ArcGIS API for JavaScript 4.2 Learning notes [5] official API Large chapters overview and content translation

Content as above, from ESRI website, connect: ArcGIS API for JavaScript 4.2

"Get Started"

Similar to the introduction of things, extract the most need to focus on a few examples. For example: Load map and view, load layers, use popup window, visualize, and use widgets. (WTF actually did not analyze you want to do things AH web In addition to the show should not have () &&*......@)

"Mapping and Views" (click into the chapter I wrote in detail)

The most basic, know the difference between map and view, can use 2D and 3D map, have a certain understanding of the layout of the map, the animation of the map also has a small use example. Also introduced are 2D3D view synchronization, Eagle Eye, North arrow and other functions. This chapter is the most basic, where the first section introduces the parameter meaning of the entry function.

"Layers"

This chapter is very large and seems to be related to geographic data. Read it sequentially:

Supports multi-layer overlay display

Support feature layer, scene layer (directly to the image, the introduction of a box-shaped stereoscopic object scene layer), Vector tile layer (This is very powerful AH), image layer, stream layer, CSV layer, Openstreet map layer, web tile layer, Point cloud Layer (the more 110 million of LiDAR point clouds data can be loaded in)

Among them, Mapimagelayer and Imagerylayer have a heavy introduction, the former do not know what is, the latter is the image layer (raster layer). This is also the most critical of the data.

Finally, I would like to ask: how the layer of this thing, how to create (check API should be able to find out how to create an instance)? How does the data get from the hard drive? Do you need a server environment? (yet to be resolved)

"Visualization"

This chapter is the symbol of custom and color, style management, mainly visual aspects of the work, on the web can not be ugly, the most important feature of the Web is "demo", visualization This chapter is born for this. This chapter is a wide variety of content but not difficult, simple to see the past is a custom symbol, color settings, ribbon settings, and the desktop version of the same. In a short period of time can not be read, after the functional chapters to complete the study and then proceed.

"Popups"

Popups means a popup window, the first one is the display of coordinates as an example.

Pop-ups are also a fairly basic feature, because the results of some query functions need to be used in this way.

Next: Use a template that pops up a small window, fix the position of the popups (Dock, left and right relative fixed)

Then there is the content that is needed on the popups, and the official presentation of forms, multimedia, documents, and charts.

Finally, you can also add buttons to the pop-up window (the official demo of Zoom and measurement), or you can customize your own features (jump to something else)

"Graphics"

This chapter is simple, similar to GDI, and adds graphics to the view. Supports 2D and 3D view additions.

"Searching"

This chapter is a spatial query. But it's a widget-based query that doesn't seem to have been given at the bottom.

You can query using the search widget, which is available on the local map vendors, and they look like. The difference is that this is Webgis, not a commercial GIS, which can be customized by itself.

Of course, can also be 3D, 2D map to filter queries, click Query.

ESRI also provides the oldest way to display query results on a table.

"Analysis"

This chapter is spatial analysis, although not as strong as ArcMap and ArcGIS Pro on desktop, but enough for the underlying business.

The spatial analysis of Webgis is mainly: Buffer analysis and network analysis. The network analysis in the example solves the shortest path and is much more friendly than the desktop version (see my ArcGIS Network analyst album).

In addition, the official provides: visual domain analysis, hot spot Analysis, query elevation (point elevation and line elevation change, and so on, line elevation This example is a little operation unfriendly).

"Widgets"

This is a custom UI, a large layout can be used in a third-party JS Library, the Map UI control to the ESRI bar.

Look down, mainly:

Home button control, Layer list control, legend control, anchor control, map print to local disk control, track position control (flat), navigation positioning control (for navigation), Quick Layout control (widgets too much can be managed with one thing, view object UI properties)

ESRI is powerful: widgets seem to be customizable (support for third-party JS control libraries!) Like angular, React), I saw the word custom, but did not look down, because the controls and functions provided have met most of the requirements. Even the widget can get a skin for it.

Tremble, human.

"More 3D"

This chapter is related to the digital elevation model, which enables 3D visualization using geodetic elevations and controls the camera's position and angle.

At the same time, the elevation information can be superimposed on the feature class for elevation 3D display.

I also saw a fun thing: control the Sun (that is, control the angle of sunlight, depending on the time), is actually the control of the environment.

AJS 3D engine can be expanded, even mentioned Threejs public 3D engine Library (Threejs, document is less difficult to read).

ESRI provides the ability to detect WEBGL, because 3D support requires WebGL, which is definitely not possible if the browser doesn't support it.

"Other"

Here are some miscellaneous items, such as obtaining data from a server, licensing, connecting to a server, and so on.

API from the big class ESRI, there are the following level of modules and classes with the first-level module:

Classes: Basemap, Camera, Color, config, Graphic, Ground, kernel, popuptemplate, request, Viewpoint, WebMap, Webscene

First-class module:/core/geometry/identity/layers/portal/renderers/support/symbols/tasks/views/webmap/webscene/widgets

Some of the important level two or three modules are shown below

/core:/accessorsupport/workers

/geometry:/support

/layers:/support

/renderers:/smartmapping/statistics/smartmapping/symbology/support

/symbols:/support

/tasks:/support

/views:/3d/layers/ui

/widgets:/support

For API Reference, wait for a certain time will do class diagram, not finished to be continued. In fact, the official API has been very good, but there is no Chinese version, need to use the people to do some work.

Finally, use API Reference.

ArcGIS API for JavaScript 4.2 Learning notes [5] official API Large chapters overview and content translation