在nvue中富文本rich-text不显示和图片不显示的解决

原创已于 2022-05-05 09:13:09 修改 · 3k 阅读

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#javascript #前端 #html

于 2022-02-18 10:39:47 首次发布

本文主要介绍在nvue中遇到的富文本和图片显示问题。当使用nvue展示富文本时，虽然在H5端正常，但在真机调试时却无法显示。通过在common文件下创建html-parser.js并进行相应处理，解决了富文本显示问题。对于图片不显示，可以通过设置img标签的宽高或者自定义方法和标签属性来实现显示。

一、问题：
①使用nvue展示富文本，H5端可以显示，而真机调试时却啥也不显示。
②将文件换成vue即可都展示。

<rich-text :nodes="content" style="font-size: 14px;"></rich-text>

		data() {
			return {
				content: `
					<div style="text-align:center;">
						<p>露从今夜白，月是故乡明</p>
						<img src="https://cdn.uviewui.com/uview/swiper/2.jpg" style="width:550upx;height: 220upx" />
					</div>
				`
			}
		},

二、解决办法：
在common文件下新建html-parser.js文件，代码如下：


// Regular Expressions for parsing tags and attributes
var startTag = /^<([-A-Za-z0-9_]+)((?:\s+[a-zA-Z_:][-a-zA-Z0-9_:.]*(?:\s*=\s*(?:(?:"[^"]*")|(?:'[^']*')|[^>\s]+))?)*)\s*(\/?)>/;
var endTag = /^<\/([-A-Za-z0-9_]+)[^>]*>/;
var attr = /([a-zA-Z_:][-a-zA-Z0-9_:.]*)(?:\s*=\s*(?:(?:"((?:\\.|[^"])*)")|(?:'((?:\\.|[^'])*)')|([^>\s]+)))?/g; // Empty Elements - HTML 5

var empty = makeMap('area,base,basefont,br,col,frame,hr,img,input,link,meta,param,embed,command,keygen,source,track,wbr'); // Block Elements - HTML 5
// fixed by xxx 将 ins 标签从块级名单中移除

var block = makeMap('a,address,article,applet,aside,audio,blockquote,button,canvas,center,dd,del,dir,div,dl,dt,fieldset,figcaption,figure,footer,form,frameset,h1,h2,h3,h4,h5,h6,header,hgroup,hr,iframe,isindex,li,map,menu,noframes,noscript,object,ol,output,p,pre,section,script,table,tbody,td,tfoot,th,thead,tr,ul,video'); // Inline Elements - HTML 5

var inline = makeMap('abbr,acronym,applet,b,basefont,bdo,big,br,button,cite,code,del,dfn,em,font,i,iframe,img,input,ins,kbd,label,map,object,q,s,samp,script,select,small,span,strike,strong,sub,sup,textarea,tt,u,var'); // Elements that you can, intentionally, leave open
// (and which close themselves)

var closeSelf = makeMap('colgroup,dd,dt,li,options,p,td,tfoot,th,thead,tr'); // Attributes that have their values filled in disabled="disabled"

var fillAttrs = makeMap('checked,compact,declare,defer,disabled,ismap,multiple,nohref,noresize,noshade,nowrap,readonly,selected'); // Special Elements (can contain anything)

var special = makeMap('script,style');
function HTMLParser(html, handler) {
  var index;
  var chars;
  var match;
  var stack = [];
  var last = html;

  stack.last = function () {
    return this[this.length - 1];
  };

  while (html) {
    chars = true; // Make sure we're not in a script or style element

    if (!stack.last() || !special[stack.last()]) {
      // Comment
      if (html.indexOf('<!--') == 0) {
        index = html.indexOf('-->');

        if (index >= 0) {
          if (handler.comment) {
            handler.comment(html.substring(4, index));
          }

          html = html.substring(index + 3);
          chars = false;
        } // end tag

      } else if (html.indexOf('</') == 0) {
        match = html.match(endTag);

        if (match) {
          html = html.substring(match[0].length);
          match[0].replace(endTag, parseEndTag);
          chars = false;
        } // start tag

      } else if (html.indexOf('<') == 0) {
        match = html.match(startTag);

        if (match) {
          html = html.substring(match[0].length);
          match[0].replace(startTag, parseStartTag);
          chars = false;
        }
      }

      if (chars) {
        index = html.indexOf('<');
        var text = index < 0 ? html : html.substring(0, index);
        html = index < 0 ? '' : html.substring(index);

        if (handler.chars) {
          handler.chars(text);
        }
      }
    } else {
      html = html.replace(new RegExp('([\\s\\S]*?)<\/' + stack.last() + '[^>]*>'), function (all, text) {
        text = text.replace(/<!--([\s\S]*?)-->|<!\[CDATA\[([\s\S]*?)]]>/g, '$1$2');

        if (handler.chars) {
          handler.chars(text);
        }

        return '';
      });
      parseEndTag('', stack.last());
    }

    if (html == last) {
      throw 'Parse Error: ' + html;
    }

    last = html;
  } // Clean up any remaining tags


  parseEndTag();

  function parseStartTag(tag, tagName, rest, unary) {
    tagName = tagName.toLowerCase();

    if (block[tagName]) {
      while (stack.last() && inline[stack.last()]) {
        parseEndTag('', stack.last());
      }
    }

    if (closeSelf[tagName] && stack.last() == tagName) {
      parseEndTag('', tagName);
    }

    unary = empty[tagName] || !!unary;

    if (!unary) {
      stack.push(tagName);
    }

    if (handler.start) {
      var attrs = [];
      rest.replace(attr, function (match, name) {
        var value = arguments[2] ? arguments[2] : arguments[3] ? arguments[3] : arguments[4] ? arguments[4] : fillAttrs[name] ? name : '';
        attrs.push({
          name: name,
          value: value,
          escaped: value.replace(/(^|[^\\])"/g, '$1\\\"') // "

        });
      });

      if (handler.start) {
        handler.start(tagName, attrs, unary);
      }
    }
  }

  function parseEndTag(tag, tagName) {
    // If no tag name is provided, clean shop
    if (!tagName) {
      var pos = 0;
    } // Find the closest opened tag of the same type
    else {
        for (var pos = stack.length - 1; pos >= 0; pos--) {
          if (stack[pos] == tagName) {
            break;
          }
        }
      }

    if (pos >= 0) {
      // Close all the open elements, up the stack
      for (var i = stack.length - 1; i >= pos; i--) {
        if (handler.end) {
          handler.end(stack[i]);
        }
      } // Remove the open elements from the stack


      stack.length = pos;
    }
  }
}

function makeMap(str) {
  var obj = {};
  var items = str.split(',');

  for (var i = 0; i < items.length; i++) {
    obj[items[i]] = true;
  }

  return obj;
}

function removeDOCTYPE(html) {
  return html.replace(/<\?xml.*\?>\n/, '').replace(/<!doctype.*>\n/, '').replace(/<!DOCTYPE.*>\n/, '');
}

function parseAttrs(attrs) {
  return attrs.reduce(function (pre, attr) {
    var value = attr.value;
    var name = attr.name;

    if (pre[name]) {
			pre[name] = pre[name] + " " + value;
    } else {
			pre[name] = value;
    }

    return pre;
  }, {});
}

function parseHtml(html) {
  html = removeDOCTYPE(html);
  var stacks = [];
  var results = {
    node: 'root',
    children: []
  };
  HTMLParser(html, {
    start: function start(tag, attrs, unary) {
      var node = {
        name: tag
      };

      if (attrs.length !== 0) {
        node.attrs = parseAttrs(attrs);
      }

      if (unary) {
        var parent = stacks[0] || results;

        if (!parent.children) {
          parent.children = [];
        }

        parent.children.push(node);
      } else {
        stacks.unshift(node);
      }
    },
    end: function end(tag) {
      var node = stacks.shift();
      if (node.name !== tag) console.error('invalid state: mismatch end tag');

      if (stacks.length === 0) {
        results.children.push(node);
      } else {
        var parent = stacks[0];

        if (!parent.children) {
          parent.children = [];
        }

        parent.children.push(node);
      }
    },
    chars: function chars(text) {
      var node = {
        type: 'text',
        text: text
      };

      if (stacks.length === 0) {
        results.children.push(node);
      } else {
        var parent = stacks[0];

        if (!parent.children) {
          parent.children = [];
        }

        parent.children.push(node);
      }
    },
    comment: function comment(text) {
      var node = {
        node: 'comment',
        text: text
      };
      var parent = stacks[0];

      if (!parent.children) {
        parent.children = [];
      }

      parent.children.push(node);
    }
  });
  return results.children;
}

export default parseHtml;

三、使用

<template>
	<view class="u-content">
		<rich-text :nodes="content" style="font-size: 14px;"></rich-text>
	</view>
</template>

<script>
	import htmlParser from '../../common/html-parser'
	export default {
		data() {
			return {
				content: []
			}
		},
		onLoad() {
			this.initText();
		},
		methods: {
			initText() {
				// 请求回来后的参数，此处模拟一下
				const arr = `
					<div style="text-align:center;">
						<p>露从今夜白，月是故乡明</p>
						<img src="https://cdn.uviewui.com/uview/swiper/2.jpg" style="width:550upx;height: 220upx" />
					</div>
				`;
				this.content = htmlParser(arr);
			}
		}
	}
</script>

如此便可展示富文本了。

四、图片展示

如果富文本中的图片不显示，
①只需要在img标签设置宽高即可；
②也可以自定义方法和标签属性处理，参考模板如下：

<script>
	import htmlParser from '../../common/html-parser'

	// 给图片设置带比例的宽和高
	function parseImgs(nodes) {
		nodes.forEach(node => {
			if (
				node.name === 'img' &&
				node.attrs &&
				node.attrs['data-img-size-val']
			) {
				const sizes = node.attrs['data-img-size-val'].split(',')
				const width = uni.upx2px(720 * 0.9)
				const height = parseInt(width * (sizes[1] / sizes[0]))
				node.attrs.style = `width:${width};height:${height};`
			}
			if (Array.isArray(node.children)) {
				parseImgs(node.children)
			}
		})
		return nodes
	}
	export default {
		data() {
			return {
				content: []
			}
		},
		onLoad() {
			this.initText();
		},
		methods: {
			initText() {
				// 请求回来后的参数，此处模拟一下（图片要有 data-img-size-val 属性）
				const arr = `
					<div style="text-align:center;">
						<p>露从今夜白，月是故乡明</p>
						<img src="https://cdn.uviewui.com/uview/swiper/2.jpg" data-img-size-val="750, 550" />
					</div>
				`;
				const nodes = htmlParser(arr);
				// #ifdef APP-PLUS-NVUE
				parseImgs(nodes)
				// #endif
				this.content = nodes
			}
		}
	}
</script>