Extjs simple model and store - json

Question

I have a simple model, let's say:
Ext.define('UserModel', {
extend: 'Ext.data.Model',
fields: [
{name: 'firstname', type: 'string'},
{name: 'lastname', type: 'string'}
]
});
And a json file that looks like this:
{
"DatabaseInJSON": {
"Users": [
{
"KeyFirstName": "John",
"KeyLastName": "Doe"
},{
"KeyFirstName": "James",
"KeyLastName": "Howlett"
}
],
"OtherStuffWeDontCareAbout": [
...
]
}
}
My question is:
If I create a store like this, how can i map the attribute "firstname" from my model to "KeyFirstName" from my json ?
Ext.define('my.custom.Store', {
extend: 'Ext.data.Store',
model: 'UserModel',
proxy: {
type: 'ajax',
url: 'path/to/my/file.json',
reader: {
type: 'json',
rootProperty: 'DatabaseInJSON'
}
}
});

Answer 1

You need to either employ mapping or a convert function
Have a look at the demo here which demonstrates both in action.
For the sake of the demo I turned your store into a memory proxy store and you are I presume also accessing your rootProperty wrong as it should be rootProperty: 'DatabaseInJSON.Users'
Code:
Ext.application({
name: 'Fiddle',
launch: function() {
myData = {
"DatabaseInJSON": {
"Users": [{
"KeyFirstName": "John",
"KeyLastName": "Doe"
}, {
"KeyFirstName": "James",
"KeyLastName": "Howlett"
}],
"OtherStuffWeDontCareAbout": {}
}
};
Ext.define('UserModel', {
extend: 'Ext.data.Model',
fields: [{
name: 'firstname',
mapping: 'KeyFirstName',
type: 'string'
}, {
name: 'lastname',
convert: function(v, record) {
return record.data.KeyLastName;
},
type: 'string'
}]
});
Ext.define('my.custom.Store', {
extend: 'Ext.data.Store',
model: 'UserModel',
proxy: {
type: 'memory',
reader: {
type: 'json',
rootProperty: 'DatabaseInJSON.Users'
}
}
});
myStore = Ext.create('my.custom.Store', {
data: myData
});
console.log(myStore.getRange());
}
});

Answer 2

Generally your Json properties should match the same names of your fields so that the reader can read them properly, to map 'KeyFirstName' to 'firstname' I think your best option would be to create a mapping in the field definition on the model.
This would apply this globally for all requests and I believe it would reverse the mapping when it come to saving the data.
To use the mapping in your case, you would need something like:
Ext.define('UserModel', {
extend: 'Ext.data.Model',
fields: [
{name: 'firstname', type: 'string', mapping: function(data) { return data.KeyFirstName; } },
{name: 'lastname', type: 'string', mapping: function(data) { return data.KeyLastName; } }
]
});
Other than changing the format of the JSON data, the only other way I can think of would be to override the read or getResponseData method of the JsonReader