I am using fastapi and BaseModel from pydantic to validate and document the JSON schema for an API return.
This works well for a fixed return but I have optional parameters that change the return so I would like to include it in the validation but for it not to fail when the parameter is missing and the field is not returned in the API.
For example: I have an optional boolean parameter called transparency when this is set to true I return a block called search_transparency with the elastic query returned.
{
"info": {
"totalrecords": 52
},
"records": [],
"search_transparency": {"full_query": "blah blah"}
}
If the parameter transparency=true is not set I want the return to be:
{
"info": {
"totalrecords": 52
},
"records": []
}
However, when I set that element to be Optional in pydantic, I get this returned instead:
{
"info": {
"totalrecords": 52
},
"records": [],
"search_transparency": None
}
I have something similar for the fields under records. The default is a minimal return of fields but if you set the parameter full=true then you get many more fields returned. I would like to handle this in a similar way with the fields just being absent rather than shown with a value of None.
This is how I am handling it with pydantic:
class Info(BaseModel):
totalrecords: int
class Transparency(BaseModel):
full_query: str
class V1Place(BaseModel):
name: str
class V1PlaceAPI(BaseModel):
info: Info
records: List[V1Place] = []
search_transparency: Optional[Transparency]
and this is how I am enforcing the validation with fastapi:
#app.get("/api/v1/place/search", response_model=V1PlaceAPI, tags=["v1_api"])
I have a suspicion that maybe what I am trying to achieve is poor API practice, maybe I am not supposed to have variable returns.
Should I instead be creating multiple separate endpoints to handle this?
eg. api/v1/place/search?q=test vs api/v1/place/full/transparent/search?q=test
EDIT
More detail of my API function:
#app.get("/api/v1/place/search", response_model=V1PlaceAPI, tags=["v1_api"])
def v1_place_search(q: str = Query(None, min_length=3, max_length=500, title="search through all place fields"),
transparency: Optional[bool] = None,
offset: Optional[int] = Query(0),
limit: Optional[int] = Query(15)):
search_limit = offset + limit
results, transparency_query = ESQuery(client=es_client,
index='places',
transparency=transparency,
track_hits=True,
offset=offset,
limit=search_limit)
return v1_place_parse(results.to_dict(),
show_transparency=transparency_query)
where ESQuery just returns an elasticsearch response.
And this is my parse function:
def v1_place_parse(resp, show_transparency=None):
"""This takes a response from elasticsearch and parses it for our legacy V1 elasticapi
Args:
resp (dict): This is the response from Search.execute after passing to_dict()
Returns:
dict: A dictionary that is passed to API
"""
new_resp = {}
total_records = resp['hits']['total']['value']
query_records = len(resp.get('hits', {}).get('hits', []))
new_resp['info'] = {'totalrecords': total_records,
'totalrecords_relation': resp['hits']['total']['relation'],
'totalrecordsperquery': query_records,
}
if show_transparency is not None:
search_string = show_transparency.get('query', '')
new_resp['search_transparency'] = {'full_query': str(search_string),
'components': {}}
new_resp['records'] = []
for hit in resp.get('hits', {}).get('hits', []):
new_record = hit['_source']
new_resp['records'].append(new_record)
return new_resp
Probably excluding that field if it is None can get the job done.
Just add a response_model_exclude_none = True as a path parameter
#app.get(
"/api/v1/place/search",
response_model=V1PlaceAPI,
tags=["v1_api"],
response_model_exclude_none=True,
)
You can customize your Response model even more, here is a well explained answer of mine I really suggest you check it out.
I'm trying to access a property of an object using a dynamic name. Is this possible?
const something = { bar: "Foobar!" };
const foo = 'bar';
something.foo; // The idea is to access something.bar, getting "Foobar!"
There are two ways to access properties of an object:
Dot notation: something.bar
Bracket notation: something['bar']
The value between the brackets can be any expression. Therefore, if the property name is stored in a variable, you have to use bracket notation:
var something = {
bar: 'foo'
};
var foo = 'bar';
// both x = something[foo] and something[foo] = x work as expected
console.log(something[foo]);
console.log(something.bar)
This is my solution:
function resolve(path, obj) {
return path.split('.').reduce(function(prev, curr) {
return prev ? prev[curr] : null
}, obj || self)
}
Usage examples:
resolve("document.body.style.width")
// or
resolve("style.width", document.body)
// or even use array indexes
// (someObject has been defined in the question)
resolve("part.0.size", someObject)
// returns null when intermediate properties are not defined:
resolve('properties.that.do.not.exist', {hello:'world'})
In javascript we can access with:
dot notation - foo.bar
square brackets - foo[someVar] or foo["string"]
But only second case allows to access properties dynamically:
var foo = { pName1 : 1, pName2 : [1, {foo : bar }, 3] , ...}
var name = "pName"
var num = 1;
foo[name + num]; // 1
// --
var a = 2;
var b = 1;
var c = "foo";
foo[name + a][b][c]; // bar
Following is an ES6 example of how you can access the property of an object using a property name that has been dynamically generated by concatenating two strings.
var suffix = " name";
var person = {
["first" + suffix]: "Nicholas",
["last" + suffix]: "Zakas"
};
console.log(person["first name"]); // "Nicholas"
console.log(person["last name"]); // "Zakas"
This is called computed property names
You can achieve this in quite a few different ways.
let foo = {
bar: 'Hello World'
};
foo.bar;
foo['bar'];
The bracket notation is specially powerful as it let's you access a property based on a variable:
let foo = {
bar: 'Hello World'
};
let prop = 'bar';
foo[prop];
This can be extended to looping over every property of an object. This can be seem redundant due to newer JavaScript constructs such as for ... of ..., but helps illustrate a use case:
let foo = {
bar: 'Hello World',
baz: 'How are you doing?',
last: 'Quite alright'
};
for (let prop in foo.getOwnPropertyNames()) {
console.log(foo[prop]);
}
Both dot and bracket notation also work as expected for nested objects:
let foo = {
bar: {
baz: 'Hello World'
}
};
foo.bar.baz;
foo['bar']['baz'];
foo.bar['baz'];
foo['bar'].baz;
Object destructuring
We could also consider object destructuring as a means to access a property in an object, but as follows:
let foo = {
bar: 'Hello World',
baz: 'How are you doing?',
last: 'Quite alright'
};
let prop = 'last';
let { bar, baz, [prop]: customName } = foo;
// bar = 'Hello World'
// baz = 'How are you doing?'
// customName = 'Quite alright'
You can do it like this using Lodash get
_.get(object, 'a[0].b.c');
UPDATED
Accessing root properties in an object is easily achieved with obj[variable], but getting nested complicates things. Not to write already written code I suggest to use lodash.get.
Example
// Accessing root property
var rootProp = 'rootPropert';
_.get(object, rootProp, defaultValue);
// Accessing nested property
var listOfNestedProperties = [var1, var2];
_.get(object, listOfNestedProperties);
Lodash get can be used in different ways, the documentation lodash.get
To access a property dynamically, simply use square brackets [] as follows:
const something = { bar: "Foobar!" };
const userInput = 'bar';
console.log(something[userInput])
The problem
There's a major gotchya in that solution! (I'm surprised other answers have not brought this up yet). Often you only want to access properties that you've put onto that object yourself, you don't want to grab inherited properties.
Here's an illustration of this issue. Here we have an innocent-looking program, but it has a subtle bug - can you spot it?
const agesOfUsers = { sam: 16, sally: 22 }
const username = prompt('Enter a username:')
if (agesOfUsers[username] !== undefined) {
console.log(`${username} is ${agesOfUsers[username]} years old`)
} else {
console.log(`${username} is not found`)
}
When prompted for a username, if you supply "toString" as a username, it'll give you the following message: "toString is function toString() { [native code] } years old". The issue is that agesOfUsers is an object, and as such, automatically inherits certain properties like .toString() from the base Object class. You can look here for a full list of properties that all objects inherit.
Solutions
Use a Map data structure instead. The stored contents of a map don't suffer from prototype issues, so they provide a clean solution to this problem.
const agesOfUsers = new Map()
agesOfUsers.set('sam', 16)
agesOfUsers.set('sally', 2)
console.log(agesOfUsers.get('sam')) // 16
Use an object with a null prototype, instead of the default prototype. You can use Object.create(null) to create such an object. This sort of object does not suffer from these prototype issues, because you've explicitly created it in a way that it does not inherit anything.
const agesOfUsers = Object.create(null)
agesOfUsers.sam = 16
agesOfUsers.sally = 22;
console.log(agesOfUsers['sam']) // 16
console.log(agesOfUsers['toString']) // undefined - toString was not inherited
You can use Object.hasOwn(yourObj, attrName) to first check if the dynamic key you wish to access is directly on the object and not inherited (learn more here). This is a relatively newer feature, so check the compatibility tables before dropping it into your code. Before Object.hasOwn(yourObj, attrName) came around, you would achieve this same effect via Object.prototype.hasOwnProperty.call(yourObj, attrName). Sometimes, you might see code using yourObj.hasOwnProperty(attrName) too, which sometimes works but it has some pitfalls that you can read about here.
// Try entering the property name "toString",
// you'll see it gets handled correctly.
const user = { name: 'sam', age: 16 }
const propName = prompt('Enter a property name:')
if (Object.hasOwn(user, propName)) {
console.log(`${propName} = ${user[propName]}`)
} else {
console.log(`${propName} is not found`)
}
If you know the key you're trying to use will never be the name of an inherited property (e.g. maybe they're numbers, or they all have the same prefix, etc), you can choose to use the original solution.
I came across a case where I thought I wanted to pass the "address" of an object property as data to another function and populate the object (with AJAX), do lookup from address array, and display in that other function. I couldn't use dot notation without doing string acrobatics so I thought an array might be nice to pass instead. I ended-up doing something different anyway, but seemed related to this post.
Here's a sample of a language file object like the one I wanted data from:
const locs = {
"audioPlayer": {
"controls": {
"start": "start",
"stop": "stop"
},
"heading": "Use controls to start and stop audio."
}
}
I wanted to be able to pass an array such as: ["audioPlayer", "controls", "stop"] to access the language text, "stop" in this case.
I created this little function that looks-up the "least specific" (first) address parameter, and reassigns the returned object to itself. Then it is ready to look-up the next-most-specific address parameter if one exists.
function getText(selectionArray, obj) {
selectionArray.forEach(key => {
obj = obj[key];
});
return obj;
}
usage:
/* returns 'stop' */
console.log(getText(["audioPlayer", "controls", "stop"], locs));
/* returns 'use controls to start and stop audio.' */
console.log(getText(["audioPlayer", "heading"], locs));
ES5 // Check Deeply Nested Variables
This simple piece of code can check for deeply nested variable / value existence without having to check each variable along the way...
var getValue = function( s, context ){
return Function.call( context || null, 'return ' + s )();
}
Ex. - a deeply nested array of objects:
a = [
{
b : [
{
a : 1,
b : [
{
c : 1,
d : 2 // we want to check for this
}
]
}
]
}
]
Instead of :
if(a && a[0] && a[0].b && a[0].b[0] && a[0].b[0].b && a[0].b[0].b[0] && a[0].b[0].b[0].d && a[0].b[0].b[0].d == 2 ) // true
We can now :
if( getValue('a[0].b[0].b[0].d') == 2 ) // true
Cheers!
Others have already mentioned 'dot' and 'square' syntaxes so I want to cover accessing functions and sending parameters in a similar fashion.
Code jsfiddle
var obj = {method:function(p1,p2,p3){console.log("method:",arguments)}}
var str = "method('p1', 'p2', 'p3');"
var match = str.match(/^\s*(\S+)\((.*)\);\s*$/);
var func = match[1]
var parameters = match[2].split(',');
for(var i = 0; i < parameters.length; ++i) {
// clean up param begninning
parameters[i] = parameters[i].replace(/^\s*['"]?/,'');
// clean up param end
parameters[i] = parameters[i].replace(/['"]?\s*$/,'');
}
obj[func](parameters); // sends parameters as array
obj[func].apply(this, parameters); // sends parameters as individual values
I asked a question that kinda duplicated on this topic a while back, and after excessive research, and seeing a lot of information missing that should be here, I feel I have something valuable to add to this older post.
Firstly I want to address that there are several ways to obtain the value of a property and store it in a dynamic Variable. The first most popular, and easiest way IMHO would be:
let properyValue = element.style['enter-a-property'];
however I rarely go this route because it doesn't work on property values assigned via style-sheets. To give you an example, I'll demonstrate with a bit of pseudo code.
let elem = document.getElementById('someDiv');
let cssProp = elem.style['width'];
Using the code example above; if the width property of the div element that was stored in the 'elem' variable was styled in a CSS style-sheet, and not styled inside of its HTML tag, you are without a doubt going to get a return value of undefined stored inside of the cssProp variable. The undefined value occurs because in-order to get the correct value, the code written inside a CSS Style-Sheet needs to be computed in-order to get the value, therefore; you must use a method that will compute the value of the property who's value lies within the style-sheet.
Henceforth the getComputedStyle() method!
function getCssProp(){
let ele = document.getElementById("test");
let cssProp = window.getComputedStyle(ele,null).getPropertyValue("width");
}
W3Schools getComputedValue Doc This gives a good example, and lets you play with it, however, this link Mozilla CSS getComputedValue doc talks about the getComputedValue function in detail, and should be read by any aspiring developer who isn't totally clear on this subject.
As a side note, the getComputedValue method only gets, it does not set. This, obviously is a major downside, however there is a method that gets from CSS style-sheets, as well as sets values, though it is not standard Javascript.
The JQuery method...
$(selector).css(property,value)
...does get, and does set. It is what I use, the only downside is you got to know JQuery, but this is honestly one of the very many good reasons that every Javascript Developer should learn JQuery, it just makes life easy, and offers methods, like this one, which is not available with standard Javascript.
Hope this helps someone!!!
For anyone looking to set the value of a nested variable, here is how to do it:
const _ = require('lodash'); //import lodash module
var object = { 'a': [{ 'b': { 'c': 3 } }] };
_.set(object, 'a[0].b.c', 4);
console.log(object.a[0].b.c);
// => 4
Documentation: https://lodash.com/docs/4.17.15#set
Also, documentation if you want to get a value: https://lodash.com/docs/4.17.15#get
You can do dynamically access the property of an object using the bracket notation. This would look like this obj[yourKey] however JavaScript objects are really not designed to dynamically updated or read. They are intended to be defined on initialisation.
In case you want to dynamically assign and access key value pairs you should use a map instead.
const yourKey = 'yourKey';
// initialise it with the value
const map1 = new Map([
['yourKey', 'yourValue']
]);
// initialise empty then dynamically assign
const map2 = new Map();
map2.set(yourKey, 'yourValue');
console.log(map1.get(yourKey));
console.log(map2.get(yourKey));
demo object example
let obj = {
name: {
first_name: "Bugs",
last_name: "Founder",
role: "Programmer"
}
}
dotted string key for getting the value of
let key = "name.first_name"
Function
const getValueByDottedKeys = (obj, strKey)=>{
let keys = strKey.split(".")
let value = obj[keys[0]];
for(let i=1;i<keys.length;i++){
value = value[keys[i]]
}
return value
}
Calling getValueByDottedKeys function
value = getValueByDottedKeys(obj, key)
console.log(value)
output
Bugs
const getValueByDottedKeys = (obj, strKey)=>{
let keys = strKey.split(".")
let value = obj[keys[0]];
for(let i=1;i<keys.length;i++){
value = value[keys[i]]
}
return value
}
let obj = {
name: {
first_name: "Bugs",
last_name: "Founder",
role: "Programmer"
}
}
let key = "name.first_name"
value = getValueByDottedKeys(obj, key)
console.log(value)
I bumped into the same problem, but the lodash module is limited when handling nested properties. I wrote a more general solution following the idea of a recursive descendent parser. This solution is available in the following Gist:
Recursive descent object dereferencing
Finding Object by reference without, strings,
Note make sure the object you pass in is cloned , i use cloneDeep from lodash for that
if object looks like
const obj = {data: ['an Object',{person: {name: {first:'nick', last:'gray'} }]
path looks like
const objectPath = ['data',1,'person',name','last']
then call below method and it will return the sub object by path given
const child = findObjectByPath(obj, objectPath)
alert( child) // alerts "last"
const findObjectByPath = (objectIn: any, path: any[]) => {
let obj = objectIn
for (let i = 0; i <= path.length - 1; i++) {
const item = path[i]
// keep going up to the next parent
obj = obj[item] // this is by reference
}
return obj
}
You can use getter in Javascript
getter Docs
Check inside the Object whether the property in question exists,
If it does not exist, take it from the window
const something = {
get: (n) => this.n || something.n || window[n]
};
You should use JSON.parse, take a look at https://www.w3schools.com/js/js_json_parse.asp
const obj = JSON.parse('{ "name":"John", "age":30, "city":"New York"}')
console.log(obj.name)
console.log(obj.age)
Answer:
It turns out I had neglected to use the new keyword when creating the class instance. The code in the question itself is fine.
Question:
I have a fairly simple class where the constructor calls another method on the class (editor_for_node). The call happens inside a jQuery each() loop, but I've also tried moving it outside.
define ['jquery'], ($) ->
class Editor
constructor: (#node, #data, #template) ->
#node.widgets().each (i, elem) =>
data = if #data then #data[i] else null
node = $(elem)
#editor_for_node node, data
editor_for_node: (node, data) ->
console.log 'hello!'
return {
'Editor': Editor,
}
When the line #editor_for_node node, data gets called, I get an error (in Firebug) saying this.editor_for_node is not a function.
I really can't see why this isn't working properly, the only possible source of weirdness that I can see is my use of require.js's define function at the start.
Edit: Generated output
(function() {
define(['jquery'], function($) {
var Editor;
Editor = (function() {
Editor.name = 'Editor';
function Editor(node, data, template) {
var _this = this;
this.node = node;
this.data = data;
this.template = template;
this.node.widgets().each(function(i, elem) {
data = _this.data ? _this.data[i] : null;
node = $(elem);
return _this.editor_for_node(node, data);
});
}
Editor.prototype.editor_for_node = function(node, data) {
return console.log('hello!');
};
return Editor;
})();
return {
'Editor': Editor
};
});
}).call(this);
First: Which version of CoffeeScript are you using? The fat arrow has been a source of bugs in certain previous releases.
If you're using the latest (1.3.1), then I'm going to go ahead and say that this is an indentation issue. When I copy and paste your code, it works fine. Are you mixing tabs and spaces? Verify that the compiled output contains the line
Editor.prototype.editor_for_node = ...
Update: See the comments on this answer. Turns out the problem was that the new keyword wasn't being used when invoking the constructor.
I have a number of FilteringSelect elements within my Zend Framework application that are working fine but they are based on simple queries.
I now need to create a FilteringSelect that will allow me to select the id of one table while displaying the text of field in a related table, i.e. I have two tables groomservices and groomprocedures which are related (i.e. groomprocedures.groomProceduresID has many groomservices.procedure).
The form I'm trying to create is for an appointments table which has many groomservices.groomServicesID values. I want the user to be able to see the name of the procedure while saving the value of the groomservices.groomServicesID using the FilteringSelect.
So far I've not been able to do this in that my FilteringSelect displays nothing, I'm sure this can be done just that the fault is with my inexperience with Zend,Doctrine and Dojo
I'm not sure if my problem is with my autocomplete action(including the query) or with the FilteringSelect element.
Can anyone spot where I've gone wrong in the code sections below, I need to get this working.
My autocomplete action within my controller
public function gserviceAction()
{
// disable layout and view rendering
$this->_helper->layout->disableLayout();
$this->getHelper('viewRenderer')->setNoRender(true);
// get a list of all grooming services IDs and related procedures
$qry= Doctrine_Query::create()
->select('g.groomServicesID,p.groomProcedure')
->from('PetManager_Model_Groomservices g')
->leftJoin('g.PetManager_Model_Groomprocedures p');
$result=$qry->fetchArray();
//generate and return JSON string
$data = new Zend_Dojo_Data('g.groomServicesID',$result);
echo $data->toJson();
}
My FilteringSelect element code
// Create a autocomplete select input for the service
$gservice = new Zend_Dojo_Form_Element_FilteringSelect('gapmtService');
$gservice->setLabel('Proceedure');
$gservice->setOptions(array(
'autocomplete' => true,
'storeID' => 'gserviceStore',
'storeType' => 'dojo.data.ItemFileReadStore',
'storeParams' => array('url' => "/groomappointments/appointment/gservice"),
'dijitParams' => array('searchAttr' => 'groomProcedure')))
->setRequired(true)
->addValidator('NotEmpty', true)
->addFilter('HTMLEntities')
->addFilter('StringToLower')
->addFilter('StringTrim');
Many thanks in advance,
Graham
P.S. orgot to mention I tried the following query in mysql and I gave me what I'm looking for I believe the Doctine query evaluates to the same.
select groomservices.groomservicesID,groomprocedures.groomprocedure from groomprocedures left join groomservices on groomprocedures.groomproceduresID =groomservices.groomProcedure
But I'm not sure if I formatted the query correctly in Doctrine.
EDIT in relation to the flammon's comments
Ok I've set the code to the following but I'm still not getting anything to display.
public function gserviceAction()
{
$ajaxContext = $this->_helper->getHelper('AjaxContext');
$ajaxContext->addActionContexts(array(
'gservice' => 'json'
));
// get a list of all grooming services IDs and related procedures
$qry= Doctrine_Query::create()
->select('g.groomServicesID AS id,p.groomprocedure AS name')
->from('PetManager_Model_Groomservices g')
->leftJoin('g.PetManager_Model_Groomprocedures p');
$this->view->model = (object) array();
$this->view->model->identifier = 'id';
$this->view->model->label = 'name';
$this->view->model->items = array();
$tableRows = $this->dbTable->fetchAll($qry);
foreach ($tableRows as $row) {
$this->view->model->items[] = $row->toArray();
}
}
I'm sure the fault lies with me.
It looks like there's a problem with the data that you're putting in the ItemFileReadStore.
Here are a few pointers.
Consider extending Zend_Rest_Controller for your services. It'll be easier to manage your contexts and your views. You'll be able to do something like this:
public function init()
{
$ajaxContext = $this->_helper->getHelper('AjaxContext');
$ajaxContext->addActionContexts(array(
'gservice' => 'json'
));
}
And it will eliminate the need for the following in each of you service actions.
// disable layout and view rendering
$this->_helper->layout->disableLayout();
$this->getHelper('viewRenderer')->setNoRender(true);
You'll need to either pass the format parameter or use the following plugin to help with the context switch. Passing the format parameter is simpler but it pollutes the url with ?format=json. Here's the Zend documentation on AjaxContext.
Here's a plugin that you can use if you don't want to pass the format parameter.
class Application_Plugin_AcceptHandler extends Zend_Controller_Plugin_Abstract
{
public function dispatchLoopStartup(Zend_Controller_Request_Abstract $request)
{
if (!$request instanceof Zend_Controller_Request_Http) {
return;
}
$header = $request->getHeader('Accept');
switch (true) {
case (strstr($header, 'application/json')):
Zend_Registry::get('logger')->log('Setting format to json', Zend_Log::INFO);
$request->setParam('format', 'json');
break;
case (strstr($header, 'application/xml')
&& (!strstr($header, 'html'))):
Zend_Registry::get('logger')->log('Setting format to xml', Zend_Log::INFO);
$request->setParam('format', 'xml');
break;
default:
Zend_Registry::get('logger')->log('Setting format to html', Zend_Log::INFO);
break;
}
}
}
In your controller, instead of echoing the data, create view variables that dojo expects. See this document for the format.
$this->view->model = (object) array();
$this->view->model->identifier = 'id';
$this->view->model->label = 'name';
$this->view->model->items = array();
In your controller, fetch your table rows:
$tableRows = $this->dbTable->fetchAll($select);
or, if you've put model code in a function, it might look more like:
$tableRows = $this->dbTable->fetchGroomProcedures();
Put your row data in the model->items[] array:
foreach ($tableRows as $row) {
$this->view->model->items[] = $row->toArray();
}
Create a view, view/scripts/appointment/gservice.json.phtml and in it put
Zend_Json::encode($this->model)
Use Firebug to see what is returned from your service.