niamleeson

Array

• Two Sum
• Best Time to Buy and Sell Stock
• Contains Duplicate
• Product of Array Except Self
• Maximum Subarray
• Maximum Product Subarray
• Find Minimum in Rotated Sorted Array

niamleeson

import MapboxGL, {LngLatLike, MercatorCoordinate} from 'mapbox-gl';
import React, {useEffect, useState} from 'react';
import {withMap} from 'react-mapbox-gl/lib-esm/context';

import {FeatureCollection} from 'geojson';
import * as THREE from 'three';
import {GLTFLoader} from 'three/examples/jsm/loaders/GLTFLoader';

export interface SpritePaint {
  gltfPath: string;

niamleeson

Two well-known algorithms for polyline simplification are the Douglas Peucker and Visvalingam algorithms.

The Douglas Peucker algorithm uses a recursive divide-and-conquer approach. It starts by drawing a straight line from the first point to the last point. Then it finds the intermediate point that is furthest away from the straight line and deems this the "most important" and splits the polyline into two halves at that point. This process is repeated on both halves until the distance of the intermediate point is below a certain threshold, after which all points on that sub-polyline are thrown away since they have a negligible impact on the overall shape.

The Visvalingam algorithm works from the inside-out. It starts by computing the area of the triangle formed by each consecutive three points along the polyline. Then the midpoint of the triangle with the least area is thrown out since those three points are the closest to colinear and the area of triangles on either side are recomputed. The process

niamleeson

function download(fileUrl, apiPath, callback) {
        var url = require('url'),
            http = require('http'),
            p = url.parse(fileUrl),           
            timeout = 10000; 
        
        var file = fs.createWriteStream(apiPath);
        
        var timeout_wrapper = function( req ) {
            return function() {

niamleeson

import Reconciler from 'react-reconciler'
import omit from 'lodash/omit'
import capitalize from 'lodash/capitalize'
import { actions as elementActions } from './store/elements'
import * as Elements from './elements'

const roots = new Map()
const emptyObject = {}

const Renderer = Reconciler({

niamleeson

Shallow

Real unit test (isolation, no children render)

Simple shallow

Calls:

• constructor
• render

niamleeson

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Element

Box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent
• elem.clientLeft, elem.clientTop, elem.clientWidth, elem.clientHeight
• elem.getClientRects(), elem.getBoundingClientRect()

niamleeson

import { Directive, Input, TemplateRef, ViewContainerRef, EmbeddedViewRef, ChangeDetectorRef } from '@angular/core';
import { Observable } from 'rxjs/Observable';
import { Subscription } from 'rxjs/Subscription';

@Directive({
    selector: '[streamContext][streamContextOn]'
})
export class StreamContext {
    @Input() streamContextOn: Observable<any>;
    templateRef: TemplateRef<any>;

niamleeson

⇐ back to the gist-blog at jrw.fi

Advanced SCSS

Or, 16 cool things you may not have known your stylesheets could do. I'd rather have kept it to a nice round number like 10, but they just kept coming. Sorry.

I've been using SCSS/SASS for most of my styling work since 2009, and I'm a huge fan of Compass (by the great @chriseppstein). It really helped many of us through the darkest cross-browser crap. Even though browsers are increasingly playing nice with CSS, another problem has become very topical: managing the complexity in stylesheets as our in-browser apps get larger and larger. SCSS is an indispensable tool for dealing with this.

This isn't an introduction to the language by a long shot; many things probably won't make sense unless you have some SCSS under your belt already. That said, if you're not yet comfy with the basics, check out the aweso

niamleeson

import { NgFor } from '@angular/common'
import { Component, QueryList, TemplateRef, ViewChild, ViewChildren, ViewContainerRef } from '@angular/core'

@Component({
  directives: [
    NgFor
  ],
  selector: 'component',
  template: `
    <ul><li #item *ngFor="let number of list">{{number}}</li></ul>