ExtJS model associations with jsonapi specification - json

Question

We are creating a new version our API (v2) adopting the JSON:API specification (https://jsonapi.org/). I'm not being able to port the ExtJS model associations (belongs_to) to the new pattern.
The ExtJS documentation only shows how to use a nested relation in the same root node (https://docs.sencha.com/extjs/4.2.2/#!/api/Ext.data.association.Association).
v1 data (sample):
{
"data": [
{
"id": 1,
"description": "Software Development",
"area_id": 1,
"area": {
"id": 1,
"code": "01",
"description": "Headquarters"
}
},
],
"meta": {
"success": true,
"count": 1
}
}
v2 data (sample):
{
"data": [
{
"id": "1",
"type": "maint_service_nature",
"attributes": {
"id": 1,
"description": "Software Development",
"area_id": 1
},
"relationships": {
"area": {
"data": {
"id": "1",
"type": "area"
}
}
}
}
],
"included": [
{
"id": "1",
"type": "area",
"attributes": {
"id": 1,
"code": "01",
"description": "Headquarters"
}
}
],
"meta": {
"success": true,
"count": 1
}
}
My model:
Ext.define('Suite.model.MaintServiceNature', {
extend: 'Ext.data.Model',
fields: [
{ desc: "Id", name: 'id', type: 'int', useNull: true },
{ desc: "Area", name: 'area_id', type: 'int', useNull: true },
{ desc: "Description", name: 'description', type: 'string', useNull: true, tableIdentification: true }
],
associations: [
{
type: 'belongsTo',
model: 'Suite.model.Area',
foreignKey: 'area_id',
associationKey: 'area',
instanceName: 'Area',
getterName: 'getArea',
setterName: 'setArea',
reader: {
type: 'json',
root: false
}
}
],
proxy: {
type: 'rest',
url: App.getConf('restBaseUrlV2') + '/maint_service_natures',
reader: {
type: 'json',
root: 'data',
record: 'attributes',
totalProperty: 'meta.count',
successProperty: 'meta.success',
messageProperty: 'meta.errors'
}
}
});
Any ideias on how to setup the association to work with the v2 data?

Answer 1

I'm honestly taking a stab at this one... I haven't used Ext JS 4 in years, and I wouldn't structure my JSON like JSON:API does, but I think the only way you can accomplish this is by rolling your own reader class. Given that you have generic properties for your data structure, this reader should work for all scenarios... although, I'm not too familiar with JSON:API, so I could be totally wrong. Either way, this is what I've come up with.
Ext.application({
name: 'Fiddle',
launch: function () {
Ext.define('MyReader', {
extend: 'Ext.data.reader.Json',
alias: 'reader.myReader',
root: 'data',
totalProperty: 'meta.count',
successProperty: 'meta.success',
messageProperty: 'meta.errors',
/**
* #override
*/
extractData: function (root) {
var me = this,
ModelClass = me.model,
length = root.length,
records = new Array(length),
dataConverter,
convertedValues, node, record, i;
for (i = 0; i < length; i++) {
node = root[i];
var attrs = node.attributes;
if (node.isModel) {
// If we're given a model instance in the data, just push it on
// without doing any conversion
records[i] = node;
} else {
// Create a record with an empty data object.
// Populate that data object by extracting and converting field values from raw data.
// Must pass the ID to use because we pass no data for the constructor to pluck an ID from
records[i] = record = new ModelClass(undefined, me.getId(attrs), attrs, convertedValues = {});
// If the server did not include an id in the response data, the Model constructor will mark the record as phantom.
// We need to set phantom to false here because records created from a server response using a reader by definition are not phantom records.
record.phantom = false;
// Use generated function to extract all fields at once
me.convertRecordData(convertedValues, attrs, record, me.applyDefaults);
if (me.implicitIncludes && record.associations.length) {
me.readAssociated(record, node);
}
}
}
return records;
}
});
Ext.define('Suite.model.Area', {
extend: 'Ext.data.Model',
fields: [{
name: 'type',
type: 'string'
}]
});
Ext.define('Suite.model.MaintServiceNature', {
extend: 'Ext.data.Model',
fields: [{
desc: "Id",
name: 'id',
type: 'int',
useNull: true
}, {
desc: "Area",
name: 'area_id',
type: 'int',
useNull: true
}, {
desc: "Description",
name: 'description',
type: 'string',
useNull: true,
tableIdentification: true
}],
associations: [{
type: 'belongsTo',
model: 'Suite.model.Area',
associatedName: 'Area',
foreignKey: 'area_id',
associationKey: 'relationships.area.data',
instanceName: 'Area',
getterName: 'getArea',
setterName: 'setArea'
}],
proxy: {
type: 'rest',
url: 'data1.json',
reader: {
type: 'myReader'
}
}
});
Suite.model.MaintServiceNature.load(null, {
callback: function (record) {
console.log(record.getData(true));
}
});
}
});