Using Card Data in Trello Power-Up - javascript

I'm looking for a way to use Trello data in a powerup I am developing. I can get the powerup working as long as I have everything I need during TrelloPowerUp.initialize(), but the data I need is only accessible through Promises. This includes card, board, and powerup data stored through the API. The data Trello gives me access to includes the board, card, plugin IDs, and the command. Since the powerup is expected to return an array, I can't figure out a way to access any other kind of data.
Here is a simple concrete example. In it I would like to check the name of a card and display a badge accordingly.
In the example,
t grants access to the client library
card grants access to the following data:
{
"context":{
"board":"55db14fd3e104ac8b105bd75",
"card":"563b532e4e998440d0d88e62",
"command":"card-badges",
"plugin":"564ddf493f184b88ea5ddc0e"
},
"locale":"en-US"
}
Example
Here is the code to initialize card-badges. Notice that the function should return an array.
TrelloPowerUp.initialize({
'card-badges': function(t, card) {
var badge_text,
badge_color;
// returns a promise with the card name
t.card('name').then(function (name) {
if (name == "foo") {
badge_text = "contingent text";
badge_color = "contingent color";
}
});
return [{
text: badge_text,
icon: './images/icon.png',
color: badge_color
}]
}
});
Obviously this code doesn't work. The initialize function seems to be set up without regard to promises. Even the dynamic option, which takes a function as a parameter, is expected to return an array.
None of this makes sense to me, since storing and retrieving powerup data in cards is also done via promises (t.set(), t.get()). Since I don't even seem to be able to access powerup data, I feel like I am missing something in my assessment.
Is there a way to get access to the data available in promises while initializing powerups?

The trick is to return a promise to trello. The promise should return the data Trello is looking for. E.g.
TrelloPowerUp.initialize({
'card-badges': function(t, card) {
// returns a promise with the card name
var promise = t.card('name').then(function (name) {
var badge_text,
badge_color;
if (name == "foo") {
badge_text = "contingent text";
badge_color = "contingent color";
}
return [{
text: badge_text,
icon: './images/icon.png',
color: badge_color
}]
});
return promise;
}
});

Related

How to collect and return aggregated data as an Array from a table in Protractor?

I am trying to aggregate a list of dates from a data table, written in Angular, in a Protractor test. I'm doing the aggregation from a PageObject class that is called in the Protractor test. I know that my code is successfully grabbing the text I want, but when I try to console.log the returned array, I get an empty array. I'm still new to Javascript/Typescript, Angular, and Protractor and this may be a result of my newness to the asynchronous nature of this development environment.
Code is as follows,
The PageObject SpecMapper class with method:
import { browser, element, by } from 'protractor';
export class SpecMapperPage {
getImportDateSubmittedColumnValues() {
let stringDatesArray: Array<string> = [];
// currently this css selector gets rows in both import and export tables
// TODO: get better identifiers on the import and export tables and columns
element.all(by.css('md-card-content tbody tr.ng-tns-c3-0')).each(function(row, index){
// check outerHTML for presence of "unclickable", the rows in the export table
row.getAttribute('outerHTML').then(function(outerHTML:string) {
// specifically look for rows without unclickable
if(outerHTML.indexOf("unclickable") < 0){
// grab the columns and get the third column, where the date submitted field is
// TODO: get better identifiers on the import and export columns
row.all(by.css("td.ng-tns-c3-0")).get(2).getText().then(function(text:string) {
stringDatesArray.push(text);
});
}
});
});
return stringDatesArray;
}
}
I know it's not the prettiest code, but it's temporary place holder while my devs make me better attributes/classes/ids to grab my variables. Key things to note is that I create a string Array to hold the values I consider relevant to be returned when the method is finished.
I used WebStorm and put a breakpoint at the stringDatesArray.push(text) and return stringDatesArray lines. The first line shows that the text variable has a string variable that I'm looking for and is successfully getting pushed. I see the success in debug mode as I can see the stringDatesArray and see the values in it. The second line though, the array return, shows that the local variable stringDatesArray is empty. This is echoed in the following code when I try to console.log the array:
The Protractor run Spec class with my test in it:
import { SpecMapperPage } from "./app.po";
import {browser, ExpectedConditions} from "protractor";
describe('spec mapper app', () => {
let page: SpecMapperPage;
let PROJECT_ID: string = '57';
let PROJECT_NAME: string = 'DO NOT DELETE - AUTOMATED TESTING PROJECT';
beforeEach(() => {
page = new SpecMapperPage();
});
describe('import/export page', () => {
it('verify sort order is desc', () => {
browser.waitForAngularEnabled(false);
// Step 1: Launch Map Data from Dashboard
page.navigateTo(PROJECT_ID);
browser.driver.sleep(5000).then(() => {
// Verify: Mapping Screen displays
// Verify on the specmapper page by checking the breadcrumbs
expect(page.getProjectNameBreadCrumbText()).toContain(PROJECT_NAME);
expect(page.getProjectMapperBreadCrumbText()).toEqual("MAPPER");
// Verify: Verify Latest Submitted Date is displayed at the top
// Verify: Verify the Submitted Date column is in descending order
console.log(page.getImportDateSubmittedColumnValues());
});
});
});
});
I acknowledge that this code is not actively using the niceties of Protractor, there's a known issue with our app that will not be addressed for a couple of months, so I am accessing the driver directly 99% of the time.
You'll note that I call the method I posted above as the very last line in the browser.driver.sleep().then() clause, page.getImportDateSubmittedColumnValues().
I thought maybe I was running into asynchronous issues with the call being done before the page was loaded, thus I put it in the .then() clause; but learned with debugging that was not the case. This code should work once I have the array returning properly though.
The console.log is printing an empty [] array. That is synonymous with the results I saw when debugging the above method directly in the PageObject SpecMapper class. I wish to do some verification that the strings are returned properly formatted, and then I'm going to do some date order comparisons. I feel like returning an array of data retrieved from a page is not an unusual request, but I can't seem to find a good way to Google what I'm trying to do.
My apologies if I am hitting some very obvious roadblock, I'm still learning the nuances of Typescript/Angular/Protractor. Thank you for your consideration!
My attempted to used collated promises seemed promising, but fell through on execution.
My Updated PageObject SpecMapper Class
import {browser, element, by, protractor} from 'protractor';
export class SpecMapperPage {
getImportDateSubmittedColumnValues() {
let promisesArray = [];
let stringDatesArray: Array<string> = [];
// This CSS selector grabs the import table and any cells with the label .created-date
element.all(by.css('.import-component .created-date')).each(function(cell, index) {
// cell.getText().then(function(text:string) {
// console.log(text);
// });
promisesArray.push(cell.getText());
});
return protractor.promise.all(promisesArray).then(function(results) {
for(let result of results) {
stringDatesArray.push(result);
}
return stringDatesArray;
});
}
}
My Updated Spec test Using The Updated SpecMapper PO Class
import { SpecMapperPage } from "./specMapper.po";
import {browser, ExpectedConditions} from "protractor";
describe('spec mapper app', () => {
let page: SpecMapperPage;
let PROJECT_ID: string = '57';
let PROJECT_NAME: string = 'DO NOT DELETE - AUTOMATED TESTING PROJECT';
beforeEach(() => {
page = new SpecMapperPage();
});
describe('import/export page', () => {
it('TC2963: ImportComponentGrid_ShouldDefaultSortBySubmittedDateInDescendingOrder_WhenPageIsLoaded', () => {
browser.waitForAngularEnabled(false);
// Step 1: Launch Map Data from Dashboard
page.navigateTo(PROJECT_ID);
browser.driver.sleep(5000).then(() => {
// Verify: Mapping Screen displays
// Verify on the specmapper page by checking the breadcrumbs
expect(page.getProjectNameBreadCrumbText()).toContain(PROJECT_NAME);
expect(page.getProjectMapperBreadCrumbText()).toEqual("MAPPER");
// Verify: Verify Latest Submitted Date is displayed at the top
// Verify: Verify the Submitted Date column is in descending order
page.getImportDateSubmittedColumnValues().then(function(results) {
for(let value of results) {
console.log("a value is: " + value);
}
});
});
});
});
});
When I breakpoint in the PO class at the return stringDatesArray; line, I have the following variables in my differing scopes. Note that the promisesArray has 3 objects, but the results array going into the protractor.promise.all( block has 0 objects. I'm not sure what my disconnect is. :/
I think I'm running into a scopes problem that I am having issues understanding. You'll note the commented out promise resolution on the getText(), and this was my POC proving that I am getting the string values I'm expecting, so I'm not sure why it's not working in the Promise Array structure presented as a solution below.
Only other related question that I could find has to do with grabbing a particular row of a table, not specifically aggregating the data to be returned for test verification in Protractor. You can find it here if you're interested.
As you've alluded to your issue is caused by the console.log returning the value of the variable before its actually been populated.
I've taken a snippet from this answer which should allow you to solve it: Is there a way to resolve multiple promises with Protractor?
var x = element(by.id('x')).sendKeys('xxx');
var y = element(by.id('y')).sendKeys('yyy');
var z = element(by.id('z')).sendKeys('zzz');
myFun(x,y,z);
//isEnabled() is contained in the expect() function, so it'll wait for
// myFun() promise to be fulfilled
expect(element(by.id('myButton')).isEnabled()).toBe(true);
// in a common function library
function myFun(Xel,Yel,Zel) {
return protractor.promise.all([Xel,Yel,Zel]).then(function(results){
var xText = results[0];
var yText = results[1];
var zText = results[2];
});
}
So in your code it would be something like
getImportDateSubmittedColumnValues() {
let promisesArray = [];
let stringDatesArray: Array<string> = [];
// currently this css selector gets rows in both import and export tables
// TODO: get better identifiers on the import and export tables and columns
element.all(by.css('md-card-content tbody tr.ng-tns-c3-0')).each(function(row, index){
// check outerHTML for presence of "unclickable", the rows in the export table
row.getAttribute('outerHTML').then(function(outerHTML:string) {
// specifically look for rows without unclickable
if(outerHTML.indexOf("unclickable") < 0){
// grab the columns and get the third column, where the date submitted field is
// TODO: get better identifiers on the import and export columns
promisesArray.push(row.all(by.css("td.ng-tns-c3-0")).get(2).getText());
}
});
});
return protractor.promise.all(promisesArray).then(function(results){
// In here you'll have access to the results
});
}
Theres quite a few different ways you could do it. You could process the data in that method at the end or I think you could return the array within that "then", and access it like so:
page.getImportDateSubmittedColumnValues().then((res) =>{
//And then here you will have access to the array
})
I don't do the Typescript but if you're just looking to get an array of locator texts back from your method, something resembling this should work...
getImportDateSubmittedColumnValues() {
let stringDatesArray: Array<string> = [];
$$('.import-component .created-date').each((cell, index) => {
cell.getText().then(text => {
stringDatesArray.push(text);
});
}).then(() => {
return stringDatesArray;
});
}
The answer ended up related to the answer posted on How do I return the response from an asynchronous call?
The final PageObject class function:
import {browser, element, by, protractor} from 'protractor';
export class SpecMapperPage {
getImportDateSubmittedColumnValues() {
let stringDatesArray: Array<string> = [];
let promisesArray = [];
// return a promise promising that stringDatesArray will have an array of dates
return new Promise((resolve, reject) => {
// This CSS selector grabs the import table and any cells with the label .created-date
element.all(by.css('.import-component .created-date')).map((cell) => {
// Gather all the getText's we want the text from
promisesArray.push(cell.getText());
}).then(() => {
protractor.promise.all(promisesArray).then((results) => {
// Resolve the getText's values and shove into array we want to return
for(let result of results) {
stringDatesArray.push(result);
}
}).then(() => {
// Set the filled array as the resolution to the returned promise
resolve(stringDatesArray);
});
});
});
}
}
The final test class:
import { SpecMapperPage } from "./specMapper.po";
import {browser, ExpectedConditions} from "protractor";
describe('spec mapper app', () => {
let page: SpecMapperPage;
let PROJECT_ID: string = '57';
let PROJECT_NAME: string = 'DO NOT DELETE - AUTOMATED TESTING PROJECT';
beforeEach(() => {
page = new SpecMapperPage();
});
describe('import/export page', () => {
it('TC2963: ImportComponentGrid_ShouldDefaultSortBySubmittedDateInDescendingOrder_WhenPageIsLoaded', () => {
browser.waitForAngularEnabled(false);
// Step 1: Launch Map Data from Dashboard
page.navigateTo(PROJECT_ID);
browser.driver.sleep(5000).then(() => {
// Verify: Mapping Screen displays
// Verify on the specmapper page by checking the breadcrumbs
expect(page.getProjectNameBreadCrumbText()).toContain(PROJECT_NAME);
expect(page.getProjectMapperBreadCrumbText()).toEqual("MAPPER");
// Verify: Verify Latest Submitted Date is displayed at the top
// Verify: Verify the Submitted Date column is in descending order
page.getImportDateSubmittedColumnValues().then((results) => {
console.log(results);
});
});
});
});
});
The biggest thing was waiting for the different calls to get done running and then waiting for the stringDataArray to be filled. That required the promise(resolve,reject) structure I found in the SO post noted above. I ended up using the lambda (()=>{}) function calls instead of declared (function(){}) for a cleaner look, the method works the same either way. None of the other proposed solutions successfully propagated the array of strings back to my test. I'm working in Typescript, with Protractor.

AngularJS and Restangular, trying to convert update method to API

I'm trying to convert my basic crud operations into an API that multiple components of my application can use.
I have successfully converted all methods, except the update one because it calls for each property on the object to be declared before the put request can be executed.
controller
$scope.update = function(testimonial, id) {
var data = {
name: testimonial.name,
message: testimonial.message
};
dataService.update(uri, data, $scope.id).then(function(response) {
console.log('Successfully updated!');
},
function(error) {
console.log('Error updating.');
});
}
dataService
dataService.update = function(uri, data, id) {
var rest = Restangular.one(uri, id);
angular.forEach(data, function(value, key) {
// needs to be in the format below
// rest.key = data.key
});
// needs to output something like this, depending on what the data is passed
// rest.name = data.name;
// rest.message = data.message;
return rest.put();
}
I tried to describe the problem in the codes comments, but to reiterate I cannot figure out how to generate something like rest.name = data.name; without specifying the name property because the update function shouldn't need to know the object properties.
Here is what the update method looked like before I started trying to make it usable by any of my components (this works)
Testimonial.update = function(testimonial, id) {
var rest = Restangular.one('testimonials', id);
rest.name = testimonial.name;
rest.message = testimonial.message;
return rest.put();
}
How can I recreate this without any specific properties parameters hard-coded in?
Also, my project has included lo-dash, if that helps, I don't know where to start with this problem. Thanks a ton for any advice!
Try like
angular.extend(rest,testimonial)
https://docs.angularjs.org/api/ng/function/angular.extend

Route's Model Hook with Ember Data "filter" not loading dependent computed property

Hopefully you can help me! :)
My issue is that I have a Route that looks like this which I'm expecting to populate a list of items... i.e. "only the tagged ones, please", but it doesn't:
App.TaggedItemsListRoute = App.ItemsRoute.extend({
model: function() {
var store = this.get("store");
var storePromise = store.find("item", { has_tags: true });
var filtered = store.filter("item", function(item) {
return item.get("hasTags");
});
return storePromise.then(function(response) {
return filtered;
});
}
});
Now... that just plain doesn't work because "hasTags" returns false because it relies on "tags" which returns a ManyArray which is temporarily empty beacuse it hasn't resolved yet (see models below). This seems crappy to me. It's saying "Hey I've gone none in me!" but what I want it to be saying is "please recalculate me later" and the filter is looking for a boolean, but what I want to pass it is "hey, don't resolve the filter until all hasTags have resolved" or at least to recompute the ManyArray that it passes.
If I just pass back a promise as the return value for the filter then it sort of works...
return item.get("tags").then(function(tags){ return item.get("hasTags"); });
Except that it's actually not, beacuse filter is getting a Promise, but it's not aware of promises, apparently, so when it's looking for a boolean it gets a promise which it evaluates as true, and then it pretty much shows all the items in the list. That's not a problem until I go to a different route for items which has, say, all the items on it, then come back... and BAM it's got all the items in it... hm....
The following is how I've "gotten around" it temporarily ... ie it's still buggy, but I can live with it...
App.TaggedItemsListRoute = App.ItemsRoute.extend({
model: function() {
var store = this.get("store");
var storePromise = store.find("item", { has_tags: true });
var filtered = store.filter("item", function(item) {
var tags = item.get("tags");
if tags.get("isFulfilled") {
return item.get("hasTags");
} else {
return tags.then(function() {
return item.get("hasTags");
});
}
});
return storePromise.then(function(response) {
return filtered;
});
}
});
I think the only way to really get around this at this stage would be to use RSVP.all... any thoughts?
Actually one thing I haven't tried which I might go try now is to use setupController to do the filtering. The only trouble there would be that ALL the items would get loaded inot the list and then visually "jump back" to a filtered state after about 1 second. Painful!
Models
My Ember App (Ember 1.5.1) has two models (Ember Data beta7): Item and Tag. Item hasMany Tags.
App.Item = DS.Model.extend({
tags: DS.hasMany("tag", inverse: "item", async: true),
hasTags: function() {
return !Em.isEmpty(this.get("tags"));
}.property("tags")
});
App.Tag = DS.Model.extend(
item: DS.belongsTo("item", inverse: "tags"),
hasItem: function() {
return !Em.isEmpty(this.get("item"))
}.property("item")
);
If I change the model to the following, it actually does print something to the logs when I go to the route above, so it is fulfilling the promise.
App.Item = DS.Model.extend({
tags: DS.hasMany("tag", inverse: "item", async: true),
hasTags: function() {
this.get("tags").then(function(tags) {
console.log("The tags are loding if this is printed");
});
return !Em.isEmpty(this.get("tags"));
}.property("tags")
});
This is a spin off question from Ember Data hasMany async observed property "simple" issue because I didn't really explain my quesiton well enough and was actually asking the wrong question. I originally thought I could modify my model "hasTags" property to behave correctly in the context of my Route but I now don't think that will work properly...
This seems like a perfectly good candidate for RSVP.all. BTW if you want a rundown on RSVP I gave a talk on it a few weeks back (don't pay too much attention too it, pizza came halfway through and I got hungry, http://www.youtube.com/watch?v=8WXgm4_V85E ). Regardless, your filter obviously depends on the tag collection promises being resolved, before it should be executed. So, it would be appropriate to wait for those to resolve before executing the filter.
App.TaggedItemsListRoute = App.ItemsRoute.extend({
model: function() {
var store = this.get("store");
return store.find("item", { has_tags: true }).then(function(items){
var tagPromises = items.getEach('tags');
return Ember.RSVP.all(tagPromises).then(function(tagCollections){
// at this point all tags have been received
// build your filter, and resolve that
return store.filter("item", function(item) {
return item.get("hasTags");
});
});
});
}
});
Example using a similar idea with colors (I only show it if the relationship has 3 associated colors)
http://emberjs.jsbin.com/OxIDiVU/454/edit
On a separate note, if you felt like you wanted this hook to resolve immediately, and populate magically after, you could cheat and return an array, then populate the array once the results have come back from the server, allowing your app to seem like it's reacting super quick (by drawing something on the page, then magically filling in as the results come pouring in).
App.TaggedItemsListRoute = App.ItemsRoute.extend({
model: function() {
var store = this.get("store"),
quickResults = [];
store.find("item", { has_tags: true }).then(function(items){
var tagPromises = items.getEach('tags');
return Ember.RSVP.all(tagPromises).then(function(tagCollections){
// at this point all tags have been received
// build your filter, and resolve that
return store.filter("item", function(item) {
return item.get("hasTags");
});
});
}).then(function(filterResults){
filterResults.forEach(function(item){
quickResults.pushObject(item);
});
});
return quickResults;
}
});
Example of quick results, returns immediately (I only show it if the relationship has 3 associated colors)
http://emberjs.jsbin.com/OxIDiVU/455/edit

Breeze Partial initializer

I have a Single Page Application that is working pretty well so far but I have run into an issue I am unable to figure out. I am using breeze to populate a list of projects to be displayed in a table. There is way more info than what I actually need so I am doing a projection on the data. I want to add a knockout computed onto the entity. So to accomplish this I registered and entity constructor like so...
metadataStore.registerEntityTypeCtor(entityNames.project, function () { this.isPartial = false; }, initializeProject);
The initializeProject function uses some of the values in the project to determine what the values should be for the computed. For example if the Project.Type == "P" then the rowClass should = "Red".
The problem I am having is that all the properties of Project are null except for the ProjNum which happens to be the key. I believe the issue is because I am doing the projection because I have registered other initializers for other types and they work just fine. Is there a way to make this work?
EDIT: I thought I would just add a little more detail for clarification. The values of all the properties are set to knockout observables, when I interrogate the properties using the javascript debugger in Chrome the _latestValue of any of the properties is null. The only property that is set is the ProjNum which is also the entity key.
EDIT2: Here is the client side code that does the projection
var getProjectPartials = function (projectObservable, username, forceRemote) {
var p1 = new breeze.Predicate("ProjManager", "==", username);
var p2 = new breeze.Predicate("ApprovalStatus", "!=", "X");
var p3 = new breeze.Predicate("ApprovalStatus", "!=", "C");
var select = 'ProjNum,Title,Type,ApprovalStatus,CurrentStep,StartDate,ProjTargetDate,CurTargDate';
var isQaUser = cookies.getCookie("IsQaUser");
if (isQaUser == "True") {
p1 = new breeze.Predicate("QAManager", "==", username);
select = select + ',QAManager';
} else {
select = select + ',ProjManager';
}
var query = entityQuery
.from('Projects')
.where(p1.and(p2).and(p3))
.select(select);
if (!forceRemote) {
var p = getLocal(query);
if (p.length > 1) {
projectObservable(p);
return Q.resolve();
}
}
return manager.executeQuery(query).then(querySucceeded).fail(queryFailed);
function querySucceeded(data) {
var list = partialMapper.mapDtosToEntities(
manager,
data.results,
model.entityNames.project,
'ProjNum'
);
if (projectObservable) {
projectObservable(list);
}
log('Retrieved projects using breeze', data, true);
}
};
and the code for the partialMapper.mapDtosToEntities function.
var defaultExtension = { isPartial: true };
function mapDtosToEntities(manager,dtos,entityName,keyName,extendWith) {
return dtos.map(dtoToEntityMapper);
function dtoToEntityMapper(dto) {
var keyValue = dto[keyName];
var entity = manager.getEntityByKey(entityName, keyValue);
if (!entity) {
extendWith = $.extend({}, extendWith || defaultExtension);
extendWith[keyName] = keyValue;
entity = manager.createEntity(entityName, extendWith);
}
mapToEntity(entity, dto);
entity.entityAspect.setUnchanged();
return entity;
}
function mapToEntity(entity, dto) {
for (var prop in dto) {
if (dto.hasOwnProperty(prop)) {
entity[prop](dto[prop]);
}
}
return entity;
}
}
EDIT3: Looks like it was my mistake. I found the error when I looked closer at initializeProject. Below is what the function looked like before i fixed it.
function initializeProject(project) {
project.rowClass = ko.computed(function() {
if (project.Type == "R") {
return "project-list-item info";
} else if (project.Type == "P") {
return "project-list-item error";
}
return "project-list-item";
});
}
the issue was with project.Type I should have used project.Type() since it is an observable. It is a silly mistake that I have made too many times since starting this project.
EDIT4: Inside initializeProject some parts are working and others aren't. When I try to access project.ProjTargetDate() I get null, same with project.StartDate(). Because of the Null value I get an error thrown from the moment library as I am working with these dates to determine when a project is late. I tried removing the select from the client query and the call to the partial entity mapper and when I did that everything worked fine.
You seem to be getting closer. I think a few more guard clauses in your initializeProject method would help and, when working with Knockout, one is constantly battling the issue of parentheses.
Btw, I highly recommend the Knockout Context Debugger plugin for Chrome for diagnosing binding problems.
Try toType()
You're working very hard with your DTO mapping, following along with John's code from his course. Since then there's a new way to get projection data into an entity: add toType(...) to the end of the query like this:
var query = entityQuery
.from('Projects')
.where(p1.and(p2).and(p3))
.select(select)
.toType('Project'); // cast to Project
It won't solve everything but you may be able to do away with the dto mapping.
Consider DTOs on the server
I should have pointed this out first. If you're always cutting this data down to size, why not define the client-facing model to suit your client. Create DTO classes of the right shape(s) and project into them on the server before sending data over the wire.
You can also build metadata to match those DTOs so that Project on the client has exactly the properties it should have there ... and no more.
I'm writing about this now. Should have a page on it in a week or so.

Javascript Data Layer Architecture Assistance

I'm making a fairly complex HTML 5 + Javascript game. The client is going to have to download images and data at different points of the game depending on the area they are at. I'm having a huge problem resolving some issues with the Data Layer portion of the Javascript architecture.
The problems I need to solve with the Data Layer:
Data used in the application that becomes outdated needs to be automatically updated whenever calls are made to the server that retrieve fresh data.
Data retrieved from the server should be stored locally to reduce any overhead that would come from requesting the same data twice.
Any portion of the code that needs access to data should be able to retrieve it easily and in a uniform way regardless of whether the data is available locally already.
What I've tried to do to accomplish this is build a data layer that has two main components:
1. The portion of the layer that gives access to the data (through get* methods)
2. The portion of the layer that stores and synchronizes local data with data from the server.
The workflow is as follows:
When the game needs access to some data it calls get* method in the data layer for that data, passing a callback function.
bs.data.getInventory({ teamId: this.refTeam.PartyId, callback: this.inventories.initialize.bind(this.inventories) });
The get* method determines whether the data is already available locally. If so it either returns the data directly (if no callback was specified) or calls the callback function passing it the data.
If the data is not available, it stores the callback method locally (setupListener) and makes a call to the communication object passing the originally requested information along.
getInventory: function (obj) {
if ((obj.teamId && !this.teamInventory[obj.teamId]) || obj.refresh) {
this.setupListener(this.inventoryNotifier, obj);
bs.com.getInventory({ teamId: obj.teamId });
}
else if (typeof (obj.callback) === "function") {
if (obj.teamId) {
obj.callback(this.team[obj.teamId].InventoryList);
}
}
else {
if (obj.teamId) {
return this.team[obj.teamId].InventoryList;
}
}
}
The communication object then makes an ajax call to the server and waits for the data to return.
When the data is returned a call is made to the data layer again asking it to publish the retrieved data.
getInventory: function (obj) {
if (obj.teamId) {
this.doAjaxCall({ orig: obj, url: "/Item/GetTeamEquipment/" + obj.teamId, event: "inventoryRefreshed" });
}
},
doAjaxCall: function (obj) {
var that = this;
if (!this.inprocess[obj.url + obj.data]) {
this.inprocess[obj.url + obj.data] = true;
$.ajax({
type: obj.type || "GET",
contentType: "application/json; charset=utf-8",
dataType: "json",
data: obj.data,
url: obj.url,
async: true,
success: function (data) {
try {
ig.fire(bs.com, obj.event, { data: data, orig: obj.orig });
}
catch (ex) {
// this enables ajaxComplete to fire
ig.log(ex.message + '\n' + ex.stack);
}
finally {
that.inprocess[obj.url + obj.data] = false;
}
},
error: function () { that.inprocess[obj.url + obj.data] = false; }
});
}
}
The data layer then stores all of the data in a local object and finally calls the original callback function, passing it the requested data.
publishInventory: function (data) {
if (!this.inventory) this.inventory = {};
for (var i = 0; i < data.data.length; i++) {
if (this.inventory[data.data[i].Id]) {
this.preservingUpdate(this.inventory[data.data[i].Id], data.data[i]);
}
else {
this.inventory[data.data[i].Id] = data.data[i];
}
}
// if we pulled this inventory for a team, update the team
// with the inventory
if (data.orig.teamId && this.team[data.orig.teamId]) {
this.teamInventory[data.orig.teamId] = true;
this.team[data.orig.teamId].InventoryList = [];
for (var i = 0; i < data.data.length; i++) {
this.team[data.orig.teamId].InventoryList.push(data.data[i]);
}
}
// set up the data we'll notify with
var notifyData = [];
for (var i = 0; i < data.data.length; i++) {
notifyData.push(this.inventory[data.data[i].Id]);
}
ig.fire(this.inventoryNotifier, "refresh", notifyData, null, true);
}
There are several problems with this that bother me constantly. I'll list them in order of most annoying :).
Anytime I have to add a call that goes through this process it takes too much time to do so. (at least an hour)
The amount of jumping and callback passing gets confusing and seems very prone to errors.
The hierarchical way in which I am storing the data is incredibly difficult to synchronize and manage. More on that next.
Regarding issue #3 above, if I have objects in the data layer that are being stored that have a structure that looks like this:
this.Account = {Battles[{ Teams: [{ TeamId: 392, Characters: [{}] }] }]}
this.Teams[392] = {Characters: [{}]}
Because I want to store Teams in a way where I can pass the TeamId to retrieve the data (e.g. return Teams[392];) but I also want to store the teams in relation to the Battles in which they exist (this.Account.Battles[0].Teams[0]); I have a nightmare of a time keeping each instance of the same team fresh and maintaining the same object identity (so I am not actually storing it twice and so that my data will automatically update wherever it is being used which is objective #1 of the data layer).
It just seems so messy and jumbled.
I really appreciate any help.
Thanks
You should consider using jquery's deferred objects.
Example:
var deferredObject = $.Deferred();
$.ajax({
...
success: function(data){
deferredObject.resolve(data);
}
});
return deferredObject;
Now with the deferredObject returned, you can attach callbacks to it like this:
var inventoryDfd = getInventory();
$.when(inventoryDfd).done(function(){
// code that needs data to continue
}
and you're probably less prone to errors. You can even nest deferred objects, or combine them so that a callback isn't called until multiple server calls are downloaded.
+1 for Backbone -- it does some great heavy lifting for you.
Also look at the Memoizer in Douglas Crockford's book Javascript the Good Parts. It's dense, but awesome. I hacked it up to make the memo data store optional, and added more things like the ability to set a value without having to query first -- e.g. to handle data freshness.

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