions are:
url : function() {
var base = getUrl(this.collection);
if (this.isNew()) return base;
return base + (base.charAt(base.length - 1) == '/' ? '' : '/') + this.id;
},
parse : function(resp) {
return resp;
},
and you could try something like:
parse: function(resp, xhr) {
this._url = xhr.getResponseHeader('location')
return resp
}
url: function() {
return this._url
}
Yes, backbone.js really wants the result of a save (be it PUT or POST) to be a parseable body which can be used to update the model. If, as you say, you have influence over the API, you should see if you can arrange for the content body to contain the resource attributes.
As you point out, its makes little sense to make a second over-the-wire call to fully materialize the model.
It may be that a status code of 200 is more appropriate. Purists may believe that a 201 status code implies only a location is returned and not the entity. Clearly, that doesn't make sense in this case.
With Backbone 0.9.9, I couldn't get the accepted answer to work. The signature of the parse function seems to have changed in an older version, and the xhr object is no longer available in the function signature.
This is an example of what I did, to make it work with Backbone v0.9.9 and jQuery 1.8.3 (using a Deferred Object/Promise), relying on the jqXHR object returned by Backbone.Model.save() :
window.CompanyView = Backbone.View.extend({
// ... omitted other functions...
// Invoked on a form submit
createCompany: function(event) {
event.preventDefault();
// Store a reference to the model for use in the promise
var model = this.model;
// Backbone.Model.save returns a jqXHR object
var xhr = model.save();
xhr.done(function(resp, status, xhr) {
if (!model.get("id") && status == "success" && xhr.status == 201) {
var location = xhr.getResponseHeader("location");
if (location) {
// The REST API sends back a Location header of format http://foo/rest/companys/id
// Split and obtain the last fragment
var fragments = location.split("/");
var id = fragments[fragments.length - 1];
// Set the id attribute of the Backbone model. This also updates the id property
model.set("id", id);
app.navigate('companys/' + model.id, {trigger: true});
}
}
});
}
});
I did not use the success callback that could be specified in the options hash provided to the Backbone.Model.save function, since that callback is invoked before the XHR response is received. That is, it is pointless to store a reference to the jqXHR object and use it in the success callback, since the jqXHR would not contain any response headers (yet) when the callback is invoked.
Another other to solve this would be to write a custom Backbone.sync implementation, but I didn't prefer this approach.