Getting to Know Web GIS. Pinde Fu

Читать онлайн книгу.

Getting to Know Web GIS - Pinde Fu


Скачать книгу
panel, including media types such as a map, 3D scene, image, and videoStory Map CascadeSMCreates a visually and editorially engaging full-screen scrolling experience blending narrative text, maps, 3D scenes, images, and videosPresenting a series of mapsStory Map SeriesSM - Tabbed LayoutUses a set of tabsStory Map Series - Side Accordion LayoutUses an expandable panelStory Map Series - Bulleted LayoutUses numbered bullets, one per mapPresenting a dynamic collection of crowdsourced photosStory Map CrowdsourceSMPublishes and manages a crowdsourced story to which anyone can contribute photos with captions. Display the collected photos along with their locations, captions, and descriptions.A curated list of points of interestStory Map ShortlistSMPresents a set of places organized into a set of tabs based on themes.Comparing two maps or two layers of a single web mapStory Map SwipeSMUsers can slide the swipe tool back and forth to compare one map theme to a second map theme.Story Map SpyglassSMSimilar to Swipe but enables users to peer through one map to another using a spyglass function.Presenting one mapStory Map BasicPresents a map via a very simple minimalist user interface.

      You can create a story map in either ArcGIS Online or Esri Story Maps:

       ArcGIS Online: For example, you can share a web map, click Create a Web App, and choose a story map template.

       Esri Story Map website: You can select a type of story map and follow the builder wizard.

      ArcGIS Solutions apps

      ArcGIS Solutions provides a gallery of free templates to jumpstart your projects. The templates typically include app source code. Some templates also include data models, layers, maps, and sample web services. The data model and map styles are created based on industry best practices and emerging trends. ArcGIS Solutions apps cover almost all industries. The apps focus mostly on the web and mobile platforms and occasionally on the desktop platform.

      You can search for templates in ArcGIS Solutions by products, industries, and keywords. For each template, you can read its introduction, requirements, and contents in the package. You can also try the app live, download the template, configure the app, and deploy it.

      ArcGIS Solutions provides a rich collection of configurable apps for almost all industries.

      Configuring ArcGIS Solutions web apps typically involves editing the config.js file. In this file, you replace the default URLs of the maps and layers with those URLs of your maps and layers and replace the default attribute field names with those field names of your data. Deploying these web apps typically requires a web server such as Apache, Microsoft IIS (Internet Information Service), or other products. You can set up your own web server or purchase a web hosting service. Once you have a web server, deploying a JavaScript web app is essentially copying the files to a folder under your web server’s web root, for example, C:\inetpub\wwwroot for IIS.

      Basic components of a Web GIS app

      Today’s Web GIS best practices recommend that a Web GIS app should have basemaps, operational layers, and tools. ArcGIS supports this practice and makes it easy for you to create Web GIS apps.

      The basic components of a Web GIS app.

      Basemap layers

      Basemaps provide a reference or context for your Web GIS app. ArcGIS provides a collection of fast-responding basemaps. Most of the time, you can use them without worrying about creating them.

       ArcGIS provides a gallery of basemaps, including image tiles and vector tiles. These maps all have multiple scales with global coverage.

       In addition, you can use your own map services as basemaps (open the map viewer, click Add > Add Layer from Web, and select the Use as Basemap box).

       ArcGIS provides a global elevation service on which basemaps can be draped. This service supports 3D web scenes.

      ArcGIS provides a gallery of basemaps and an elevation service to support both 2D and 3D web maps and apps.

      Operational layers

      Operational layers are theme layers that you and your end users mostly use.

       You can use layers from ArcGIS Online, Living Atlas of the World, and ArcGIS Open Data (http://opendata.arcgis.com) as your operational layers. These layers span a range of subjects and can support maps and apps of almost every subject. You can search in these rich collections and discover layers that fit your needs.

       You can also use your own data as operational layers. ArcGIS Online and ArcGIS Enterprise support operational layers from a variety of formats including CSV, TXT, GPX (GPS exchange), shapefiles, and a variety of web services types.

      Tools

      Tools perform tasks beyond mapping, including common tasks such as query, geocoding, routing, and more specialized tasks such as the workflows and big data analysis that implement specific logic for an enterprise.

       Most ArcGIS web layers support flexible queries.

       ArcGIS Online provides rich and extensive spatial analysis tools for you to ask questions and solve spatial problems.

       ArcGIS Enterprise provides standard analysis tools, big data analysis tools, raster analysis tools, and allows you to publish custom web tools, in other words, geoprocessing services.

      Web services, the foundation of today’s Web GIS

      Web services technology is at the heart of today’s Web GIS. The previously mentioned three types of components of Web GIS apps are almost all based on web services. For example, basemaps are often tile services, operational layers are often feature services, and many tools are based on geoprocessing services.

      Early Web GIS was not based on web services; instead, it consisted mostly of stand-alone websites where GIS data and functions were available only to their own clients and couldn’t be reused in other systems. This situation greatly limited the reusability of Web GIS resources. As a result, the level of effort to create Web GIS apps was high. In the later 1990s, web services technology was conceived. A web service is essentially a program that runs on a web server and exposes programing interfaces for clients to consume over the web. Web services have many advantages, especially their flexibility in being reused and remixed in many web apps.

      Over the years, the main web services interface style has evolved from Simple Object Access Protocol (SOAP) to Representational State Transfer (REST). REST is considered “the command line of the web,” and relies on URLs to send requests and pass parameters. REST became the preferred web service interface type because of its simplicity and efficiency for the


Скачать книгу