ol/source/TileWMS.js

父类

ol/source/TileImage-TileImage

主要功能

WMS服务提供的底图图层源。

参数：TileWMS({})

方法

/**
* @module ol/source/TileWMS
*/
import {DEFAULT_WMS_VERSION} from './common.js';
import TileImage from './TileImage.js';
import WMSServerType from './WMSServerType.js';
import {appendParams} from '../uri.js';
import {assert} from '../asserts.js';
import {assign} from '../obj.js';
import {buffer, createEmpty} from '../extent.js';
import {buffer as bufferSize, scale as scaleSize, toSize} from '../size.js';
import {calculateSourceResolution} from '../reproj.js';
import {compareVersions} from '../string.js';
import {get as getProjection, transform, transformExtent} from '../proj.js';
import {modulo} from '../math.js';
import {hash as tileCoordHash} from '../tilecoord.js';
/**
* @typedef {Object} Options
* @property {import("./Source.js").AttributionLike} [attributions] Attributions.
* @property {boolean} [attributionsCollapsible=true] Attributions are collapsible.
* @property {number} [cacheSize] Initial tile cache size. Will auto-grow to hold at least the number of tiles in the viewport.
* @property {null|string} [crossOrigin] The `crossOrigin` attribute for loaded images.
Note that
* you must provide a `crossOrigin` value if you want to access pixel data with the Canvas renderer.
* See https://developer.mozilla.org/en-US/docs/Web/HTML/CORS_enabled_image for more detail.
* @property {boolean} [imageSmoothing=true] Enable image smoothing.
* @property {Object<string,*>} params WMS request parameters.
* At least a `LAYERS` param is required. `STYLES` is
* `''` by default. `VERSION` is `1.3.0` by default. `WIDTH`, `HEIGHT`, `BBOX`
* and `CRS` (`SRS` for WMS version < 1.3.0) will be set dynamically.
* @property {number} [gutter=0]
* The size in pixels of the gutter around image tiles to ignore. By setting
* this property to a non-zero value, images will be requested that are wider
* and taller than the tile size by a value of `2 x gutter`.
* Using a non-zero value allows artifacts of rendering at tile edges to be
* ignored. If you control the WMS service it is recommended to address
* "artifacts at tile edges" issues by properly configuring the WMS service. For
* example, MapServer has a `tile_map_edge_buffer` configuration parameter for
* this. See https://mapserver.org/output/tile_mode.html.
* @property {boolean} [hidpi=true] Use the `ol/Map#pixelRatio` value when requesting
* the image from the remote server.
* @property {import("../proj.js").ProjectionLike} [projection] Projection. Default is the view projection.
* @property {number} [reprojectionErrorThreshold=0.5] Maximum allowed reprojection error (in pixels).
* Higher values can increase reprojection performance, but decrease precision.
* @property {typeof import("../ImageTile.js").default} [tileClass] Class used to instantiate image tiles.
* Default is {@link module:ol/ImageTile~ImageTile}.
* @property {import("../tilegrid/TileGrid.js").default} [tileGrid] Tile grid. Base this on the resolutions,
* tilesize and extent supported by the server.
* If this is not defined, a default grid will be used: if there is a projection
* extent, the grid will be based on that; if not, a grid based on a global
* extent with origin at 0,0 will be used..
* @property {import("./WMSServerType.js").default|string} [serverType]
* The type of the remote WMS server. Currently only used when `hidpi` is
* `true`.
* @property {import("../Tile.js").LoadFunction} [tileLoadFunction] Optional function to load a tile given a URL. The default is
* ```js
* function(imageTile, src) {
*
imageTile.getImage().src = src;
* };
* ```
* @property {string} [url] WMS service URL.
* @property {Array<string>} [urls] WMS service urls.
* Use this instead of `url` when the WMS supports multiple urls for GetMap requests.
* @property {boolean} [wrapX=true] Whether to wrap the world horizontally.
* When set to `false`, only one world
* will be rendered. When `true`, tiles will be requested for one world only,
* but they will be wrapped horizontally to render multiple worlds.
* @property {number} [transition] Duration of the opacity transition for rendering.
* To disable the opacity transition, pass `transition: 0`.
* @property {number|import("../array.js").NearestDirectionFunction} [zDirection=0]
* Choose whether to use tiles with a higher or lower zoom level when between integer
* zoom levels. See {@link module:ol/tilegrid/TileGrid~TileGrid#getZForResolution}.
*/
/**
* @classdesc
* Layer source for tile data from WMS servers.
* @api
*/
class TileWMS extends TileImage {
/**
* @param {Options} [opt_options] Tile WMS options.
*/
constructor(opt_options) {
const options = opt_options ? opt_options : /** @type {Options} */ ({});
const params = options.params || {};
const transparent = 'TRANSPARENT' in params ? params['TRANSPARENT'] : true;
super({
attributions: options.attributions,
attributionsCollapsible: options.attributionsCollapsible,
cacheSize: options.cacheSize,
crossOrigin: options.crossOrigin,
imageSmoothing: options.imageSmoothing,
opaque: !transparent,
projection: options.projection,
reprojectionErrorThreshold: options.reprojectionErrorThreshold,
tileClass: options.tileClass,
tileGrid: options.tileGrid,
tileLoadFunction: options.tileLoadFunction,
url: options.url,
urls: options.urls,
wrapX: options.wrapX !== undefined ? options.wrapX : true,
transition: options.transition,
zDirection: options.zDirection,
});
/**
* @private
* @type {number}
*/
this.gutter_ = options.gutter !== undefined ? options.gutter : 0;
/**
* @private
* @type {!Object}
*/
this.params_ = params;
/**
* @private
* @type {boolean}
*/
this.v13_ = true;
/**
* @private
* @type {import("./WMSServerType.js").default|undefined}
*/
this.serverType_ =
/** @type {import("./WMSServerType.js").default|undefined} */ (
options.serverType
);
/**
* @private
* @type {boolean}
*/
this.hidpi_ = options.hidpi !== undefined ? options.hidpi : true;
/**
* @private
* @type {import("../extent.js").Extent}
*/
this.tmpExtent_ = createEmpty();
this.updateV13_();
this.setKey(this.getKeyForParams_());
}
/**
* Return the GetFeatureInfo URL for the passed coordinate, resolution, and
* projection. Return `undefined` if the GetFeatureInfo URL cannot be
* constructed.
* @param {import("../coordinate.js").Coordinate} coordinate Coordinate.
* @param {number} resolution Resolution.
* @param {import("../proj.js").ProjectionLike} projection Projection.
* @param {!Object} params GetFeatureInfo params. `INFO_FORMAT` at least should
*
be provided. If `QUERY_LAYERS` is not provided then the layers specified
*
in the `LAYERS` parameter will be used. `VERSION` should not be
*
specified here.
* @return {string|undefined} GetFeatureInfo URL.
* @api
*/
getFeatureInfoUrl(coordinate, resolution, projection, params) {
const projectionObj = getProjection(projection);
const sourceProjectionObj = this.getProjection();
let tileGrid = this.getTileGrid();
if (!tileGrid) {
tileGrid = this.getTileGridForProjection(projectionObj);
}
const z = tileGrid.getZForResolution(resolution, this.zDirection);
const tileCoord = tileGrid.getTileCoordForCoordAndZ(coordinate, z);
if (tileGrid.getResolutions().length <= tileCoord[0]) {
return undefined;
}
let tileResolution = tileGrid.getResolution(tileCoord[0]);
let tileExtent = tileGrid.getTileCoordExtent(tileCoord, this.tmpExtent_);
let tileSize = toSize(tileGrid.getTileSize(tileCoord[0]), this.tmpSize);
const gutter = this.gutter_;
if (gutter !== 0) {
tileSize = bufferSize(tileSize, gutter, this.tmpSize);
tileExtent = buffer(tileExtent, tileResolution * gutter, tileExtent);
}
if (sourceProjectionObj && sourceProjectionObj !== projectionObj) {
tileResolution = calculateSourceResolution(
sourceProjectionObj,
projectionObj,
coordinate,
tileResolution
);
tileExtent = transformExtent(
tileExtent,
projectionObj,
sourceProjectionObj
);
coordinate = transform(coordinate, projectionObj, sourceProjectionObj);
}
const baseParams = {
'SERVICE': 'WMS',
'VERSION': DEFAULT_WMS_VERSION,
'REQUEST': 'GetFeatureInfo',
'FORMAT': 'image/png',
'TRANSPARENT': true,
'QUERY_LAYERS': this.params_['LAYERS'],
};
assign(baseParams, this.params_, params);
const x = Math.floor((coordinate[0] - tileExtent[0]) / tileResolution);
const y = Math.floor((tileExtent[3] - coordinate[1]) / tileResolution);
baseParams[this.v13_ ? 'I' : 'X'] = x;
baseParams[this.v13_ ? 'J' : 'Y'] = y;
return this.getRequestUrl_(
tileCoord,
tileSize,
tileExtent,
1,
sourceProjectionObj || projectionObj,
baseParams
);
}
/**
* Return the GetLegendGraphic URL, optionally optimized for the passed
* resolution and possibly including any passed specific parameters. Returns
* `undefined` if the GetLegendGraphic URL cannot be constructed.
*
* @param {number} [resolution] Resolution. If set to undefined, `SCALE`
*
will not be calculated and included in URL.
* @param {Object} [params] GetLegendGraphic params. If `LAYER` is set, the
*
request is generated for this wms layer, else it will try to use the
*
configured wms layer. Default `FORMAT` is `image/png`.
*
`VERSION` should not be specified here.
* @return {string|undefined} GetLegendGraphic URL.
* @api
*/
getLegendUrl(resolution, params) {
if (this.urls[0] === undefined) {
return undefined;
}
const baseParams = {
'SERVICE': 'WMS',
'VERSION': DEFAULT_WMS_VERSION,
'REQUEST': 'GetLegendGraphic',
'FORMAT': 'image/png',
};
if (params === undefined || params['LAYER'] === undefined) {
const layers = this.params_.LAYERS;
const isSingleLayer = !Array.isArray(layers) || layers.length === 1;
if (!isSingleLayer) {
return undefined;
}
baseParams['LAYER'] = layers;
}
if (resolution !== undefined) {
const mpu = this.getProjection()
? this.getProjection().getMetersPerUnit()
: 1;
const pixelSize = 0.00028;
baseParams['SCALE'] = (resolution * mpu) / pixelSize;
}
assign(baseParams, params);
return appendParams(/** @type {string} */ (this.urls[0]), baseParams);
}
/**
* @return {number} Gutter.
*/
getGutter() {
return this.gutter_;
}
/**
* Get the user-provided params, i.e. those passed to the constructor through
* the "params" option, and possibly updated using the updateParams method.
* @return {Object} Params.
* @api
*/
getParams() {
return this.params_;
}
/**
* @param {import("../tilecoord.js").TileCoord} tileCoord Tile coordinate.
* @param {import("../size.js").Size} tileSize Tile size.
* @param {import("../extent.js").Extent} tileExtent Tile extent.
* @param {number} pixelRatio Pixel ratio.
* @param {import("../proj/Projection.js").default} projection Projection.
* @param {Object} params Params.
* @return {string|undefined} Request URL.
* @private
*/
getRequestUrl_(
tileCoord,
tileSize,
tileExtent,
pixelRatio,
projection,
params
) {
const urls = this.urls;
if (!urls) {
return undefined;
}
params['WIDTH'] = tileSize[0];
params['HEIGHT'] = tileSize[1];
params[this.v13_ ? 'CRS' : 'SRS'] = projection.getCode();
if (!('STYLES' in this.params_)) {
params['STYLES'] = '';
}
if (pixelRatio != 1) {
switch (this.serverType_) {
case WMSServerType.GEOSERVER:
const dpi = (90 * pixelRatio + 0.5) | 0;
if ('FORMAT_OPTIONS' in params) {
params['FORMAT_OPTIONS'] += ';dpi:' + dpi;
} else {
params['FORMAT_OPTIONS'] = 'dpi:' + dpi;
}
break;
case WMSServerType.MAPSERVER:
params['MAP_RESOLUTION'] = 90 * pixelRatio;
break;
case WMSServerType.CARMENTA_SERVER:
case WMSServerType.QGIS:
params['DPI'] = 90 * pixelRatio;
break;
default:
assert(false, 52); // Unknown `serverType` configured
break;
}
}
const axisOrientation = projection.getAxisOrientation();
const bbox = tileExtent;
if (this.v13_ && axisOrientation.substr(0, 2) == 'ne') {
let tmp;
tmp = tileExtent[0];
bbox[0] = tileExtent[1];
bbox[1] = tmp;
tmp = tileExtent[2];
bbox[2] = tileExtent[3];
bbox[3] = tmp;
}
params['BBOX'] = bbox.join(',');
let url;
if (urls.length == 1) {
url = urls[0];
} else {
const index = modulo(tileCoordHash(tileCoord), urls.length);
url = urls[index];
}
return appendParams(url, params);
}
/**
* Get the tile pixel ratio for this source.
* @param {number} pixelRatio Pixel ratio.
* @return {number} Tile pixel ratio.
*/
getTilePixelRatio(pixelRatio) {
return !this.hidpi_ || this.serverType_ === undefined ? 1 : pixelRatio;
}
/**
* @private
* @return {string} The key for the current params.
*/
getKeyForParams_() {
let i = 0;
const res = [];
for (const key in this.params_) {
res[i++] = key + '-' + this.params_[key];
}
return res.join('/');
}
/**
* Update the user-provided params.
* @param {Object} params Params.
* @api
*/
updateParams(params) {
assign(this.params_, params);
this.updateV13_();
this.setKey(this.getKeyForParams_());
}
/**
* @private
*/
updateV13_() {
const version = this.params_['VERSION'] || DEFAULT_WMS_VERSION;
this.v13_ = compareVersions(version, '1.3') >= 0;
}
/**
* @param {import("../tilecoord.js").TileCoord} tileCoord The tile coordinate
* @param {number} pixelRatio The pixel ratio
* @param {import("../proj/Projection.js").default} projection The projection
* @return {string|undefined} The tile URL
* @override
*/
tileUrlFunction(tileCoord, pixelRatio, projection) {
let tileGrid = this.getTileGrid();
if (!tileGrid) {
tileGrid = this.getTileGridForProjection(projection);
}
if (tileGrid.getResolutions().length <= tileCoord[0]) {
return undefined;
}
if (pixelRatio != 1 && (!this.hidpi_ || this.serverType_ === undefined)) {
pixelRatio = 1;
}
const tileResolution = tileGrid.getResolution(tileCoord[0]);
let tileExtent = tileGrid.getTileCoordExtent(tileCoord, this.tmpExtent_);
let tileSize = toSize(tileGrid.getTileSize(tileCoord[0]), this.tmpSize);
const gutter = this.gutter_;
if (gutter !== 0) {
tileSize = bufferSize(tileSize, gutter, this.tmpSize);
tileExtent = buffer(tileExtent, tileResolution * gutter, tileExtent);
}
if (pixelRatio != 1) {
tileSize = scaleSize(tileSize, pixelRatio, this.tmpSize);
}
const baseParams = {
'SERVICE': 'WMS',
'VERSION': DEFAULT_WMS_VERSION,
'REQUEST': 'GetMap',
'FORMAT': 'image/png',
'TRANSPARENT': true,
};
assign(baseParams, this.params_);
return this.getRequestUrl_(
tileCoord,
tileSize,
tileExtent,
pixelRatio,
projection,
baseParams
);
}
}
export default TileWMS;

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